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Jake, what are your thoughts with this combo?

78.4 c/w crank
94B Mahles
type 4 cylinders
Type 1 rods (Scat OEM 311B's)
86a cam
42 x 36 heads
mild port/polish
9-9.5:1 C/R

Louie

Sounds descent BUT that cam is long legged. It will rev right to 6500 out of the box....

The 311 rods are going to need radical clearance work, it would be much better just to but a set of H beams.. The 311 rod loses alot of strength when you take it down that much.

I have a set of "B" 94mm Mahle pistons hitting EBAY this week, actually 3-4 sets! Just ensure that you have the proper skirt clearance with the TI pistons in the TIV cylinders, else you'll smoke a skirt if they are too tight.

Well the only reason I ask is because I already have the 94B's and type 4 cylinders. I remember you telling me that about the piston skirt and cylinder clearance. What is the recommended clearance to run? Also will the stock mahle rings that come with the 94's be adequate? Cam-wise, would the 163 or 86 be better suited for this combo? Since I already have most of the parts, it's just a matter of switching out parts and some case work, could you do the machine work needed on the cylinders, case, and rods?

Louie

Louie, I could do the case work no problem....

I have a cam that may work VERY well for you @ 9:1

OK cool, either way (2176 or 2270) I would still need to send you the case. If I send you the P/C's, could you fit them as well, for the proper clearance, so that they work together? As for the rods, well that's a no brainer, CB H beams, unless you have other thoughts for the rods.

Louie

I might be in for one of those cams as well.

I also have a set of 94b's sitting here, what are your thoughts on this combo longevity/cooling and offset pin wise? Better, worse or same as 96's?

I know there is no replacement for displacement.

So far my plan is:

78 crank
CB rods
ceramic lifters
914 2.0 mild heads (already have)
SDS FI w/crankfire (already have)

Going into a 914, street maybe the odd AX for fun, I'm OK with losing a bit of hp for longevity.

The 94 bore works okay, but it does need some added cylinder shim. Our 96s have a higher pin height than the 94B TI piston.. Its as high as you can go!

If 96mm KB's are used, would the deck height be closer to .000" deck? If I understand correctly, the tighter the quench/squish area the more efficient the engine runs. So if you run a .000" deck, what do you do to the heads to get the desired .040" deck and not have to use the copper shims to attain a streetable C/R?

Louie

zero deck and a .040 step milled into the head is the best way to fly.. Much better than copper gaskets

OK!

Now if I build the 94B w/type 4 cylinder, the piston would have more of a negative deck (pistons sticking out of cylinder) and the only way to alleviate this is by adding barrel shims to attain .000" deck and then have the heads step milled the .040", correct?

Does the 100cc's displacement make a big difference in performance between the 2176 and the 2270?

Sorry for all the questions, which probably seem trivial, but the more I ask the better I'm informed.

Louie

I'm ready to get started!!!! IRS did me good this year.

Louie

call me tonite at my direct line. I'll PM you the #

How do you receive using PM?

Louie

bpcatdog wrote:How do you receive using PM?

Louie

On the STF home page you can click on your Inbox on the right hand side of the page or click on UserPanel up the top of any page and follow your nose.

HTH

Jake,

This is concerning what we spoke about last night as far as the heads go. Do the heads need to be ported and polished or will upgrading the heads to the 42 x 36 valves be sufficient for my 94 x 78.4 combo?

Louie