914/6 Conversion Project, Identifying Engine Specs Options

[Dugo16]

I recently picked up a 914/6 conversion project car. I am in the process of trying to figure out what is in the engine without fully disassembling it since it appears to be in good shape. Engine is out of the car. Here is what I know so far.

- 1972 911T Case (911/07)
- 90mm Cylinders (90zn2)
- K1819n heads (one is a K1819g)
- 40IDS3C carbs

Trying to figure out what cam and crankshaft are in there.

Valve lift measurements below where measured with a dial gauge placed on the valve retainer.

- Intake lift .402
- Exhaust lift .376

Stock cam?

I figure the crank is a 66mm but it could be also be a 70.4mm from what I have read. Anyway to figure that out without disassembly?

Thanks in advance for any info. I appreciate the massive amount of knowledge the 914world community has!

-Doug

[targa72e]

for early cranks 2 plugs on flywheel end is 66mm one plug is 70.4.

john

[Dugo16]

for early cranks 2 plugs on flywheel end is 66mm one plug is 70.4.

john

Thanks John. It is has two plugs so 66mm crank. That confirms a short-stroke 2.5.

[porschetub]

for early cranks 2 plugs on flywheel end is 66mm one plug is 70.4.

john

Thanks John. It is has two plugs so 66mm crank. That confirms a short-stroke 2.5.

I wasn't aware you could run 90mm pistons with a short stroke crank, seem to remember 86mm is the largest short stroke kit available ? think the the 86mm kit gives displacement over just over 2.3 litre .
Regardless of that sounds like it you a good motor, mine is a 71 2.2T motor and with a few mods it is a fun drive , but changing cams apparently wakes up an otherwise tame engine as many have done.
Good luck in your build, cheers.