GT40 MKIV with a Big Block

Hello,

I am beginning to think about a G40 project and I'm considering doing either a MKIV or a MKII and would like to use a big block and make the car as authentic as possible. I'm trying to undertand if the RCR kits can accomodate a big block motor (considering an all aluminum 427ci or a 482ci) and what would be the pro's and cons of this approach vs. say a 427ci SBF. I am most concerned about Transaxle choices and how well these combos can stand up to the torque that would be generated.

I would also be interested in anyone's thoughts on the RCR kits in terms of accuracy (as compared to the orginal GT40s), overall quality, experience with RCR as a manufacturer, etc. I think that RCR may be the only source for a MKIV at this point. If I go the MKII route, I would be considering RCR, ERA, and Superformance so thoughts as to which of those might be the best choice for me would also be much appreciated.

Thanks very much in advance for helping me.

- Fred

Hey Fred,
I noticed that this is your first post, so welcome to the club!!

First of all, you are on the right track. I too am a person who'd like to keep things as true to the original idea as possible, but with some modern touches. When I went to visit Fran's shop a year ago, we looked at a MkIV for my friend Nick. Fran pointed out that it is setup with the BBF powertrain as an option and he pointed out there is "acres of room back there" to quote his phrayse.

To compare, I have seen a Superformance MkII as well as their Cobra. I'll tell you that these cars are beautiful. They are true to the original and are fantastic. I'll take nothing away from Superformace and not speak badly of them one bit. That being said, you get them as a turn key minus car. You install the powertrain and hook everything up and off you go.

RCR on the other hand, offers you many different options as to how you want your car delivered. You can get it as a kit or as a roller or as a turnkey minus or as a running driving car. Another thing that has prompted me to jump on the RCR bandwagon is that I called Fran one day and got his voicemail. Not even 10 minutes later he was returning my phone call. I have called Fran multiple times and each time he remembers me and talks to me as long as he can as he's a busy guy. That level of customer service got me hooked. When I took a trip to the factory, he showed us everything there and went out of his way to make us feel at home. The build quality is superb and his attention to detail as well as improved driver & passenger comfort is amazing. He made improvements where he can and where he felt was needed. If you get the chance, I highly suggest touring his facility as well as checking out the other cars on your list. That will help you decide, no one else can make the final decision.

Anyway, you're asking about the pros & cons of a BBF vs stroked SBF. Well if you're looking to do an aluminum BBF, you're already looking at some serious cash to build the engine. You're going to make some serious power outta that thing. The same could be done with a SBF (all aluminum motor, big power, etc.) but probably a lot cheaper. I was reading about some new Kaase heads that are direct bolt ons for the 460 and are a semi-hemi and an upgraded design with insane flow numbers. Honestly in my opinion, I'd say go BBF if you build a MkIV. As far as transaxles go, I think the Ricardo will take the power and give you 6 gears to work with. I'd talk with Fran and see if he makes the adaptor to make it work together (which I think he does or can).

Ok, so in tying my post up, I'll point out a few things...

1 - Welcome to the board!!
2 - RCR offers all you could ask for and more.
3 - If you have the means, go BBF in the MkIV.
4 - Ricardo gearbox.

Laters,

Brian

Brian, you need to do some homework on the larger Ford engines, Fred is looking at the Alloy FE engine-- 390/427 etc--- NOT the 385 based 429/460 etc that Kaase plays with & a T44 box is the 'only' one that 'looks' right in one of these babys!!

Now bear with me while I check's me spellin cos we are not allowed to edit our posts on the RCR freds.

Brian and Jac Mac,

Thanks both for responding to my post. I understand that a T44 is basically impossible to get. I don't know much about the Ricardo gearbox that Brian mentioned. I would be looking at an FE big block. Can you guys help me understand what options that I would have as far as a transaxle goes and how much torque the choices can stand? I have an aluminum 482 ci FE in a Cobra and that motor made over 600 ft-lbs of torque so I want to be careful that I don't overdo it in a GT40 if the driveline won't stand up to high torque.

- Fred

jac mac said:

Brian, you need to do some homework on the larger Ford engines, Fred is looking at the Alloy FE engine-- 390/427 etc--- NOT the 385 based 429/460 etc that Kaase plays with & a T44 box is the 'only' one that 'looks' right in one of these babys!!

Now bear with me while I check's me spellin cos we are not allowed to edit our posts on the RCR freds.

Click to expand...

We can't edit in here? Oh hell.

Yeah, my bad on the FE engines. Dove makes some killer blocks and I believe they have a Cammer conversion too. Yeah they do, just checked. Here's the link...

Dove Manufacturing

I think that'd be insane to pop a Cammer 427 in there. LOL Talk about unique!!

As for the transaxle, I figured that the big block would benefit from the 6 gears available in the Ricardo. Make it a little more street friendly. I know these transaxles will hold up to well over 800 ft. lbs. with the addition of an oil cooler.

Just my thoughts though. :thumbsup:

Thanks Brian. I've heard that the Prosche 930 Transaxle might be a choice to consider. Any thoughts on that?

-Fred

Fred, I sent you a pm.

The original car had a FE and a 4 speed T44. If you have the budget you could build a aluminum FE and negate some if not all of the weight penalty associated with the big block versus the stroked 351.

930 Porsche 4 speeds have been put behind 600ft/lb in a lot of turbo Porsche's. I believe that a good core rebuilt by a professional shop would be OK if you let them know what you intend to do with it and follow their recommendation. The T44 option just really isn't one. As far as I know there are not really any available unless you are connected and have lots of money. Then you will be forced to using very limited spares and vendors to support it. Two sponsors on this forum, Carquip and California Motorsports would both be a good choice to discuss this with.

With that much torque 4 speeds are more than enough. I would put in gear ratios that will allow you to cruise at about 2800 RPM @ 80mph in 4th and red-line at about 60mph in 1st. 2nd and 3rd to suite. On tack you will never use 1st and almost never use 2nd with that much power. A 3.25 ish final and a 1 to 1 4th gear will get you up to over 150MPH at a reasonable red line around 6600 or so.

Thank you Howard. Can anyone tell me how the Prosche 930 transaxle compares to the original T44 in terms of size, weight, and appearance? Some pics of the two would also be great if anyone has them. Thanks,

- Fred

Regarding aftermarket FE blocks - Dove would be the absolute last choice. They have a history of foundry issues and product delays.

The two choices are Pond and Shelby.

FYI

2124 said:

Regarding aftermarket FE blocks - Dove would be the absolute last choice. They have a history of foundry issues and product delays.

The two choices are Pond and Shelby.

FYI

Click to expand...

Is there a reason that Genesis isn't mentioned, or did they stop producing their alloy block?

I'm not sure why but the two major FE engine builders I am familiar with use either the Shelby or the Pond block. The Genesis is available as far as I know.

Either block but ask the engine builders first.. If you don't stroke it the ZF box should hold it. Ricardo is the strongest(and most expensive) and the Mendeola is not yet available as I'm told.
Brian,we discussed the 'Cammer' in another thread and it's too wide. My friend up the road has a freshened one ready to go into a '65 A/FX Comet. It's a BIG engine and you could probably build the whole car for the cost of the motor.

Hi Fred,
Here is a photo of my 930 transaxle. The bellhousing is custom made. They don't come like that out of the box. There is normally a flange on the front of the box that extends about 2". This was machined away in my case to fix the bellhousing. Sorry I don't have a photo of it pre-worked, as I was not the one responsible for doing it.
Anyway, hope it helps.

Martin

fkemmerer said:

Thank you Howard. Can anyone tell me how the Prosche 930 transaxle compares to the original T44 in terms of size, weight, and appearance? Some pics of the two would also be great if anyone has them. Thanks,

- Fred

Click to expand...

Fred, the T44 is a totally different animal and looks nothing like the other boxes. Their was a gentlemen reproducing them, I am not sure if he is still building the boxes, however the price a couple of years ago was approx $33,000-35,000. I can look for his contact info if you are serious. The quickest way to see what a T44 looks like is to search the forum. There should be pictures of Jim G.'s rebuilt box. Good luck to you. Where are you located?

heres an original T-44

Gregg said:

Fred, the T44 is a totally different animal and looks nothing like the other boxes. Their was a gentlemen reproducing them, I am not sure if he is still building the boxes, however the price a couple of years ago was approx $33,000-35,000. I can look for his contact info if you are serious. The quickest way to see what a T44 looks like is to search the forum. There should be pictures of Jim G.'s rebuilt box. Good luck to you. Where are you located?

Click to expand...

Thanks Gregg. I am in New Hampshire. Do you have any idea how the Prosche 930 box would compare to the T-44 in terms of weight, size, and strength?

Thanks!

- Fred

Thanks for posting the pictures guys!

- Fred

Wow, haven't cought up on this thread in a bit. OK, here goes...

Dove engines - Oops, my bad. Haven't actually seen an aluminum FE, plus hadn't heard about Dove sucking. LOL

Cammer - I remember that thread now, again, my bad. Go for some Boss 427 heads on that thing!! LOL

Transaxles - As for the torque and power output being able to pull this car around, you're absolutely right. My option on the 6 speed was a quick ratio with an overdrive. But that also means more shifting involved. I have heard the 930 boxes are crazy strong, lots of people running them in big power cars. I am a little more familiar with the Ricardo in terms of strength and I figured that if the money was available, that'd be the option to consider.

Anyway, thanks for clearing up my mistakes guys!! :thumbsup:

I'm still a young-un here and not quite up to speed on all the original equipment of these cars. I'm learning though!! This is definitely the place to find knowledgable car guys, that's for sure.

Laters,

Brian