Cost to go to 78mm stroke??, anyone have some numbers??? Options

[Mueller]

Seems like Jake will be out of reach for the next few weeks...so...anyone know the cost differance between staying at 71mm and upgrading to 78mm stroke?

my rods already need to be re-worked due to the pistons I'm going to use, so no loss there, I'm guessing new rods would be in order for the longer stroke....I have no idea what crank is going to cost, nor the rods....can a 1.8 crank be used so that I can at least sell my 2.0 rods and crank to help cover the additional costs??

[eeyore]

I got the impression from the Excellence article that 71mm cranks are fettled / welded by DPR to go to 78mm, so the 71mm crank is a core. As for 66m cranks, I get the feeling those aren't used since the 1911 package was floated to address excess 1.7/1.8 parts inventory. I think the 2.0 rods are a write off since T1 style wrist pins (22mm?) are preferred.

[Dave_Darling]

Mike, get over to http://www.aircooled.net and look at the prices for stroker cranks and H-beam rods. Get Type I journals, as their rods are a lot cheaper than Type IV ones.

I don't know if a 78mm crank throw requires a reduced-base-circle cam or not. If so, that's extra work for you to do.

And don't forget all the time you will spend quadruple-checking everything and grinding down anything that interferes...

--DD

[DNHunt]

Pistons, rods, 71mm crank as a core, reduced base circle cam and some clearancing of the case. It gets pricey. I'm not sure how much more.

Dave

[jwalters]

I was told by the folks at Demello cranks that as long as you stay with no more than 78mm and use the type 1 rod with the inside bolts, that no clearancing should have to be performed--------they did say that on the odd chance you had one of those odd cases from a european bus then some work might need to be done, the key is CB style rods w/ the 22mm pin

Hope this helps (IMG:style_emoticons/default/beerchug.gif)

[lapuwali]

I'd love to hear a definitive answer to this. My impression is that 74mm is as far as you can go w/o having to worry about cam or case clearance issues, and 78.4mm is as far as you can go w/o having to grind bits of the case 100% of the time, and having to use the special cam.

[DNHunt]

I just finished putting one together, The CB rods had a tiny bit removed and the case was clearanced by Jake. None of it was dramatic but it was definitly worked on.

Dave

[cgnj]

Ok, here is my two cents.
66mm crank is a core. At 78.4 you will need a reduced base circle cam. I used Scat rods. I have not used the CB super rod. I have gleaned from STF that it requires little or no clearancing.
My crank was $450 from aircooled, no core. You may get a better deal with Demello or DPR, plus get a core for your crank.
CB super rods are about $270.
KBs are $300 at aircooled.
You should be able to fetch something with the 2.0 Crank and rods.
Machine your cylinders. Thats the difference.

Carlos

[my15window]

I think I paid about 350.00 for his 76 crank, he balanced the fly wheel and ground down the rods He is the guy to go to though, he does all of F.A.T.S work and tons of other companies check out his web page, then check out FAT performances, cash talks too...

[Jake Raby]

I can do it in my sleep guys... The clearance is nothing to worry about when you get all the parts from someone that KNOWS the clearances.

I don't use stock 2.0 rods for ANYTHING! 74mm stroke is no easier to build than a 78 with the right matching components. The problem to this point is finding THE person that can set you up with EXACTLY what works, clears, fits and won't break. If you buy many of the parts from establishments now you still have to clearance the rods, but where? How much do you take from them? Then you have to have them balanced!

Same goes for the camshaft.. How much of a reduced base circle? What will fit? How much is enough or too much lift??

The issue is having to buy a cam from one place, a crank from someone else, and rods from someone else- Thats about to become a thing of the past. (IMG:style_emoticons/default/blink.gif)

BTW- I wouldn't use a crank other than DPR if someone held a gun to my head. Email me for some pics of "Others" work.... I spin DPR cranks with my design to over 8,000 sustained RPM with no sweat. One of my new customers this year threw a counterweight off of a Demello crank that went clean through the case and through the body of his F prod 914! It took out 15,000 bucks of other parts with it! All cranks are NOT created equal! Alot of them are made from cores that would not clean up for a stock job... I send my cores in for the work to be done and throw 1/4 of them away in the process of looking for the best ones. Its not uncommon to find cracked journals, loose fitting flywheels and etc from the "Others"....... Been there and done that!

here are the prices you asked for

Crank= 485.00 (TI journals)
Rods= 280
Clearancing = Included with rod price (IMG:style_emoticons/default/boldblue.gif)
Camshaft= 175.00 (custom grind with reduced base circle designed for the heads being used as well as the crank/rod clearance)

Hell as far as the case clearancing goes if you buy the stuff from someone that puts their heart and soul into this you might even get a template of what to clearance and where to do it from! The clearance work is simple..

Building less than a 78 stroke is just plain a waste of time, this is super easy this way and give tremendous amounts of torque!

Ask DNHunt how easy it is to build when you do it my way... He knows first hand..

I can literally do it wearing a blindfold!

Patience guys... Patience... I'm working 18 hours a day trying to remedy these issues!

[Mueller]

cool...thanks for the input everyone.....guess I'll be going with a stroker motor (IMG:style_emoticons/default/mueba.gif)

now to sell my turbochargers before I get any more "bright" ideas, hahaha

[Jake Raby]

Gimme 4-5 weeks :-)

[Mueller]

no problem.........it gives me time to build the intake system for it (IMG:style_emoticons/default/welder.gif) (IMG:style_emoticons/default/smash.gif)

[bernbomb914]

mike I have the 78.4 from DTM cost was 425.00 I didnt need to worry about cam as it cleared. machined the case. bought spacers from rimco and push rods from rimco, they have to measured first. If I was to do it over I would have done a 76.4 stroke (IMG:style_emoticons/default/confused24.gif) as that is as large as porsche goes. and I would use 102 nickys to get the Cubic Inches. just my opinion.

Bernie (IMG:style_emoticons/default/confused24.gif)

[Jake Raby]

78x102 is hard to beat...

The 102s are all mine now. Charles gave me the exclusive rights to them for all the research I have given him!

[Bleyseng]

damn Mike, you gonna build a 102x78 monster for your daily driver 914? Kewl!

Geoff

[anthony]

Jake is that 4-5 weeks before you have these kits for sale on the web site? Or 4-5 weeks to receive a crank/rods/etc. after an order?

I was going to build a 2056 but I think I should go 78xsomething.

Jake, just for the sake of curiosity, what is the approximate hp/torque for a 78x102 Nickies engine?

[Jake Raby]

There are no approximates! I have had a 78x102 make 200HP and 200 on torque, and others designed for longevity make 180..

My standard base engine for a 78x102 makes 195 and 205 on torque at the flywheel. Thats of course with the heads that it REQUIRES. Big bores don't play with headwork!

It'll be 4-5 weeks until I can show you guys what I'm doing around here...

delivery times will be in days- Not weeks.

[jr91472]

ok, now I am getting excited (IMG:style_emoticons/default/boldblue.gif) (IMG:style_emoticons/default/boldblue.gif)

[Britain Smith]

Here is a picture of the 78mm crank installed in my case with a reduced base circle cam. I have a Raby cam in their now, but you get the idea.

-Britain

(IMG:http://www.britainsmith.com/Porsche/912Project/TurboMotor/BottomEnd/images/128_2821_JPG.jpg)