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Q intake conversion project to standard GM style !

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Paul P
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Q intake conversion project to standard GM style !

Post by Paul P » Thu Oct 02, 2014 10:14 am

Hi guys,

We have a couple of guys who have done this and I am starting a challenge to do a "how to" pictorial thread showing all the parts and pieces necessary to make this swap. I think it will help untold ownes of the Q motors because right now if you have one (or in the case of cruiser owners, two) you are at the mercy of the diminishing supply and sometimes outrageous prices for a replacement, and even then the replacement may only have a limited lifespan left.

The Q intake is unique in small block GM lore. It has the distributor and thermostat on the same end of the intake. No other GM intake anywhere has this "feature".

http://img.photobucket.com/albums/v472/ ... take-1.jpg

On my own ChrisCraftCommander.com forum, this has been a somewhat quiet thread but as of lately we are going to try to ramp it up and document this in detail and of course we will want to share every detail of it here. In the event anyone here already has done this or has any commentary, please offer it up and we wll work together to try to help a lot of people who may be able to benefit from this conversion.

Here is the "get started" challenge........comments/contributions/tech issues welcome please.
http://www.network54.com/Forum/424840/m ... 1412260611
1956 17' CC Sportsman, 300-hp
1957 17' CC Sportsman, 95-hp
1966 20' CC fiberglass Sea Skiff, 210-hp+
1973 23' CC Lancer inboard project, 427/375-hp.
1966 38' CC Commander Express, 427/300-hp(2)

So many boats.........so little time.....but what a way to go!!

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mfine
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Re: Q intake conversion project to standard GM style !

Post by mfine » Fri Oct 03, 2014 7:52 am

This will be a huge help today and become even more important down the road. Thank you for doing this among all your contributions to the hobby!

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Re: Q intake conversion project to standard GM style !

Post by Paul P » Fri Oct 03, 2014 9:07 am

Hey thanks for the good words, I agree it will help a lot of people and that's why we're doing it.

I have already had 27 people in Europe express interest, not sure how many here in the US but rest assured, there are a lot of these motors out there.

My main question right now that has yet to be answered is this:

"does the Q thermostat block have the same bolt pattern as the F thermostat block" ??

The reason I ask this is, the F thermostat block will fit almost ANY GM or aftermarket intake. If the Q is the same bolt pattern, then Q owners will be able to conveniently re-position this part over the hole in the GM or aftermarket intake and easily bridge the gap with rubber hose. If the Q thermostat block won't fit the same bolt hole pattern, then this is still possible but the Q owner will have to find a recycled or new thermostat block for a stock GM intake and there are a lot of options out there, new, pre-owned, ebay, Sierra, etc.

Naturally we're hopeful the Q t-stat block will just fit nicely, save everyone some $$ and we can move on. If anyone has a gasket set or these parts in their shop to compare, please to do and let us know.

Our intent is to prepare a "how to" complete with NAPA hose numbers, photos, etc. :-)

regards,

Paul
1956 17' CC Sportsman, 300-hp
1957 17' CC Sportsman, 95-hp
1966 20' CC fiberglass Sea Skiff, 210-hp+
1973 23' CC Lancer inboard project, 427/375-hp.
1966 38' CC Commander Express, 427/300-hp(2)

So many boats.........so little time.....but what a way to go!!

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mfine
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Re: Q intake conversion project to standard GM style !

Post by mfine » Fri Oct 03, 2014 3:31 pm

Paul,

When looking at something as unique and convoluted as the Q manifold, I generally wonder "what were those "idiots" thinking?"

From my perspective, the evidence suggests that the engineers at Chris Craft working on engines actually were pretty smart "idiots", and when they made mistakes it was generally doing too little, not too much. So why would they make a new intake manifold for the Q series if there were cheap and easy alternatives?

The best answer I have come up with is that they wanted/needed to have the hot water exit at the high end of the engine, presumably to avoid air or steam pockets. I am interested in what your thoughts are about this issue and what if anything you plan to do to deal with it?

The thoughts I had were to either...

A) block off the water passages into the manifold and pull the water out of the end of the heads like the early 283. This requires adding an outlet port on the upper end of each head plus a custom 2 in 2 out thermostat block ($$$$$)

or

B) Tap a pair of holes in the new manifold on the distributor end where it blocks off the water passages and run a couple of small lines, say 1/8", from there to the exhaust in order to allow gasses to vent and a small amount of water to flow. The manifold I looked at was an Edelbrock 2101 and I THINK this might be doable, but there is a support ridge right down the middle of where I would want to drill and tap so it wont be super easy.

Anyone have any experience or thoughts to share?

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Re: Q intake conversion project to standard GM style !

Post by quitchabitchin » Fri Oct 03, 2014 6:32 pm

I have to first figure out how to plumb the Vintage Edelbrock M1 Exhaust Manifolds, then on to the intake.

I do however have a viable cast iron candidate in a 300HP 327 manifold when you do get this figured out Paul. I don't think this job is all that difficult. I would guess that the thermostat is on the flywheel end so the warm water could be easily dumped into the exhaust risers utilizing the front ports.

The original Q manifold has small ports to accept 1/8" copper lines from the exhaust that would release steam from the exhaust manifolds that would build up due to the steep angle of installation, not the other way around as MFine is suggesting. The intake should never be hot enough to create steam, if it is, you've got bigger issues than releasing it.
FLASH1969 Chris Craft Cavalier Ski-230 HP 327Q

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mfine
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Re: Q intake conversion project to standard GM style !

Post by mfine » Fri Oct 03, 2014 6:51 pm

The issue isnt a hot intake manifold, but the forward/upper cylinders and that end of the heads. Water enters the lower rear of the block, and usually exits the upper forward end of the heads. With a standard manifold it will enter the rear of the block and exit at the rear of the heads. Any air ingested (or steam) seems like it will collect at the upper end of the head and keep collecting. Too much air and local temps will pass 212 and then you will get steam to make matters worse.

Even without trapped air, I would suggest monitoring the temps at both ends of the block and heads to make sure you are getting even cooling and not too much flow at the low end and not enough at the front.

As I said, I am pretty sure CC didn't spend the time and money to come up with the Q manifold if there wasn't a problem they needed to solve.

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Re: Q intake conversion project to standard GM style !

Post by jim g » Fri Oct 03, 2014 10:44 pm

The main problem your forgetting is the Q intake is a low profile intake. Like the aluminum 283 flywheel forward intake. Were the F series and aftermarket manifolds are the standard height. For a while starting in the 70's Chris Craft was no longer suppling the aluminum 283 intake. They had a service bulletin that gave you the part numbers you would need to fit the Q intake to the flywheel forward 283.

So the first thing you have to think about is height before anything else.

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Re: Q intake conversion project to standard GM style !

Post by Paul P » Sat Oct 04, 2014 10:26 am

Hey GREAT FEEDBACK and insight ! Thanks guys.

That's what collaboration is all about :-)

First the clearance issue. Chris-Craft was obsessed with making a compact motor, with good reason and they did their job well. From a performance point of view they did it too well, because the performance is compromised with the squatty (poor) intake design which in my view, is "inferior" to something like the Edelbrock Performer RPM intake, which of course is a taller unit. Many of the Q installations in cruisers have no clearnce issue, but some do, and most of the runabouts do. The solution for "some" of the runabout guys would be to modify the motor box or use an old style compact iron F-type or standard GM style intake that was equally squatty. Our friend Kris did the motor box tweak with his installation (that has run successfully, being somewhat of an example of theory and practice coming together in real terms). Still there may be clearance issues but in most cases there are ways to deal with that.

Now for the air pocket issue. I have reviewed the issues and I think the concern is quite astute and valid from a theory point of view but wonder how it actually works in practice, and by saying that I am NOT discounting the concern. Kris just sent me a note about his conversion and promised photos and a step by step outline, and said "yes it does work". So that will be interesting to see what he did and I will post it and share it of course.

The best way to solve a problem is AVOID the problem, and CC did that by placing their tstat on all motors in a high location that would collect the air bubble if any. By doing a conversion, looking at where the water level would actually be at rest and under way, there does seem to be room for an air pocket, that when mildy pressurized by sea water intake and circulating pump water flow might stay there in an upper part of the block or head and cause a hot spot, but any air pocket of such could also be flushed out by flow...........this is where theory and practice come together and make me wonder.

Erring on the conservative side would be best, and it would be great if we could find a place to make an easy tap (as suggested in a previous post), perhaps with nipple and rubber hose connection just to be sure any air in that upper region would have a way to get out. By doing so naturally there would be water flow through this tube but if it was a small enough diameter tap and hose it would be inconsequential to the overall system. I have not looked in detail just yet, but I am thinking one tap at the top of the motor area, either port or starboard, would solve this problem, and don't think two would be needed due to the way a boat would rock back and forth and flow would help purge the system; it would be great if there was an area on the aluminum aftermarket intakes to make a tap of this kind (great thought, thanks to mfine).
Excellent noodling on this guys, we need to find a system that works and preserves the machinery.

Regards,

Paul
1956 17' CC Sportsman, 300-hp
1957 17' CC Sportsman, 95-hp
1966 20' CC fiberglass Sea Skiff, 210-hp+
1973 23' CC Lancer inboard project, 427/375-hp.
1966 38' CC Commander Express, 427/300-hp(2)

So many boats.........so little time.....but what a way to go!!

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Re: Q intake conversion project to standard GM style !

Post by jim g » Sat Oct 04, 2014 10:57 am

The F series is not a low profile intake. The correct F series intake is the GM 300hp intake that GM used on many of there engines. The only low profile intakes that were made are the Q series and the 283 aluminum flywheel forward one. Now crusader, flagship and others also made their own versions of low profile intakes to fit there engines.

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Re: Q intake conversion project to standard GM style !

Post by Paul P » Sun Oct 05, 2014 6:03 am

Jim you are correct, i was using relative terms, and the F is taller than the Q but is still a fairly compact design.
I have an early 283 style, 327F, and 327Q in the family so i can confirm numbers and clearances if needed.

Here is something of interest on the performance side, not totally applicable for us but somewhat: the Q intake would have finished way below the worst intake tested here (IMHO). :-)
http://www.carcraft.com/techarticles/13 ... ewall.html

Regards
Paul
1956 17' CC Sportsman, 300-hp
1957 17' CC Sportsman, 95-hp
1966 20' CC fiberglass Sea Skiff, 210-hp+
1973 23' CC Lancer inboard project, 427/375-hp.
1966 38' CC Commander Express, 427/300-hp(2)

So many boats.........so little time.....but what a way to go!!

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mfine
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Re: Q intake conversion project to standard GM style !

Post by mfine » Sun Oct 05, 2014 7:14 am

Paul,

If you look at the water pathway in the heads, there is a water exit at both ends. The intake manifold blocks one end, and there is no crossover in the block, so the only way for air or water to mix between the two sides is at through the open end on the intake which will be the bottom. In short, I think if there is a need to tap the upper end, you will need to tap both sides. It shouldn't be a lot of work or expense, especially with aluminum intakes.

The fact that someone is running a converted engine without any air bleed is encouraging.

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Re: Q intake conversion project to standard GM style !

Post by Paul P » Sun Oct 05, 2014 7:33 am

Yep, agree, i was thinking about a vent namely for the block but air pockets could be at each head

I saw the ridge you noted, they all seem to have that, Weiand seems to have a bit more metal there.
I am wondering about a hole at the side of the ridge i see on the RPM model. By the way, WD-40 is not a very good lubticant but it mskes a excellent tspping fluid for aluminum.

OSCO made a replacement for the Q motor, but with zero performance benefits.

Paul
1956 17' CC Sportsman, 300-hp
1957 17' CC Sportsman, 95-hp
1966 20' CC fiberglass Sea Skiff, 210-hp+
1973 23' CC Lancer inboard project, 427/375-hp.
1966 38' CC Commander Express, 427/300-hp(2)

So many boats.........so little time.....but what a way to go!!

jim g
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Re: Q intake conversion project to standard GM style !

Post by jim g » Sun Oct 05, 2014 8:24 am

Paul,

Your right about the the F is shorter the the stock 283 intake, but it is taller then the 283 low profile and the Q. But also remember the 283 low profile and the Q have the angle built into them for the carb to sit level. The F doesn't and chris craft never supplied a wedge on the F's. So if you have height clearances the F probably won't work. Same if your running a steep shaft angle like most of the runabouts. You would probably have to much angle on the carb.

As for the Osco they made the aluminum low profile 283 intake which they discontinued 4 years or so years ago. I have never seen in there catalogs or in person one for the Q.

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Re: Q intake conversion project to standard GM style !

Post by jim g » Sun Oct 05, 2014 8:45 am

The reason the Q have the air bleeds is for the air bubbles that build up at the top of the exhaust manifold. The 283 is a 3 pass system and the F series is a 2 pass system. Which means how many times the water flows in a different direction in the exhaust manifold. This is the reason you can't use Barr replacement manifolds on the flywheel forward 283. Because there pattern maker left one of the dividers out. So at the most it can only be a 2 pass manifold.

The Q system is a 1 pass system so the water is coming in at the front and filling all 4 side of the manifold. This is why air pockets build up at the front of the manifold. This is the reason the Q has the small copper vents lines between the manifold and the intake.

So depending on how much your changing you need to keep in mind the flow of the manifolds.

One other thing. The F and Q series cooling system was called themocon develvo engine cooling system. These systems were patented in the US patent office and giving patent numbers. The is a patent number on the one of the engine tags. Someone might want to research this as the patent papers will describe the system and how it suppose to work.

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Re: Q intake conversion project to standard GM style !

Post by Paul P » Mon Oct 06, 2014 1:26 pm

mfine wrote:The issue isnt a hot intake manifold, but the forward/upper cylinders and that end of the heads. Water enters the lower rear of the block, and usually exits the upper forward end of the heads. With a standard manifold it will enter the rear of the block and exit at the rear of the heads. Any air ingested (or steam) seems like it will collect at the upper end of the head and keep collecting. Too much air and local temps will pass 212 and then you will get steam to make matters worse.

Even without trapped air, I would suggest monitoring the temps at both ends of the block and heads to make sure you are getting even cooling and not too much flow at the low end and not enough at the front.

As I said, I am pretty sure CC didn't spend the time and money to come up with the Q manifold if there wasn't a problem they needed to solve.

Doing a little research on my own, I see there are numerous GM engines from the inline six to the new generation, that have "steam holes" in the block for the very reason you stated. Good one !

So now the search is on for a viable solution and your earlier comment about tapping into a water passage on the dry end of the intake is intriguing. Looking at the logical choice by volume and popularity, the Edelbrock RPM, yes indeed there is a ridge there, but wait.........drumroll please........LOOK at the RPM Air Gap, heck it looks like it has the holes already drilled or partially tapped already !!! Only problem with the Air Gap, it's a tall intake.

However, I have discovered some intresting metal bosses on the Weiand intake that could make it easier to tap, with an intake not so tall. There are options, we need to find the best one.
Attachments
Weiand.jpg
Weiand Street Warrior
rpm air gap.jpg
The Edelbrock AIR GAP intake
marine rpm.jpg
The standard Edelbrock (marine) RPM
The Edelbrock RPM in marine form
1956 17' CC Sportsman, 300-hp
1957 17' CC Sportsman, 95-hp
1966 20' CC fiberglass Sea Skiff, 210-hp+
1973 23' CC Lancer inboard project, 427/375-hp.
1966 38' CC Commander Express, 427/300-hp(2)

So many boats.........so little time.....but what a way to go!!

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mfine
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Re: Q intake conversion project to standard GM style !

Post by mfine » Mon Oct 06, 2014 2:10 pm

Bingo! The 7501 is already drilled and tapped. It will cost you $100 more than a 2101 and more importantly will be .700" taller BEFORE You add a carb wedge. If you have the room it is probably a great choice though for performance and convenience. With no exhaust crossover and the said gap the carb and intake charge will stay cooler, but you will have to lose the old exhaust heated chokes.

I think drilling a smaller hole next to the ridge on a 2101 or 2601 etc will also work. If there is not enough room to drill it straight, you could probably angle the hole.

I am curious why you are focusing on the RPM series from edelbrock over the standard performer or air gap performer. The standard is supposed to focus the power band from 500-5500 rpm and the RPM manifolds move it to 1500-6500. Since you are going to have to do a lot more than change the manifold to get a Q to run reliably at 5500-6500 rpm wouldn't the standard performer be a better choice?

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Re: Q intake conversion project to standard GM style !

Post by Paul P » Mon Oct 06, 2014 2:18 pm

Good question !

Through research on a variety of engines and projects for myself and others, it "appears" the RPM is of course a high RPM intake, thus the name, but it also appears it beats the standard Performer in all engine speeds (sometimes by a small margin). This appears to be the case with the 427, and I think it is for the small block GM motors too.

So for this reason I generally look at the RPM as the one from Edelbrock but I like that Air Gap too, and the fact that it has no crossover is of no concern to me. Using a good (synthetic) oil with enough ZDDP (Like Mobil-1 15w50, which I have used in my 427 motors for almost 20 years) and gentle use until the engine is warm, will do just fine for me. I see little need to be cooking a carb in the dead of summer, in an engine box. :-)

None of the Edelbrock aluminum intakes are built with a heat crossover, even though they might look that way from topsides.

Regards,

Paul
1956 17' CC Sportsman, 300-hp
1957 17' CC Sportsman, 95-hp
1966 20' CC fiberglass Sea Skiff, 210-hp+
1973 23' CC Lancer inboard project, 427/375-hp.
1966 38' CC Commander Express, 427/300-hp(2)

So many boats.........so little time.....but what a way to go!!

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Re: Q intake conversion project to standard GM style !

Post by Paul P » Mon Oct 06, 2014 2:23 pm

Did anyone ever find out if the Q thermostat chunk will mate up to the standard GM intake manifold bolt hole and gasket ?

Surely there must have been some degree of standardization at CC.

regards,

Paul
1956 17' CC Sportsman, 300-hp
1957 17' CC Sportsman, 95-hp
1966 20' CC fiberglass Sea Skiff, 210-hp+
1973 23' CC Lancer inboard project, 427/375-hp.
1966 38' CC Commander Express, 427/300-hp(2)

So many boats.........so little time.....but what a way to go!!

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mfine
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Re: Q intake conversion project to standard GM style !

Post by mfine » Mon Oct 06, 2014 3:14 pm

I don't know anything about the standard carb setup on the Q's, but my comment on the exhaust crossover was more for the old coil spring style chokes as I agree, if the water is soft enough to boat on without blades, there is no need to cook the carb. Personally I would junk the spring choke if it had one, but I had the impression you were looking for a minimal changes required solution.

Send me a Q engine and I will tell you if the thermostat housing fits. Heck, send me a 350Q and I will do the manifold swap and even send you back your old high dollar intake manifold along with details on what I had to do to make it work. If the engine you send me comes packaged in an XK-19 I will add in a nice thank you note and perhaps a small cash reward.

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Re: Q intake conversion project to standard GM style !

Post by Paul P » Mon Oct 06, 2014 4:59 pm

The crossover has been a topic of discussion and debate, some seem to think they can't live without it, an others like me think it is just a vestige of the automotive origin of our boats, so any aftermarket intake without the crossover is a good one as far as I am concerned. I don't mean to be preaching to the choir, but of course they were intended to warm up cars fast in the wintertime, and we normally don't go boating in the wintertime. Sitting atop hot iron in an engine box is flirting with vapor lock or fuel boil-out and hard starting.

The heat furnace on the 427 and I believe the 327Q (maybe others too) is fed heat via a tube from the exhaust log. It may be positioned at the crossover location for rapid response but it's not directly hooked to the crossover.

I tried and tried to get my head activated chokes to work. One did, the other never seemed to get warm for some strange reason. However, since I converted the engines to a 50,000 volt system, I don't need a choke, seriously. I just prime the accelerator pump a few times and they fire up nicely with lots of electrical motivation at the spark plugs which are gapped .055"

Back to the Q intake conversion issue.......................

So far the only issues we have are clearance and steam venting.

Clearance:Either you have it or you don't. In which case, if you don't have clearance and the height is a serious issuse, such as touching the underside of a cruiser fold down hatch (as opposed to a motor box that can easily be modified) then one must look for a very low profile aftermarket or stock iron intake to use.

Steam Venting:The tapping solutions you have noted appear to be quite viable, so that is resolved. Any tapping into the intake area to reach the water passage can be routed to the stock location on the Q exhaust manifolds.

Thermostat:We will assume the thermostat will bolt directly from the Q to any other GM or aftermarket intake manifold unti proven wrong, and until such time we confirm this with an actual project,.

Plumbing:With the revised thermostat location there is a need to get water back to the front of the motor. This could potentially be done along the top of the motor if it is kept clear of the linkage and other things. There will need to be a hands on look at the plumbing needs, and it seems there may be proper diameter hoses with bends that can come off the t-stat, and also off the pump, joined in the middle with a length of copper pipe. We'll see how that goes.

So it appears anyone out there faced with spending $1200 for a Q intake "because there are no other alternatives and the supply is limited" could very easily obtain a nice performance upgrade by converting to a superior flowing aluminum intake for $200, then getting a new #1409 Edelbrock marine carb for $320, a phenolic spacer for $30, and a 50,000 volt marine distributor from Performance Distributors (our friend Steve Davis, of Davis Unified Ignitiion, DUI) and still have money left over for some gaskets, a new flame arrestor, and a $100 or $200 dinner with friends.

I have not heard back from my friend, Kris, who has done this, but as soon as I do I will be posting the info.
At some point we should post a kit of parts, with plumbing hoses and budget info so people can see what they are potentially faced with.

Any additional comments or suggestions are welcome ! :-)


Regards,

Paul
1956 17' CC Sportsman, 300-hp
1957 17' CC Sportsman, 95-hp
1966 20' CC fiberglass Sea Skiff, 210-hp+
1973 23' CC Lancer inboard project, 427/375-hp.
1966 38' CC Commander Express, 427/300-hp(2)

So many boats.........so little time.....but what a way to go!!

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mfine
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Re: Q intake conversion project to standard GM style !

Post by mfine » Mon Oct 06, 2014 5:57 pm

You left out carb wedge $40-$60, and I think the phenolic spacer is probably overkill combined with the airgap manifold a wedge and two sets of gaskets.

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Re: Q intake conversion project to standard GM style !

Post by Paul P » Mon Oct 06, 2014 7:03 pm

I actually meant "phenolic wedge"

Here is the one i use

http://www.marinepartssource.com/partde ... no=3527746



I am also using a 4-hole spacer on the 427 to build a little more torque

Regards

Paul
1956 17' CC Sportsman, 300-hp
1957 17' CC Sportsman, 95-hp
1966 20' CC fiberglass Sea Skiff, 210-hp+
1973 23' CC Lancer inboard project, 427/375-hp.
1966 38' CC Commander Express, 427/300-hp(2)

So many boats.........so little time.....but what a way to go!!

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drrot
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Re: Q intake conversion project to standard GM style !

Post by drrot » Tue Oct 07, 2014 8:22 am

The Q manifold had thermostat bolt holes 3 1/2" apart. Standard Chevrolet is about 3 1/4". Could be made to work. The standard Chevrolet manifold is recessed for the thermostat. The Q manifold is flat and the recess is in the thermostat housing. Also a small obstacle.
You could always call me. I get about half the price quoted for Q manifolds.
Jim Staib
www.finewoodboats.com


1947 Penn Yan 12' Cartopper WXH474611
1950 Chris-Craft 22' Sportsman U-22-1532
1957 Chris-Craft 26' Sea Skiff SK-26-515
1968 Century 17' Resorter FG-68-174

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Re: Q intake conversion project to standard GM style !

Post by Paul P » Tue Oct 07, 2014 10:07 am

Jim thanks for the update on the Q thermostat spacing.
That is much appreciated, and I hope this info will potentially help someone some day.
It may actually help me, as my family has two Q engines in a 31 Commander now.
We'll drill down on that one further (pun intended) and see if there is an easy fix to allow the Q thermostat to be re-positioned to the standard intake bolt pattern. That would make it one step easier for people to make this adaptation and avoid having to buy an F-type (or similar) thermostat block.

Knowing you have access to Q manifolds is good, and that gives people an option.
Anyone interested in originality will benefit from knowing this.
It is my understanding the supply of new Q intakes is gone or severely limited, but essentially we are faced with using recycled parts for the Q motors now (or soon will be).

If someone out there needs a direct Q replacement, and Jim does not have a good one, then finding one on ebay might solve the problem on the short term, but it is still an old Q intake with an unknown remaining life span. Some of these are already 45 years old, and internal condition is tough to evaluate. In a twin engine application it's double jeapordy..........if you replace a bad one you'll know the other one could go out at any time. I suppose someone could swap out both of them at the same time to a new aftermarket intake, put the old one up for sale, and let someone else enjoy the old iron.

This is especially sensitive for me because my family has a 31 Commander with a pair of 327Q motors, and if one side went out, then replacing just one side would make me wonder how many days were left until the other one went out, and then I would be faced with finding another suitable replacement, etc., etc.. If I get into one side, I will most certainly replace both of them at the same time with a new aluminum aftermarket product. The 31 Commander has plenty of clearance, and I like the notion of a 327Q putting out 250-hp instead of 230 anyway :-)

For people considering the swap to an aftermarket intake like the Edelbrock or Weiand, realize many or most of these do not have the exhaust crossover, but neither does the Q intake.

Regards,

Paul
1956 17' CC Sportsman, 300-hp
1957 17' CC Sportsman, 95-hp
1966 20' CC fiberglass Sea Skiff, 210-hp+
1973 23' CC Lancer inboard project, 427/375-hp.
1966 38' CC Commander Express, 427/300-hp(2)

So many boats.........so little time.....but what a way to go!!

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Paul P
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Re: Q intake conversion project to standard GM style !

Post by Paul P » Tue Oct 07, 2014 12:04 pm

Note the height called out within this chart.

It is noted that even with the low clearance version of the Air Gap Performer, the manufacturer says "will not fit under the stock Corvette hood", so if you have a Q motor and a tight clearance to the underside of the motor box, they you will have to add some height to the bottom edge of that box :-)

Also for you performance guys, note the difference in performance between the 5" tall Air Gap, and the 5-1/2" Air Gap RPM; the power numbers change significantly but the torque at 3000 rpm is actually better with the lower style intake.

If you have the room, a 1"tall 4-hole spacer is an inexpensive way to increase torque in the lower rpm ranges (say 5000 and below) on just about any motor; if you use a spacer, avoid the open plenum kind unless you are running a go-fast boat and perhaps a single plane intake, which is not recommended for our runabouts or cruiser applications.

Full disclosure here......I never met a motor I didn't really want to hot rod. This all makes for interesting reading, no real conclusions drawn at this time. Just submitting the performance information as a point of info.

regards,

Paul
Attachments
intake list.jpg
1956 17' CC Sportsman, 300-hp
1957 17' CC Sportsman, 95-hp
1966 20' CC fiberglass Sea Skiff, 210-hp+
1973 23' CC Lancer inboard project, 427/375-hp.
1966 38' CC Commander Express, 427/300-hp(2)

So many boats.........so little time.....but what a way to go!!

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mfine
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Joined: Sun Jun 06, 2010 8:16 pm
Location: Pittsford and Penn Yan NY

Re: Q intake conversion project to standard GM style !

Post by mfine » Tue Oct 07, 2014 2:10 pm

I still think the lower airflow of a 327 at 3000 rpm vs a 406 at 3000 rpm is going to significantly reduce the differences between the different manifolds for our "normal" applications. If you are going to spin your 327Q at 5500 rpm to get 350hp out of it, then that is a different discussion, albeit a fun one as long as we are spending your money and not mine!

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Paul P
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Re: Q intake conversion project to standard GM style !

Post by Paul P » Tue Oct 07, 2014 7:16 pm

Agreed, the test motor is a relative example and a constant for evaluation of all intakes tested, with larger displacement, higher compression, and more aggressive camshaft.

If a particular intake provides a certain level of relative performance when compared to others on the test motor, then I think the same relative conclusions can be made for other motors of similar design (in relative terms). That is why I think a good intake would boost power by 20 horses and not bring too optimistic, :-) erring on the conservative side.

Regards,

Paul
1956 17' CC Sportsman, 300-hp
1957 17' CC Sportsman, 95-hp
1966 20' CC fiberglass Sea Skiff, 210-hp+
1973 23' CC Lancer inboard project, 427/375-hp.
1966 38' CC Commander Express, 427/300-hp(2)

So many boats.........so little time.....but what a way to go!!

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quitchabitchin
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Location: Oxford, OH
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Re: Q intake conversion project to standard GM style !

Post by quitchabitchin » Tue Oct 07, 2014 8:31 pm

Paul,

The Q choke is directly connected to the exhaust as you stated and works just fine in my engine. I have never had any issue from it.

Why do you think there is a need to switch to the Edelbrock 1409? It is a 650 CFM carb vs 425 from the stock Carter AVS, which is certainly enough carb for even a lightly modified 327/350Q. I think this is just an extra expense that will not gain you many performance benefits.

I will have to measure my clearance, but can state that i don't have much, maybe an inch this goes for the flame arrestor as well as the distributor cap. (Which explains the need for a crab style low profile cap).

I can provide measurements if you need any, I just haven't had much time the past week or so.
FLASH1969 Chris Craft Cavalier Ski-230 HP 327Q

CCABC Board of Directors Member

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Paul P
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Re: Q intake conversion project to standard GM style !

Post by Paul P » Wed Oct 08, 2014 7:51 am

Hey I agree the 1409 is not necessarily a performance upgrade, but it is a square bore carb that mates up beautifully with the performance intake manifolds. Some of the older boats (with the smaller carbs) are choked by virtue of really poor intakes, and the aftermarket intakes that are available all use the bigger square bore size. I found out about this when I converted a 327 dressed in 283 ancillary equipment over to a 300-hp rocket for my 17-foot 1956 CC Sportsman Utility.

I think I made a reference to the 1409 was made because it was on my mind, due to the purchased a 327F with a carb that was totally rusted shut. Rather than fight that battle at the time, I opted for a 1409 which (at 600 cfm) works great on the small V8 even though it is more carb than it (or the 427) really need. On that swap I used a 4-hole phenolic wedge after a little experimentation to help the weighted linkage work properly, etc.

Even on my hotted up 427 project I opted for the 1409, simply no need to jump up to the 750 cfm marine once we do the math. The 1409 is the smallest marine carb readily available at a "reasonable" price. We have seen it work well on small and large motors, and the 1410 750cfm carb they provide is really only suitable for go-fast boats.

If you need any info on the 1409, or are considering the swap on your motor or a future motor, I've been all through the process twice, including drilling and tapping for the PCV, here is that link. The castings are almost identical to the AFB, they are basically a clone of the 625 cfm AFB that came stock on the 300-hp CC 427 marine engines.

http://www.network54.com/Forum/424840/thread/1343278350

The 1409 does work well on the 327F.............see photo :-) On that boat I have clearance for a performance intake, which I seriously think will pick up 15 to 20-hp so maybe I'll do the swap on that one for next season.

Regards,

Paul
Attachments
SkiffrunOctober18.jpg
1956 17' CC Sportsman, 300-hp
1957 17' CC Sportsman, 95-hp
1966 20' CC fiberglass Sea Skiff, 210-hp+
1973 23' CC Lancer inboard project, 427/375-hp.
1966 38' CC Commander Express, 427/300-hp(2)

So many boats.........so little time.....but what a way to go!!

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