The L engine calculator that someone posted on the site....

Here it is here for those who dont have it....

Well i was fiddling ( which i often find myself doing....idle hands...well you know ) and i was thinking about putting an L28 crank into an L24 ( interesting idea eh? ) well with the stock 240Z head from 71 - 73 ( e88 ) the compression jumped to a nice 12.54....a lil high for my taste =) and the gas

HOWEVER when mixed with a P79 head and a 1mm HKS gasket the compression goes to a nice 10.6 : 1....( 10.3 with the std gasket ) now would this be a nice lil compression set-up or what? do you think it would work? what im curious about is the deck clearence? will my pistons come over the deck? out?

Tell me what you think..

Matt

see...told ya it would be a compression increase. even 10.6 is pushing it for 91 octane (highest only to 100, at $5 a gallon). I believe 91 octane is rated to fuel a maximum of 10.5:1 compression...but that is pretty much its limit. Your bound to get "pingy" and wont get the full potential out of the engine. But thats only what ive read...not from experience

well my worry is the deck clearence...are the pistons gonna stick out the top?

and there was a displacement inscrease also, the stock 240Z has 2393 ( 2.4L )CC's of displacement, when replaced with the L28 crank is ups to 2565CC's of displacment. ( 2.6L )

Matt

p.s. if i use the std gasket i get a 10.3CR...easily run that on 91 Octane, also a thing of octane booster each tank doesn't bother me much, i dont drive much =)

not sure about the clearance but i would assume that since your increasing the length of the stroke that it would move above deck

If you used the 280 rods it probably would, but it all depends on which pistons and rods you used with the 280 crank. You could probably use the 240 rods with 240 pistons on the 280 crank and be OK. With todays pump gas you should shoot for less than 10.75:1 for sure, any more and you have to use an additive to control the detonation.

There is an article in an old Z car magazine where a guy did this exact thing in his 240. It came out to 2663cc or something like that. He just had it for sale on ebay less than two weeks ago. If you have any of the old issues of the original Z Car magazine it's in the Nov/Dec 1997 issue.

Oops, after I re-read your post I looked up the article, he used a 280 block with a 240 crank, not the other way around.