Chris Craft 283 - can't get above 2500RPMs

Hello,

I have a 20' 1956 Chris Craft Holiday with a 283 / 185 HP engine and cannot get faster than 2500RPM. I had the carb rebuilt and even put in some GUNK fuel system cleaner. Sounds great, no vibrations, etc.

Appreciate any suggestions or direction.

 

Update.......

Had a friend that came over.....

Did a couple of things.

1st: Had the manifold cover on backwards on one side and the rockers were rubbing against the covers... Oil was actually coming out and the metal "pulsed" due to them pressing on the cover. Thought is that they might have gotten stuck. I am a novice........ and did not know they could go on backwards.

2nd: Adjusted the choke. I had lots of trouble starting the engine when it was hot and adjusted the choke far to the opposite side. I can start when the engine is warm, but it looked like the 3rd and 4th barrels were not opening up due to that adjustment. Gonna take her out and see what happens.

 

Could be both those things certainly the choke flap restricting air flow.

Ive never heard of forcing on the rocker covers before and yes you might have bent a valve and lost a cylinder or 2.

What to say-- well you might have cost yourself more money trying to do this yourself.

Im reluctant to tell you what to do because to be honest you cant do it.

You need 2 new rocker boxes for a start.

 

Thanks Frosty. Appreciate the honesty.

I thought this forum was to educate people..........

In life, we start out not knowing what we are doing and often learn from our mistakes. This indeed might be costly mistake and I have learned.

Again, appreciate your comments and silence on telling me what to do. I feel I have learned a lot over the years (in different areas) and teach my children to try and that they can " do anything". Not sure you know what I can or cannot do from a post....but again appreciate the response.

I can tell you I do not look forward to knowing everything like you and turning into a judgmental (fill in the word that fits).

Best,

Rich

 

You would find that what ever I tell you from the other end of this internet connection, you would do more damage. I can not imagine doing what you have done so further surprises would be probable.

Replace the rocker covers with new gaskets, don't overtighten!!!!

Do a compression test, the cost of equipment is small. Mark all the plug leads so you replace them in the correct order, replace the pugs while they are out.

Get a manual and re set the choke mechanism, it is adjust able on the thermostatic bi metal coil. There is a vernier adjustment marker so you can return to previous adjustments.

The choke should be fully open when hot and full closed when cold.

To assist a cold start pump the gas a few times before cranking.

 

The worst that's happened to your valve train is a few bent push rods, which aren't very difficult to replace. Loosen the rockers, swivel them away, pull the push rods and replace them, it's literally that simple. Of course the cam lobe should be on the "flat" side when the rockers are loosened.

The valve covers might have some dents, but they'll still be serviceable, assuming you haven't bend anything else, forcing them on.

The secondaries and choke linkages are fairly easy to fix/adjust on that engine. Do yourself a big favor and get a manual for that engine and go through the tune up section, where you'll learn how to make these adjustments. The push rod replacement can be found in the "valve lash" section, which will also show you which valves you can work on, with the engine in a particular position.

Lastly those old style 4 bolt covers are known for leaking. A good solution is larger brackets under the hold down bolts.

 

Pulling out a push rod may seem easy providing you shake the hell out of it to shake it off the follower/ lifter . Due to suction the follow can come out of its hole and the inlet manifold removal will be necessary to replace it.

 

On the first generation small block, removing push rods is quite simple. Common repair practices can eliminate any concern, over a lifter remaining stuck to the push rod.

 

Its nothing to do with Chevrolet or small blocks its the cup of the lifter not wanting to let go of the push rod due to suction of the oil from the round cup of the push rod sitting in the hollow bottom of the lifter. Its same thing from a Ford to an MGB to a small block.

Its general mechanical awareness to shake the hell out of it to make sure it wont bring the lifter with it.

 

Post a photo or your carb

 

You can shake it if you like, but a quick shot with an air hose is more reliable and a bit faster too. The reason it's easy on a small block is the clearance the push rod has coming up through the head, which isn't as generous on other engines.