Logo
FULL SITE MENU

454 not running on all cilinders

W

wimpertjo

New member
Hi everyone,

I am writing from The Netherlands where knowledge about crusaders is scarce Im afraid.
I have two Crusader 454's RH and LH
they have Quadrajet carbs and electronic ignitions.
One is running beautifully, the RH is running on 5 cilinders.
Before I took them out of the boat to paint them they were both running great.

All sparks (new) give a spark. I have the RH timing set up.
I've changed out the carburators and also the entire ignitions, but none of that helps.
The nr 3 and 5 dont do anything the sparks in there still look new.

Now I will do a compression test tomorrow, but I cant figure out why that would have changed as I didnt take the engines about.
I took off the exhaust manifolds to powdercoat them, but their back with new gaskets.

both my rotors are turning cw, whicj I know is what they are supposed to do. my starter engines each go in a different direction but I put them back in the right engine otherwise my rotors would turn CCW (right?)

I have the firing order in 12756348 (as is market on the plate above the drive).

Any suggestions?

https://www.youtube.com/watch?v=7OWHCe5H93o

thats how she runs now
 
Last edited:
I think you have a couple of wires crossed. Are you sure they are all going to the right plugs? (More than one good mechanic has messed that up.) Sounds reasonable when it throttles up, but she's definitely not running smoothly at idle.

If the wiring is okay, and the 'trouble' cylinders are getting spark, then you must have some valves hanging up. (These motors are famous for stuck exhaust valves.) Pull the valve covers and spin it over with the plugs out, watching the valves on those cylinders to see if they close properly.

Good luck!

Jeff
 
So I tested the compression and found that my nr 3 was at 60 where the rest was at 90
and the nr 2 was at 0.
I took off the valve cover and found
IMG_5013.jpg

the outlet valve of the nr 2 cilinder is stuck. and the plunger is off. so what now??
 
both rocker arms don't look good on #2; I'd agree a teardown is in order but I'd be inclined to look for a cause before getting into it...
 
Started taking her apart. 3 headbolts are heavily coroded and I cant get grip on it.... so tomorrow I'll try to weld something on them.

Unknown-1.jpgUnknown.jpg
 
If you still can't get them out, drill the bolt heads off.

Jeff

PS: I'd try that FIRST so you don't have to drill the weld as well. Use a sharp set of cobalt drills.
 
took off one side today
IMG_5020.jpgIMG_5021.jpg

its clear that two cilinders werent doing anything as the valves are completely black there.
Still cant undertstand why the one valve is open and stays open. Its not bent ore anything. Any way bringing the head to the shop tomorrow
 
looks like a fair amount of rust in #2's bore...can't tell about the others from the single pic.

Agreed, it hasn't been running on all 8 for sure!!

Is the real light colored spot on the intake of #2 due to the removal process or is something mechanical going on there, too?

Stuck valve - if the spring is intact, likely to be interference between the stem & the guide.
 
So I took off the second head.
strange enough here too one is much better than the rest combustion wise.
These heads will be professionly taken care off, what I cant figure out is what has happened to make this happen
IMG_5028.jpg
 
What can make an exhaust valve stick is that the engine has sat for many months without running. On a valve in the down position the exposed upper part of the stem can rust and then hang up on the valve seal when the valve tries to retract into it's normal closed position. I have a boat in the tropics that is stored in the heat of the summer when I am gone and this has been a problem. I imagine it could happen anywhere, but perhaps not as fast in cooler weather. If you see a lot of corrosion on the stems of your exhaust valves, that may be what caused the problem. Also getting a little salt into the exhaust manifold by elbow failures (water leaks) or by operational mistakes (backing down in big waves, allowing the boat to roll excessively on a drift, etc.) will greatly speed up the rust progression.
 
I don't know how to stop it, at least without a lot of trouble. Exhaust valves made out of exotic material (that will not rust) are available some places but expensive. I thought about pulling the valve covers and relaxing the rocker arms on the exhaust valves that are depressed and then readjusting when I recommission the boat. Big hassle on my boat to get the covers off. Or about "fogging" the engine to try and coat the exhaust valve stems, but I doubt I would get enough rust prevention material up to that spot. Probably fogging would do a better job of coating all my sensors to my dismay!

The best answer for me would be to never let the boat sit idle for more than 30 days, but I would need a lot of airplane tickets to do that.

If anyone has any good ideas I also have an interest.
 
Back
Top