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What size crank in a Type IV with no clearancing??
vassy66T1 - March 16th, 2009 at 04:16 PM

Hi

Building the wifey's motor for her '72 and have some 94mm P&B and AMC heads and want to see what size crank we can go to without too many problems.
I read 78mm on the shop talk but would like some local feedback.
I am keeping the heads stock (they are new) for the moment and most likely the carbs stock as well (budget ... grrrr) but with a view to better carbs and a head job (don't let your mind wander) when we have funds to allow later.
From what I've read the clearance from cam to rods seems tobe the issue.
Look forward to your input.
Marcus


66deluxe - April 13th, 2009 at 04:03 PM

You'd be better off keeping the 71mm stroke if your using the stock rods, you can go 76mm stroke with stock rods but then piston skirts will hit crank due to rods. A cam change and an upsize in valves to 42x36mm will give you more than enough power and torque for the bus. I'm building a 2270cc type 4 for my bug, i need to clearance the case for this size crank.

Damo.


vassy66T1 - April 14th, 2009 at 09:09 AM

Thanks for the reply Damo

If I go to a 78mm then what length rods would I be looking at?
The engine was previously an 1800cc so I don't have a 2l crank or rods hence we thought of biting the bullet to up the cubes.


LIFE IN THE LOW LANE - April 15th, 2009 at 07:43 PM

5.4" rods would be ok. I am using 78 stroker and 105mm P&B's with rods of this length. 2700cc of fun loving subaru beating torque......