Building a Set of Aluminum Heads for My 302.

[skullandbones]

Hi guys and gals,

I'm starting on a new project that will probably bleed into the summer months. It will be my first set of new heads for the roadster. Now I have a set of GT40P heads that were acquired in an engine buy from a hot rodder. I ported them and replaced the appropriate components. The engine is running fine even though the heads have limitations. The flow rates are not adequate at app 196 cfm on the intake runners. I knew that going in but also knew that they are better than the stock heads. You can only go so far with these heads as they have small intakes compared to the popular aftermarket heads. I believe these are about 1.8 or 1.85. I do like the small combustion bowls at 58 cc. I had the heads shaved which may have brought my compression to about 9.5 to 9.7 according to calculation charts and articles about these heads. So that's where I'm at right now. Like I said, the engine is running fine but with the E303 cam, upgraded injectors, headers, and manifold it seems that the heads are the engine's weak link at this point.

I ordered some bare as cast aluminum heads that have 210 intake runners and 62cc bowls. My plan is to evaluate the runners when I get them to decide if I need further work or just assemble with good components as is. If they are good, I will polish only. That's why I need some help from the community out there. If you can suggest the parts, especially the intake valves and springs (specifics), I will be very grateful. My plan is to keep the cam, injectors, etc, pretty much the same. There will be some adjustments and tweeking to get it back together but I want to do as little as possible to keep the setup similar to what I have now.

I will be doing a dyno pull on the engine as is and later this year I will redyno the new setup. BTW: the new aluminum heads will be fitted for 2.02 intakes, 1.6 exhaust, 210 intake runners (estimate of flow is ~285 cfm) That I don't have absolute documentation to verify yet. There is no deadline for this because it is just a project I been thinking about for a long time. I love the roadster and the engine as is but you know what happens; we need more power if it is 250 hp or 800 hp. Sooner or later, we need more power!

Thanks for your help in advance,

WEK.

[Bob Cowan]

I ordered some bare as cast aluminum heads that have 210 intake runners and 62cc bowls.

WEK.

What brand are these heads? If they're inexpensive Chinese e-bay specials, my advice is to toss them in to the back yard as new habitats for furry woodland creatures, and starting over.

[skullandbones]

Hi Bob,

I figured I would be asked that question. They are Speedmaster (Pro Comp). My plan is to evaluate them tomorrow when they arrive. You could be right. I have gotten some very mixed accounts of these products. I will not keep them if they are crappy like you say. But curiosity got the best of me. Let's say just as one possible scenario that they are acceptable, do you have recommendations for the intakes and springs (for roller cam)? Have you had these or know anyone who has tried them? The only other product I have from them so far are fuel rails. They are very nice and are working as designed.

Had to do an edit as I had my flow number for the GT40Ps wrong.

Thanks, WEK.

[Bob Cowan]

Lots of people have tried to re-work those heads with poor results. Lots of time and money has been spent, with either no gain or a net loss in power. They look good, but don't perform well. I wouldn't waste any time on them. If possible, send them back for a refund.

http://www.coloradospeed.com/buyer-beware-speedmaster-ezp-88.html

[skullandbones]

I received my aluminum heads today with the resolve to put them right back in the boxes and return them if I was not pleased. I am keeping them. After inspection and running them by three trusted associates (a machinist, engineer who owns a Harley Shop and does porting/polishing and flow benches their work in house, and a fabricator who is a racer). I got thumbs up from all three. The engineer was the most critical, of course. He suggested taking off the casting ridge in the exhaust ports and blending the back sides of the valve seats on the intake runners. There is remarkably little casting defects in the runners but a few ridges and transition points that need some further smoothing. I expected this and also expected to spend a few hours to clean them up. From what I've heard and comparing them from my recollection of some other heads, I think these are clones of the Edelbrock Victor Jrs. For my application which is a mildly built 302, they should improve air flow significantly. The GT40P heads have a small intake that I could not increase so the flow is restrictive at about 196 from .4 and pretty much the same with further lift. These heads will not have that restriction. The exhaust side is better than the ported GT40Ps. Port matching looks like it's going to be easier than I anticipated.

I want to build the heads with components that I can spec out and be sure of their quality and reliability. I have some ideas already and sources but I would really like to hear from head builders and hot rodders who have done their own head work to see what components you would recommend. I don't think I will need dual valve springs but I will make sure they fit the need of the roller cam. There are a few idiosyncrasies with aluminum heads I will have to adapt to. This is my first set ever. I will be dyno testing the engine as is and then dynoing it after the head change. I probably will also change the intake at that time so it won't be a perfect test but it will be telling. Can't wait to get started. I do expect an increase in hp and torque as the difference in valves will be 1.845/1.58 (I think) and 2.02/1.6. The runners may be a little too big resulting in some loss of performance but if they run as I expect, I can live with them on this engine and then transfer them to the next engine which will have more displacement/bigger cam and should be able to handle the runners better. Also, difference in weight of 43 to 24.5 for bare heads. I plan to use a stud girdle and adjustable push rod guides. I'm also going to use studs instead of head bolts.

So if there are any spring, valve, and other component suggestions, I will be glad to hear it.

WEK.