Shelby Alum Heads--Pros and Cons

[shelbygt500]

Advice for a newbie on this subject would be appreciated. I'm going with the Shelby alloy block, but should I go with their "matching" heads? Sure are alot of Shelby blocks with Edelbrock and other heads on them...why not Shelby? Is it price, performance, or both?

[Burnd]

I spoke with Ed Schiff (Sales Manager) last year and their engineer, Bob Rice (who was very upfront & helpful). I was building for performance and not purist/correct applicatons and Rice said they are good quality but are focused more for historically correct applications. Ed seemed to have more focus on Carroll Shelby's name being on the heads than my interest in flow numbers. I don't mean it in an offensive way; from an investment standpoint it has value. From a performance standpoint; it doesn't mean squat (to me). Their heads are designed for 425 HP and "correctness" and Shelby's name is stamped on them. Having said that; you can still have them reworked for performance like any other set of heads. For ME; the bang for the buck wasn't there to justify the cost. I could do significantly better with KC's and get outstanding flow numbers out of a set of Edlebrocks.

Bernie

[shelbygt500]

Thanks, helpful. I wanna get to 550-600HP. Sounds like a fair amount of machining on the Shelby product will be necessary, and even then you might not get the flow and overall performance that you can get with another product. So you pay extra for the name and, in the interest of "correctness," lesser performance. If someone has machined Shelby heads in order to derive maximum, or at least improved, performance...I'd be interested in their comments on the outcome.

[Burnd]

You might want to read this. Coming form someone with the integrity of Jay; you might want to do some serious checking on that block before you put it together.

http://www.network54.com/Forum/74182...Block+problems

Good luck with the project.

Bernie

[Sizzler]

The biggest issue with the Shelby heads is their gigantic chamber volumes.

Nowadays, performance heads are designed with small chambers...72, 76 cc. Shelby chambers are in the 80's before any sort of cleanup. That size chamber will work, will work well if your engine is in the 500 cubic inch range, but generally speaking, are just too big otherwise. Some CJ heads for comparison sake (and the new Blue Thunder heads I hear) are in the low 60 cc range chamber size-wise.

[CSX 4027]

There are a heck of a lot more limiting factors with FE heads. That includes all makes. To make 600 isn't all that difficult depending on how you plan to drive the car. IE..Cubes, Stroke, Compression.

[ERA Chas]

Let me attempt to stop some myths before they become "fact".
My Shelbys cc'd 77.7 cc average across all eight chambers, with less than 1cc total difference.
The exhaust port floor is raised .250", the short turn is improved and of course, 2.250" intakes are arranged to nest in the chamber better than my previously worked iron MR's, which also had 2.250's installed.
Net gain, about 30 HP.
This on my 427" SO. With enough cam and induction 550-580 is about what they'll produce [i]on a 427-sized engine.[I
If Mike LeFevers can chime in here, he will provide expert data since he developed, dynoed and sold them when he worked at Shelby.
I did [i]not[i] buy them for CS signature, correctness or investor value.

[Burnd]

Originally Posted by ERA Chas

Let me attempt to stop some myths before they become "fact".
I did [i]not[i] buy them for CS signature, correctness or investor value.

Sorry: I didn't mean for the perception to be a put-down or insulting. You missed my point. I know they're good heads. "I" was originally going to buy them. However; after going through the numbers and in my case "FOR THE MONEY", I could do better with KC's stage ll heads (sh*t-to-pay ratio on dollars). As I recall; it was about a grand more (purchase and porting) to get the Shelby's to equal the flow rates of the KC ported Edelbrocks. Off the shelf they are designed for 425 HP (as per the Shelby shop's statement). The off-the-shelf price of the Shelby heads are obviouosly much higher compared to Edelbrocks; or half the country would be buying them. However, you still have to take them to a stage ll or lll to get the flow rates decent for higher performance. I had a budget of 15 grand on a 650HP race motor and I wanted that saved money put into Lunatti Rods and T&D rockers (which are expensive) with a focus being on durability under race conditions. Flow numbers are flow numbers; they don't disintegrate under duress. The original poster wanted to know why so many Shelby blocks have Edelbrock heads on them and I answered his question honestly; purely, "bang for the buck". A lot of gear heads don't have an open cash register and they can equal the quality & performance "cheaper" with modified Edelbrocks.

[Sizzler]

amen, the choir hears you.

[RedCSX1]

One head that was not mentioned is Blue Thunder which for high performance application is far superior to Edlebrock and Shelby. But when I last checked required Tand D style rockers. They are around the cost of Shelby Aluminum. Precision Oil Pumps sell them bare or complete with machine work done.

http://www.precisionoilpumps.com/

Talk with Doug and he can fill you in if you are interested in finding out more about BT heads.

[shelbygt500]

I've also gotten some private messages that I thought were fair and balanced...some from known engine builders you would all recognize...seems the Shelby heads need alot or work and even then don't necessarily perform as well as Edel. and Blue Thunder. I'll take the Shelby block and skip their heads...goin' Edelbrock. Thanks for the input.

[Power Surge]

If I was in the market for a set of alloy heads, I'd get the MR Blue Thunders. I have no desire to spend the extra $$ for the Shelby heads, and I don't care that they has CS on them. Also, I think the Shelby heads only work with a real 427 block, because of the valve size. I know that KC has a killer ported Edelbrock head, but I don't like the non-original look of the Edelbrocks. So I'd go with the Blue Thunders.

[ERA Chas]

No apology needed or offense taken. My post was not intended as a "defense" of Shels. Absolutely E'Brocks, as improved by KCR, George, Mike and several others are killer and best bang for buck. I just wanted to state clearly that the improvement was substantial for my combination at 427 inches, even above my previously modified iron MR's.
BT's heads also are super with a very small amount of work. I watched Barry Rabotnick make 751 HP with his 509" FE. (Note the gains are larger with larger displacements.) In fact Barry should chime in here since he's now in the FE business with his new company "Survivor Motorsports".
Forgot to mention that my Shels were Stage III in earlier post. On a subjective level, the castings were beautiful and flawless with quality valves, springs, keepers and Ti retainers.
I'm a sucker for that kind of stuff too, but not his signature. The BT's too, are well done but I've heard some E'Brocks need TLC.

[Barry_R]

I also sell Blue Thunder parts. Having run a set of very well prepped Edelbrocks in the FE that was featured in the July 2004 Hot Rod article, and having recently competed in the Engine Masters Challenge with a Blue Thunder equipped FE - - I have a pretty good feel for the upsides and downsides of both.

The Blue Thunders appear to have a definite advantage as the performance target moves north. The revised plug location and the updated chamber can't really be duplicated without either welding or "porter's special" Edelbrock castings. The advantage does come at the cost of added valvetrain work - and of course the price. I consider the Blue Thunder to have the best potential as a race or near race head. I made 752HP with these on 91 octane.

Edelbrocks are hands down price leaders. The cost is low enough to negate the value of any original heads unless absolute original appearance is mandatory. They have obvious and proven potential in the right hands. I've made right at 700HP with some (OK - only 699). As shipped they are nothing special from a performance perspective - but are excellent "cores" to start out with. Keith has taken them much further in serious race applications.

Shelby stuff appears to fall in a sightly different position than either. They have the cache of the Shelby name, appear to be quite a bit higher performance oriented than the Edelbrock heads are "out of the box". That noted, they don't incorporate the updated characteristics of the Blue Thunders. With moderate potential relative to the cost they are probably best suited for someone who wants a bolt on high performance head.

The one not mentioned in the thread was Dove. They are alternately worshipped and cursed - - sometimes by the same builder - - sometimes in the same sentence. Nobody has developed more iterations of the FE head, nobody has been doing them longer (other than Ford). Many of the fastest FEs in the country have Dove heads. Other Dove heads are holding open doors and propping up shelves - - its been a grab bag - - but to his credit Jim Dove has never quit trying. He was FE when FE wan't cool.

http://www.survivalmotorsports.com/Bluethunderfe.html

[ERA Chas]

Oops!
Sorry Barry, Survival Motorsports!

[hoppy]

I bought the KC stage II heads and his "custom grind" Comp hydraulic roller cam. Had Mike Lefevers do the install. The difference on my 428 SCJ is astounding. Have no other comparisons to make but I could not be happier.