small displacement builds

[Shuie]

I think I want to build something with a smaller single plug pump gas street motor & 901 gearbox. Something that I could put into a hotrod early 912 conversion, or maybe my 914. Im thinking of something like a mag case 2.0T-2.2T core built out to 2.4 w/a 70.4mm crank with decent cams & carbs. I don't want to get into a lot of extra machine shop labor w/twin plugs, etc..

I want a reliable long lasting street engine similar to (but maybe a little hotter than) my last 2.4T motor. Just to put a number on it I'll say I want 150-175hp and good torque. Im assuming I'd be buying new P&Cs. How much compression and how much of a cam can I use with the stock heads in either? How much work would need to be done to the case?

TIA

edit: I did some searching and found the answer to the question about the rods. I just ordered a new copy of Wayne's rebuild book and the Bruce Anderson manuals.

[tom1394racing]

You might want to consider having your cylinders bored to 86 mm and using a set of 9.5 CR JE pistons. This gives a 2.5 liter. Have your intake ports opened up to 35 mm and use a modified S cam grind with S lift and E lobe centers.

I am considering a similar build with MFI for a '70E I am restoring.

[HawgRyder]

If you have one available...I would go with an Aluminum case.
They seem to hold up better (stud pulling..case shifting...etc.).
And if you are going to bore the case for bigger jugs...they are easier to cut.
Also...they polish up nicely...LOL.
Bob

[Daves911L]

I like the notion of small bore, reasonable HP, and long lived; always following that philosophy for my projects. Stick with a 66mm crank. You could comfortably go anywhere from 2.0 up to 2.5 liters that way. The short stroke motors have a noticeably different feel from the bigger throws, very eager revving, and under-stressed. Go for a reasonable CR. Stay below 9.5:1 with single plugs. Be conservative with cams too. An E grind is smooth, strong, and tractable. The mag case is just fine for these motors. Where people get into trouble with them is cutting the cylinder spigots too large and trying to build too much hp (hp=heat=stress=failure).

[burtm5]

For thirty years I DE'd a 2.2 T with 90mm P/C E cams, webers. had to add a Carrera style cooler when tracked. had about 170 hp ran on regular gas on street although I put in 93 at track. Nice combo even thought BA didn't advise it, because you have about 8.0 compression and machine work on case. Back in the early 80s you were limited to 8.5 rs pistons whereas today you can get JEs for any CR. best