I have a forklift with a commercial slant 6

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Daverockxxzz

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I have a Forklift with a commercial slant six that dies after ten minutes... I would like to replace with an automotive slant six from a cuda...I am not sure but I think the forklift is a "Champ", and I don't know the year of the cuda engine that my friend says I can have... Any info would be appreciated... Thanks
 
Seriously. Unless there's more you're not telling us (engine smokes, engine has a hole in the side of the block...) the correct solution to "engine stalls" is not "replace engine", it's "find and fix problem". What diagnosis have you done so far?
 
If the engine you have now stalls out after 10 minutes, your replacement engine will likely stall out after 10 minutes.

Stalling is usually fuel delivery, ignition or something other than the actual engine.
 
slantsixdan said:
Seriously. Unless there's more you're not telling us (engine smokes, engine has a hole in the side of the block...) the correct solution to "engine stalls" is not "replace engine", it's "find and fix problem". What diagnosis have you done so far?
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We have replaced the coil(2X), electronic ignition system, porcelain resistor, carburetor boiled out and adjusted, plugs and wiring...we have had two seasoned heavy equipment mechanics who have tried to solve the issue, and it appears that the engine is getting fuel and spark... If it starts and dies after ten minutes it will not restart under any conditions til the following day...we thought the coil was most likely issue and replaced with new, and when that did not resolve the issue we used a coil we know was working and still the issue is persistent... We also put in a new electric inline fuel pump... So...any ideas we might have overlooked?
 
Gas tank venting? If it's not it will only run a short time then the pump won't be able to pull anymore. Leave the gas cap off & fire it up.
 
GRANCUDA said:
Gas tank venting? If it's not it will only run a short time then the pump won't be able to pull anymore. Leave the gas cap off & fire it up.
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Yes, forgot to mention we did vent with gas cap off and we also tried a remote fuel tank to see if there was supply line blockage...
 
TrailBeast said:
Too tight on the valves maybe?
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When it runs for 10 minutes, no smoke engine sounds fine, if valves are problem it would have to have self-adjusted, and I would think if anything looser from wear rather than too tight. We have not opened up the engine....
 
Daverockxxzz said:
When it runs for 10 minutes, no smoke engine sounds fine, if valves are problem it would have to have self-adjusted, and I would think if anything looser from wear rather than too tight. We have not opened up the engine....
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Not valve trains.
They tighten as they wear believe it or not and can very well hold valves open when they warm up and parts expand.
I won't be offended if you want to ask about that in your thread.:D

OH, it is in the thread. Duh:D
 
TrailBeast said:
Not valve trains.
They tighten as they wear believe it or not and can very well hold valves open when they warm up and parts expand.
I won't be offended if you want to ask about that in your thread.:D
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If the compression test is good is this still a possibility or not?
 
Daverockxxzz said:
If the compression test is good is this still a possibility or not?
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Oh yea.
It could be holding the valves open when warmed up if they are tight.
When it's cool enough to do a comp test they are closing all the way again so the comp reads fine.
Totally possible.

If this is the cause it probably just needs the valves adjusted.
 
Of course the above would not apply to an engine with hydraulic lifters (your self adjust thought) but I think most slants are adjustable aren't they.
Maybe I'm wrong but you mentioned the scenario of it and I came up with something that might apply that has apparently not been checked, when in fact it should have been probably long before this point in the game.
I'm actually kind of surprised the seasoned guys haven't checked that yet.

Motors don't quit after 10 min for no solvable reason.:D
 
Which parts have you replaced when you say you've "replaced the electronic ignition system"?

I don't think much of your "two seasoned heavy equipment mechanics" -- it sounds to me like they're taking random guesses and throwing random parts at the problem rather than doing proper diagnosis. You've got fuel (how do you know/where and how are you checking?) and spark (how do you know/where and how are you checking) when the engine will run...which one of them do you NOT have when it won't run (how do you know/where and how are you checking)?

It's not valves too tight -- if they're tight enough to make the engine fail to start, it would barely run (if at all) ever.

This problem is not going to be difficult to fix, but it's going to take proper diagnosis.
 
when it quits running, do you have good spark? Is the choke open fully? If you work the accelerator linkage at the carb, can you see fuel squirting into the carb venturi? If you have fuel and spark, you just need proper ignition timing.
You mentioned replacing electronic ignition. Why was that done? What year engine are we talking about? Does it have spark plug tubes? If not, then I think it is an hydraulic lifter engine, which might be important to know.
 
I agree with rustycowll69 on checking to see if you have spark and fuel squirting in the carb after it dies. Could this be vapor lock happening? But only after running the engine for 10 mins doesn't sound like it is. 10 mins is a short period of time. I say fuel or spark/electrical is the issue. Again check for spark and fuel squirting in the carb after it dies. Go from there....

 
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