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How to build a 4.0 OHV for power, some limits and tips...


so up to now iv herd both ways that you can and you cant use stock valve train with the 422
 
so up to now iv herd both ways that you can and you cant use stock valve train with the 422

The 4 engines that I've built up - 2 with the 410 and 2 with the 422, have all required longer pushrods.

I would recommend getting a pushrod length checking tool and verifying when installing either of these cams - that's what I used.........

Bird
 
The 4 engines that I've built up - 2 with the 410 and 2 with the 422, have all required longer pushrods.

I would recommend getting a pushrod length checking tool and verifying when installing either of these cams - that's what I used.........

Bird

About how much longer?
 
BLU! Be very wary of posts that guys make claiming this or that.

For sure and certain longer pushrods are NOT NEEDED! The guy has no idea what he is talking about.

High lift cams may require shorter pushrods but the two cams in question are good to use as delivered with stock pushrods.

The pushrod goes between the lifter which is caged in a bore and the rocker which is also caged to it's mounting. Using longer pushrods would solve NOTHING.. as there is no problem to be solved.

AND if the pushrod is as little as 1/8" longer the hyd lifter may be bottomed out and cause the valve to stay partly open intermittantly! THIS would be very bad. The valves would burn and the engine would run like shit.

Using solid lifters the extra length would be adjusted out just to keep the engine running.

Big JIm
 
....unless it was ground on reduced base circles (hint hint)
 
Were that the case Comp cams would proudly deliver the needed length pushrods with the cam!

The last thing the cam company wants is complaints. They want satisfied customers.

In this particular instance the cam company says to use stock pushrods.

Big JIm:wub::hottubfun:

....unless it was ground on reduced base circles (hint hint)
 
BLU! Be very wary of posts that guys make claiming this or that.

Big JIm

I think Blu also needs to follow your advice as it pertains to what you may have to say also......................

Built any performance 4.0's lately, Jim? (I'm not talking about just 'bolt-ons')

Several of us over on the 'other site' have put together some decent performing 4.0's and I don't remember a single one of them being able to use 'stock' pushrods - the 4 of them I built, all needed longer pushrods to maintain proper lifter loading, but, as I said in my previous post (which you obviously didn't read), a pushrod length checker is recommended to verify. I don't give out specific lengths any longer as there's too many variables to deal with to get the lifter plunger at .030 preload. Smith Brothers (recommended by Dennis at Comp Cams a long time ago) is more than happy to provide an adjustable pushrod to check these out.

A stock pushrod with no preload on the lifter can easily wear out the rocker arm from the constant 'slamming'.


Bird
 
True, but if that were the case, wouldnt you think they would offer the upgraded valve springs needed to run the 422 cam too?

I havent seen where it says to use stock pushrods anywhere, but what I can say is this.
Whats the 4.0 known for, push rod and rocker arm wear. What takes up the slack,the lifter. What happens when the lifter has no more room for adjustment, it cant compensate for the reduced base circles, let alone the factory cam. Now if you upgraded to Deltas hardened pushrods and rocker arms, the lifter might have enough travel to compensate. I cant offer any personal experience to that. Im not saying it can, nor am I saying it cant. But to someone, that might be a beginning to a recipe for success.

Bird beat me to it....If anyone knows, its him.
 
what are the length of stock push rods? because in my searching most people have to order 5.5 inch long push rods and they run procomp 988 springs i dont understand what the big fight is about. if someone would do a little searching they would find the info i just gay. you need new push rods and valve springs with this cam swap
 
if i were to bore a firts gen 4.0 over to a 4" bore what pistons would work? sbc? sbf?
 
A stock pushrod with no preload on the lifter can easily wear out the rocker arms

I think Blu also needs to follow your advice as it pertains to what you may have to say also......................

Built any performance 4.0's lately, Jim? (I'm not talking about just 'bolt-ons')

Several of us over on the 'other site' have put together some decent performing 4.0's and I don't remember a single one of them being able to use 'stock' pushrods - the 4 of them I built, all needed longer pushrods to maintain proper lifter loading, but, as I said in my previous post (which you obviously didn't read), a pushrod length checker is recommended to verify. I don't give out specific lengths any longer as there's too many variables to deal with to get the lifter plunger at .030 preload. Smith Brothers (recommended by Dennis at Comp Cams a long time ago) is more than happy to provide an adjustable pushrod to check these out.

A stock pushrod with no preload on the lifter can easily wear out the rocker arm from the constant 'slamming'.


Bird

I am learning the importance of proper valve train geometry and plan on doing a custom high compression noss build with a #422 cam but i see no one has commented in quite a few years so taking a shot in the dark for some much needed info... So since hydraulic lifters require a preload between .020" & .060"would you just add .030" to the final measurement of your adjustable pushrod once you adjusted the slack and the pushrod/rocker arm is snug??
#WheneverYouChangeCamsYouMustChangePushrods! #TomMorranoRancingHasSomeNice4.0Upgrades #KeepingThe4.0Alive #TorqueMonster
 
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Another Shot In The Dark

Its mentioned in the original post from Doug904 that you could simply bolt on a C&L 73mm MAF as an upgrade, I see they are still available and seem legit has anyone used one and actually seen positive results?? Also i figure after all the mods your MAF would be the final bottle neck to hinder performance so has anyone found any upgrades outside of this?? and we all know carving out your MAF like a thanksgiving turkey will do nothing but ruin performance and confuse the computer.
 
I’m trying to find the MAF. Is it just the housing that needs to change or is there also a sensor? I’m trying to get my Bronco 2 to not run so rich with the injector upgrade.

Thanks
 

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