if the valves are floating then he used the wrong spring /valve combo for the cam he chose. Again, he goofed.

If he is looking to switch to 1.5's he is trying to lessen the valve lift because he has either piston to valve contact or he is binding the springs with too much lift. Either way it was not set up right and swaping rockers to lower the lift is a bandaid to a problem he created by not checking thigs out before hand.

He very well could of had somone else put it together and if he as the head builder is willing to fix it then let him. I would however insist that the rockers not be changed, and that the cam/valve/spring combo be set up properly instead.

Oh and you still need more details. We really shouldn't pass judgment on the builder with no real facts and details.

 

See, this is what has me worried. I'm not an expert at engines, but it just seems like common sense that there's other damage. Yes, I think he's obviously missed something.

 

He's making it out like the 1.6's are just too much for the street. The last thing I want him to do is "bandaid" the real issue. Just the thought of that considering the time and money that I gave him is ridiculous.

 

The engine builder did almost everthing with the exception of porting and building the heads. His head porting guy did that job. I haven't heard the results of the leak test yet, but the fact that you're convinced that the only reasonable purpose of going to smaller rockers is because of piston to valve clearance, I'm wondering if they really did have "plenty" of clearance as he previously told me.

If the valves are kissing the pistons, they've got to be damaged, right?

 

not always...but the leak down will tell all

 

I'll post the leak numbers of all cylinders when I receive the results.

 

It has to be some odd problem.......this builder is somewhat well known for what he specializes in, the class most of his engines are in......

I'm sure he will figure it out.........

 

+1.

If you try to run standard style rockers on these heads, it's going to cause some goofy valvetrain geometry. AFR recommends using stud girdles with those heads (due to the valve spacing being different than a normal SBC) at a minimum and they specifically say this setup shouldn't be run on the street.

Sounds like you need a set of shaft mount rockers for those heads.

My .02.

 

A stud girdle has been on since day one. AFR told me that the LT4 220 heads required shaft mount rockers while the 210's did not. This was precisely the reason I went with the 210's. And you're saying that now they don't recommend this set up for the street?

Never heard of the valve spacing being different, I'm not sure if the engine builder even knows that. I talked to AFR the other day and told them my set up, and the tech that I talked to said the springs are fine for my street application???

 

My mistake. When I posted I thought I had read you have the AFR 220 heads.

 

Well I'm glad that possibility is eliminated.

Back to main issue, it seems that "stronger" pushrods and rockers are only going to do a better job at smashing other parts! Am I incorrect in this "common sense" assumption, or would less than strong enough metals regarding these two components cause all these problems?

I'm also really mixed by the responses of others that say reducing the ratio is to cure the problem that he's claiming-too agressive a ramp rate. Others have said it's most likely becuase the valves are kissing the pistons.

I'm still waiting for the leak down numbers...

 

honestly if the valves made contact with the pistons you would 99.9% of the time had bent a valve, or all the valves. I just cant see that happening the more I think about it. You would have destroyed your intake valves to have also damaged the exhaust side.

It is possible that he used a lesser quality pushrod and rocker arm and the problem is fixable with just a rocker arm change and new push rods of better quality. What I don't under stand is the change in rocker ratio. The higher ratio 1.6's will put more stress on the push rod and other components but I dont see why he just cant use better parts that can handle the abuse (assuming there is no other reason for the damaged pushrods). If the only issue is the abuse of the solid roller ramp rates then use better parts that can handle it. If the ratio is the problem (too much valve lift) then he is at fault for not checking this before he turned it over to you. Maybe a ratio change will fix it, only he can be sure of that.

 

No weaker rockers, studs and pushrods deflect more and make for more inaccurate valve movement from the intended path of the valve. That means seat bounce on closing of the valve which with a exhaust valve means bent valves.

 

update?

 

[QUOTE=Projectz28;5001240]honestly if the valves made contact with the pistons you would 99.9% of the time had bent a valve, or all the valves. I just cant see that happening the more I think about it. You would have destroyed your intake valves to have also damaged the exhaust side.


I had a bigblock run for about a year and 3000 miles of hard use with the valves touching the pistons. I found out the hard way... one final 6000rpm blast was interupted by a clunk 0 rpm, some smoke and alot of coasting... when I finally stopped I got out and saw antifreeze dripping from my exhaust...

Pulled off a valve cover and saw 1 rocker/valve spring about 1" higher than all the rest... pulled the heads of and saw 1 cyl with a busted valve and all pistons had clean rings around the top where the intake valve has been touching the piston... no bent valves.. just one that finally broke from all the piston to valve tapping. Total damage from this included:
1) Piston pushed broken valve into head, opening up coolant passage
2) ALl that coolant under pressure was sucked into the next avail cylinder and attempted to compress at 6000rpm
3) The cyl that attempted to compress liquid at 6000rpm resulted in a bent rod, bent and cracked crankshaft, expanded and cracked cylinder wall (the rod was compressed and wouldnt allow the crank to rotate.. bottom of piston would hit the crank counter weights but it never made it when it locked up (6000rpm to 0 in 1 piston stroke = impressive)

You may want to find some way to inpect the piston (rent a borescope and check for clean area's on the pistons that resemble valve contact), if you find it demand you get all new valves and the problem resolved.

Before the valve broke, it ran fine.. only standard valvetrain noise.. nothing crazy.