2.0 aluminum case mods ?

[Jimmy18E]

Guys,

I currently have a pretty maxed out 2.7 Short Stroke built on a fully prepped (Ollies) 7R case that is putting down 264 Wheel HP. Was shooting for 270 RWHP, fell short by 6 HP, not broken in yet, so maybe on the next dyno run.

After reading all the horror stories about mag cases in high HP applications I picked up an early aluminum 2.0 case that has already been bored out for the cylinders, but that is it.

I am planning on having it sent out for all the mods and either swap everything over to it very soon or sitting on it until (if) the 7R case acts up with any problems.

So, what needs to be done?

Already bored out for the jugs. Besides oil squiters and being machined for the newer cam boxes, what needs/should be done?

Ok to shuffle pin an aluminum case? Does it need to be lined bored like a mag case?


Thanks for the help.

Jimmy

[sithot]

Already bored out for the jugs. Besides oil squiters and being machined for the newer cam boxes, what needs/should be done?
Ok to shuffle pin an aluminum case? Does it need to be lined bored like a mag case?

Line boring isn't a bad idea IF it needs it.
Do you have the correct intermediate shaft for a sand cast case? No bearings.
You will need an oil pump upgrade so the case needs machine work for that.
Shuffle pins aren't a bad idea.

The best case I can make for an aluminum case is an early turbo case. Most everything you need is already done.

Calling Ed Mayo....

Tom

[Jimmy18E]

Thanks for the input..

I need to stick with the early 2.0 case and not the early 3.0 turbo case.... my parts will not swap over....

It came with the original intermediate shaft/gear. I have a GT-3 oil pump and you are correct, it will need that modification and I will have the line bore checked. I know that was needed with the mag cases, was not sure on the aluminum case. I like the shuffle pinning but again, was not sure about it on the aluminum case, will get that done.

Anything else that was not listed in the above two posts?

Thanks.....

Jimmy

[gled49]

You didn't say what kind of intake you are running. If it is MFI you will need to weld pump supports on the case. Gordon

[Jimmy18E]

Thanks....

Main components are: 46 PMOs. DC-62 cams, Extreme heads, LN 93mm jugs, JE pistons with compression at 10:7:1(mix 112 octane every tank), Pauter modded crank, Twin plugged, GT3 oil pump, Pauter rods, 901 shop headers, modded M&K muffler....

If I do the swap sooner than later,thinking about bumping up to a DC80 cam. My motor makes peak at 7800 and flattens out to 8K.

Thanks again,

Jimmy

[Neil '67 911S]

The oil by-pass modification should be done.

[edmayo]

Line boring isn't a bad idea IF it needs it.
Do you have the correct intermediate shaft for a sand cast case? No bearings.
You will need an oil pump upgrade so the case needs machine work for that.
Shuffle pins aren't a bad idea.

The best case I can make for an aluminum case is an early turbo case. Most everything you need is already done.

Calling Ed Mayo....

Tom

I don't line bore even mag cases, ever try to get line bore size mains? I set the boring bar to the stock dimension which then only cuts that part which has gone out of round, which is usually the portion of the bearing bore perpendicular to the cylinders. I think shuffle pining an aluminum case is fine. I'm not so sure about having one machined for the insert bearing type intermediate shaft. The one we had done leaked badly at that point of the case.
If you boat tail the mains I suggest doing that by hand, not as a machine cutting process. Machining evidently leaves sharp edges that may crack later on. You'll also need to have the thermostat housing opened up to take the later thermostat. If you're running a later size distributor you'll also need to have that opening machined larger and the mounting boss welded on.

[sithot]

Now you (really) know.

Experience doused with common sense and frugality. That's the guy my money is on.

Tom

[YTNUKLR]

All in one list:
-Oil Bypass mod is SOP with a later oil pump, usually about $75
-Add Oil Squirters - for the pistons - like all '71 + engines - $2-300
-Machine for your GT3 oil pump (won't fit otherwise)...can be done with a hand (die) grinder
-If you want to run a later throttle linkage or MFI (*ever*) , you need to add the boss that the MFI pump would stand on, above Cyl #3
-I have never had an aluminum case not have a straight and in-spec linebore, so can't comment, but I would not expect to need a linebore
-For engines that are frequently seeing 7k+ rpm, I like the shuffle-pinning ($300)...the factory never did this though
-Boat-tailing the main webs...I think this is a waste of time/money...the factory never did this...I would set up a vacuum style crankcase like the GT3 and then you don't need to worry about windage losses--because there's no air inside the case!
-Get the early type intermediate shaft...when it wears out the aluminum where it rides (which will be a long damn time), only then replace it with a later style shaft and later style bearings...even better, upgrade to the 964/993 or GT3/959 intermediate shaft and matching crankshaft gear

HtH

[914-6gt]

You didn't say what kind of intake you are running. If it is MFI you will need to weld pump supports on the case. Gordon

My contribution to this post. Check it out, what we did with my early two-liter aluminum crankcase. A work of art...

Before


After


Here is the "MFI" pump support mod implemented to an unpreceedented level (that I'm aware). Here is how it was done


Same attention to detail with the mod for the 30mm neck 2.8 RSR Marelli distributor, it looks like an original casting, not a mod. How it was done...


The 2.8 RSR Late Marelli drops right-in just like it does on my 3.0 liter RSR case.


...a couple of more photos to follow...