NOHOME
NOHOME UberDork
10/20/15 11:41 a.m.

So I bought a set of Pro Comp heads for the Molvo project. The difference in price between them and the name brands, by the time they arrive in Canada, is close to $1000.

The engine is going to have a quiet life for the most part. No racing and no need to "win" any competitive events other than look cool and be reliable. Main reason for wanting alloy heads is the weight reduction and the bit of bling.

If I go on the net I can find all kinds of comments. Most of the naysayers tend to be a bit rabid on the "No Chinese Stuff for me Bro" without any real-life or micrometer based experience. The expectations seems to be that they want the $700 head to be as good as the $2000 heads.

So, has anyone here actually put them on the car and can provide some real world feedback on how they perform in a mild street application? If there are consistent weaknesses, what was done to address them? My concession to the china bit is that they are going to come apart and get measured and inspected before use. At a glance, I see nothing wrong with the castings themselves.

ross2004
ross2004 Reader
10/20/15 11:51 a.m.

I think it's less casting and more component cheapness. If you're not running a real aggressive cam at highish RPMs, they should be ok from what I gathered.

bravenrace
bravenrace MegaDork
10/20/15 12:09 p.m.

Hmm, I paid under $1100 for my Trick Flow heads.

NOHOME
NOHOME UberDork
10/20/15 12:12 p.m.
bravenrace wrote: Hmm, I paid under $1100 for my Trick Flow heads.

Double that to land them in Canada. Exchange rate, 13% sales tax, duty and shipping plus UPS fees on top of the shipping all add up.

I would still take the TF heads apart before I used them.

bravenrace
bravenrace MegaDork
10/20/15 12:21 p.m.
NOHOME wrote:
bravenrace wrote: Hmm, I paid under $1100 for my Trick Flow heads.
Double that to land them in Canada. Exchange rate, 13% sales tax, duty and shipping plus UPS fees on top of the shipping all add up. I would still take the TF heads apart before I used them.

Forgot about the Canadian thing. What makes you think I didn't check my heads before I used them? That would be a rookie mistake, and I'm no rookie. Actually, TF is about a mile from my house. I had them built right in front of me, so no need to check them.

oldeskewltoy
oldeskewltoy UltraDork
10/20/15 12:29 p.m.

besides checking assembly and the parts.... not knowing what all is usually done for the alloy/pro-comp heads....

check chamber volumes for equality... different valve depths can change chamber volume....

Are the valves back cut to meet the seat? you might use some dye and see if the back cut meets the contact point on the valve.

If you have access to a flow bench....... check flow @ .100" through your cams peak lift. Ideally it is less than 2% between the best and worst.

NOHOME
NOHOME UberDork
10/20/15 1:15 p.m.
oldeskewltoy wrote: besides checking assembly and the parts.... not knowing what all is usually done for the alloy/pro-comp heads.... check chamber volumes for equality... different valve depths can change chamber volume.... Are the valves back cut to meet the seat? you might use some dye and see if the back cut meets the contact point on the valve. If you have access to a flow bench....... check flow @ .100" through your cams peak lift. Ideally it is less than 2% between the best and worst.

Not too worried about chamber volume. Would have to be way off to matter in an engine that wont see 5000 rpm.

The back of the valves I am almost assuming are going to be in need of attention. Spring rate at height is the other one I want to see about. Seals are pretty much a given unless I can be convinced that they are up to the task.

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