427 Trivia Question

[CSX 4027]

How many of you either know for a fact or believe that some ORIGINAL 427 cars came with HIGH RISERS?

[427 S/O]

I believe back then, you could probably order just about anything you wanted.

[REAL 1]

The orig Comp cars had high risers.

[Traveller]

I'm going to guess none of the 427s came with high rise manifolds.

I'm basing this on the fact that you'd have to have a bigger scoop to accomidate it and I don't remember seeing any pictures of comp cars with a tall hood scoop.

[Anthony]

The single four dual plane intake for Hi-riser heads (C4AEsomething) is only 1/2" higher than the single four dual plane for med riser heads. I know, I measured them. The dual four intake for high riser heads I believe is alot taller, and required the bubble on T-bolt cars. I don't have one to measure.

Although it is written that the comp cars came standard with Hi-riser heads, I think most came with med riser. I think all, definitely most, of the S/C's came with med risers. I had asked this question to somebody who has owned an original for a long time, somebody who I thought was very knowledgeable on these cars, and he said he knew of one car that he thought came originally with HR heads. There may be more.

[CSX 4027]

I just looked at an original 427 street car that was restored with s high riser single 4 set up and it fits under a no-hood scoop original hood. I was surprised. If that is the case, I wonder why more do not use the high riser on the replica. I would. It is a better design and makes more power through better anle to the valve and flow.

[Anthony]

I'm not sure if any of the street cars ever came with HR heads, although I would think Shelby would install any engine you wanted. Although it was a CSX30## car, the car I was told about was I think a comp car, not an S/C. I can't remember if the guy I talked to knew or told me if it came with aluminum or iron HR heads.

I have the HR single four intake, and the correct Lemans carb #3255-1.

I know the owner of CSX3106, and he has it set up with a stock stroke 427 CO, with the DOVE Paquet port HR heads ( basically a HR intake port with the floor raised to reduce the size to a med riser size). He epoxied (filled in) the intake runners of the single four intake to match the heads. 13:1, dry sump, 670 honest hp. He took me for a ride. That car is fast.

[Byots]

Search old threads for additional discussion on this. The issue of high risers at Shelby American and in Cobras in lare part comes down to the time period examined. In the latter part of '64 and very early '65, the high riser was the only head considered for and used on (prototype, 3002, etc) the comp 427 cars as the medium rise didn't exist yet. An old pubicity shot shows a high riser 1x4 in a production comp car engine bay - probably the first car (I think 3004). The '65 homologation paperwork lists the 58mm webers, the intake manifolds for which were only made for the HR.

Around Feb '65 Ford/SA documents specify the aluminum head MR as the official "light weight" comp car engine, although if there ever was a full-blown factory team 427 effort, SA would have likely still used HR heads due to their enhanced performance. There were a handful of aluminum HR heads made that carry ASK numbers that are close to that on the aluminum 390 block (alum 427 sleeved down), these were used at least on the flip top and the initial engine in 3002. Because Ford shifted their attention to the GT40 and SA didn't receive homologation on the 427 car in '65, Ford was pushing the new MR engines and SA just installed what they received on most cars, not having any real reason to do otherwise - all comp cars went to independents.

3002 did run maybe 3 races as a "team" car, but there isn't alot of evidence as to whether HR heads were used (other than the way the car arrived at SA). For the most part, race efforts with 3002 were mostly to fine tune the handling and reliability, the standard 1x4 MR performed well in the car, so they weren't at that point much concerned with maximizing power. In fact, people involved with the cars back then remember having alot of 427 engine failures (a major reason the dry sump was developed) and the HR would just make that situation worse due to the higher rpm operating band.

So, in terms of the actual initial intentions of Shelby American, the aluminum HR head is the "factory team" piece, but what ultimately was installed in most comp cars was probably the aluminum MR head (perhaps a couple comp cars "came" with the HR). The August '65 dated big block Cobra SA Bill of Material shows something like 12 or 14 aluminum head MR engines in inventory at that time, so even those were rare, probably only around that many ended up in cars (some were likely blown up in testing).

[Traveller]

Originally posted by CSX 4027


I just looked at an original 427 street car that was restored with s high riser single 4 set up and it fits under a no-hood scoop original hood........ I wonder why more do not use the high riser on the replica. .....

That is a surprise.

All I can tell you is that I run CJ heads and an aluminum PI manifold and there's not a 1/4 left of clearence on my street ERA.

Of course, it's a replica, not an exact-lica.

[CRZN427]

Lots of things escape me lately, but I remember reading that Ford created the "Tunnel Port" manifold, which was a medium riser, that breathed better than the high riser.

The article said that it took the racing officials quite a while to catch on since the Fords using the tunnel port manifold were winning with apparently "stock" setups. The high riser would cause the hoods on the Ford racing cars to either be modified higher or have a scoop which was a dead give away that the engines were not stock.

[badrich]

CSX 427: I think the main reason why you don't see more hi-risers on replicas is that they aren't that well suited for the street. They have very good mid-range power and excellent top end, which is great for racing or track use, but their lack of low-end torque makes them suck for street driving and even autocrossing. While I was in the market I went for a test drive in a machine with a hi-riser setup, and around 3K RPMs it went like hell, very impressive, but then it had an extra tall hood scoop ... just didn't look right. ; ) Rich