I need to vent a little...

I have about 2000 miles on my 383 stroker build. I am running AFR 205 heads with a CompCams solid roller cam and roller rockers. I smoked my street clutch a few hundred miles ago, so my engine builder and I decided to switch it out for a Hays strip pressure plate and clutch. After a few launches, the clutch it finally applying my power at the launch, my engine builder noticed a funny valve noise. We decided to pull the valve covers and check the rockers. We have tightened them per Comp specs about a month ago, but we figured better safe than sorry. Several of the rockers were "slightly" loose, so we decided to pull the rockers, stud girtle, and push rods to see what everything looked like. That is when we noticed three valve stems were grooved. The were already showing signs of horseshoeing! WTF...We are running 1.7:1 rockers with a 280ish duration cam. The lift is only about .630 or so. What is the deal??? The heads are rated well withing that lift and the valve lash was on the money or even a little loose of Comp specs, so I feel comfident we did nothing wrong. I am calling AFR tomorrow to see if they will warranty all the valves, but it appears several of the valves are just poor quality. Frankly, I have lost faith in them. Not all the valves are showing this wear, but for how long? There was no noticable signs of rocker issues or push rod issues, which points just at the valve material.

After switching from coke to burbon and switching from working on the valves to drinking and bitching, we called a few engine guys. Several recommended using valve caps becuase of similar issues. Anyone have experience with these? Do they work? Is it just better to get better valves? Anyone here had any problems with AFR and their valves? I am tempted to pull all the valves and switch all of them out with something else...maybe Ferrea titanium valves or something that will not fail. I am just chapped that I paid really good money for good heads, which have performed well so far, but wore out in less than 2000 miles! I now have to take the engine apart and basically start over. I realize I am making more horsepower than many people who use AFR heads, but you would think their 205 race heads and their components would be up to the task.

Dang! I am really glad my buddy caught this before I broke a rocker or dropped a valve and destroyed the motor!

 

Are you sure rocker arm geometry was correct? Just cuz lash is right doesn't mean geometry is right. And what oil were you running?

 

+! also what were your spring rates?

 

I had to switch from 1.7 rockers to 1.6 on my engine with afr heads.
I too have a comp roller cam, I forget the specs but high 573 or something.
Mine is a blower grind.
When my engine guys were putting it together he was messing with a pushrod length checker and told me the 1.7 would trash my valves! IDK enough about geometry to guess what the Diff is but its enough.

 

The geometry was perfect. We had to clearance the rockers so they would not bind on the springs, but the wear was smack in the middle of the valve stem tip. We measured for push rod length before installing anything, so that is right on as well. It basically looks like a worn u grove in tip of the valve stem. As for springs, they are stock AFR springs and rated within range for a Comp roller cam. I would have to call AFR to get the specs. I guess they could be crazy stiff springs installed incorrectly or something. I have not check the spring rate. I called and spoke with AFR before ordering anything because I had heard horrors about AFR springs and valve float, cam flatening, etc. They assured me that their current stock springs were perfect for CompCams requirements. I guess the 1.7:1 rockers could have caused some problems, but the springs are rated for up to .700 lift and I am only running .630 or so. The difference between 1.7:1 and the stock 1.6:1 rockers are only about .038 valve lift. That is enough to help with performance, but I would not think it would create any material issues. As for oil, I am running Valvaline VR1 Racing oil SAE50, so that should not be an issue. The Texas heat almost requires 50weight in performance engines and I like the VR1 for the additives. We used a bunch of assembly lube, so nothing should have had an issue there. I am really thinking AFR has some bad valve material out there, especially since other hotrodder around here automatically put valve caps on because of similar experiences.

I am pulling the intake today to look at the cam. Hopefully it is ok. I am still steaming and at this point do not know what to change out.

 

very sorry to hear.
I'd call AFR, give them the exact specs as well as the problem (the middle of stem ground). maybe they've heard of it before or have any other advise

 

Your issue is making me rethink my head decision for my 39,,,, while I did not order AFR's,,, I am thinking it might be about time to order some Vic Jr's...

As a matter of fact.... I am going to sell the pos budget performance heads I just bought....

It is too damn much trouble to fix issues similar to yours after installation...

Thanks for the wake up call....

 

JMD, I do what I can...

My engine builder spoke to AFR and the local AFR distributor. AFR said no warranty on the valves. The AFR distributor said he has been seeing some exhaust and a few intake valve failures due to being too soft.

The AFR heads made great power, and I am very happy with the performance but also very disappointed with the quality of the valves. It is going to cost $600 to put lash caps on the all the valves. I am currently pricing Ferrea titanium valves and will probably go that route just in case the valves are too soft and fail in another spot other than the valve tip.

Anyone have any other valve manufacturer suggestions other than Ferrea?

For anyone running 400+hp and thinking about AFR heads, I would buy bare heads and put your own valves and springs in. Wish I would have done that 2000 miles ago!

 

After rereading my post, I want everyone to know I am not trashing AFR. I am just a little ticked that they did not hold up. If you consider AFR, please think about getting good quality valves and springs. I am running a 460hp motor on street gas, so things will get stressed. I tried to buy good solid parts and thought the AFR 205 race heads were up to the challenge. Guess not...or at least not for more than 2000 miles.

JMD, I looked into the new Edelbrock RPM XTREME CYLINDER HEADS. They outflow the AFRs and have the same size intake runner (185cc) so velocity should be comparable if not better than 185 AFRs. I would have gone that route except I needed a little more size for my stroker. The Vic Jr. do not flow as well as AFRs and the AFR 205s have smaller runners than the Vic Jr. 210s which means the AFR heads should have more velocity. This was my thinking, but if the Vic Jrs. have better components, then that may be the smarter route.

 

Ok, the performance shop here in town does not recommend going Titanium without really beefying up the valve seats. So....it looks like lash caps which is what a bunch of guys here are doing straight out the box.