Early alu block rebuild
 

Hi There,
Have an engine block date 11/64 type 901/01 number 900601 only got the block...
I'am about to perform the oil bypass on it. put a carrera oil pump in it.
and want to use the chain housings and hydraulic chain tensioners etc; of a 3,2 engine.
Is this possible? Will the chain housings and tensioners etc. fit? Since I haven't got the originals...
ALso what kind of crankshaft should I use? 2,4/2,7?

I guess the cylinders should be 80 mm

The engine will have to be mounted on a rebuild 902/1 5-speed box and all the stuff should find it's way into a 1965 912 race-look project....

Oh yes got two 901/03 2.0 L engines lying around for parts to. One with alu cylinders and one with cast iron cylinders....crankshaft etc are also available from that engine....
Thks

I recommend getting original chain housings, they look better on a '65-68 car (original). Get some for a non-centerlube cam car, and non-solex carbs, late '66-'68 (NOT magnesium, aluminum).

The 3.2 housings will fit but you need to machine the case to accept them. For this reason it's probably not much more expensive/difficult to locate originals.

You can use any crankshaft '65-77 with the 6-bolt flywheel end. 66mm stroke (2.0/2.2) with counterweight, 66mm stroke w/o counterweight ('69-71 911T), 70.4mm stroke (2.4/2.7)

Cylinders - you can use 80mm (2.0), 84mm (2.2), bore the 84mm to 85mm (custom pistons), or get all the way to 88mm with LN Engineering Nickies slip-fit cylinders. Technically, you could go to 93mm with Nickies cylinders on that case, but you have to machine the openings on the case from 92mm to 97mm.

Use the formula 6(pi)(bore radius)^2(stroke) to calculate displacement. You can build anything from 1991cc - 2869cc with that case (and it will be reliable).

Your 901/03 has the 80mm cylinders, and should have a counterweight 66mm crankshaft.

Most of this depends on your budget. If you can afford a normal engine rebuild, how much more can you afford?

I should have a 1-800 number for this question...;)

Thks for the info...
It's on a bit of a shoe string but offcourse I'll be putting new bearings and on in it. and do the modifications on oil bypass and oil pump....
As for the chain housings I'll try to source them '66-'68 items, Is uppose I can use the covers of the 3.2 on them? The covers with the opening for the hydraulic lines....
Think I will settle for one of the 901/03 crank shafts and use the aluminium 80 mm cylinders/pistons (if they're worth recovering). Put new rings on it and use the the valve train of that engine...
Remember to put in new valve guides....
Is it worth boring out the inlet and exhaust ports of the cylinder heads, they are now 32 mm. Was thinking of boring them out to 36mm INT/35mm EXH. Can I bore them out myself with a standing drill? Would that gain anything (how much Hp?)? INtake valve = 42 mm and exhaust = 38 mm
Thks

Carrera chain covers wont fit, use tensioner guards. The valves are still small but what you can do is use 84mm cylinders, 2.2 or 2.4 which slip in and get some 2.7S CIS heads which will bolt right on giving you large ports and large valves. The 2.2 to 2.7 valves tend to be expensive.
Bruce

Hi , I have a set of 2.7 heads for sale. They are completly rebuilt. New valves, guides, seats and springs. they haven't been ported. They are from a 1974 base model so think they are 34mm . Price $1000.00
Jeff