GT40s Engines

[Guest]

Gordon, You are de man! You just described the engine I want to build. Maybe a slight over bore on a 4 bolt main block. I have been trying to get somebody to give an opinion on Siamese cylinders, like in the new Dart SBF or FMS. The new Dart sounds like a real jewel and for you guys who just gotta stroke em, they come in 4 deck heights and you can get the 4 bolt mains in 351 or 302 diameter. There are a whole bunch of other features, too many to list here. With FMS, do you go with cast iron or is the alloy block worth the extra cash (I am leaning towards no for this use.) Or, should I just bolt on a girdle? ;-)

Lightest strongest pistons and rods I can find (short of titanium rods as I think they maybe out of my price range; feel free to prove me wrong, please!.) Steel crank with all of it balanced to the Nth. Medium short stack EFI w/Electromotive ECU. I would love to build a variable length runner intake. (Designed one flying home one night, but I'll be danged if BMW didn't already have one exactly like it.) I am still studying heads. I think Bennett's philosophy of porting is dead on, but his heads have raised exhaust ports and I don't think my KMW headers will fit them (again, tell my I'm wrong, please!) I really like the Jessel shaft mount rocker system using very strong springs. Cam and lifters?? I really would like some input on this area: I really like the drivability of hyd. rollers, but it makes sense that these would limit rpms. What is the best compromise for cam and lifters for a high reving street/road race engine without having to readjust the valve lash everyother weekend?? You all may think I'm crazy, but I also want a gear drive for the cam. I love the sound, but I wouldn't buy a set made to make extra noise: I'm not into doing things for effect.
I have found a shop that really knows how to do a G50(-50) right; they do most of the Ultima modifications. (If the cost gets to high, the Quiafe would get a long, hard look.)

So that is my dream setup for somewhere down the road a bit. It is easier to pick parts for the drag race engine since that is what most Mustang guys are building. Any guidance on the road engine is greatly appreciate.

[ May 10, 2002: Message edited by: Lynn Larsen ]

 

Rod/Stroke ratios:
I am wondering what is the longest stroke that can ran anything close to a 1.75: 1 rod/stroke ratio, with and without special wristpins and rings?
Or, how much shorter the rods can be.
Honda's 8400 rpm Type R integra runs about 1.5: 1 I believe..

?

 

[Ron Earp]

You only need to look to motorcycles and World Superbike to find out how low the rod ratio can be. The Honda S2000 and Type Rs aren't anything compared to what exists in this world of high-revving power makers. I'll check some articles and see what I can find.

R

[ May 11, 2002: Message edited by: R. Earp ]

 

[Gordon Levy]

Lynn, It would be best to talk about what you want out of your engine at length. Please call me at 480-446-8442.

 

[Hershal Byrd]

I got a call from Gordon that my engine was
finish and I just had to run over to his shop
to see it. Man, is that thing purdy !

I cant wait to start it up.
Most of you guys know by now that Gordon
not only builds great engines but he races
what he sells. He has the knowledge to
produce the kind of engines for different
applications. I wanted the combination
of street and track and I believe that's
what I got. I have driven a cobra with
one of Gordon's small blocks. It pulls
through the gears with a constant force
pushing you back in your seat.

Hersh

 

[Guest]

I just wanted to make one more comment about a reving vs torquey engine. Remember guys it is not one or the other, just where on the continuum of Torque X RPM = HP your engine falls. By definition a revving engine will be highly balanced with a light rotating mass and will have some torque, certainly enough for a GT40. An engine like this run on the street, reaching its maximum RPM infrequently, should last very well! Certainly longer than an engine that has been stroked to the point that the rings are up in the wrist pin or that the pistons start oscillating within the bore. But, don't get me wrong, I am not saying a torquey, stoked engine is bad: I completely agree with the fun factor this type of engine can provide and understand there is probably more opportunity to use this kind of power. I just ask you to understand that there are some advantages (and fun) by having an engine that is on the otherside of the equation.

 

[ChrisL]

Hersh,
If you get a buzz out of being pushed back in your seat in the Cobra, just wait till you experience the feeling of being pushed UP in the seat in your '40 (given the reclined possition) WOW!

Lynn,
I agree that the preferred characteristics of your engine can be a very personal thing. Even so, I also tend to lean towards your way of thinking. On a car as light as the '40, even "modest" torque at low revs can be more than enough, but when you can combine that with the music of high reving engine in full song... well its just the nearest thing to heaven on earth for me.

 

There are many, many combinations that will work. Each of us has our own set of goals. To me, spinning past 6500 for any length of time is walking the tightrope. I'm going for larger displacement, with a 4.2 bore and 3.85 stroke. That dials out to about 427 cid, and with the Gurney heads and injection, will give 600/600 any day any time. Stretching for the last few ponies always costs the most, and hastens the time between rebuilds. Good luck to all.

Roger

 

[Guest]

I am in Detroit on business and my meetings ended early. Since it is Memorial Day weekend, flights are booked solid, so I found my self with some time on my hands this afternoon. I looked through the yellow pages under Automotive, Peformance and Racing where I saw a listing for Kinsler Fuel Injection which turned out to be about a mile and half from where I am staying in Troy. I drove down and while I was looking for Kinsler, I spotted a sign saying Dart Machine. I went in and talked with the folks and they were real nice. The new 4 bolt main SBF block is now finally available in limited numbers to the public. Roush, who was involved with the developement, got the first 60 of them, but they are swinging into full production and the blocks will become more and more plentiful soon. For now, Dart is supplying their best distributors. When I return home, I will post the spec sheet they gave me. I am more convinced than ever that this block will be perfect for both ends of the spectrum: those that want big cubes and torque and those that want short piston travel and high revs. These blocks were designed to handle anything up to and including turbocharged, alcohol burners putting out HP in the 4 digit range. For more info see Dart Machine

After talking with Dart, I did go to Kinsler's. Again, very nice folks who were pleased to show me around and some of the beautiful work they do there. This included a number of Magnesium intakes for outlaws that weigh about 3 pounds. One thing is clear, when Kinsler equipment is ordered, it is made to suit your needs. They definitely don't build off the shelf kits that are one size fits all. The largest collection of any sort of parts was maybe a dozen or so. They also handle a number of ECU units and their catalog has an extremely comprehensive comparison matrix of many of the available units.

Many of you may know that the GT40 that GM bought ended up with the Sr. Kinsler. It is now undergoing a replacement of the engine following a blown oil line and seized bottom end. I also learned that in recent demonstration of the new Ford GT40, the input shaft on the RBT transaxle was wrung off in 1/4 mile time tests.

Needless to say this one of the best layovers I have had in all my travels. There were several high tech automotive interests within a 4 block radius. Its a good thing that my wife doesn't let me carry the check book and I got hungry or I'd have a lot of parts and no money right now.

 

[Jim Glickenhaus]

Dear Lynn
Next time you're stuck in Detroit check out The Henry Ford Museam in Dearborn. Besides J5,the only car made in America to have won LeMans,is a bunch of cool stuff.
Best
Jim