Engine for Superformance

[aji]

It would seem to me most any engine can be made to have superformance. Just put the superformance parts in it.

I run 355 and 406 SBC iron V8 with stock intakes and headers. The 355 revs much nicer but does not have the low end torque of the 406, both make about 375-400hp and over 425lbs of torque.

If I was building a V8 it would be at least 4 in bore with a short stroke crank and long rods. The would be around 377ci displacement.

Myself. I'm building a audi 2.23L 20valve turbo straight 5 with Motronic Bosch EFI.

I also have an all aluminum block/heads Alfa Romeo 3L 24valve V6 with Bosch Motronic EFI that will also be built up.

I really have no ideas on the HP figures for the moment. I want to revs to be higher and the weight of the engine to be less then a iron V8, This should not be a problem.

Have fun building your engine!

 

[CliffBeer]

Before this becomes Ferrari Chat, feedback from Kevin would be in order

It sounds like what Kevin wants (from his comments ... shifter carts, etc) is more of a race treatement vs. a car to pick up the kids from school in. One of the hardest part of the build, picking really what you want to do with it.

Carb (Non Weber) vs EFI, again depends on what you might want to do. The EFI will be more time consuming to get running from scratch (plumbing, electrical, and least of all tuning), looks cool, but in the long run I really can't see why people think it makes such a huge difference. EFI definitly has the look over the carb. I have a TWM injection for my car, and it will only likely find its way on the car after I have nothing else to do to it or pump the rods out the side and do a rebuild. The carb is pretty simple and lacks no ability to make power and still has good drivablity, just does not look at hot as the stacks.

Too much coffee this morning, sorry for the ramble!

Sandy

Sandy, thanks, good we've got focused types like you to keep things on topic. Perhaps next time however you can just skip over my posts as I don't want to distract you with such needless information.

 

[Nathan]

Great thread. Still trying to figure out whats best. Whatever that means. SPF and the CAV dealer are really close to me so I will try to meet with them both in 2 weeks. Ones in Tokyo one doesn't have a car in stock.

First I got to say I simply love Stack type injection. Looks cool as hell and performs really well.

I have twm with haltech in my porsche on a race motor. It's a toy!!! Plain and simple. I can't imagine wanting to try and tune it down to be a daily driver which is the impression I get from alot here. Yeah it sucks ass in traffic and the car hates to be under 3000rpm but it's a sports car. It does idle well but doesn't like to move without a good rev.

Don't let people scare you into detuning your car so it has a nice idle and cruises at 2000rpm. 500hp is way more then you need. So go for 600 rockonsmile The throttle is an infinite pedal not an on off switch-which coming from turbo cars is a lesson I am still trying to learn.

 

[Mark Worthington]

Re: 302 W CID Combo's.

You may be getting confused with all the capacities being talked about here.
331 is 4.030" bore x 3.25" stroke in 8.200" deck block. Std + Ford 302 Block
347 is 4.030" bore x 3.40" stroke in 8.200" deck block. " " " " "
348 is 4.125" bore x 3.25" stroke in 8.200" deck block.( Dart Iron/Alloy)
364 is 4.125" bore x 3.40" stroke in 8.200" deck block. " " "

Now to add to the mix; All of the above in kit or crate form use a 5.400" long connecting rod.

With the 3.25" stroke this give's a rod ratio of 1.66 to 1. On the 3.40" stroke it gives a rod ratio of 1.59 to 1. While this brings a lot of factors like bore wear ,friction etc, into play the biggest difference is in the way you, the driver will notice it. The 3.25" stroke versions are quite happy to rev up to 7/8000 rpm while the 3.40" stroke gets quite harsh or mechanical above 7000 rpm. In a car like the GT40 I feel the shorter stroke versions are more suited.

Jac Mac has brought the tech. In my opinion, the ideal setup would be a short-stroke alloy-block 348 with solid lifters, cammed for 7,500 rpm, and stack EFI. I expect that 500 streetable hp would be readily attainable with such a setup, and grown men would break into tears when they hear it at full song.

 

[JCoop]

Correct me if I'm wrong but the 351 based motors do not have the same firing order as the 289/302/460; which I'm told the bundle of snakes 180degree exhaust system was designed for. It wouldn't sound the same and the pulse-extractor effect wouldn't apply, I think. My 302 w/Webers sounds wildly awesome as compared to a friend's GTD w/ 351 @ 4500 RPMs.

 

[Sandy]

Correct me if I'm wrong but the 351 based motors do not have the same firing order as the 289/302/460; which I'm told the bundle of snakes 180degree exhaust system was designed for. It wouldn't sound the same and the pulse-extractor effect wouldn't apply, I think. My 302 w/Webers sounds wildly awesome as compared to a friend's GTD w/ 351 @ 4500 RPMs.

I had asked the firing order question a long while ago too (302 vs 351) and I think it does not matter. I think the question came up as I run 351 firing order (in a 331) in the mustang and most of the roller cams that I had were that way as well.

1-3-7-2-6-5-4-8 Late 5 Oh's, and 351
1-5-4-2-6-3-7-8 Early SBF's
(I hope I got them right...)

I guess the easiest way is to look at the pipes and collectors and map to the above and see if it seems like it would change the effect of the bundle o' snake. My guess not really. My mustang has a Dr. Gas X Pipe on it (regular car headers) and it is very Gt-40'sh sounding.

[edited]

If this helps, it looks like the headers on my engine are mapped like this (hard to tell from the pics but looks like this) -

Left Right
8 - 2 7 - 4 Top
| x | | x |
5 - 3 6 - 1 Bottom

Looking at the rear of the collectors from the back of the car. The number is cylinder of engine it connects to.

Sandy

 

[Ron Earp]

Ray,

The biggest thing I've found (heard) that alters the sound is the muffler configuration. A GT40 that has a single muffler at the rear sounds very different from one that has two separate mufflers. A lot of GT40s have a single box at the rear and this masks the "certain sound" that the engine produces at high RPM.

R

 

[Daryl Adams]

Kevin, I just came upon this thread today, but thought I'd let you know about my Superformance, for what it's worth. My MKI ships from South Africa on Friday and is going to Dennis Olthoff's race shop for the installation of a Roush engine. I ordered the stroked 302 (353 IR), as I felt the smaller block was the only correct choice from a historic perspective. I'm getting the 8 stack injection system, and the engine is reported to make 480 HP. I'm thinking that's more than enough. I live north of you in Barrington Hills, so you're welcome to stop by and check the car out. I'm not sure what the timetable will be, as the backlog in delivery of ZF transaxles is delaying things.

 

[Sandy]

Ron -

Interesting observation, I have not seen (well herd) many GT40s so don't have a good point of reference. The muffler that Fran used was a dyno-max dual in/out, but the cut-away shows a nice 'X' across the 2 pipes. I like the single pipe/muffler look better but Fran's muffler guy said that this is a better set up for the engine for some reason. It will not be that hard to change if it doesn't meet the 'certain sound' (Some new collectors/mufflers and the plasma cutter is worst case, but hoping it will all be good... my glass is half full!)

The other thnings that have always made a good sounding engine irrespective of mufflers was High Compression and a mechanical Cam. The 8 stacks I'm sure also adds to the enjoyment.

A ways off for me at this point, but having the sound is a definite part of the package!

BTW Ron, the SPF MK1 Car (In beautiful Gulf trim) is a fantastic looking car, nice looking bits.

 

[Ron Earp]

Sandy,

completely agree with you on the induction and cam, as well as compression. The mufflers are a big standout thing and to me was the thing that killed the sound on some of the cars I've heard when the banks get all mixed in a big chamber. No matter what, with the induction and valve train you have it'll sound killer. Throw in some of those noisy cam gears and you'd be deaf!

R

 

[Mike]

2 cents: The firing order on SBF's depends on the cam, i.e. a 302 or a 351 can use the same cams. The cams designed for the 351 have the 13726548 order, the 302's have the 15426378 order. I have used both cams in my 302/347. All you have to do is switch the distributor wires to match the order (and tell the computer).

The 180 degree exhaust crosses the middle cylinders from each side to the opposite sides collector, so cyls. 2&3 on the right exhaust into the left collector, as 6&7 on the left exhaust into the right collector. The theory is that with evenly spaced exhaust pulses, you maximize the harmonics ( as opposed to having 2 cylinders from the same side puff in a row, screwing up the pulse timing). If you plot the firing order against the side/collector it empties into, you see you get a left right sequence; (cyl 1)right, (cyl3)cross to left, (cyl7) x to right, (cyl2) x to left,(cyl6) x to to right, (cyl5)left,4R,8L,1R etc. Normal headers have 3 and 2 on the right puffing in succession, as do 6&5 on the left.

Several threads address the RPM vs. power results of different systems, but consensus and experience suggests that 8 stack induction is going to give you mid range power. If you want 7000+ peaks, a carb/throttle body on a big plenum mainfold seems to be the answer. Our administrator has looked into this in depth, I believe. Ron? Somebody talked about 7500 RPM and 8 stacks. I don't think you can do that very easily or cheaply. (My cam 236/242 roller spec says peak T/HP are 4900/6800+. Dyno says T/HP 4800/5300-6500 with an absolutely flat HP curve from 5300 on up; no increase/peak. That's with 90mm velocity stacks).

Good Luck,
Mike

 

[DBLDREW]

2 cents: The firing order on SBF's depends on the cam, i.e. a 302 or a 351 can use the same cams. The cams designed for the 351 have the 17326548 order,

Just to clarify the fireing order is 13726548 not 17326548. I’m sure it was just a simple typo, but we don’t want to confuse anybody.

 

[Mike]

Oops. Sorry. There's a good description of exhaust theory at this web site: "http://www.ssheaders.com/header.htm".

Mike

 

[DBLDREW]

The crossover exhaust that is designed for the 15426378 firing order will work the same on the 13726548 firing order. Both firing orders follow the same left and right side exhaust pulse. If we look at the firing order of both and we figure the cylinder 1-4 is the left side and 5-8 is the right, while the cylinder 2 and 6 have crossed over, so 2 would now be right side and 6 would be left. If we cycle through the firing order twice we get the following left right pulse pattern.


15426378
L-R-L-R-L-L-R-R-L-R-L-R-L-L-R-R

13726548
L-L-R-R-L-R-L-R-L-L-R-R-L-R-L-R

So if we look at the bold patter they are following the same left right pulse pattern. Following the bold pattern in the first example we then have the L-R-L-R-L-L-R-R and following the bold in the second example we have L-R-L-R but then if we loop back and start the firing order over again we get the L-L-R-R so we are still maintaining the exact same L-R pulse pattern regardless which firing order we go with.

 

[Sandy]

Excellent DBLDREW/MIKE thanks for the info, I think that this was the idea that was in the old posts about the header and firing orders. I was just too lazy to do the final step and map it all out

Sandy

 

[Mike]

Man, it's terrible getting old... mind starts to go... confusion...
O.K. DBLD is right on. My 180 degree set up is also correct. The middle cyls. on SBFs must be crossed for alternating pulses.
Proof:
Defining L/R: Looking from the rear of car forward, cyls, 1,2,3 & 4 are on the Right/pax side, with cyl.#1 the furthest forward, next to pax; 5-8 on left/driver's side, with cyl5 the firthest forward, next to driver.

SBF 180 degree pipes have cyls 2&3 cross to LEFT collector, 6&7 cross to RIGHT.
With the correct/no typo 351 cammed firing order of 13726548, we get:
1R,3L,7R,2L,6R,5L,4R,8L,1R etc.
Similarly, for the 302 cammed order 15426378, we get:
1R,5L,4R,2L,6R,3L,7R,8L,1R etc.
Q.E.D.
Both firing orders work, and I have run both on the same exhaust with no difference in sound or operation ( can't say performance, obviously, as the new cam is beefier).
Hope all of this BS is useful to Kevinl
Now I'll go back and re-edit my first post.
Alohas, Mike

 

[Steve Briscoe]

Kevin, I just came upon this thread today, but thought I'd let you know about my Superformance, for what it's worth. My MKI ships from South Africa on Friday and is going to Dennis Olthoff's race shop for the installation of a Roush engine. I ordered the stroked 302 (353 IR), as I felt the smaller block was the only correct choice from a historic perspective. I'm getting the 8 stack injection system, and the engine is reported to make 480 HP. I'm thinking that's more than enough. I live north of you in Barrington Hills, so you're welcome to stop by and check the car out. I'm not sure what the timetable will be, as the backlog in delivery of ZF transaxles is delaying things.

I spoke with Todd Andrews at Roush yesterday and he described a motor that goes into production soon that is very similar to your description above. He said the new 5.0 liter based motor would produce a hair less than 500 horses. Must be the same one. Aluminum block option is an additional 3K. I asked him if they could make the cam a little hotter for me since I lose about 15% of the sea level power due to altitude. He doesn't think they can do that because all Roush motor configurations are tested extensively. He will check further. So, if I went with a 480 horse motor, I would wind up with at least 15% loss of power at the wheels. 3% for every 1,000 feet in altitude. I don't know enough about the 40 to estimate the loss of power between the crank and the rear wheels. I'll be interested to see how you like that 8 stack. Maybe it will help to offset any power loss.

 

[Kevin M]

Just to keep this in perspective, he is looking at a MK II. The Mk II never had a 289 / 302 based motor. The Mk II's were all powered by the 427 side oiler FE motor. They were not high RPM screamers, that was the Mk I's. The 427 FE made 500 HP and 480 ft/lbs of torque and redlined at 6,500 RPM. In the longer races the drivers usually kept them to no more than 6,200 RPM in the interests of having the motor last the race.

The racing 427's all used a single 4bl carb on an aluminum dual plane intake manifold. They never used Webers on that engine.

All of the Superformance GT40 Mk II's I have seen or read about were using the Roush 402 or 427 Windsor engines. For a street car, I have doubts about exceeding 500 HP. (Even that may be high).

The 351 based engine is 1" taller (plus any additional height in the manifold) and 2" wider than the 302. It is much smaller than the 427 FE which was in the original car. The FE isn't really practical, you can't install air conditioning and it intrudes into the passenger compartment.

From your description of your planned use, I would look hard at an aluminum Dart Windsor block with a 3.750" to 4.000" crank giving you a 400 to 427. Keep it fairly mild with a hydraulic roller cam and a reline of no more than 6,500 RPM. Even that might be a lot of motor for street use. A 3.500" crank would give you a 374 cu in motor making 450 to 475 HP and might be a good compromise.

You need to get a ride in something with similar weight and power, either a GT40 or a Cobra with 450 to 500 HP. Then you will have a basis to evaluate from.

Good Luck,

Kevin

 

[Dutton]

Per Rons request... TEST.