Speedy

But why? First a spring breaks, then a pushrod breaks. It's not normal for either to break at 15,000. Thrown rod? I think he's right about coming back to it later when he has more enthusiasm.

Adam1203

iTrader: (5)

Im fine with that and I agree that the valve is probably bent. But there is more to it then that. because how does a bend exhaust valve on the #5 cylinder take out the intake valves push rod on #5 cylinder? because it was the exhaust valve that broke the spring but it was the intake valve that broke the push rod. there has to be more damage then just a bent valve. I mean if it the exhaust valve was bent that bad that it could clip or jam the intake valve to the point it broke the intake valves push rod how did it hold air pressure? when we shut the compressor off it bleed of very very slowly I would think it would be a big rush of air if it was bent that badly.

I think a chunk of the valve or piston broke free and jammed the intake valve when it went to open and that's what broke the #5 cylinder intake valves push rod. But until I take it apart this is all conjecture.

Wicked94Z

iTrader: (26)

Ok missed it was intake and exhaust separate issues, thought it was same valve

Adam1203

iTrader: (5)

I think a lot of people think its the same valve. I don't think I explained it very clearly the first time around.

SS RRR

iTrader: (2)

My guess is the lifters were being tossed and a valve kissed a piston. Hope not!

Adam1203

iTrader: (5)

I figured I would give you guys an update.

I pulled the motor and got the heads off and I have no damage. I am not sure why the spring broke nor the push rod on the next valve over. I took the heads to the machine shop and had them clean them up they said the valves were all good I had them install the beehive springs that comp recommends.

How often do you guys recommend I check my springs?

Also do you guys have any neat tricks for finding the push rod length?

Speedy

Get yourself a pushrod length checker and go over the travel on your valve setup. A broken spring sends off alarm bells that the rods may be too long, causing the springs to bind.

Adam1203

iTrader: (5)

Speedy I am running the stock rods and pistons. I have stock heads and valves. As far as I know this is the first time the heads have been machined. The block was decked. If You want I cant post a picture of the engine when it was just rebuilt with the 1# at top dead center. I also have a pic of the 5# cylinder.

Speedy

If the heads were milled and the block was decked and you are using aftermarket rockers you absolutely must get the pushrod length correct. What may appear okay at TDC won't be okay above 5000rpm. Look at the springs, if you see any kind of imprint on the tops of the coils after running the engine you have a pushrod problem. To me the problem seems evident that your pushrods are too long.

Your rocker travel should be exactly in the center of the valve tips and there should be absolutely no marks on the spring coils from bind.

Adam1203

iTrader: (5)

They may have been to long. I checked them with the marker trick but maybe I was wrong.

Should I be using a solid lifter (making them solid) when I check the lenght. I already bought a comp push rod checker tool

noice

Yes the lifter must be solid. I can post some of reher-morrison's setup proceedure if you want. Looking through the thread it appears you had some kind of binding problem in the valvetrain geometry. You might need to check the installed height of the springs.

Adam1203

iTrader: (5)

yes can you please post them.

The new springs where checked and installed by the machine shop. The old ones I did my self.

BALLSS

OP

Comp bee hives (26915 or 26918) spec a installed height of 1.800". stock AL heads with stock length valves spec 1.700"-1.750" installed height. So if the spring pockets were not machined down your bee hives may be slightly tight. With a mild lift cam this really is not a problem but on high lift cams running 1:6 RR you could get close to coil bind but again the 502 is not a really high lift cam. You can certainly check with the shop that did your heads and ask what installed height they put the springs in.

on your PR length given the head & block work, cam and 1:6 RR your PR length likely needs to be slightly shorter than 7.200". If you have a solid lifter (or make one solid) and even use a light "test spring" you can buy thae mark the tip of valve and lash that one then rotate engine over by hand 2 times. if witness mark is slightly towards exhaust you need a shorter PR. Closer to intake a longer one (not likely). adjust the PR check tool to 7.150" and test again. Instead of doing the "turn the PR x thread deal" I measure the length of the PR with a caliper I have. Aftermarket PR come in lengths of .050 typically so that is why measure 7.150 then 7.100 if necessary. yeah you can order 7.121" or whatever length custom ones but you are not building a $100k race motor.

with the proper length PR rotate engine by hand and carefully look at spring when it is fully compressed to see if there is any contact between springs or RR is hitting retainer anywhere.

Also on lash make sure you are really at "zero" and you don't over tighten the lash. zero is when there is no more up/down PR movement, not when there is resistance spining the PR with your fingers. If your lash is to tight essentially colapseing the plunger in lifter...when you hit high RPM's you can easily bend PR or break springs that way.

Adam1203

iTrader: (5)

Thanks for the advice guys .I'm going to go back and finish it in about 2 weeks. Ill post up everything I do. Hopefully you guys will correct any mistakes I may make.