I have a dream! Building a Wayne recommended 2.4
 

Hey Everyone!

I was looking through Wayne's engine book a few nights ago and stumbled on the recommended engines section. He specifies a neat sounding 2.4 essentially built from a 2.2E with a 2.4/2.7 crank. It's buit on 2.2E cams and 2.2E pistons. He says it's about a 10:1 motor that runs well on pump gas and makes a bit more power than a 2.4 because of the higher compression ratio and cams that are a great compromise between high end and drivability. I realized that I have most of the parts just sitting around the garage and started dreaming of putting one of these motors together. However, before I can start any serious thinking about this I need to have a plan... :)

I need to start with some questions:

First:
I presently have a 2.2T with E cams and Zeniths. I have been informed by the PO that it may have 2.2E pistons. It definitely has T cylinders. Is there a way to tell what kind of pistons you have while the engine is still being used in a running and driving car? (basically, without tearing it down) I have Carrera tensioners installed now, and they will be used in any build.

Second:
Should this be using the 2.2 or 2.4/2.7 rods?

Third:
Are 2.2 and 2.4 cylinders the same? I assume there isn't any serious problem using T cylinders with E pistons?

Fourth:
Here is the tough one: what is the most cost effective way to do this?

I've contemplated getting a 2.4 shortblock, but I'm concerned my distributor wouldn't work (I think the shaft size is different.) Not the end of the world if that's the only problem, but I just rebuilt my distributor and I like it. (it's a 231 159 006 from a 2.2E)

I'm afraid to crack a case because I don't want to create an issue with a different crank that may bind with standard size bearings, requiring line boring and (expensive) oversize bearings. I understand the cranks, bearings and cases all sort of wear each other in, and that it isn't as simple as just changing a crank.

Goal is to have a reliable motor, still running carbs, used for weekend driving and maybe an extremely rare (less than once a year) DE. No requirement to overbuild, the goal is to build with all used Porsche parts. There will be a new gasket kit, new oil return tubes, new rings, rebuilt 2.2T heads, and the other necessary stuff when digging into a motor.

So, if this was your project, and you were planning on using absolute minimum funds and all used parts, what would you do? I'm especially curious about the crank/case issue. Used 2.4 shortblock, or just split a 2.2 and drop in the later crank?

All opinions and suggestions are welcome.

Thanks!
Dan

Hi Dan,

Came back from a vacation expecting to see news on your transmission project, and here you are starting something else! We seem to have a lot of common projects...

This is more or less what I did, with the exception of using JE 9.5:1 pistons instead of original porsche ones. First, my thread, if you haven't seen it: http://forums.pelicanparts.com/911-engine-rebuilding-forum/565928-caterinos-1970-engine-rebuild.html


I think no.

2.4/2.7 rods are necessary. Sets can be had for reasonable money, ~$200

You wouldn't have any problems with your cast iron T cylinders in a 2.2 case. I'm not sure if they would go into a 2.4 case. Need to check spigot diameters, I forget. I bored and honed my original cylinders to 85mm, fit to custom pistons.

I know your current case isn't original, so there's no sentimental reasons for keeping it. I think you might get a 2.4 shortblock for not a ton more than you'd pay for the crank and rods. One possible issue you could have with putting original E pistons on a longer stroke crank is skirt/case interference. I never got a clear answer on this, but in many cases I believe case modification (case web grinding) is necessary. Not so for JEs which have a shallower skirt. I would imagine that a 2.4 case would have better clearance, but maybe later pistons had shallower skirts? Beyond my expertise. The later case would also have squirters, which would be nice.

So assuming a good shortblock that you didn't have to split, that would seem the better option, although I know most will recommend splitting it anyway, checking the bore, replacing bearings, etc........!

But what else do you have to do with all your spare time and money??

Mike

The transmission project is def. still out there, and somewhere near my #1 priority.

This is just a pipe dream at the moment. However, if I know what I need, then taking advantage of future "opportunities" becomes a possibility. ;)

Right now my motor runs great, but I'm already getting a bit of the itch... "how much better could it be if..."

It's also fun to imagine doing it on a shoestring, out of someone else's useless parts.

One last note: I am not attached in any way to my case. In fact, many of the studs in the case just pull right out when retorqued. I had this trouble on the chainboxes and on a stud that comes out of the bottom of the case near the #1 cylinder. As a further point against this case, according to my research, this is not a case with piston squirters. That was a '71 change, and this is most certianly a '70 case.

Thanks for the input!
Dan