Jaybird's official 2.7 rebuild thread - Page 7

jaybird840 · 07-21-2009, 04:34 AM

Well, things are progressing.... I got my carb bodies back from Paul Abbott at Performance oriented. He fit new plates, and rebushed the shafts. I'm glad I sent them now. I never could find a pulley bolt, and pelican didn't have one in stock. I didn't want to take the chance on having to order one from Deutschland, so I found a 12x1.5x30mm bolt at my local bolt house. I had planned on taking a hacksaw to it to shorten it, and the counter guy looked at me and said... "why don't you take it to the machinist next door?" I had been in the bolt shop dozens of times, but never knew there was a "real" machinist in the area. Turns out this has been the guy I've been trying to find for awhile--a true machinist. Fabricates with CAD, does tig welding, etc. Long story short (no pun intended), he cut my bolt off to 22mm for free. Fit like a charm. The mailman also brought me a present yesterday--a 3.2 Carrera intake. I've dreamt of a Megasquirt install for years (waay before this project). My thought is to get the motor up and running with carbs first, and see how they do. If I can get them tuned properly, I'll probably just leave them on the car. If not, I'll probably install the Carrera intake and MSII. Here are pics of the mockup with both....

and with the carbs.....

Let me know what you guys think.... Has anyone ever solved the 3.2 intake injector divot issue? I read one thread where the guy made bakelite spacers and blended the injector divot so the Carrera injector spray was not interfered with by the CIS divot in the head. I'd prefer a solution like this, as I'm definitely not pulling the heads off for the next 20 years or so!! We're getting close!

David Borden · David Borden's Garage

mmmm pretty! Im looking at doing the mega squirt kit as well... Very impressive setup. What would be really trick, would be to use your carbs at Throttle Bodies and machine injector bosses in the manifolds

Looking forward to you post about your first fire and drive!

David

jaybird840 · 08-11-2009, 06:49 AM

Hi All,

Please read my post in the Tech forum about wiring the alternator... Thanks!

http://forums.pelicanparts.com/porsche-911-technical-forum/491036-alternator-wiring-advice-914-6-conversion.html#post4829433

effvee · 08-11-2009, 04:28 PM

Hi, I received my case today. The seller sold me the case, and internals. I believe the stroke is 70mm X 90mm. I would really like to try and get more bore and stroke out of it safely. Maybe 74mm X 92 or 94, I have asked this before, however everyone say keep it stock. Can anyone tell me if a 2.7 case can handle 92 or 94mm? Let say I will get the pistons made from J&E, have the piston wrist pin relocated up some into the piston, in order to compensate for the stroke. I had the process done to my type IV engine. Will a 74mm fit into a 2.7 case?

kenikh · 08-11-2009, 04:39 PM

No on all counts. Stud spacing is too small and main bearings are the wrong size on 2.7 case.

Bob Goding · 08-11-2009, 05:24 PM

It seems to be pretty well known that the magnesium case[7R] is just about at the limit at 2.7---they got to 90mm by using the thinwall alloy barrel.If you look at how close the stud holes are ,to the edge of the cyl. spigot bore ,there just isnt any more room if you want to use inserts .I did timeserts and its close --casesavers must be marginal ,

I looked up Bruce Andersons book and it appears there were 92mm[2.8] and 95mm [3.0]cylinders,but lots of associated problems-he does not recommend them for a street engine.-----But nothing is impossible,so go for it ,if thats what you want.
A used 3.2 or 3.6 might be cheaper in the long run.
Good luck.

[ Just my opinion---its worth what it cost!]

effvee · 08-11-2009, 07:11 PM

Hi, thanks for responding. Tomorrow I'll look and see whats, what. 2.7 in a bug or 914 will work also. Being from the VW side and seeing what was done and not being able to, so everyone has stated, in the VW world. The Mag case of the type one VW case was supposed to only have 85mm, but it was taken up to 90mm and even 92 thin wall. The webbing and journals were still stock, but look what Gene Berg did with a stock case. That's way my questions, I'd love to try some 92 or even 94s in with a 74mm stroker; add custom J&E pistons with relocated wrist pins. Where can I find a copy of the Bruce Andersons book, need to keep hope alive

Bob Goding · 07:29 PM

Try here--http://www.pelicanparts.com/catalog/ShopCart/BOOK/POR_BOOK_bkptec-detail.htm

Porsche 911 Performance Handbook $25.95
Making your Porsche 911 run right and run fast is not a lot of hot air. These are not tall tales or even whale tales. One of America’s foremost Porsche-philes and 911 technical experts... more...

effvee · 08-12-2009, 03:37 AM

Hi, I hope to do a wilcall. I did when I ordered the rebuild and modify book, if so I'll pick up the books Saturday. Thanks very much

gsmith660 · 08-12-2009, 11:39 AM

Quote:

Originally Posted by effvee

Hi, thanks for responding. Tomorrow I'll look and see whats, what. 2.7 in a bug or 914 will work also. Being from the VW side and seeing what was done and not being able to, so everyone has stated, in the VW world. The Mag case of the type one VW case was supposed to only have 85mm, but it was taken up to 90mm and even 92 thin wall. The webbing and journals were still stock, but look what Gene Berg did with a stock case. That's way my questions, I'd love to try some 92 or even 94s in with a 74mm stroker; add custom J&E pistons with relocated wrist pins. Where can I find a copy of the Bruce Andersons book, need to keep hope alive

Anything is possible just look at my 2.7 turbo app. according to the chart I found in the turbo forum I am running about 13.3:1 comp. ratio

kenikh · 08-12-2009, 12:08 PM

Quote:

Originally Posted by effvee

Hi, thanks for responding. Tomorrow I'll look and see whats, what. 2.7 in a bug or 914 will work also. Being from the VW side and seeing what was done and not being able to, so everyone has stated, in the VW world. The Mag case of the type one VW case was supposed to only have 85mm, but it was taken up to 90mm and even 92 thin wall. The webbing and journals were still stock, but look what Gene Berg did with a stock case. That's way my questions, I'd love to try some 92 or even 94s in with a 74mm stroker; add custom J&E pistons with relocated wrist pins. Where can I find a copy of the Bruce Andersons book, need to keep hope alive

You can't fit a 3" ball in a 2" hole any more than you can fit a 94mm piston in a hole constrained to 94mm by the threads of the case studs; no room for the cylinder. 93mm is max with the 94mm bore and even that is below the recommended skirt thickkness specs of the strongest aluminum cylinder you can get, the Nickie. 92mm is a nice option on Nickies, but wouldn't use bored Mahle Nikasil cylinders for this kind of engine. If you plan on turboing it, forget about it. I am using a 7R mag case for my turbo project and won't go with a bore any larger than 85mm for strength reasons.

As far stroke goes you have the clearance for a larger crank, but NO ONE makes one for the early crank journals. Berg made his own crank (clean sheet specs) and you are talking about offset grinding a Porsche crank. Only two cranks work in a 2.7 case: the 66mm and the 70.4mm 6 bolt main cranks. The 70.4mm crank is basically a 66mm crank offset ground from a 57mm rod journal to a 52mm (2.04") rod journal (variance in math is from differences in fillet radius). There is only the tiniest bit of meat on the 70.4mm crank to get a longer throw: you can go to 2" Clevite Nascar bearings which would get you a theortical stroke of 71.6mm (1.2mm longer) and only if you can maintain a reasonable fillet diameter after grinding.

I come from the VW old school; my '71 Fastback has a Berg 5 speed, a 2 liter Berg cranked stroker motor on Mahle slipper skirt 88s, dual Weber DCNFs, Clyde Berg ported heads...the works. VW left a lot more meat on the motors for screwing around than Porsche did.

I tired f---in around with the same questions you have now way back when. Take the shortcut and learn from what I have.

Don Settergren · Don Settergren's Garage

jaybird840: Thanks for the alternator update - very useful! How's the progress? We're all looking forward to your performance stats with that engine in your 914. 0-60 in ???

Dick Shift · Dick Shift's Garage

they look like std. inserts. Probibly ok but if you want the best chance of studs staying go to the bigger oversize insert installed buy Ollie's Machine - the "Old School" Porsche machine shop Santa Ana, CA 1-714-558-7334 in Cali.

Dick Shift · Dick Shift's Garage

Looks like no inserts to me.
Ist size inserts [ana; timeserts] better than nothing, but if you want the best chance of studs staying in go to the bigger oversize insert installed buy Ollie's Machine - the "Old School" Porsche machine shop Santa Ana, CA 1-714-558-7334.

effvee · 08-12-2009, 04:44 PM

Hi, well today I had a very close look. Yep the time serts are that close. I really don't want to throw money at this project. So now one option is turbing, 8.5 compression and enjoy the ride. I could still have the crank cross drilled and stroked, but maybe turbo charging will just have to do it. So now it back to reading.

Thanks again everyone

Dick Shift · Dick Shift's Garage

but maybe turbo charging will just have to do it. So now it back to reading.

My experience with turbocharging a 2.7 case WILL lead to case studs pulling!!! Regardless of any inserts/timeserts. Just a matter of time.

jaybird840 · 08-12-2009, 06:12 PM

I still don't have the alternator issue worked out.... Any help?

gsmith660 · 08-12-2009, 07:33 PM

Wasn't my post any help?

effvee · 08-13-2009, 03:43 AM

Quote:

Originally Posted by Dick Shift

but maybe turbo charging will just have to do it. So now it back to reading.

My experience with turbocharging a 2.7 case WILL lead to case studs pulling!!! Regardless of any inserts/timeserts. Just a matter of time.

Good morning, I'm not sure if VW mag and Porsche mag are the same metals, I hope so. I am aware that I am on a Porsche site, but in the VW site lbs of boost on the mag case seem to hold up ok. 10lbs of boost is enough for my project. Also in Porsche's reving into the high rpms for torque and horse power, is a factor also. I would like a very mild turbo cam, have my boost and power band come on sooner much lower in the rpm's will greatly help in the time serts (ah I hope

)

jaybird840 · 08-13-2009, 04:50 AM

GSmith,
Yes, you're post was most helpful--thanks! I hope my post didn't sound ungrateful. I still haven't figured out what to do with the harness for sure. The 914 wiring diagram helps some. I just found this post, which I think will help me more than anything...

914-6 conversion alt ?'S PLEASE

How I interpret these two comparative pictures is that my B+ connection will be a solo 8 gauge wire to the starter. The blue D+ wire on a 911 is actually red on the 914. So, 14ga brown to "d-", 14ga red to "d+" "DF" stays open (internally regulated alternator). I guess I'll wire it up like that, and see what happens...