Club Cobra - 427 Side-oiler - approx. horsepower?

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- - 427 Side-oiler - approx. horsepower? (http://www.clubcobra.com/forums/429-460-engine-talk/101323-427-side-oiler-approx-horsepower.html)

dcdoug

12-07-2009 07:47 AM

Quote:

Originally Posted by patrickt (Post 1007470)

Hopefully it doesn't have anything more potent than the over-the-counter "K" cam (which is what I have). That's about as far as you want to go with a Ford solid lifter cam and still enjoy it on the street. The next step up to that cam was the "B" cam, which kept the same lobes, but brought the separation angle in closer together. He won't like that.

I have a "B" cam, .526 lift and I find it fine to drive on the street, although I wouldn't want to drive it all day long in traffic (but who would do that anyway).

patrickt

12-07-2009 08:06 AM

Quote:

Originally Posted by dcdoug (Post 1007493)

I have a "B" cam, .526 lift and I find it fine to drive on the street, although I wouldn't want to drive it all day long in traffic (but who would do that anyway).

That's right, you do have the "B" cam. In fact, your engine build is one of the most period accurate builds that I'm familiar with -- Doug, if you happen to have a dyno sheet, that would put this thread to rest.

patrickt

12-07-2009 08:12 AM

The "D" Cam

BTW, when I mentioned the "D" cam, I meant the C8AZ-6250-D cam, not the mild mannered C3AZ-6250-D cam (someone sent me an email). Only Ford would differentiate a lion from a lamb by using an "8" instead of a "3" in the middle of a long string of otherwise identical letters and numbers.:JEKYLHYDE

elmariachi

12-07-2009 08:16 AM

Quote:

Originally Posted by undy (Post 1007462)

Actually 600s. Carl's Ford has an exclusive deal with Holley and they continue to manufacture exacts copies of the BK-BJs and the BC-BDs expressly for Carl's Ford.

Correct @ 600 cfm. I just bought a pair, Merry Christmas to me.

Quote:

Originally Posted by vector1 (Post 1007480)

looks like your numbers are inflated. i'll take the newer edelbrock aluminum heads over your unworked medium riser heads anyday.

I am quite comfortable that the engine dyno work I paid for was accurate. No doubt a set of worked Edelbrock heads would flow and perform better. But I wouldn't trade my virgin MR heads for a set of stock Edelbrocks.

FFR428

12-07-2009 08:38 AM

Quote:

Originally Posted by car4jim (Post 1007356)

There was a show on Speed channel where they dyno'ed all the big blocks from the 60's. They tested a 427 FE that looked relatively stock. It seems to recall around 500 HP. Anyone see the show that can confirm?

Just to add that engine in the shoot out had tunnelport heads and intake which were over the counter parts only. So it can't really be called stock as no production 427 cars came with tunnelport heads/intake from the factory. The Hemi that topped the field as we all know was a ringer.

Gunner

12-07-2009 09:43 AM

I think I've made the point I stepped in to make: that 1960s engine tech is good for about 1.1 HP per cube and no more, not while retaining anything like street driveability. Even drag engines of the day didn't have significantly higher power ratios. Speculation about what modern tech adds, and how that relates to old tech capabilities, is meaningless anecdotal bar chat.

I'll throw in one more datum: If anyone could get the most out of these engines for road racing purposes, it was Shelby working with Ford. He hit the wall in the power curve right about where I've stated it. When he wanted more power, he didn't screw around with tech that was as-yet undeveloped (extensive porting, valve changes, displacement increases, deep-breathing intakes of normal size, etc.) No, even Unca Shelby "cheated" and just grabbed a Paxton or two off the shelf.

If Shelby couldn't do it in the day, I'd venture to say it couldn't be done.

elmariachi

12-07-2009 10:07 AM

Quote:

Originally Posted by Gunner (Post 1007515)

I think I've made the point I stepped in to make: that 1960s engine tech is good for about 1.1 HP per cube and no more, not while retaining anything like street driveability. If Shelby couldn't do it in the day, I'd venture to say it couldn't be done.

Which opens up another conversation. Every interview I have seen with Shelby about engine HP ratings, he always says stuff like "Ford published 335HP to make the Feds happy, but that 428 Cobra Jet was putting out more like 500HP." Interesting that I rebuilt their acclaimed 425HP side oiler back to nominal specs plus a bit more cam and barely exceeded the "published" HP. Where's my 100+HP bump that was supposedly "built-in?":LOL:

dcdoug

12-07-2009 12:04 PM

Quote:

Originally Posted by patrickt (Post 1007496)

I don't have a dyno sheet, but will post when I get it dynoed (chassis dyno obviously) probably this spring. If it matters, my builder (Dwight Powell), who has been building these engines since 1968, said it would make about 500hp. He has been building 427/428 engines for long enough that I wouldn't doubt him, but there are a lot of knowledgeable folks on this forum that will have different opinions. :)

For comparison purposes, I have an NOS 427 SO block and steel crank (standard bore and stroke), NOS medium riser heads (not ported), NOS LeMans rods and TRW pistons (11:1), "B" cam, blue thunder intake, Holley 750.

Gunner

12-07-2009 01:40 PM

Quote:

Originally Posted by dcdoug (Post 1007562)

I have an NOS 427 SO block and steel crank (standard bore and stroke), NOS medium riser heads (not ported), NOS LeMans rods and TRW pistons (11:1), "B" cam, blue thunder intake, Holley 750.

I'm looking forward to the dyno results.

Of course, I look forward to finding an NOS SO block in a flea market, too... :D

patrickt

12-07-2009 01:46 PM

Quote:

Originally Posted by Gunner (Post 1007603)

I'm looking forward to the dyno results.

Of course, I look forward to finding an NOS SO block in a flea market, too... :D

I think Doug's engine dyno numbers will give an honest representation of what an unmolested/unmodified SO block really made. Granted his has the bigger "B" cam, and over on the SAAC site there's a chart that says Shelby tended to use the "K" cam, but I don't know if all that's true or not. Ron would know, though -- I don't know why they wouldn't have used the "B" cam on the track anyway. Maybe the "K" cam was only on the street.

EDIT -- I looked at the chart again, the "B" cam was used quite a bit. http://www.nvsaac.com/shelbyparts/camshafts.htm

dcdoug

12-07-2009 02:21 PM

Quote:

Originally Posted by patrickt (Post 1007607)

I think Doug's engine dyno numbers will give an honest representation of what an unmolested/unmodified SO block really made.

I think the Blue Thunder intake is supposed to flow better than an original sidewinder although it is pretty true to the original design, but other than that, should be pretty close. Not sure on the size of the Holley on the single 4bbl cars either, but I'm sure someone knows that. :)

dcdoug

12-07-2009 02:29 PM

Quote:

Originally Posted by Gunner (Post 1007603)

I'm looking forward to the dyno results.

Of course, I look forward to finding an NOS SO block in a flea market, too... :D

One of the fun things about Dwight was that he had NOS 428 and 427 blocks (supposedly the 427 blocks were unused NASCAR blocks that were left over after they changed the rules) stacked around like cord wood. Lots of other NOS parts too - one of the reasons I couldn't resist going with a more original build despite weight and other "disadvantages". Funny, regardless of the HP I am actually making, I don't feel underpowered. :D

Gunner

12-07-2009 02:44 PM

Patrick nailed it in another thread, I think: anything over 400HP flywheel is gravy in these cars. It can be fun gravy when there's a lot of it, but unless you're a straightline numbers fanatic the diff between 400 and 500 isn't going to mean much.

I'm making somewhere around 450-460 at best and it's satisfying, all I can reasonably handle and extremely driveable. I hope to smooth out the response with some detailed carb tuning but don't care where the HP goes in the process.

I'd love to be able to boast a truly original engine. :)

elmariachi

12-07-2009 02:46 PM

Quote:

Originally Posted by Gunner (Post 1007630)

I'm making somewhere around 450-460 at best and it's satisfying

At the flywheel or rear wheels? How do you know?

Gunner

12-07-2009 03:01 PM

Quote:

Originally Posted by elmariachi (Post 1007632)

At the flywheel or rear wheels? How do you know?

Original flywheel dyno sheet from Danbury is 440 and 475 with no attempts at optimization, just a bolt-together of Joe L's standard 428 build.

I've replaced a boggy Holley with the Speed Demon and run the timing forward a step. While all my dialing in so far has been old-school, I eliminated the bog and it's a lot more responsive. Either the engine was down on power when I got it and I've restored it to original tune, or I've added a bit.

I plan to add some O2 bungs and do a sharper tuning job across the band before a dyno run and tune sometime in the spring.

Anthony

12-07-2009 03:02 PM

Quote:

Originally Posted by Ibr8k4vetts (Post 1007450)

Anthony,
How well dose that cam idle or dose it?

It idles fine when warm, a little rough when cold. The problem is that valve lash changes with temperature. Since it is an iron block, the valve lash doesn't tighten up much when cold (about 0.006"), but if it were an all aluminum engine, cold starting would be more of a problem, around 50 degrees and less.

Anthony

12-07-2009 03:07 PM

Quote:

Originally Posted by Gunner (Post 1007636)

Original flywheel dyno sheet from Danbury is 440 and 475 with no attempts at optimization, just a bolt-together of Joe L's standard 428 build..

It's a mistake not to get your engine chassis dyno tuned. I picked up about 60 HP and 80 ft-lbs having it dyno tuned. Maybe 400 HP is a good number for just throwing an engine together, but there may be significant room for improvement, like in my case.

Gunner

12-07-2009 03:14 PM

Quote:

Originally Posted by Anthony (Post 1007643)

I'm sure there's power in there for the finding. The original owner never bothered and I can't fit it in until the spring - but I'm definitely headed there.

Anthony

12-07-2009 03:35 PM

Quote:

Originally Posted by dcdoug (Post 1007624)

Of all the dual planes, the blue thunder in general makes the most power, more than the sidewinder and performer rpm, but not by much.

From my understanding, the original carburetors were 780cfm vac secondary, but many racers bought /upgraded to the 850 cfm. I'm running a Holley List # 3255-1 (780 cfm), 3255 was for MR engines, 3255-1 for highrisers, as original equipped on crate engines. 3259 (735 cfm) for 289 HiPo's. I'm sure there were other carbs as well

elmariachi

12-07-2009 03:37 PM

Quote:

Originally Posted by Gunner (Post 1007636)

Original flywheel dyno sheet from Danbury is 440 and 475 with no attempts at optimization, just a bolt-together of Joe L's standard 428 build.

For a point of reference, can you remind me/us what's in your build (block/heads/cam)?

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