1x4 428 w/ 427 lowrise intake...Changes

[NKOTB]

Hi fellas,

I bought my car just a about a month ago, and am in the process of refreshing it in terms of general PM, tuning, and authenticity. I'm heading in the pure street style direction(no side pipes, no scoop, no stripes, no bar), and am currently mulling over what to do with my engine in terms of it's height in the frame - it sticks up about 1-2 inches above the hood plane. What I think I have is a 428CJ (C6ME, 352 stamp) block with iron heads, a C3AE-H 427 low rise intake and a holley 750 1x4 carb setup.

Part of me would like to get the height down so I can use a solid hood, a la' steet style, and I'm thinking a blue-thunder mid-rise intake would get me there... but I have come up with the following questions for the group:

Questions:
- Is there anything particulary good or wierd about the build I have?
- In terms of street style authenticity, other than 2x4's, am I headed in the right direction?

Thanks ya'll,

David

[Carnut427]

The mid-rise, or more correctly medium riser intake will put the carb higher than the low riser manifold you have. Post the casting #s of your heads (located between the middle two spark plugs) and perhaps someone will look them up to see if they're "short" or "tall" port low riser heads. The "tall" port heads will better match your 427 low riser intake, which has "tall" port low riser intake runners. I don't know of any parts combination that will put the carb lower than what you have...

Dan

[NKOTB]

Dan,

Thanks for your response. The casting number on the heads is C3AE-H. The intake is actually, I believe, a police interceptor intake...

So for clarity it should be a c6me 428 block, with c3AE-H '63/ 427 c.i.d. high performance low riser heads (2.08" intake valves, 1.64" exhaust valves & a 73-76cc chamber size), and then finally a 428 PI intake...

here's a pic:
http://www.barrett-jackson.com/image...A2_111_Eng.jpg

Does this give you enough to tell? Sorry for the mis-statements - I'm kind of learning as I go.

Thanks,
David

[flwolfman]

You can't always tell my the casting numbers. I have two 390's with the C6ME casting numbers. The bore size doesn't lie. Good luck with yours! Jim

[NKOTB]

Jim,

Thanks for your response. What you say is true, but I'm pretty confident that it's a 428...

I guesss what I'm still trying to answer is the hood clearance question & if changing intakes will drop the upper assemblies enough to clear a solid hood.

As a bonus, I was hoping someone would help me with ideas on how to get the most reliable performance out of what I could go to with a lower height intake...

[Carnut427]

Your heads and intake are all "tall" port low risers, excellent performers. Equal parts to a Cobra Jet motor if it is indeed a 428...still excellent parts for a 390. I know of no intake that will lower the carb. Perhaps someone else does. If you're set on no hood scoop, lower the motor...lotsa work. I'm not that familiar with Contemporary Cobras, but they were ERA's biggest competitors (in the northeast) when they were still "alive". I never did hear the story of why they went out of business. There were enough of them made that someone should be able to tell you how to get it under the hood; how about a drop-base air cleaner?
Good Luck,

Dan

[NKOTB]

Thanks Dan,

Good to hear the parts mix is a good one for performance, if not albeit for my asthetic goals... I'll put out an APB to the CCX folks as you suggest... I really don't wanna lower the motor.... Thanks again, DD

[SCOBRAC]

I'm not familliar enough with a Contemporary with no scoop to say whether it will fit or not. I don't think the FE will fit without it but I dunno. Your build is straight forward enough, all FE's are the same save a few idiosincrocies in the side oiler. My impression of the 1x4 intake is generally poor. I have a few photos in my gallery of an intake swap I did on the Batmobile my 427 center oiler powered Barris Kustom. It had an Edelbrock F-427 on it that is directly patterned after the ford lowrise unit. I wouldn't use the ford unit for a couple reasons. The first is it is 43 years old and will be likely to exibit casting porosity or fitment issues leading to reduced performance, oil consumption or water leakage. The second is the early pattern 427 intakes were not terribly robust performing.

I found upon freshening that the 427 Medium Rise heads on the Batmobile were extensively ported and polished. The F-427 seemed solid enough but I suspected it wouldn't port out to the dimensions I needed. I opted instead for the Edelbrock RPM Performer. The only change I made was match porting the intake to the heads but I picked up an easy 50 hp over the F-427.

I was pretty curious why this was and this is what I found. If you want a "stock" manifold go find a 428 CJ unit. Get rid of the early 427 lowrise or opt for the RPM Performer. In this mild comparison it netted 30 hp over the stock intake / F-427 pattern. I similarly needed hood clearance for the new intake. Here's what I did...



http://www.network54.com/Forum/74182...nifold+Comparo

Say hi any time...

[NKOTB]

Michael,

Thanks so much for your reply... Just the stuff I was looking for. Ironically, I had just read the FE link last night, and am now coming to the place where I'm considering doing just as you did: getting a performer, having the logo's ground off & the ports matched, and then have it painted the same ford blue that the block and heads are. ( think it was correct for street 428's blocks, heads, intakes and surge tanks to be blue). I'm beginning to I can maybe live with the riveted hood being glassed smooth & be done with the fuss.

Thanks again for your experience,

David

[A Snake]

What I haven't seen or heard yet is whether or not you have actually tried to put the hood on. You can't go by the sides or the tops of the fenders. Remember your hood has a side to side curve as well as front to back. Let me know if you've tried the hood or not. I might have some suggestions based on what you report.

Al

"If some is good, more is better. And too much is just enough." --Carroll Shelby

[Carnut427]

SCOBRAC, I'm not discounting anything you said, but in NKOTB"s second post he states he believes the intake is a Police Interceptor unit, far better than the early 427 units, and on par with the CJ unit, but 54 lbs. lighter. I have no idea how much better an Edelbrock RPM unit is, probably measureably, but less improvement on low riser heads compared to medium risers with their larger valves; also, the carb may sit higher on the Edelbrock unit. There was a post a while back comparing some of these intakes, but I'll be darned if I can find it...
A Snake, good point.

Dan

[Carnut427]

This intake comparison is on a motor comparable to yours, NKOTB...good info for you performance-wise (and you can probably sell the Police Interceptor intake for a good price as it's generally thought to be an excellent intake, at least in some circles). Alas, it doesn't help with the hood clearance issue...check into different air cleaners for that.

[NKOTB]

ASnake,
Thanks for your reply. Yes it currently has a scoop because of the current assemblies height... (see my gallery pics). Thanks again for the possibilities though...

Carnut427,
Yes, that's correct. To your point, I'm planning a trip to Southern Automotive here soon, and will work with Bill Parham to decide:
1- if there is a shorter upper assembly combo to be had, or
2- if the PI intake is optimized for the heads, or
3- if it makes more sense to optimize what i have, vs changing out the intake for a port-matched Blue thunder or Edelbrock RPM unit...

Since I'm re-painting the car anyway, I'm getting more comfortable with the idea of leaving the scoop on but just having it glassed smooth into the hood, as opposed to the current riveted appearance.

I guess the real question is how will a port-matched PI intake perform versus a port-matched BT or RD RPM intake, when mated to 427 low riser heads (2.08" intake valves, 1.64" exhaust valves & a 73-76cc chamber size)... If there's only a nominal performance difference, within reliable and coomon operating ranges, I'm thinking I'll go with the simpler and less expensive option...

My nagging thought is regarding what I've read, the BT intake is an improved version of the PI... if those improvements are really seen only in conjunction with medium rise heads, then optimizing the PI may be the smartest thing to do until I get the itch for new heads.

Thoughts?

Thanks ya'll,
David

[SCOBRAC]

I just realized he mentioned it was a PI intake, thanks for the clarification. unfortuantely the PI intakes were virtually identical to the lowrise intakes. The comparison to the 427 / F-427 is pretty close. The PI intakes were repaced by the sidewinder intakes which were replaced by the CJ intakes. The RPM performer and the CJ intakes are both more medium rise in nature and port size.

[NKOTB]

how does porting the 427 low riser heads (2.08" intake valves, 1.64" exhaust valves & a 73-76cc chamber size) to yield around a 280/210 cfm for intake/exhaust sound? And then port match the intake to the heads, throw in replacement valves, and a valve job, & be done with it?

(This was suggested from a known builder)

[Carnut427]

Originally Posted by SCOBRAC

The PI intakes were repaced by the sidewinder intakes which were replaced by the CJ intakes. The RPM performer and the CJ intakes are both more medium rise in nature and port size.

I'm not sure of the order of the intakes, as I believe the sidewinder has an earlier casting date, although I haven't varified that. The sidewinder was the single 4 medium riser intake, the PI & CJ were for low riser engines. I checked my yellow Ford Performance book for port sizes, and according to that you're correct, the PI & CJ intakes have medium riser sized ports. I never realized that before. Strange that the CJ head ports are so much larger, although I guess that's not really abnormal. As a side note, the Ford Performance book lists medium riser heads as having 2.34" tall ports, the same as the CJs, and I know that's not true. I'm going to have to find another source to back up what this book states.

NKOTB, using the formula .257 x number of cylinders x cfm at max cam lift, 280 cfm will give you around 575 hp, although I don't think you'll be able to achieve 280 cfm without going to larger valves. I believe 2.150 intakes and 1.75 exhausts will fit in your combustion chamber, although the valves will be shrouded without having some clearance cut around the valves, giving you a bit larger combustion chamber and lowering your compression with your current pistons. This could be remedied by a smaller dish in the piston to bring the compression back up. My memory is fading on this, but I believe you can make the above valves by using .100 longer than stock BB Chevy intake valves, cutting the head size down and putting a back cut on the valves to narrow the valve margin. The back cut will also improve flow. Varify the lengths of the stock Ford valve and BB chevy intake + .100 before buying the valves and doing this, as there may be a flaw in my memory bank.

Dan

[NKOTB]

Dan,

Very cool. Thanks... Hopefully I can do something a little simpler than the valve cutting you mention... I would be quite happy with 500hp @ the flywheel, so maybe just the head work, and larger, but less radical valve work will refresh things enough to make me happy... Thanks again for the brain power!

DD

[A Snake]

Ok I looked at the pics. The car is a nice typical Contemporary...just like mine. Before I forget, I suggest that you DON'T blend in the hood scoop if you want the car to bear it's current resemblence to an original. Also, just so you know, the original street versions had 428 enginesw/dual 4's. Some owners didn't like it and either made Shelby change them to a 427 or did it themselves. Who knows how many survive today with original 428's in them. The dual 4 setup also had very thin Stellings and Hellings air cleaners and the dual 4 manifold is enough lower to make the set up fit under the hood without a scoop. If you want a good clear picture of how an original 427 set up looks in a Contemporary, check my gallery. The manifold is the correct "Sidewinder" and even has Shelby cast into it. Back in the '60's, the Shelby team did some tweaks to make the manifold flow better at WOT and and high RPM than the original Ford version. The engine and it's "accessories" are exact to original as can be seen in the B/W engine pics.

You might want to make note of the shape of the front bumper hoop on my car. I opted NOt to use Contemporary's part because 1. it was stainless steel not chrome and 2. it wasn't shaped like an original.

Granted, an original S/C has quick jacks, but what the heck....I didn't care for the look so mine is half street and half S/C. Street cars don't have side pipes and roll bars either. Funny thing though, I've been asked for the serial number by people who purportedly know Cobras. Go figure.

As to the performance of the "non-competition" dual plane manifolds mentioned in this thread, there is only so much that can be done or for that matter, needs to be done. Clean up the ports and match them to the heads and let it go. I would defy the average person to notice the difference at full throttle let alone just driving around. This comes from one with 40 years experience with FE Fords. Bench racing is great fun and inexpensive though! The average car buff who looks under your hood has no idea what he is looking at with these old Fords.

Remember this if nothing else. You have a 2350# car with at least 400 HP and a very short wheelbase. Push your luck in it and someone who loves you will be getting a very sad phone call. The engine you see in my car Dyno'd out to 482HP @ 6100RPM and I got several good scares before I finally woke up and realized that I was really tempting fate when I pushed it. Just concentrate on going places, having fun and enjoying having people admire your car......you'll live a lot longer. Ignore Shelby's words below.

Al

"If some is good, more is better. And too much is just enough." --Carroll Shelby

[NKOTB]

Thanks for the thoughful reply... If I may respond with some questions & comments...

Originally Posted by A Snake

I suggest that you DON'T blend in the hood scoop if you want the car to bear it's current resemblence to an original. Also, just so you know, the original street versions had 428 enginesw/dual 4's...

I'm wondering how the riveted version would be considered more original, as all true street versions, that I've ever seen, had molded & smoothed scoops.... (reference csx3121 & csx 3260) Agreed though that most all Contemporary streets' have them riveted... if these csx's i mention are aberations, can you please refer me to better references than I have... I'm always open to more correct info. than I have today.

Also, in terms of the 2x4 428, yes you are correct in that the 2x4 is an original configuration that would help with my height issue, but do you mean to say that a 1x4 428 PI is incorrect? I ask because have seen several photo's of original street 428's that were purported to "unmolested", and they had either 1x4 OR 2x4 carb set-ups... Just wanting to clarify if you thought the 1x4 on a street was not "correct".

Originally Posted by A Snake

...Street cars don't have side pipes and roll bars either...

Right on. Hence my lack of the same... my current exhausts are undercar, but terminate & kick out just in front of the rear tires... This will be remedied in the coming weeks though. Soon they'll go all the way to the rear, and have the correct chromed sleeves.

Originally Posted by A Snake

...Clean up the ports and match them to the heads and let it go...

Probably exactly what I will do... I'm going in with the idea of a full preventive maintenance check, and if in that check, we find that things are already set up pretty well, then it'll end up as a thorough tune up. If we find that the parts are just bolted up, and no port or intake optimization/matching has been done, then this will be done to "re-fresh" & optimize (not maximize) the build. Have no worries, I'm not going for stupid power or the resulting activities here, just a build that is optimized for what it is - a street cobra, not a comp or S/C. Thanks though for the warnings of experience. I think the part that keeps me the sanest is knowing that I have no roll-bar, and that healthy respect/fear and caution is the best safety mechanism I can employ.

Thanks for you thoughts on my responses,

Sincerely,
David

[Carnut427]

David, street Cobras didn't have hood scoops; you probably already knew that. However, street Cobra owners were known to install hood scoops, roll bars, side pipes, etc. to get the "look" they were after...and the hood scoops did come riveted on from the factory. When I built mine, I too wanted a street car, but I wanted it with side pipes, roll bar and the hood scoop...and it took me a while to accept the fact that, to be as original a period piece as possible, I'd have to accept the riveted on hood scoop. It's what they call building the car as original, "warts and all".

On the other hand, it's your car, build it your way. (Yes, that was intentionally inserted to confuse you.)

Sidewinder intakes came on side oilers (medium risers). I don't know if any 428s came with a single four on Cobras, surely Shelby would have installed one if that's what you wanted; a low riser intake would have been period correct on a 428, and the sidewinder and PI intakes have the same casting date of '66. CJ intakes have a '68 casting date. While we're talking Medium and Low risers, let's clarify that, while the ports were different between the two, the carb height is also higher on Medium risers. A Medium riser intake will fit on low riser heads, with a possible port mismatch.

Dan