I have a dream! Building a Wayne recommended 2.4

[daniel911T]

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

[mcaterino]

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: Caterino's 1970 engine rebuild

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?

I think no.

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

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

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

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.

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

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

[daniel911T]

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