Ok the cam and valvetrain are in my sig so here is the deal....

Try to start the car as it turns over it seems to try to fire in random sequences no rhyme or reason no almost starting then dying almost a backfire in fact very possibly a backfire. the car is getting spark and fuel. i had the valves ground to clean them up but did not have the valve seats ground could that cause this much of a problem, also as i was cranking 3 of the rockers dropped off to the side in other words came off the valve, do the 1.52 roller tipped rockers need guides? Also I put a new cap and rotor on the opti, I do not believe so but can the rotor be put on 180 degrees off?

 

if your car is not running and rockers are coming off my first guess would be incorrect valve lash

 

I agree. Remember, in order to correctly set lifter preload, the lifter has to be to the base circle of the camshaft lobe.

Since your engine will not start and run, you have to set them with the engine off. The most fool-proof way is to use the Exhaust Opening/Intake Closing method, which is the method I recommend and well as the one the big cam companies do too.

It essentially involves the INTAKE pushrod movement in order to set the EXHAUST and then to watch the EXHAUST pushrod to set the INTAKE.

Not sure if the the step-by step is posted here, so if you need me to, I write up for you.

Jake

 

Well be glad you found the rocker problem before the engine started.

You need either guide plates or rockers with some sort or ridge or washer at the tip to hold the rocker in place. Sounds like you have neither.

On the rocker adjustment. Couple weeks ago a guy calls me and says his car cranks after a cam swap but acts like no compression. I asked him how he adjustyed the valves and he used the "spin the pushrod" method of finding zero lash. Well what he found was the bottom of the lifter plunger travel and then added 1/2 turn. Was hanging the valves open.

I suspect you did basically the same thing.

Som experianced guys get by with the spin the pushrod thing but most guys will endup WAY WAY too tight like that.

Move the pushrod vertically between the rocker and lifter, when it doesn't move any more that is zero.

First though you have to sort out the rocker problem, if in doubt about what you bought post some pictures or part numbers.

 

The part number of the rockers is COMP Cams 1412-1 i see now that i definately need guide plates as other sets have the small washers at the ends of the roller... I adjusted my rocker arms incorrectly for sure I've heard so many ways to do it the challenge is sorting the bad from the good. I am still being told I need to have my valve seats reworked and that is why the car is not running could that be the culprit in this case?

 

Also i forgot to ask is the base circle of the lt4 hot cam smaller than that of the stock lt1 cam? thanks for the help guys

 

Question?Why did you grind the valves but not the seats?

 

its a long story that i dont feel like getting into but i was told that it would be fine as the seats were pretty clean i was under the impression that it would maybe backfire a little until they seat again.

 

Far as the seats, depends on how closely the angles and diameters match, I do not believe that is the cause of not running, I think the missadjustment is, but it is possible the seats need to be done.

With a lot of this stuff it is a MISTAKE to go BLINDLY screwing up the stock stuff.

The stock valve job is decent and I would not trust BillyBob's machine to improve upon it. Need good equipment in good hands and that is more rare than you would think.

There are a LOT of hacks out there.

 

yes i know all about the hacks some dumb bastard couldn't put a helicoil in my head i could have done it but there also was an exhaust stud broken off in there and i didn't feel like messing with it myself, but is the lt4 hotcam base circle smaller than the stock lt1 cam?

 

No, there's no difference in the base circles.

There are several different ways to set lifter preload and all of them will work, BUT only if the correct procedure is followed. The BIG difference among them is one method is less error prone than the others. That would be the EO/IC method.

Jake

 

I have seen more guys have issues with finding zero lash than finding the base circle.

 

I'm a firm advocate in the up and down method too. The often recommended "spin the pushrod with your fingers until you feel slight resistance" causes a lot of problems.

What's a "slight resistance" to one person isn't to another.

Jake

West Point ROCKS!

 

I think if you are doing rockers with Posilocks and your rocker studs aren't boogered up, you can find zero lash by hand tightening them. You should be able to feel it as you tighten the nut if you dont have binding parts or nicked up threads. It is a little harder to feel with a wrench.

 

The point I was trying to make is "Zero lash ain't Zero lash" unless the lifter is on the base circle of the cam lobe.

That's the starting point; turning the engine until the lifter is on the base circle of the lobe. It's the most critical step. If the lifter is on the lobe's ramp or nose, the preload adjustment will always be off.

Same principle as when degreeing in a camshaft.
Finding Absolute TDC is the most critical step. If it's not found, all the readings that are taken afterwards will be skewed.

Just trying to help.

Jake

West Point ROCKS!