Can the forum pls assist with this question?

[Wayne 962]

I just got back into town after being gone for a while, and I'm short on time. Here's the note:

Att Wayne Dempsey,

hello Pelicans, I am an old customer down here in Perth Western Australia. I have been buying parts from you (Glenn Sager) for yeas now.
I have a '71T a '73S and negotiating on a '66 as well as a '77 Carrera. Yes I like my 911s, maybe the next one will be a GT3 996 Cup Car.

Anyway I have been exchanging photos with Glenn regarding the two cars we both have. My '71T is a CA girl, I bought back in 1996, restored it into a very nice road car and it morfed into a casual track/road car, early 2004. In 2006 I acquired the '73S as a rolling shell only, and put it into storage while I proceeded to make the '71 into a S/T replica race car. Everything that came off the '71 was to go onto the '73. And as time went along, I acquired more and more bits, to the extent, that all the original bits (bonnets, bumpers fenders, Reccaro seats, door panels etc, have also gone into storage). The '71 is a horrible road car, now stripped out to 950kgs, mostly glass panels, no sound deadener, lightweight period race seats, so very noisy, very bumpy as well what with the full Elephant suspension. It complies for our CAMS Historic racing, which means its a faithful restoration totally to how it was raced in Australia in 1971. Not good on the road but a fantastic track car, though slightly underpowered as I did not do enough work on the heads or cams!

I have done all the work myself body, panel and paint and all mechanical, except engine build. And since the '71 was a totally original car right down to the last nut and bolt before it became the S/T. And as we know prices have rocketed! Anyway I am at engine build stages, again and I don't want to make the same mistakes, as when I built the 2.3 race engine, it kept the 64mm crank, its a very very good 2.2 engine, just not a high revving race engine. I have now done extensive (expensive) heads ported and polished, fully rebuilt, and with big springs for high revs (8000+) and I have had billet race cams custom built by Australia best cam builder.

OK, my question is, after reading your books, 'How to Build and Modify' and '101 Projects' Bruce Andersons 2nd edition 911 Performance Handbook and even Mitchell Sam Rossi book, I am still not sure if what I have is going to be suitable?!

1.
For the new S/T engine I have a 2.2 3R aluminium case, 70.4 crank, all polished etc, 2.7 heads ported and big springs Mahl 85mm cylinders and 9.5:1 JE pistons. On page 135 of Waynes (rest his sole) book, he talks about what can be done. 90mm bore, where as I have only 85mm (also to comply with my race regulations of a .100 maximum increase from 2.2 to 2.3), it talks about reducing the stoke and loosing the compression. And what rods can I use, do I just use Porsche rods, or do I need to get Carrillo's, what about some of these other much less expensive make now available out of America.
Can I use the 3.2 rods, which ones do I use? I have three (good) mates who own their own machine shops, my Porsche mechanics are too busy, and TOO expensive, so I am doing the engines with my machine shop mates. One owns the crank grinding business and has the knowledge and machines for even the rod work. My other mate, in fact does all the Porsche heads anyway. The third mate owns his own engine build shop, he has a twin turbo '84 911. Though he would not know about modifying the oil bypass or the oil squirters, though the crank mate can do it, if he knows what he has to do. Same as modifying the 7R casing for the MFI on the 2.5 below (2).

So as you can see, I have the guys who can do 'their' bit, but not anyone who exactly knows the intricacies of Porsche engines. And apart from me reading all four books twice and thrice, I am not so sure I have the ability to actually do the work myself.

2.
The RS engine is another case, (I have a 2.4S and 2.7S out of a '74, Gus Pfizer has rebuilt the MFI to match to the 2.7) as that 2.5 engine is going to use a 7R casing with 2.4 (massively ported, bench tested at 350hp flow, if thats the right description) heads. That engine also has a 70.4 crank, (I have three spare cranks, in fact I have spare everything, enough to make another engine, as well as another complete 2.2T with MFI, of which I have four MFI pumps). Gus also has a MFI pump that can be converted into a RSR pump, good for the 2.5 even the real 2.8RSR engine. My 2.5 engine has JE cylinders and pistons, 10:1. I have acquired a 3.2 Carrera oil pump, is that going to be sufficient, some of the guys said I need bigger, but I am running out of money (or have wasted my money!).

So before I jump in neck deep, and buy all the bits I am short off for both engines with you, can yo help out and give me some guidance?
The RS will be a fast Tarmac car, the R/T will remain a race car, as its had too much invested, and its about to go off and get another paint job. The '66 as a standard car, the RS copy, well who can afford a real one, and mine will be as close to one as I can make it, with either the 2.7 or the 2.5RSR engine. and the '77 Carrera, just that I am starting to really appreciate the low impact bumper cars, classic's to me they are a bit like the old narrow bumper cars, many of those were made into GT3s and the likes and basically destroyed, and now the much later cars are being made into retro pre 73s, I just like the clean lines of the RS and the Carrera, maybe lucky as I have the classic 71 look as a race car, and a SWB '66 as the other two will remain stock standard.

I am not a mechanic, I am a printer, I restore cars for a hobby, learnt how to panel beat and paint, I have build V8s and 6 cylinders for our Aussi cars, I have built Alfa 105s, and Riley 9 HPs. But I am getting very worried about all the fine details for the 911. But when the engine builders want $25K each, I have to do them with my mates.

Hopefully this is not way to long for you to read and advise.

thanks for the time and good reading haha!

[rennzeit]

I'll take a stab at it...

1. If you want to build a 2.2/2.3 for regulations, you need to use the 66mm crank from a 2.0-2.2 engine. 66x85 is 2247cc. 70.4x85mm will make a 2396cc. Both cranks you can use factory rods with ARP bolts or for more $ Pauter or Carillo rods. 3.2 rods have a different piston pin diameter.

2. 3.2 oil pump works fine. Henry at Supertec can inspect and mod it for more flow if you want some extra security for not a lot of money. Bigger pumps (930, GT-3, 996, 993, 964) also require some case clearancing, but it's stuff you can do with a die grinder.

It looks like you're also asking about specifics on how the oil bypass modification is done. I'm not a machinist and I can't validate what this guy is doing is perfect technique, but it's the general idea.
https://www.youtube.com/watch?v=lKuceDywEJg
The hole that is being bored connects the old bypass passage that dumped into the sump, back to the oil inlet of the pump. And then the old dump port is tapped and plugged. So instead of the scavenge side having to work harder when there is too much pressure, the pressure is bypassed back to the pump inlet. That allowed Porsche to change the ratio of the pressure to scavenge sides to improve oiling. It has to be done to use a 4-rib, or newer pump like the 3.2 pump you have. Don't forget to get the updated spring and piston too!

cheers,
dug