Engine choice.

As some of you may have guessed, another GT40 may be looming on the horizon for me (am I a glutton for punishment or what?) At the moment I'm planning on using a 408 stroker I have, but what with the cost of fuel and my desire to use any finished car on a regular basis, I was wondering about the alternatives.
It may be sacrelige to put anything but a 302 in a '40, but the Cobra guys over here put the new ally blocked LS series lumps in their Cobra's and get not only excellent performance, but pretty darn good fuel economy as well.
What alternatives are there for a '40? Is the 4.6 ford any use? can it be mated to a transaxle? does it give good fuel economy?
Sorry if these topics have been covered before.
Thanks

Simon

Hi Simon,
This has to be something quite a few people must have considered at one time or another, I know I for one certainly have.
If it's a mix of power, fuel economy, weight etc and you were happy not to fit a Ford lump I'd have thought that the V8 from an 2WD Audi A8 has got to be real high on the list.
It has it's advantages, reasonably light and not too big, not bad looking, plenty of power when you want it and not too bad on fuel the rest of the time, there's a growing list of after market goodies becoming available and best of all, it has a pretty reasonable transaxle already on it.
Just that in itself makes life so much easier, mounts, drive shafts, the clutch system is all there and it's been worked out well, it's all off the shelf stuff, you could even get it serviced at your local Audi dealer!
What's the value on an A8 that's been hit hard in the rear or well rolled, could be a gem?

Although the other side of the planet --- the DRB factory has plenty of experience with Ford Windsor / Modular, (4.6-5.4) Ls1 Chev and Lexus all mated to the Porsche G50 trans in GT40s,Cobras and Ultimas www.gt40australia.com

GM sure has a good thing going with the LS_ engine. Small, light, fuel efficient, powerful in stock form, and easily modified to over 400 rwhp. If you can keep out of the throttle, you can get over 30 mpg on the highway from a 400 hp Corvette.

The Ford modular 4.6 and 5.4 engines are, by comparison, pigs.

I think the FFR GTR with a hot LS6 and a Porsche G50 gearbox would be one helluva serious ride. I think this powertrain combo could be made to work in a GT40, but there would be a fair amount of one-off fabrication.

Hi Simon
For the traditionalist you would consider only a Ford with your ZF box, but if your dareing you might consider other options such as the Audi menthioned by Stuart.I recently saw the new chevy unit that Gardner Douglas fits in there can am style car and it looks impressive and apparently fast and economical.
I'm on my secong GTD at the moment and I'm having a Chevy with Porsche G50.
This engine is being ordered shortly from Knight Racing in the UK and the spec is as follows:
Chevy small block, All alloy 7 Ltr. which is much lighter than any iron block.
640 BHP minimum with around 580 lb torque. Motec management and Kinsler fuel injection.
I have a similar engine from Knight Racing in my Ultima and trust me it goes well.
Currently a smaller output engine in the Ultima holds the world record for production cars at 0-60 in 2.7 and 0-100 in 4.9 seconds, so anything near that will suit me.
If you dont want to take out a mortgage for an engine then a near standard 302 will be more than suitable for track days and road use. The problem lies when you get used to the speed and you want a bit more 'I'ts addictive... Trust me I know '
Lots of food for thought.

If the 4.6 and 5.4 are such pigs how come a vet won't outperform a ford GT? Or for that matter a Mustang with a few mods. Go to your local track, and take a look around. Look at the new crop of super cars and see what the engine of choice is.The draw back is the width the saving grace is it is short. Aftermarket support. And best of all a ford in a ford.

Here's my 2 cents. Put in a 302,300 HP ford with a single 4 barrel and use all the rest of the money on a sequencial 6 speed quaife, rose jointed suspension, huge brakes, and wheels and tires.

They will never catch you.

[ QUOTE ]
If the 4.6 and 5.4 are such pigs how come a vet won't outperform a ford GT? Or for that matter a Mustang with a few mods. Go to your local track, and take a look around. Look at the new crop of super cars and see what the engine of choice is.The draw back is the width the saving grace is it is short. Aftermarket support. And best of all a ford in a ford.

[/ QUOTE ]

Bill, you must bleed Ford blue. I don't intend to offend you, but I hope we can engage in a little good-natured bench racing without taking things personally.

First, from what I've read, a 2006 Z06 Corvette should run dead even with a Ford GT (they both are in the range of 3.7-3.8 seconds 0-60 mph). This despite the fact that the Ford is a mid-engine car with more weight on the driven tires, and despite the fact that the Corvette is naturally aspirated while the GT is supercharged. Yeah, the Z06 is lighter than the GT, but maybe the weight of the engine has something to do with that? No doubt the 4-valve modular engines respond very well to forced induction. Of course, the only way you can make big power out of a modular engine is through forced induction, because the bore spacing limits your displacement. If you had your choice of fitting a race car with a 650-pound supercharged 550 hp engine or a 450-pound naturally aspirated 505 hp engine, which would you choose?

As for the new crop of supercars, it seems to me the hot setup is the LS6. The fastest Ultimas are running the LS6 with the Porsche G50. The Noble. FFR's new GTR. Obviously, the Z06. People are shoe-horning LS1 and LS6 engines into E36 BMWs, Datsun 240 Zs, even Miatas. Why not a modular Ford? Because they won't fit! BTW, I'm talking about cars that can dominate a road course, not a drag strip. Anything goes at the drag strip.

I'll stand by what I said earlier - the modular engines are big fat pigs compared to the LS_ engines. IMO, GT40s should use Ford pushrod engines. Other than that I don't care who's name or logo is on the valve covers.

OK OK how about a LS6 without all the GM electronics. Can they be run with a crank driven spark timing and a MSD type coil pack assembly? Does anyone make a 8 barrel FI system for them like we are using on Windsor's? If so the engine wouldn't LOOK much different than a Windsor. Put on some custom alum. valve covers and with the LS6 exhaust port layout it would look just fine.

I do agree that GM took the pushrod V8 farther than anyone else. The LS6 really is state of the art as far as this valve train design. Nice and light too. Really is a better motor than a Ford SB.

How about the supercharged Jaguar V8? It's (sort of) a Ford?

Simon

Right on Mark. I like Fords, and know some of the top mod racers in the country (see here: http://www.gt40s.com/ubbthreads/showflat.php/Cat/0/Number/67187/an/0/page/1#67187) but it is hard to beat a pushrod motor for size, packaging, and ultimately, power output. They are not dead, not by a long shot. Too bad Ford choose to go the mod motor route. They respond well to supercharging, but hell, so does a modern "Hemi" or LS6.

From that post:
"Bill, there is SEMA, then there is reality. I know a lot of folks that build 4.6L motors, a lot here at Haywood Performance in Raleigh, home of the fastest 4.6L no blower mod motor Stang in the country (one runs in the 7s). These fellows indicate you are not going to get 600+ hp out of a four valve 4.6L and pass smog without blower or without simply building an all out 281 inch race motor and it won't pass any smog restrictions.

If you think about it another way, the motor is only 4.6L or 281 inches. 100 hp per liter is a pretty high bench mark in the engine building world and would yield 460hp in the 4.6L.

600 hp naturally aspirated in the 4.6L would require 130 hp per liter, a really high specific output. Or, to look at it in inches, over 2hp per inch.

In contast the Ferrari Enzo, which I personally don't care for, has a specific output of around 110 hp per liter and is consdered quite high in that respect. Ford's own race 5.0L cammer available through Ford racing is rated at more than 400hp and less than 500hp - a far cry from 600hp and it has more displacement to boot. Specific output is less than 100hp per liter.

My personal opinion is once you guys get your mod motored cars up and running you'll find them in need of some power boost to offset the additional weight on your larger GT40s. Not knocking your cars, they are cool, but the mod motor is no torque monster and I'll bet you need to resort to a blower to keep some of your customers happy with the 4.6L motors. Don't want them getting scalded off the line by a Chebby. "

Ron

8 stack induction for LS engines is easy - Kinsler, Momar, and possibly others are making it. The momar system is about $6K with an Electromotive management system/harness, the Kinsler a bit more.

The other possibilty is using a single plane manifold with a throttle body on top and a traditional aircleaner above. Those systems seam to cost about $3500.

Both of the above make big power in the high RPM ranges. Getting 500 crank HP is no problem with a cam change, possibly valve springs etc.

'Course, the authenticity suffers.

And, it is not a problem getting 500+hp out of SB and BB Fords either. But, getting it from the mod motors is some what of a problem since stokers in this family are rare.

Simon,

I've got a ford racing block 302, forged internals, Victor junior heads, MSD ignition, ali flywheel etc for sale if your interested, its good for 450 BHP and only need intake manifold, webers, sump and valve covers. PM me if your interested and I will send you the full spec... Im asking around £4000 for it.

Doc Watson

sbud, The reason I suggested a crank driven timing wheel is the lack of room in the engine room of these cars.

Since I have been so involved in SBF's for the last few years I haven't kept up with SBC's. Do all the LS series have alum blocks? Do they all have alum heads? If not which ones do have both alum heads and blocks ?

So you have to have a blower and a dry sump.Both are cool any way and the 6.2 modular is on the way. So beware all ye unfaithful to the blue oval your time of retribution is at hand. The new vet is an awesome car no doubt about it. Ron how mush do you think our car is going to weigh? Should we start a pool? Moor than a Ferrari Enzo but less than a Ford gt.in that range some where.

I like the motors Bill, I have one in my Lightning (Frightning as my 4 year old calls it). I'm not a Blue Oval unfaithful, not at all, just that I feel Ford went the wrong way on the pushrod motors. GM and the MOPAR boys have good, light, and clean engines. And, I wouldn't be suprised if Toyota kicked one out in a few years given the Truck and, in 2007, NASCAR racing programs. Light, small, and powerful - sort of hard to beat.

I agree a SB can be made to run. We do it all the time. If you have the $$ at 4 or 500 hp you can do a sb and have something that will live for a while . But if you start pushing the envelope it start to get expensive to play at that end of the HP pool. It is far cheaper to boost a modular. A normally aspirated 4.6 can be had for less than 7 grand with a trans and all the stuff to make it run ,bolt on a Pro charger and you are off to the races. This is a bit simplified. new stuff for the modular is coming out all the time. And with the increases in ci coming.

Re: Engine choice - LS1

Howard,

if you get interested in LS engines, take a look at ls1tech.com - a good forum.

Basically, there are about 7 blocks based on the new GM architecture (with more coming). Only 1 of them, the 6 liter truck block, is iron, the rest are aluminum, as are all the heads. The Blocks most use are ls1/6 (346 cu w/o stroking), the ls2 (366 w/o stroking), the ls7 (427 w/ stock crank) and the C5R block (427, but veeery expensive). So most people now seem to focus on the ls1/2/6 for their efforts. As I noted, it is relatively easy to make 500 HP without going to forged everything, but you do have to ask the question of how stock pistons/connecting rods it will last on the track - not sure there's a 100% accurate answer. I've spoken with guys from a very reputable race shiop that say the stock rods/bolts are definitely good for 6900 rpm, past 7000 you are pushing your luck.

There are many management systems that can run these motors, though the ls2/7 have a new crank trigger wheel that delayed the adoption of the motors, but this is changing quickly.

Finally, ready to run weight on these motors seems to be about 400 lbs, maybe a little less. And the blocks/cranks are very strong, easily good for 800 HP. If someone really wants to get nuts with super/turbo charging, heavier deck heads may be called for.

I've been looking into this stuff because I'm building a T70 reproduction.

Tom

Re: Engine choice - LS1

How about a Lexus V8? anyone ever thought of using one? don't know too much about them though