Some big block questions

Hello I'm a newcommer to the forum and a future GT40 builder. I have a somewhat odd question. Has anyone tried to fit a ford big block engine from the 385 series (i.e. 429/460) into a Mk 1 chassis. Is it at all possible, even with quite a bit of reengineering, or is a Mk II chassis the only way to get big block in a gt40?

Suppose you fit a big block into a chassis (Mk I or II), what kind of transaxle can stand the torque of a big block? I suspect that the Renaults and Audis can handle the hp but not the torque. Is ZFs or G50s good enough? As I understand it ford had to design a new transaxle when they dropped the 427 into their gt40s.

 

[Bill D]

Magnus-

Fitting a 385 series bb will be extremely difficult. The engine is longer, which means it will intrude into the cockpit. And it will have a tendency to get very warm, regardless of what you do to the cooling system.

The original MkII's used a 427 and they just ate up transaxles. They finally went to some custom rear end with only 4 gears. Just too much torque.

Go with a nice stroked 351W. You will be much happier in the long run.

Bill D

 

[Mark Worthington]

Others can answer your fitment question better than I. However, it would be far simpler to use a 351W block and have it bored and stroked to realize big-block displacement, torque, and horsepower.

 

Not only will the fit of a 351 be easier but you can get just as much power with 2/3 the weight.

 

[M.B]

Hello, !

Of course it can be done..
Gearboxes will stand the torque/ depending on what power range you intend to use...
A stock smog 429 is not a very hot engine..
Why not use the FE, as it was used..
MkII´s that is...
there are cars running high torqued engines with all these gearboxes now...
Depends on your driving as well as of what engine you put in and the status of your gearbox..
If you want torque and HP.
Forget the big blocks like the guy´s say..
Very large and heavy...
Get a 302 or even the 351W.
There´s a massive amount of torque and HP to be found in these engines...
They are not "small" engines just because of the reference of "smallblock"..
You can even stroke ém to 7 litres if you´d like..

 

Bill, Mark, John and Marco,

4 cheers to you guys! That's the best way to go for the MKI.


Magnus,

If you're interested, I can hook you up with GT40GUY who builds the T-44 transaxle. They aren't cheap but they sure are strong.

Good luck my GT40 friend.

John

 

[Jim Rosenthal]

Keep in mind these cars only weigh 1000 kg ready for the road. A built up small block can easily make 450-500 hp or more. The acceleration is astonishing with that kind of power- all the weight is over the drive wheels. How fast do you need to go? I would not try to build a big block car unless you never expected to drive it on the road, there are too many problems with cooling etc. The T44 transaxle- last price I heard was 30,000 USD. That is a LOT for a gearbox. All the previous posts on this thread are right on the money- stick with a small block and spend the difference on paint, fuel and good times.

 

Thank you all for your answers. I tend to agree with you that a stroked small block probably is a better option. However, I'm going to build the car with my brother and he's a big block addict and won't settle for anything less. So in order to get him to shut up a needed some second oppinions from you guys.

Personally a stroked 351W is more than fine for me.

BTW, does anyone know how much hp & torque the Renaults and Audis can handle in, round figures, give you don't push the car to the limit all the time but on some occasions?

 

[Ron Earp]

None of them are going to handle a serious big block with large amounts of torque available throughout the RPM range. As MB said, if it is a stock big block with low power then there aren't too many worries (other than getting it in there) - but why would you want something like that? You'll have to spend some pretty serious money on a gearbox to complete the project with a hot big block.

Who's kit are you wanting to put a big block into? ERA is the only only one I know that has designed and built big block cars. ERAs MKII is setup for a big block, but it has no AC which is kind of rough for street driving. And, it is the FE motor, not the 385 series you are asking about.

It is hard enough fitting a small block into the car, I think the stroked and poked motor in the way to go. Get your brother out to look at some GT40s and he might agree.

R

[ April 18, 2002: Message edited by: Ron Earp - Administrator ]

 

[Gary Gibbs]

<BLOCKQUOTE><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><HR>Originally posted by John Schneider:
Not only will the fit of a 351 be easier but you can get just as much power with 2/3 the weight.<HR></BLOCKQUOTE>

Not to get into this too deep but...

My cast iron block, alum. head, 452 ci FE complete from steel canton road race pan to individual runner throttle bodies and alum water pump weighs 503 lb.

Does anyone have a 351 at 2/3*503 = 335 lbs?!?!

I would love to see the weights of 302, 351 and FE's with and without alum. heads and block for comparison. I am sure you can build a alum. block and head FE at ~410 - 420 lbs (and 488 to 495 CI). Now it will cost you though!

The quaife transaxle can take up to 700 hp: http://www.quaife.co.uk/product/gearbox.htm#transaxle

cost is something like $12,000 US.

 

[M.B]

Hello, !

Did not GTD put in 427´s in their "MkII" with the renault gearbox ?
There are guy´s running 500Nm small blocks, with the Renault gearboxes for instance...
Does the bigblock have to be a Top HP engine ?
In their hey day´s they were´nt so..
Enough HP and ever lasting was the deal.

 

[Mark Worthington]

<BLOCKQUOTE><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><HR>Originally posted by CCX33911:
Does anyone have a 351 at 2/3*503 = 335 lbs?!?!

I would love to see the weights of 302, 351 and FE's with and without alum. heads and block for comparison. I am sure you can build a alum. block and head FE at ~410 - 420 lbs (and 488 to 495 CI). Now it will cost you though!
<HR></BLOCKQUOTE>


I think a 351 (or stroker) built from one of the FRPP aluminum blocks could weigh in the neighborhood of 350 pounds, particularly if the crank counterweights have been shaved in an effort to build a neutral balanced engine. I'll see if I can dig up some longblock weight specs.

Have you guys seen the outfit that is back-engineering the FE block molds and plans to offer cast aluminum FE blocks? Pretty interesting stuff. http://www.genesis427.com/

 

Magnus, you have reached the issue of a big block gt40. If you are going to build your own chassis from the ground up, do what you want. The only kit that is made to hold a big block is the ERA kit. You might be able to convince them to modify it. The next problem is the transaxle, the T44 is the only one that will ever be able to take the torque. The RBT6 can take the power, if you dont get to crazy, also a Porsche G50 can handle the power, but not much torque over 600 ft pounds.
The best price I have seen on a new T44 os around $20-$25k usd. A RBT6 is around $16k usd. The RBT6 is used in the Saleen S& i believe.
If your brother really wants big block power, stroke a 351w to 427cid and put it in a mark 1 chassis or wait the 2v years and get the ERA mk 2 kit.

 

[Gary Gibbs]

I guess my point was that if you compare a apples to apples engine build up the 351 is not even close to 2/3 the weight of the FE. You can not build a cast iron block alum. head 351 at 335 lbs (I don't think but I have never weighed a alum. head 351).

How much torque can the Quaife transaxle take?

The gear ratios look a bit close (6 of them) for use with a big block though. I think you could get custom gears.

 

[Guest]

CCX33911

Talked to Quaife America today. They said the 6 speed will handle 700 ft lb of torque all day long. As far as ratios go, they have two different versions. The one with the .80 to 1 would be a little bit on the short side, but not too bad. With the 3.889 that it comes with, 6,500 rpm would be 163 mph with a 26 inch tire. They also say custom ratios are available. See the chart below:
&lt;img src="http://www.quaifeamerica.com/transmissions/transax.htm"&gt;

Jeff

 

[Guest]

Try again:
&lt;img src="http://www.quaifeamerica.com/transmissions/transax.htm"&gt;&lt;img

 

[Guest]

Last try:

 

[Guest]

Try this one

 

[Jim Glickenhaus]

If you're looking for a T-44 you have to be very, very carefull. Lee Holman is the one to talk to. $30,000+ They work very well except for right angle turns as the Weisman rear end is semi locking.

 

[Guest]

Is this it Jeff?

[ April 22, 2002: Message edited by: Lynn Larsen ]