308 Engine Rebuild & CIS to TWM Throttle Bodies Conversion Thread!

Huuh, just what are you trying to say,,,?
,, I just spent $ 2,000.00 on a set of JE's.....!
(PPffftttt,, 9.8 to 1 , , , special alloy,, larger G-pins,,, 4 rings... Hundai penta-squish design.... etc.)

Edwardo
Image Unavailable, Please Login

 

They lost their top people when CP started and their products and engineering are not as good now. While Wiseco, CP, and Mahle have been moving forward JE has been going the other direction.

 

Wiseco also keeps our strange size wristpins readily available which to my knowledge no one else does.

 

Yes. I thing to easiest way to do a 360 to 308 conversion would probably be to 360ize a 308 block with 360 crank, liners, rods, and heads. To use a 360 block you need to move the oil pump and I don't care for belt driven oil pumps so I think I'd start with a 308 block.

 

Those are nice. Looks like you optioned up for the skirt coating.

What Rifledriver said about piston mfgs. is true. Lots of changes in ownership and quality in the last 10 years. Good and bad. Applicable to valvetrain component mfgs's too.

Of the aftermarket guys, Wiseco is the only one that does their own piston blank forging.

Mahle does too but they are really an OEM although they just recently entered aftermarket. They are the best choice if cost is no object. They have the most advanced piston engineering in the world.

 

Chris,
Before work starts on your engine, see me for some special Ferrari tools the shop must use:

1) Honing/Boring torque plate that bolts on in place of the head to ensure the sleeves & block are under the same stresses that a head exerts while they're being bored or honed.

2) Crankcase boring & honing bars with angle brackets.- They're needed if the deck is being machined, and when checking the crankshaft main bearings.

While they're a well equipped shop, these are 308 unique tools & it's highly unlikely they'll have them.

 

This bring up a point.

I have heard, and logically, I believe it is correct, that you don't really need a plate, you can get the same effect by bolting and torquing a bunch of stacks of washers or hollow sleeves on each bolt location, as this will distort the block the same way, in the same amount.

Thoughts?

Doug

 

Hey Chris, you'll need this tool as well to clear the brush out of your engine bay before you proceed lol. You can lend it to Mark when you're done!.....Running for cover.....
Image Unavailable, Please Login

 

That's a new one to me.
I believe it's bogus, at least for the 308: The sleeves extend a few thou ABOVE the deck, thus the plates put pressure on the sleeves comparable to torqued down heads. (I haven't used them yet, but that's my understanding.)

In fact I have trouble believing it in general as the plate both holds the studs in alignment to each other and also distributes their compressive force much more uniformly over the deck's surface. A stack would just concentrate the compressive force closely around the stud, most likely risking damaging the deck surface in that area.

Newman,
His car has been up on a lift since the engine was pulled, so he'll need it, not for brush, but for cobwebs.

Come to think of it, mk e's bay is rapidly collecting them as well.

 

Doug,

I think your confusing the factory tool for (merely) holding the liners in place while assembling the engine. I've enclosed a photo of the "tool" I fabricated just for this purpose. The need for this tool is real, as once a liner is installed, followed by a piston/ring assembly, I really don't want that liner to move upwards...and break the o-ring seal any more than absolutely necessary.

You are correct. Retaining the liner and the application of a torque plate are two entirely different animals.

David
Image Unavailable, Please Login

 

The sleeves bring up an interesting point.

I have read that these sleeves are often/sometimes removed from the block, bored, honed and reinstalled in the block.

Did Ferrari bore/hone the sleeves in or out of the block when making these motors?

Also, has anyone actually measured the amount of distortion in the sleeve with a torque plate on? Seeing as the sleeves are not monolithic to the block, they have a degree of isolation from torque stresses applied to the block by the head studs while under torque.

On a monilithic iron V8, there are small localized areas at each head bolt hole that get slightly deformed, approximately 5/8" wide, by 1" deep, anecdotal evidence suggests that is why you can simply use a metal cylinder under each bolt rather than a plate on those motors, as the distortions do not extend any further than that. Of course, with a bunch of stacked washers or cylinders, you can't circulate 220 *F oil through the block to do hot honing to simulate actual operating conditions like you can with a torque plate.

Doug

 

You need torque plates and the main bearing caps attached/torqued to hone an engine properly and have the best chance of the bores remaining round when the engine is assembled and at operating temp. Really good shops will heat the block before honing to approximate the actual temps when running and ensure the bores are round when you NEED them to be round. Being perfectly round when the engine is cold is not all that helpful...

 

I am going to have to find and look at some X section drawings on a Ferrari block.

Those sleeves look like they really isolate the bore from the stud bosses. Almost like a Chev LS motor, where there are no head bolt/stud stress on the bore at all, since the cylinders are not connected to the block deck top/stud bosses at all, as there isn't a deck top.

Doug

 

I suspect that its not an issue either. The liners are isolated as compared to an integral sleeve plus they are a loose fit. In a boxer for example, (and I assume anything else from the period) there are issues where the liners move around in use. How important can is possibly be to have a laser straight liner that wiggles in the block? When the TR came out they made a correction to the liner fit to correct this problem.

 

Paul,

The effect of a liner 'moving around' would have a very limited effect if you look at it in degrees deviation from the ideal position, whereas the mechanical consequences of a non-cylindrical liner are plentyful.

 

Despite all the potential "hype" on the use of torque plates, my liners were precision honed out of the engine to "fit" the custom JE pistons, per their skirt to liner specs. After it was all said and done, the engine leak tested at less the 1%, hot after 1,000 kms. I'm not so sure you could do (much) better than this...although torque plates do, in theory, make good sense to me.

Personally, I don't "buy" the reoccuring statements that the liners wiggle. With a nominal +.0015 to .0020" projection above the deck, once the head is on and torqued, I just can seen the liners moving around...as the head is pressing down on their tops and headgasket failures, presuming that periodic retorques are done are few and far between.

David

 

Yes, luckydynes measured 2V engine sleeve distortion using a torque plate after the sleeves were externally honed. Presumably this would be the amount of distortion eliminated by honing with a torque plate:

Details in this thread:
Measured distortion on 308 sleeves with torque plate
http://www.ferrarichat.com/forum/showthread.php?t=176062

So clearly the torque plate did & presumably heads would distort the sleeves.
How significant is this amount of distortion?

Any way to project 4V distortion from this 2V data?

 

Redline is determined by:
Crankshaft dimensions & strength
Connecting rod dimensions, strength, & weight
Piston weight.

As far as I know you aren't changing the 1st 2, and I doubt that your new pistons will be radically lighter as the OEM pistons are already pretty light.

Thus, I wouldn't assume that redline changed.

Even if the new pistons are significantly lighter, I don't know of a way to calculate their effect on redline w/o knowing a lot more about the crank & conn rod specs. Even with the specs, it would be a non trivial analysis as it involves dynamic stresses.

 

I would think the new pistons would at the very minimum would be 20 grams lighter. The last set of pistons I had made up were for a Maserati, and the new pistons were 55grams lighter. That being the case, it would be a good idea to have your crank and other items balanced together so they play nice.

 

Chris,
Sorry for not being up to speed on your car, but what are you doing with her that requires me to see the ground through the engine compartment?

 

Chris, are you getting it ready for the Cavallino in Jan.?
You can always put on a trailer