Active Active   Unanswered Unanswered

283 engine ignition timing

Keeping your powerboat under power is a lot easier with good advice. Post your power systems questions here.

Moderators: Don Ayers, Don Vogt, Al Benton

farupp
Posts: 832
Joined: Sat Oct 29, 2005 6:25 am
Location: Charleston, SC
Contact:

283 engine ignition timing

Post by farupp » Mon Mar 08, 2010 8:44 am

I have a 283 flywheel forward engine in my Sea Skiff. I have found the ignition timing mark on my flywheel and have adjusted the timing as closely as possible at the engine manual recommended 500 rpm. It was a little difficult as the engine doesn't run smoothly at 500 rpm; it likes 700 to 750 rpm for idle.

Does that timing mark indicate TDC for the #1 cylinder or is it a few degrees in advance of TDC?

Also, the manual says to adjust the valve lash for different intake and exhaust valves at the TDC firing position for the #8 cylinder and then rotate the engine one full rotation to the TDC firing position for the #3 cylinder and adjust the remaining valves.

Are the TDC positions for the #3 and #8 cylinders marked on the flywheel in any way?

Thank you.
Frank Rupp
1959 22-foot Sea Skiff Ranger
283 Flywheel Forward engine

User avatar
evansjw44
Posts: 1865
Joined: Wed Jul 05, 2006 8:46 am
Location: Grosse Pointe Farms, MI
Contact:

Timing

Post by evansjw44 » Mon Mar 08, 2010 9:53 am

It is my belief that the timing mark is actually about 6 degrees advance. Its marked for #1 cylinder. That is why you can find two timing marks on the flywheel. One is for standard rotation and the other is for opposite rotation. The reason to set timing at 500 RPM is so that the centrifigual advance has not start to kick the timing ahead. The SBC doesn't like to idle at 500 RPM They are much happier at 700 RPM and above. Once in gear the idle speed might drop 100 RPM.

I have 327Fs in my 35' Sea Skiff. I keep the idle set at 900 RPM. The reason - If I am making headway and shift from forward to reverse my engines will stall if I don't keep the idle high enough. I turn 20x23 props with 2.5:1 reductions. To reverse the rotation and overcome the forwards water thrust puts a heavy load on those SBCs. The loss of RPM also pulls the timing back further lowering power.


As for setting valves, there i no timing mark is no mark for #3 or #8. I used to set them with the engine running and hot. Its a little tricky and it can throw oil all over but its more accurate. I changed over to hydraulic lifters and a hydraulic lifter cam. Setting valves is pain.
Jim Evans

farupp
Posts: 832
Joined: Sat Oct 29, 2005 6:25 am
Location: Charleston, SC
Contact:

Post by farupp » Mon Mar 08, 2010 11:30 am

Thanks, Jim. So far I have only found one timing mark on the flywheel; how far apart are they if there are two? Are they both drilled "dimples" (about 3/16 inch diameter) painted white in the flywheel rim? That is what I found so far and used to set the timing. I don't want to use the wrong mark but I would think the engine wouldn't run if I used the wrong one.

I am curious about this as the engine was an opposite rotation engine converted to standard rotation.

I remember setting the valve lash on a 283 engine with hydraulic lifters in my father's 1962 Chevy. Oil all over as they had to be adjusted while the engine was running. Is the valve lash in the solid lifter engine adjusted the same way: by loosening or tightening the rocker arm mounting nut?

By the way, what does SBC mean?

Thanks again, Jim.
Frank Rupp
1959 22-foot Sea Skiff Ranger
283 Flywheel Forward engine

User avatar
evansjw44
Posts: 1865
Joined: Wed Jul 05, 2006 8:46 am
Location: Grosse Pointe Farms, MI
Contact:

Excuse Me

Post by evansjw44 » Mon Mar 08, 2010 1:58 pm

SBC means small block chevy. I get too familiar with this stuff sometimes. I know my 327Fs have two marks. They are dimples painted white. But I set timing many times on my father's old 283s and maybe they had just one timing mark. I never had them apart where I would notice that. I'm pretty sure the one mark is TDC. If you only have one mark then time to that mark. I have found that if I time my 327s to the wrong mark that don't run well at all. I repainted the dimples so avoid the confusion. Chris Craft painted the right dimple for each engine and so long as the paint isn;t lost its intuitive to time to the mark you can see. If the paint gets lost then you have to think it through to get the right mark.
Jim Evans

farupp
Posts: 832
Joined: Sat Oct 29, 2005 6:25 am
Location: Charleston, SC
Contact:

Post by farupp » Mon Mar 08, 2010 2:05 pm

Thanks, Jim. I looked pretty thoroughly on the flywheel and only saw one white painted dimple so I am probably using the correct mark for ignition timing.

About adjusting the valve lash: Is it done by tightening or loosening the rocker arm hold-down nut while checking the clearance with a feeler gauge?

Thanks.
Frank Rupp
1959 22-foot Sea Skiff Ranger
283 Flywheel Forward engine

User avatar
evansjw44
Posts: 1865
Joined: Wed Jul 05, 2006 8:46 am
Location: Grosse Pointe Farms, MI
Contact:

Valve Lash

Post by evansjw44 » Mon Mar 08, 2010 2:17 pm

You adjust the pivot stud nut on each rocker arm to get the right clearance. I recall the .018 exhaust and .008 intakes. When I last set solid lifter valves (that was a while ago) I was careful to leave them a little loose. When you set them cold, the clearance will tighten when the valves heat up and there's possibility you could burn a valve. A little ticking is not a bad thing. Lots of loud ticking is a bad thing. Too loose and the valve is operating on the faster part of the cam slope and you could break a valve. The cam is contoured so that the acceloration of the lifter and valve slows as it reaches the beginning to open and the beginning to close part of the lobes.

Look out for cracked rocker arms too. That's a frequent chey problem. Racers use stud nuts with locking nuts. Seems the standard issue chevy stud nut has a habit of loosening over time.
Jim Evans

farupp
Posts: 832
Joined: Sat Oct 29, 2005 6:25 am
Location: Charleston, SC
Contact:

Post by farupp » Mon Mar 08, 2010 2:25 pm

Thanks, Jim. If I set the clearances cold is setting them two-thousands wider safe; i.e .020 exhaust and .010 intake?

I recall that the standard Chevy stud nut had threads that were eccentric in shape. I think I still have a couple laying around. They could only be adjusted a few times before they didn't hold well and had to be replaced.
Frank Rupp
1959 22-foot Sea Skiff Ranger
283 Flywheel Forward engine

User avatar
evansjw44
Posts: 1865
Joined: Wed Jul 05, 2006 8:46 am
Location: Grosse Pointe Farms, MI
Contact:

Lash

Post by evansjw44 » Mon Mar 08, 2010 3:07 pm

I'd hate to be the one that gave bad advise. I think I used .010 and .020. But I did it hot. Maybe yhou need to talk to a really good machine shop or David VanNess.
Jim Evans

farupp
Posts: 832
Joined: Sat Oct 29, 2005 6:25 am
Location: Charleston, SC
Contact:

Post by farupp » Mon Mar 08, 2010 4:31 pm

Ok. Good idea.
Frank Rupp
1959 22-foot Sea Skiff Ranger
283 Flywheel Forward engine

Gord
Posts: 160
Joined: Fri Mar 13, 2009 12:06 pm
Location: Medicine Hat Alberta Canada
Contact:

Post by Gord » Mon Mar 08, 2010 6:23 pm

Setting them cold at .20 and .10 will not hurt anything, that would be acceptable tolerance, just set them snug if doing it cold. :D
1948 U22 Sportsman
1961 28 Connie

farupp
Posts: 832
Joined: Sat Oct 29, 2005 6:25 am
Location: Charleston, SC
Contact:

Post by farupp » Mon Mar 08, 2010 6:53 pm

Thanks, Gord. I am going to check them cold and see what the settings are. The engine runs fine, and apparently has for a few years, so maybe the best course of action is to follow the old advice: "if it isn't broke don't fix it."

But, then there is always Murphy's Law!
Frank Rupp
1959 22-foot Sea Skiff Ranger
283 Flywheel Forward engine

mcisaac inc
Posts: 283
Joined: Sun Mar 23, 2008 8:34 am
Location: onekama, mi.
Contact:

Post by mcisaac inc » Mon Mar 08, 2010 10:00 pm

:D All the single four barrel 283s cc used have hydraulic lifters. They require zero valve lash. Only the corvette 283 version had solid lifters........markmcisaacinc.com

farupp
Posts: 832
Joined: Sat Oct 29, 2005 6:25 am
Location: Charleston, SC
Contact:

Post by farupp » Tue Mar 09, 2010 5:31 am

Without removing the rocker covers, how can I tell the difference between the two engines?

The 283 operator manual I received with the boat indicates that the valve clearances should be .008 intake and .018 exhaust, and says that it has mechanical (solid) lifters. The parts manual also shows solid lifters.

Did Chris Craft print two different engine manuals? One for the solid lifter engine and one for the hydraulic lifter engine?

The serial number of my engine is 817127 and it has the Rochester four-barrel carburetor.

Thanks, Mark.
Frank Rupp
1959 22-foot Sea Skiff Ranger
283 Flywheel Forward engine

mcisaac inc
Posts: 283
Joined: Sun Mar 23, 2008 8:34 am
Location: onekama, mi.
Contact:

Post by mcisaac inc » Tue Mar 09, 2010 8:19 am

:D not sure why . most repair manuals show both solid and hydraulic lifter adjustment procedures, because they are both used in those years.. The 185 hp. version of the 283 that i have used are factory equipped with hydraulic lifters. With (chevy) #1 cylinder up, adj exhaust valve 1,3,4,8, and intake valve 1,2,5,7. crank engine to #6 piston up and adj. exhaust 2,5,6,7,intake 3,4,6,8. i was always told to back rocker then tighten to zero lash, then go a 1/4 turn past zero. Others may use different technique, i am just a diyer like you.....................mark

farupp
Posts: 832
Joined: Sat Oct 29, 2005 6:25 am
Location: Charleston, SC
Contact:

Post by farupp » Tue Mar 09, 2010 8:35 am

OK, Mark. Thank you.
Frank Rupp
1959 22-foot Sea Skiff Ranger
283 Flywheel Forward engine

Gord
Posts: 160
Joined: Fri Mar 13, 2009 12:06 pm
Location: Medicine Hat Alberta Canada
Contact:

Post by Gord » Tue Mar 09, 2010 2:45 pm

Be very careful with what you are doing here, while its true most 283's were hydraulic lifters that probably has more to do with automotive engines. Marine engines are different. I cannot comment on which SBC engines had either solid or Hydraulic systems back in the day. But before you ruin a cam and lifter set plus all the bearings when the results of improper lifter adjustment go through the oiling system causing a major overhaul. Be sure you know if its hydraulic or solid lift cam. I would suggest the age of the engine would be the deciding factor solid lift cams were pretty common in the early years of this engine, but by the mid sixties very few had solid lift cams.

If its running just fine and the current settings are all pretty much the same...well that might just be the deciding factor, leave her alone.
1948 U22 Sportsman
1961 28 Connie

Gord
Posts: 160
Joined: Fri Mar 13, 2009 12:06 pm
Location: Medicine Hat Alberta Canada
Contact:

Post by Gord » Tue Mar 09, 2010 2:57 pm

One other note the 4 bbl carb would tend to suggest a higher performance engine. A higher performance engine in that time period probably had a solid lift cam.

If I were you I would check the clearance on six of the rocker arms, then pull those and inspect just to make sure there is no wear on the rocker arm if they are OK put them back using the same clearance. Do them one at a time. If they have some wear then change them. If you change them go to Jegs and get a set of roller tipped rocker arms, better yet if you do not mind adding a set of valve covers because of the hieght go for the alluminum roller rockers. They will come with a set of proper lock nuts.

Keep us posted. :D
1948 U22 Sportsman
1961 28 Connie

User avatar
evansjw44
Posts: 1865
Joined: Wed Jul 05, 2006 8:46 am
Location: Grosse Pointe Farms, MI
Contact:

Hydraulic Lifter

Post by evansjw44 » Tue Mar 09, 2010 3:04 pm

I never saw a hydraulic lifter 283. All the ones I worked on were solids. That's not to conflict with the experts here that say there were both. I just never saw one. When we sold my Father's 1963 34' Sea Skiff it had freshly rebuilt the engines and they needed to have the valves lashed after break in. The new owner didn't want me to do it so he brought in his own mechanic. He set the valves like they were hydraulics. He bent several valves and push rods. To make matters worse, he insisted that the engine builder was at fault. They were not happy replacing valves and push rods that were not their fault. And, they ate the labor to do the fix.

I don't know how you would tell the difference without pulling the intake manifold. These are old engines and could have been modified. My 327s were solid lifter but I changed them over to hydraulic. I got tired of setting valves.
Jim Evans

farupp
Posts: 832
Joined: Sat Oct 29, 2005 6:25 am
Location: Charleston, SC
Contact:

Post by farupp » Tue Mar 09, 2010 4:29 pm

My instincts say leave it alone and check them another day. The previous owner ran it this way for several years and it runs fine on the trailer. If I have a spare minute I may pull a valve cover and measure a couple of clearances to see what I have.

I have alot of other stuff to do to to get to Tavares. I haven't even used the boat yet as it has just now warmed up enough and stopped raining so that I could work on it, not to mention the kitchen expansion I am finishing up after a year.

I hope to get it in the water this weekend for a shakedown run.

Thank you all very much for the input.
Frank Rupp
1959 22-foot Sea Skiff Ranger
283 Flywheel Forward engine

jahearne
Posts: 419
Joined: Mon Nov 03, 2008 4:31 pm
Location: San Francisco
Contact:

Solid or Hydraulic

Post by jahearne » Wed Mar 10, 2010 6:56 pm

With the valve covers off find a closed valve where you can spin the pushrod with your fingers. Recommend turning the engine where the rotor cap is pointing to the no. 1 spark plug wire. Both valves no. 1 should be closed and on a cold engine you should be able to spin the pushrods by hand.

Tighten the lock nut down a couple turns until you can no longer spin the pushrod by hand. Wait a few... if you can NOT spin the pushrod by hand then it is a solid lifter. If you can spin it, then it's hydraulic because it doesn't have the oil pressure to pump it up.

BTW, my 1965 283 with over 1600 hours is hydraulic.

John
John & Wendy

farupp
Posts: 832
Joined: Sat Oct 29, 2005 6:25 am
Location: Charleston, SC
Contact:

Post by farupp » Wed Mar 10, 2010 7:27 pm

Thanks, John.

What I don't understand is that with the engine not running a hydraulic lifter will not have any oil pressure associated with it. So why would I be able to spin the pushrod after I tighten the lock nut? Does tightening the nut, thereby forcing the push rod down, push the oil out of the lifter and allow the push rod to spin?
Frank Rupp
1959 22-foot Sea Skiff Ranger
283 Flywheel Forward engine

jahearne
Posts: 419
Joined: Mon Nov 03, 2008 4:31 pm
Location: San Francisco
Contact:

Post by jahearne » Wed Mar 10, 2010 7:35 pm

There will be some oil in the lifter. Once it bleeds off, you'll be able to spin the pushrod again. Only takes a few seconds.
John & Wendy

farupp
Posts: 832
Joined: Sat Oct 29, 2005 6:25 am
Location: Charleston, SC
Contact:

Post by farupp » Wed Mar 10, 2010 7:43 pm

Thanks, John. I'll try it.
Frank Rupp
1959 22-foot Sea Skiff Ranger
283 Flywheel Forward engine

jahearne
Posts: 419
Joined: Mon Nov 03, 2008 4:31 pm
Location: San Francisco
Contact:

Post by jahearne » Thu Mar 11, 2010 10:05 pm

Either way, if the pushrod doesn't spin after you tighten it then you know it's a solid lifter.

I learn something new about my engines and boat every time I work on it. My manuals made no mention of hydraulic lifters only gave specs for solids. Turns out both engines have hydraulics. We're running 1965 283F.

Take care,
John & Wendy

User avatar
evansjw44
Posts: 1865
Joined: Wed Jul 05, 2006 8:46 am
Location: Grosse Pointe Farms, MI
Contact:

Its Odd

Post by evansjw44 » Fri Mar 12, 2010 5:29 pm

I have '67 327Fs. They're not that much different than a 283F. By my 327Fs were solid lifter from new. I changed them to hydraulic. But you say yours were hydraulic from new. I find that interesting. Maybe someone changed them before your custodianship.
Last edited by evansjw44 on Sat Mar 13, 2010 7:08 am, edited 1 time in total.
Jim Evans

jahearne
Posts: 419
Joined: Mon Nov 03, 2008 4:31 pm
Location: San Francisco
Contact:

Post by jahearne » Sat Mar 13, 2010 12:29 am

I'm glad for hydraulics. The previous owner from 12 years rebuilt the starboard engine, but the port has over 1600 hrs and he made no mention of working on that one; there's no saying that it might have been changed at some point even before the last owner.

Our Super Sport has 327F with hydraulics, but I didn't get the original block.
John & Wendy

rgmxk22
Posts: 148
Joined: Wed Jul 02, 2008 10:49 pm
Location: Ohio
Contact:

Post by rgmxk22 » Sun Mar 21, 2010 3:20 pm

Hi all,

I have to agree with Jim Evans on this one, I have never come across a CC 283 Flywheel Forward engine that did not have solid lifters. One case I'm sure of is Dad's 63 31' CC Sea Skiff, he's known this boat since day one and it has solid lifters in the engines.

What I heard and read was that GM's/Chevy's thinking wast that back then (late 50's, early 60's) was that manual transmission car's engines would have solid lifters since you could wind the rpms higher with a stick shift than with an automatic trans. So to prevent lifter pump-up associated with hydraulic lifters, they put solid lifters in the engines going stick shift cars.

That's not to say that CC didn't use some hydraulic lifters, but I also would think that for a heavy duty use like a marine engine, solid lifters would have been spec'd by CC. I also don't recall ever seeing in any of the CC engine manuals I have collected, and I have a few for the 283, 283/327F series, 430-431s and even the 350FLV HP that I have in my boat, that CC mentioned hydraulic lifters. There are valve settings for a solid lifter cam and you don't need settings for a hydraulic lifter cam since you set a hydraulic lifter at zero lash.

But over the years, who knows what changes have been made by previous owner's of our boats? So unless you know for sure that you have either solid or hydraulic lifters, it's difficult to know what to do to set the valves. But you WILL quickly ruin a solid lifter cam if you set the valves like you have hydraulic lifters. So know what you have first!

And a tip if you have to set soild lifters, you can go to a automotive speed shop like Summit Racing or a local shop and purchase a set of deflectors that clip over the valve rockers and help stop the oil from splashing all over while the engine is running as you set the valve lash.

If you are going to set a lot of valves on SBCs or any engine for that matter, you can also get an extra old steel valve cover for your engine, then cut a window in the top of the cover so you can get to the valve and rocker meet and the adjusting nuts.

As long as you cut the window so the valve cover still covers where the oil spurts out of the push rods, you can save a lot of the mess. Just make one cover that is cut out and then move it to the side of the engine you need to adjust the valves.

Ron Michael
1972 CC XK22
Ohio

jahearne
Posts: 419
Joined: Mon Nov 03, 2008 4:31 pm
Location: San Francisco
Contact:

Post by jahearne » Mon Mar 22, 2010 3:53 pm

And I confirm that none of my manuals for our 283F & 327F mention anything about hydraulic lifters. Only give specs for solid lifters. Chances are that they were replaced at some time or other.
John & Wendy

Post Reply

Who is online

Users browsing this forum: No registered users and 2 guests