PROCOMP sbc cylinder heads

arneoe · Sep 24, 2009

For those who want to look closer into a SBC budget engine project, using affordable offshore :chinese: alu heads, may find a lot of interesting information in the October issue of SUPER CHEVY. In the article THE CHUMP CHANGE CHALLENGE on page 064, they have built a 400hp 350 street engine for approx. $1000 of total spending, using a set of brand new PROCOMPs 190cc (#3002). These are as cast and compared with L98 stock heads the PROCOMPs flow far better up to .600 lift. From the measured low lifts flow of the 190cc PROCOMPS, a swap from stock iron to alus (together with a suitable cam) will significantly increase torque and hp in the usable rpm band for street use.

For my own 383 build, there has not been much progress the last three weeks, there’s much work to do outdoors before we have the first snow.

best regards
Arne

JAKE · Sep 24, 2009

A few months back when I was head hunting, my first, over-riding concern was the actual spec of the aluminum used in the casting.

Was there any indication of the aluminum spec? Re-cycled beer cans wouldn't be my first choice, LOL.

Jake

West Point ROCKS! Nation's TOP COLLEGE per Forbes Magazine!

arneoe · Sep 24, 2009

JAKE said:
A few months back when I was head hunting, my first, over-riding concern was the actual spec of the aluminum used in the casting.
.....

Very interesting subject.... please inform us which specific technical specifications have been your requirement for the selection of cylinder heads? And finally which brand and type did you chose?

Arne

Red · Sep 24, 2009

arneoe said:
For those who want to look closer into a SBC budget engine project, using affordable offshore :chinese: alu heads, may find a lot of interesting information in the October issue of SUPER CHEVY. In the article THE CHUMP CHANGE CHALLENGE on page 064, they have built a 400hp 350 street engine for approx. $1000 of total spending, using a set of brand new PROCOMPs 190cc (#3002). These are as cast and compared with L98 stock heads the PROCOMPs flow far better up to .600 lift. From the measured low lifts flow of the 190cc PROCOMPS, a swap from stock iron to alus (together with a suitable cam) will significantly increase torque and hp in the usable rpm band for street use.

For my own 383 build, there has not been much progress the last three weeks, there’s much work to do outdoors before we have the first snow.

best regards
Arne

Thanks for the heads up Arne!

JAKE · Sep 29, 2009

I'm not by any means a guru when it comes to metals but I suspect most of us know that aluminum cylinder heads are not cast from pure aluminum. They're an alloy, meaning there are other trace metals present in certain, rather precise, percentages. Metals like copper, magnesium and silicone, etc. come to mind.

These trace metals make the finished product more suitable for certain applications than others. Cylinder heads, that are exposed to all sorts of stresses and temperature changes, require a certain percentage of trace metals be added to the "aircraft grade" aluminum to give the best performance when used as cylinder head castings.

I like to see, at least, that words "aircraft grade" aluminum is shown in the ads along with the heat treating spec. From the research I did on this C355-T61 seems to be the spec touted as being best for cylinder heads.

Bottom line is, when I read an ad that makes no mention of the casting material spec, my suspicious meter goes up. What comes to mind is the rash of inferior/often breaking bolts that came out of China a while back. Makes me wonder if heads cast in China aren't being cast from old lawn chairs.

Jake

West Point ROCKS! Nation's TOP COLLEGE per Forbes Magazine!

mrvette · Sep 30, 2009

Years ago in the Chem lab wing of a company I worked at, there was a Perkin Elmer Xray mass spec machine...they froze the sample in liquid nitrogen? and then pulled it out for shooting Xrays? and then looking at the readout, the machine was not very large, really, but the readout was across the monitor screen giving all that periodic table/density? element readout....

I would THINK something like that should be fairly common today, as I"m sure it was then....

thing is, just because ONE piece of metal from ONE head is say brand X, don't mean shit that the next one is....

:shocking::beer:

arneoe · Oct 2, 2009

According to my US supplier, the the PROCOMs are of aircraft grade A356 aluminum alloy heat treated to T-6 specifications. I do not think that this is of much inferior spec to the C355-T61, which is used by DART.

http://www.dartheads.com/ftp/C355-T61 Aluminum Alloy.htm

If we leave politics for a minute, I see reasonable good quality machined cylinder heads resting here on my work bench. I have published close up pics in this very thread .... and this should prove this.... just see for your self and compare with the GM iron smog maidens which they are to replace. And again, I have no agenda with this, but I see what I see .... these PROCOMs are very well suited for my 383 mild and modest street build.

Arne

JAKE · Oct 2, 2009

arneoe said:
According to my US supplier, the the PROCOMs are of aircraft grade A356 aluminum alloy heat treated to T-6 specifications. I do not think that this is of much inferior spec to the C355-T61, which is used by DART.

http://www.dartheads.com/ftp/C355-T61 Aluminum Alloy.htm

Arne

Whatever floats your boat. Compare the differences between the two and choose your poison.

Jake

West Point ROCKS! Nation's TOP COLLEGE per Forbes Magazine!

Twin_Turbo · Oct 2, 2009

And the dart stuff is cast from fresh ingots, you can bet your azz that the Chinese stuff is made from recycled soda cans

MYBAD79 · Oct 2, 2009

Here's some good info on aluminum:

http://materials.globalspec.com/Spe...errous_Metals_Alloys/Aluminum_Aluminum_Alloys

Now, since we're talking about a casting and material quality.... the stock cast iron heads often crack, can these chinese aluminum casting really be worse than the crap that came on these cars ?? I think as long as there are no voids in the casting it should be fine.... did anyone x-ray their chinese SBC heads ??? That could reveal some very interesting details.... LOL

Finn · Oct 3, 2009

I find it tiring that the product is referred as Chinese as they are, to my understanding, Australian by Pro Comp from Victoria, Australia.

If these heads are Chinese then my American Racing Hopsters, which arrived yesterday, are Chinese, too, since that's where they are manufactured now.

JAKE · Oct 3, 2009

I don't know where the heads were cast, that wasn't even my point. In my research for sa set of heads to buy, I simply wanted to know from what they are cast.

Absence of that information makes me curious about not only the casting material being used, but also why no mention is made of the material. This applies to ALL the heads I looked at, not just yours. It's a question, not an accusation.

When I was searching the different LT1 cylinder head offerings I looked to see:

Would they fit my application (LT1), then

Company's reputation then

What material they are cast from, then

Combustion chamber size/port volume, then

Valve sizes then

Installed springs then

Flow numbers, then

Any special, non-stock parts needed, then

Cost, then

Availability, then

Any dyno comparisons/results then

Feed-back from those running those heads.

Just how I did it, pretty much in that order.

Jake

West Point ROCKS! Nation's TOP COLLEGE per Forbes Magazine!

arneoe · Oct 3, 2009

Finn said:
I find it tiring that the product is referred as Chinese as they are, to my understanding, Australian by Pro Comp from Victoria, Australia.

If these heads are Chinese then my American Racing Hopsters, which arrived yesterday, are Chinese, too, since that's where they are manufactured now.

Tjanare grabben! :friends:...

Sure:chinese:, but I think they still make wonderful wheels, regardless:
http://www.jalopyjournal.com/forum/showthread.php?t=263034

You'll find the point of contact for the PROCOMPs offered in the States here:
http://sydneyspeedsupplies.com/

Arne

Finn · Oct 3, 2009

Tjanare, Arne. :drink:

BRUTAL64 · Oct 6, 2009

Just a point of interest here. I bought a set of CHEAP China heads from a back east no name company. I just wanted to try a set to see if there would be a major difference between iron and alum heads for compression ratios.

I do my own porting, so that is not an issue. So anyway---I put five hours of porting in to each head and bolt them on. That was over 2 years ago and NOT one problem with them. I run my MULE motor hard.:beer:

arneoe · Oct 7, 2009

BRUTAL64 said:
Just a point of interest here. I bought a set of CHEAP China heads from a back east no name company. I just wanted to try a set to see if there would be a major difference between iron and alum heads for compression ratios.

I do my own porting, so that is not an issue. So anyway---I put five hours of porting in to each head and bolt them on. That was over 2 years ago and NOT one problem with them. I run my MULE motor hard.:beer:

Very interesting David. Do you have more spesific details about your cylinder heads? I think I recall they are PROCOMPs, like the ones in your avatar.

Arne

arneoe · Oct 7, 2009

JAKE said:
I don't know where the heads were cast, that wasn't even my point. In my research for sa set of heads to buy, I simply wanted to know from what they are cast.

Absence of that information makes me curious about not only the casting material being used, but also why no mention is made of the material. This applies to ALL the heads I looked at, not just yours. It's a question, not an accusation.

When I was searching the different LT1 cylinder head offerings I looked to see:

Would they fit my application (LT1), then

Company's reputation then

What material they are cast from, then

Combustion chamber size/port volume, then

Valve sizes then

Installed springs then

Flow numbers, then

Any special, non-stock parts needed, then

Cost, then

Availability, then

Any dyno comparisons/results then

Feed-back from those running those heads.

Just how I did it, pretty much in that order.

Jake

West Point ROCKS! Nation's TOP COLLEGE per Forbes Magazine!

That seems very well organized.... and which cylinder heads did you end up with Jake?

Arne

JAKE · Oct 10, 2009

arneoe said:
JAKE said:

I don't know where the heads were cast, that wasn't even my point. In my research for sa set of heads to buy, I simply wanted to know from what they are cast.

Absence of that information makes me curious about not only the casting material being used, but also why no mention is made of the material. This applies to ALL the heads I looked at, not just yours. It's a question, not an accusation.

When I was searching the different LT1 cylinder head offerings I looked to see:

Would they fit my application (LT1), then

Company's reputation then

What material they are cast from, then

Combustion chamber size/port volume, then

Valve sizes then

Installed springs then

Flow numbers, then

Any special, non-stock parts needed, then

Cost, then

Availability, then

Any dyno comparisons/results then

Feed-back from those running those heads.

Just how I did it, pretty much in that order.

Jake

West Point ROCKS! Nation's TOP COLLEGE per Forbes Magazine!

Click to expand...

That seems very well organized.... and which cylinder heads did you end up with Jake?

Arne

Dart Pro 1s. Advertised at 180ccs but I, (and others) cc'd them at 189.5. 58cc chambers and I went with thin head gaskets to keep the a CR up. I swapped to 7/16" ARP studs and used Scorpion 1.7/1.65 RRs.

Cost and Availability knocked AFR Eliminators out of the running. The Dart's were $1,350 which included the shipping from JEGS and I received them in 3 days.

Jake

West Point ROCKS! Nation's TOP COLLEGE per Forbes Magazine!

arneoe · Nov 26, 2009

Here is my first dyno simulation printout. It seems to me that my goal for a high torque engine is quite close with this combo. I have done very little to the runners, just gasket matching as described in my earlier posting. I am a little concerned about CR, but I estimate around 10:1 will do.

Arne