Yes, I've been waiting over the Holiday weekend to find out what the builder determined. He said I can pick the car up Wednesday, and that the only thing wrong with the valve train were the rockers and especially the pushrods not being strong enough.

He replaced the pushrods and rockers with a 1.5 ratio instead of the 1.6 that were on there. He said all the cylinders had ample pressure and feels confident it will operate problem free...

 

Do you think my valves are bent?


Hmmm... Sounds like a good idea for peace of mind.

 

Whats he calling ample cyl pressure? He should have provided you with the readings taken from every cylinder. Swapping rockers from 1.6-1.5 is going to net you about a 6% decrease in load on the pushrods. If your pushrods are that close to failing all i have to say is they were really on the ragged edge to start with. Also i think somewhere you said you were running comp cams hi-tech pushrods? If so those pr's are anything but weak i have run them with a ton of spring, although i dont know what diameter you're using.

This whole deal seems fishy to me, you've been through two sets of rockers and two sets of pushrods. Gee i dunno maybe its time to stop treatin the symptoms and fix the problem .

Also why does he say the rockers werent strong enough, were they failing? and if so what was thier mode of failure.

 

so the new rockers fixed it?

 

He said the second time around it was the push rods, so he installed Manley's and switched the rockers to a smaller ratio. The valvetrain seems to be holding together, but it's too noisy.

I've talked to other engine builders and they think the I'm getting valve bounce. One person in particular has said that the AFR 210 heads do not come with an adequate spring for a solid roller to live on the street. The valve bounce does explain the failure of the rockers and pushrods.

Another thing, the engine "sounds" different, it's weaker AND lazy.

 

Get the installed HT. seat pressure coil bind etc. Get all the info on the springs. Info on the cam too

I'm sure someone here can tell you if the springs are good or not.

 

thats because it IS different. You have smaller rockers and now less valve lift which has an affect on numerous areas. Less hp and a different sound are just 2 of the different things you will notice.

I still say we are either not getting the whole story here or he is not telling you the whole story.

There are way too many variables for an accurate diagnosis over the internet, but the basics are that a rocker ration change is a way to fix the symptom not the true problem.

The springs on the AFR heads are fine if they were speced out right. Sounds like they were not.

 

You need to get that car away from that quack and cut your losses, ANYONE who would agree to put a solid roller in a daily driver has no idea what they are doing. He will give you more brain damage ATTEMPTING to fix your stuff than you can handle.

Anyone I deal with where machine work is concerned would flip if I attempted to daily drive a solid roller, and would tell me up front out of the gate that if I insisted on doing it he would warranty NOTHING as far as durability was concerned. As would any reputable shop, they would at least STEARNLY warn you about the possibilites of failure in the valvetrain. Especially if this was your first build of this caliber.

With the valvetrain problems you have, that engine needs to come out, be cleaned, mocked up and fixed the right way....you keep trying to band aid it and your sound bottom end investment will be junk. Valvetrain geometry problems are NOT something you bandaid...and if 1.6 rockers are too much for the street, ask him why a stock Z06 has a 1.8 rocker from the factory!

Stop, take a deep breath and think about your options here....most of us have more time than money.....look around town, talk to some people and take the car somewhere else. EVen crate it up and send it to someone on this board, Bret Bauer, Victory racing engines and many more would most likely fix it and fix it RIGHT.

Just food for thought.

David

 

I'm going to take the engine back to him and demand that he fix it. The springs are the factory AFR LT4 210 race head springs; I've heard they are not sufficient for a solid roller cam but AFR says they're fine. *AFR has since upgraded the base spring on these heads, I have the older style spring. This all I know about the springs other than they have close to a thousand street driven miles on it.

The exact cam specs are as follows:

COMP CAMS LT1 CUSTOM SOLID ROLLER

VALVE ADJUSTMENT: INTAKE AND EXHAUST .016
GROSS VALVE LIFT: INTAKE .577 EXHAUST .583
DURATION @.015 TAPPET LIFT: INTAKE 286 EXHAUST 292
VALVE TIMING @.050: OPEN CLOSE
INT:18 BTDC 50 ABDC
EXH: 61 BBDC 13 ATDC
THESE SPECS ARE FOR CAM INSATALLED @106.0 INTAKE CENTER LINE
INTAKE EXHAUST
DURATION @ .050 248 254
LOBE LIFT .3850 .3890
LOBE SEPARATION 110.0

 

I definately think that I'm not getting the whole story...

Yes, the builder shouldn't have switched to the lower ratio rockers without ascertaining what's wrong with the valvetrain in the first place;he's claiming the 1.5 rockers are necessary to allow the cam to live on the street.

I've heard that the springs I'm running are only sufficient on a hydraulic roller cam, and will not live on the street with a solid.

 

here is what I can tell you... please dont take it the wrong way.

Who cares what you were told... numbers do not lie. The cam is not that big. Valve spring specs are what you need and not "those are fine, or not fine". Give us specs and we will tell you if the springs are good with that cam or not. You need installed height and spring load specs. Without that you are just waisting your time and ours... The builder is blowing smoke up your you know what.

My SR is almost .700" lift and I dont have any problems with the valve springs. I also used shaft mount rockers to get the job done.

I agree with fatboy... any builder who agrees to build a reliable street motor with a solid roller cam has to be either nuts or stupid. Either way you need to go somewhere else.

The rocker ratio is not a problem. Stock vehicles use ratios higher than 1.7-1.8 now a days. Changing rockers back to 1.5 is eliminating a valve lift problem.

You dropped the valve lift from .616" to .577" on the intake and from .622" to .583" on the exhaust. Dropping .039" from you valve lift tels me there is a valvetrain geometry problem or a coil bind issue.

The springs on an AFR 210 race ready head (reguardless of when you bought them) should easily handle .620" lift. If you are getting bounce then the springs are not strong set up right... plain and simple. Or they are the wrong ones. your builder should know that before he slapped a cam in.

You wouldn't buy a computer with a 500 mhz processor when the program you are running needs a 2.5 ghz processor would you?

You put valve springs on a head to match your cam... not the other way around and put in a cam to match the valve springs you already have.

 

I'm taking the car back to him and demanding that he rebuild the engine; mainly because of the metal still present in the oil despite changing the oil twice. I'll definately get the springs that were on there and have them checked, even though it may be of little help after the fact. He's saying that the springs were tested with enough pressure (never gave any seat or open pressures) to handle the cam...for what that's worth.

I'll be switching the cam out for a hydraulic on the rebuild/clean up. Even though these springs may be fine for the newer smaller hydraulic, I might buy a set of new springs just to be sure.

 

I would let him freshen the shortblock ONLY, then take the shortblock and heads to someone who knows what they are doing and let them get this valvetrain deal squared away.It needs to go to a machine shop who builds PRIMARILY race engines, this is not a stock build.

Tell him when he gets it apart, you want to inspect the crank....it may be hurt.Or need to be polished.


David

 

Either the reputable local guy, or send it all out to Carolina Auto Masters.

 

Somethining does not add up...his builder is top notch well know engine builder of RACE engines....Fast stuff too.


You need specs on those springs or something... You just don't have squat as far as info...so I guess you don't have a build sheet or something. Boggles my mind how this would happen...the guy knows his stuff and is no rookie by any means