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Billet crank for a 100/4

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wangdango

wangdango

Jedi Hopeful
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Anyone out there have one for sale? I know D Welsh makes one, but that requires their rods. Presently have Carrillo rods and would like to upgrade for piece of mind to a steel crank. I am worried that the shock of engaging/disengaging the OD (vintage racing), will break our stock NOS crank (I do not rev the engine over 5k). Any advice, guidance...... etc would be great!
Thanks
Ed
 
Ed-

Contact Mark Baker with Sports and Specialty. He does a lot of vinatge race prep on Healeys. He produced a 190 hp 100-4 motor and might have some ideas for you. Good guy doing top quality work.
https://www.sportandspecialty.com/index.html

Dougie
 
It also reduces the displacement--I believe down to just under 2500 cc's.
 
Hello wangdango. The place to go to is www.arrowprecision.co.uk. There are a number of places in the UK who could build you a crank but my recommendation would be Arrow.They would be about the best available. They bought out DKE Engineering who were the best and probably the first to build billet Healey cranks.
The reason you have to use DWR rods with their crank is because the rod journal is narrower than the original. The reason it is narrower is 1, there is no need for such a wide bearing surface these days and 2, the billet cranks are machined to give 2 "dummy main bearings". ie there is a "main bearing" between rods 1 & 2 and between rods 3 & 4. The "dummy main bearings" bridge the gap between rod journals 1 & 2 and 3 & 4 and this gives the crank greater stiffness because of the overlap of rod journals and the "dummy main" journal. To get the room needed to do this they narrow the rod journals and you get the best of both worlds.
They will make you a crank with whatever stroke you want (within reason) and it will be from the best material available.
I feel it's worth getting the billet crank because when the original one does break there is a good chance it will destroy the block and that is not a good thing.
Best regards,
bundyrum.
 
I'm new to the 100-4 crank issue. The six cylinder motors have steel forged cranks. And we do not have issues with our cranks. Is there a problem with the steel in the 100 cranks? Richard Mayor
 
BoyRacer said:
I'm new to the 100-4 crank issue. The six cylinder motors have steel forged cranks. And we do not have issues with our cranks. Is there a problem with the steel in the 100 cranks? Richard Mayor
Click to expand...
There's a name from the past, welcome aboard!

Are you playing with 100s now? You should post up some pictures of your Healey (BN7?) so these guys know who they're dealing with :wink:
 
Randy - I'll help out since Richard has been such a great assistance to me. Here's a shot of
Team Healey - PDX with our founder leading us through the Chicane at PIR. I also posted a picture in the gallery a few months back after the Portland Historics of Richard putting the wood to an E-Type.
Richard check out the racing forum also, the hardcore vintage racers have settled there.

Dougie
 
As for the 100/4 crank, stock is fine, but in racing situations, still good, but billet is best. As the "performance" levels go up, so does the stress ON EVERYTHING! Stock rods, crank, etc, not so great, this engine was never designed to turn high (over 6k revs).... Too long a stroke. But, as a Big Healey, this is what makes our cars such great racers, TONS OF TORQUE!!! You can pull just about anything on the track. Billet crank, makes for, "peace of mind." We dont have one yet, but would love to. I never turn over 5k, and have had enormous success in reliability.
 
Wangdango--

I do not race my 100 but I am not afraid to rev it up past 5500 for short periods such as during autocrosses, etc. Even during normal street driving I usually rev up to 4500 when shifting from 1 to 2 and 2 to 3.

I had the engine completely redone about 40K ago by Von Paterson (now closed) with the usual insurance internals--Carillo rods and I think JE pistons but no billet crank plus DW head, cam, header, FW, etc. OP with hot oil is still 45-50 psi at anything over 2500 rpm's. This winter I plan to pull the oil pump and check clearances on it. I think these engines are a lot stronger and more durable than we fear when set up well.

Though I agree that for racing applications nothing is too good neither do I have a billet crank in the Elva's MGA 3-bearing 1600 and run it up to 6800 when necessary.
 
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