Opinions needed. Broke a valve spring. Need a lil help. UPDATE 5/28/16

[TomD]

I just took a quick glance at the lobe catalog and I see your problem. You have two very aggressive lobes that need a lot of spring. There isn't even a spring available that will work properly with those lobes much past 6000rpm on stock heads and that's if you put the most aggressive spring you can get on there and use the lightest hardware you can get which is a project in itself. I would want at minimum 180 seat with those lobes and 520 open. 1.55 rocker ratio or all bets are off. You really need a different head with a taller valve to be able to get a set of springs that will work properly with those lobes.
If i was setting up heads for a customer if be looking for 200 on the seat


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I do have the champion iron heads. Am I still screwed?

 

[turbo89]

I do have the champion iron heads. Am I still screwed?

you don't need a cam of that size or with the ramps it has .. that's a very aggressive cam ..

sounds like a SBC guy spec'd that out

 

[TomD]

you don't need a cam of that size or with the ramps it has .. that's a very aggressive cam ..

sounds like a SBC guy spec'd that out

I think you are right.... son of a bitch....

So what's my best option? Get a new cam? Otherwise I'm gonna have to redesign the whole head set up and I'm not even sure the components exist to support the current cam.

 

[TURBOELKY]

Let me act like a younger better looking bison, with a lot less knowledge for a minute. Switching to a 1.55 rocker will relieve the intake spring of .036" and exh spring of .034". Might be cheaper to buy a new cam over buying new rockers. Those iron heads don't flow much after .500", they become very turbulent. The extra lift is just more stress on valve train components and is unnecessary. Looks like an LS cam

 

[bison]

I do have the champion iron heads. Am I still screwed?

Unless you want to keep the rpm down below 5800 and run the 1203 springs you will struggle. That cam is a no no with a stock valve length. Can't feasibly go to a longer valve on the stock heads.

 

[bison]

Let me act like a younger better looking bison, with a lot less knowledge for a minute. Switching to a 1.55 rocker will relieve the intake spring of .036" and exh spring of .034". Might be cheaper to buy a new cam over buying new rockers. Those iron heads don't flow much after .500", they become very turbulent. The extra lift is just more stress on valve train components and is unnecessary. Looks like an LS cam

The rocker swap imo isn't enough. It would take rockers and springs. To convert the heads to 1203 with the light retainer would be about $500 itself. Maybe a little more. He'd have to run the springs as tight as possible to get the pressure up and it's still borderline. Also there's too much overlap there unless he plans on running a large hot side which would raise the engines breathing room at high rpm only to be out done by valve train limitation. Yes those lobes are excellent on an LS engine.

 

[TomD]

OK really great information, thanks a lot.

So best case scenario is I convince the shop to replace the cam on their dime.

Can you guys recommend a cam that will work better with my current setup?

 

[bison]

Let me act like a younger better looking bison, with a lot less knowledge for a minute. Switching to a 1.55 rocker will relieve the intake spring of .036" and exh spring of .034". Might be cheaper to buy a new cam over buying new rockers. Those iron heads don't flow much after .500", they become very turbulent. The extra lift is just more stress on valve train components and is unnecessary. Looks like an LS cam

The rocker swap imo isn't enough. It would take rockers and springs. To convert the heads to 1203 with the light retainer would be about $500 itself. Maybe a little more. He'd have to run the springs as tight as possible to get the pressure up and it's still borderline. Also there's too much overlap there unless he plans on running a large hot side which would raise the engines breathing room at high rpm only to be out done by valve train limitation. Yes those lobes are excellent on an LS engine.

 

[bison]

OK really great information, thanks a lot.

So best case scenario is I convince the shop to replace the cam on their dime.

Can you guys recommend a cam that will work better with my current setup?

I wouldn't expect them to replace anything on their dime unless you have some kind of contract

 

[turbo89]

I wouldn't expect them to replace anything on their dime unless you have some kind of contract

Really ?? That is so not a Turbo 3.8 Grind its not even funny !

IF I went to a shop and gave them my turbo buick and said "SPEC me a cam" and that's what they put in ... I'd be LIVID ! and YES they would replace it on their dime .. that's a BS cam for what he has

 

[TURBOELKY]

OK really great information, thanks a lot.

So best case scenario is I convince the shop to replace the cam on their dime.

Can you guys recommend a cam that will work better with my current setup?

I got a billet cam spec'd for my build with old man Nick, but don't tell him I called him that. I believe Bison also has his resources. Anything would be better than what you have, even a 206/206 comp cam roller!

 

[TomD]

I have a pretty good relationship with the shop and I'm a repeat customer. I think they will make it right if I tell them very precisely why this cam will not work. When I shell out $17k for an engine, I want it to last longer than 3,000 miles.

 

[bison]

Really ?? That is so not a Turbo 3.8 Grind its not even funny !

IF I went to a shop and gave them my turbo buick and said "SPEC me a cam" and that's what they put in ... I'd be LIVID ! and YES they would replace it on their dime .. that's a BS cam for what he has

Keep in mind the word expect is just that. Expect. I wouldn't expect them to eat it. I would expect them to correct it but not necessarily eat it. Has anyone received credit on any of the shitty Chinese crap that's on the market that needs hours and hours of work to drop in? If I buy a crank from XYZ vendor and it has tapered journals and flex plate flange is out of spec, and I ask if it will need a lot of metal added to the crank to balance with a .940" pin and they say no and it needs $200 worth of Mallory added to it do they eat that?

 

[TURBOELKY]

I have a pretty good relationship with the shop and I'm a repeat customer. I think they will make it right if I tell them very precisely why this cam will not work. When I shell out $17k for an engine, I want it to last longer than 3,000 miles.

$17k?

 

[TomD]

I

Keep in mind the word expect is just that. Expect. I wouldn't expect them to eat it. I would expect them to correct it but not necessarily eat it. Has anyone received credit on any of the shitty Chinese crap that's on the market that needs hours and hours of work to drop in? If I buy a crank from XYZ vendor and it has tapered journals and flex plate flange is out of spec, and I ask if it will need a lot of metal added to the crank to balance with a .940" pin and they say no and it needs $200 worth of Mallory added to it do they eat that?

I hear you. I would hope they will do what is reasonably possible. I told them not to treat it like a small block chevy but it looks like that's what I got. I will have a courteous conversation with them and discuss my options.

 

[bison]

I have a pretty good relationship with the shop and I'm a repeat customer. I think they will make it right if I tell them very precisely why this cam will not work. When I shell out $17k for an engine, I want it to last longer than 3,000 miles.

If you want a cam that will work drop shipped message me. If overlap is between -12 and -8 at .050" pretty much anything will work for what you're doing. Also plenty of springs that will work on the stuff that is less than .550" lift. One won't really make more or less power than the other. The duration at .050" doesn't really matter. I'd stay away from anything aggressive like 3188, 3190, 3190, and the entire XFI listing. Those lobes can be made to work but it's a lot of special work to get the springs on the heads which adds more cost and the hardware is much more expensive

 

[bison]

I


I hear you. I would hope they will do what is reasonably possible. I told them not to treat it like a small block chevy but it looks like that's what I got. I will have a courteous conversation with them and discuss my options.

A small block Chevy with standard length valves will struggle on those lobes also.

 

[TomD]

A small block Chevy with standard length valves will struggle on those lobes also.

Thank you. I know you do this professionally so thanks for taking the time to help me out. I'm gonna give the shop a call tomorrow and discuss this so I may be in touch with you.

Thanks everyone.

Tom

 

[bison]

Thank you. I know you do this professionally so thanks for taking the time to help me out. I'm gonna give the shop a call tomorrow and discuss this so I may be in touch with you.

Thanks everyone.

Tom

Those lobes would become even more aggressive on a small block Chevy believe it or not due to the lobe master they use for them.

 

[Mr.Spool]

I have a pretty good relationship with the shop and I'm a repeat customer. I think they will make it right if I tell them very precisely why this cam will not work. When I shell out $17k for an engine, I want it to last longer than 3,000 miles.

they really missed the boat on this one.you should deal with an engine builder that doesn't need you to tell them how to build a 3.8 v6.thats a lot of paper to drop for this kind of mistake.