And i thought tuning was my only problem ...

THEMADTYPH00N

Active member
Re: And i thought tuning was my only problem ...

are the 7808 pushrods the correct ones for the vortecs?
i think thier comp cams also , dont really remember

On a built motor you can not just know the pushrod length. Everything from head gasket thickness to how much the heads were milled, how much the block was decked, type of lifters you have affects it. The best thing to do would be to get a adjustable length pushrod and measure the exact length you need.
 

Quickstop [UK]

Combating adversyty.
Re: And i thought tuning was my only problem ...

How exactly do you measuer the correct length? Got a link?

I have Vortecs from RPM with the Cometics and 1.6RRs with the stock length but Manley replacement rods.

I haven't run it hard yet and would rather not mangle my truck in the meantime :tdown:

Sorry this happened to you man..
 

turbodig

Active member
Re: And i thought tuning was my only problem ...

they are comp cams rockers , and the vortecs have the screw in studs .

i dont want to machine the heads so should i get 1.5's and be done with it ?

That would be the "no worries" version. 1.52s will generally make it as well.
You'd also have fewer issues with geometry assuming you have stock length pushrods.

Personally, I'd check them all first to make sure you do have an issue... run each valve up/down and check for clearance.
 

BoostedSUV

Active member
Re: And i thought tuning was my only problem ...

I agree with dig 100 percent! Verify that is your issue first. Put a ratchet on the crank pulley and turn the motor around and watch the pushrods at full lift. If they are even within a couple thousandths of touching they will deffininately touch at high RPMs or under a load. If that is the case change ALL the push rods and throw a set of 1.5 or 1.52 rockers on and be done with it. Your only other option would be to machine the push rod boses for added clearence. I already had the motor out of my truck when I realized that was the reason I bent 3 pushrods and threw them out of the motor so I had a shop machine the heads while they were off. When I had my Vortecs done I had Waller open them up for me before I got them. The easy fix is put 1.5s and new pushrods and call it a day...

My bet is that I made the right call by guessing this is your prob but verify it before you go spending any time and money. :tup:
 

Try Me

New member
Re: And i thought tuning was my only problem ...

Was the rocker loose at all? Get rid of those stock nuts and get some good poly locks on there. Also get rid of those junk ball end pushrods and get the correct lenght one peice ones. Your lucky you didnt snap that push rod and have it go down in the motor, thats not fun.
 

qbnkiller

Conflaguration Specialist
Re: And i thought tuning was my only problem ...

John beat me to it!

Check the wear mark on the valve stem surface - that's a good indicator of pushrod length. If the witness marks are right in the center, you're golden.

I am using ISKY adjustable guideplates to keep mine 'centered', but they do move around a bit.

Take a closer look at the fit of the pushrod end to the rocker arm. In the pic, it looks like they are disimilar (different style).
 

MRKING

New Parts for Old Trucks
Re: And i thought tuning was my only problem ...

thanks guys . im gonna check how close they get and see how much this is going to cost me .

not to look at this in the wrong light , but if what i bought isnt an odd combo and the heads are advertised and the best you can buy , shouldnt the holes have been opened up anyway ? New heads never milled , cometic gaskets , stock block , recommended pushrods for standard vortec swap .

I thought this was the tried and true approach to this and see it was my bad for not checking it . im only mad at myself for not catching it sooner . oh well ...
 

BoostedSUV

Active member
Re: And i thought tuning was my only problem ...

thanks guys . im gonna check how close they get and see how much this is going to cost me .

not to look at this in the wrong light , but if what i bought isnt an odd combo and the heads are advertised and the best you can buy , shouldnt the holes have been opened up anyway ? New heads never milled , cometic gaskets , stock block , recommended pushrods for standard vortec swap .

I thought this was the tried and true approach to this and see it was my bad for not checking it . im only mad at myself for not catching it sooner . oh well ...

I would think that if you bought the heads from RPM and mike knew you were using 1.6s he would certainly know to machine the push rod boses. He may have and your issue might be something else but let us know what you find.
 

Icarus-54

Donating Old Member
Re: And i thought tuning was my only problem ...

It's interesting to note that the valve that jumped is where the baffle for the valve cover is.Check the vc. for interference.Also the easiest way to check your push rod lenght is to mark the top of the valve with a magic marker to see the wear pattern.I've also noticed the comp cam magnum self-align rockers are considerably looser on the valve than most others.
Jack
 

MRKING

New Parts for Old Trucks
Re: And i thought tuning was my only problem ...

It's interesting to note that the valve that jumped is where the baffle for the valve cover is.Check the vc. for interference.
Jack

someone get this man a cookie . :tup:just looked a little closer this time at the stock vc's , sure hit the nail on the head , small scratching made a minor groove enough to catch the rocker arm and free the pushrod i imagine .i checked the other rods , no other bends , and they do come a little close to the bottom of the holes. im going to get my flip video and put it up of how close they get when moving .

thanks again .:tup: just where were you guys when i did all this 2 years ago :lol:
 

Osmosis

New member
Re: And i thought tuning was my only problem ...

My last hot rod, I had a supercharged Z28 with a 75 shot of N20. I had a N20 malfunction that caused cylinder no 6 to backfire which casued a similar looking pushrod. consequently, the backfire also scored the cam. The car seemed to run ok, but I too had to chase the problem.
 

THEMADTYPH00N

Active member
Re: And i thought tuning was my only problem ...

I would still check pushrod length just to see where you're at, since you mention you didn't do it before.
 

Osmosis

New member
Re: And i thought tuning was my only problem ...

I think summit sells a crane or comp cams pushrod length checker tool for about $50.00, that would be $50 bucks well spent here my friend:tup:
 

TYTILIDIE

METH HEAD
Re: And i thought tuning was my only problem ...

DAMN !!!! good call! I'll bet you're happier than a pig in shit right now. Feels to know it was something stupid doesn't it? Good luck, hope you get to enjoy it more now.:tup:
 

MRKING

New Parts for Old Trucks
Re: And i thought tuning was my only problem ...

I checked the wear marks on the end of the valve stems and they are directly in the middle . All the other pushrods are straight as can be and i just got back from picking up another set. They only had 1 v8 kit in stock so i will be selling 12 as a full v6 kit if anyones interested .

after its all back together , im going to let it run and triple check the rocker arms and pushrod clearances.

I want to say a big thank you to all you guys again . I would have still been worrying about this now with out everyones help , but instead i practically have it fixed with knowledge of what to look for in the future .:myclone:

Sytys , been making mechanics out of men for 18 years . :lol::tup:
 

jwaller

Evil Genius/SyTy Guru
Re: And i thought tuning was my only problem ...

thats another reason I don't use those cheap push rods. you need the 1 piece chromoly ones. they wont bend like that under the higher stress of upgraded cam,lifter,rockers or springs.
 
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