Carl Fausett

Just a note to let you all know that we are now offering this process commercially.

You might recall our long discussion about Nikasil plating the Alusil block a few years back, and we still offer that service, and it still is a viable option to repair and improve scratched 928 cylinder walls. It works well, and we have many satisfied customers.
See here: http://www.928motorsports.com/services/uschrome.html

But, we are enterring our 5th year of racing sleeved 928 engines, and we have got a finished and proven process that we know performs.

There are some benefits to sleeving the 928 engine that make it a good option for some applications.

Consider:

There are more benefits too, like added servicability and O-ringing the sleeves so the heads can remain unmodified. Those features are discussed here:
http://www.928motorsports.com/parts/...er_sleeves.php
along with prices and other information.

I'll be on-and-off the rennlist over the Thanksgiving Holiday, and will answer any questions as soon as I can.

Everybody drive safe, and enjoy your families and time off!

hacker-pschorr

Looks good Carl!!!! Few quick questions to get this ball rolling.

Head gasket - do you recommend staying with the stock unit or are you running Cometic gaskets on your car?

Maximum bore size - what is the largest bore you plan on offering with these sleeves?

Vilhuer

Have you repair welded block(s) which have had (typical to 928 engine) up/down direction cracks on cylinder tower? I have seen such damage repaired in a way that V shaped groove is done to block as down as is needed to get bottom end of crack. This is then welded shut and dry sleeve inserted in. Results have been mixed. Some seem to work while others cause problems immediatelly. Problems have been mainly in cases where original 928 piston has been used in repaired bore.

Carl Fausett

The Cometic gaskets or the O-ring is an either-or thing. Never used together.
If the owner is staying in the 100mm or 104mm bore range, I like to o-ring the sleeve and they can use the factory composite gasket. The o-ring clamps down on the fire ring at the cylinder, and the composite gasket seals the water jackets very well. O-rings can be copper or stainless steel. I have had good success with the stainless ones on stock head gaskets.

When a customer specifies big bore like 4.125", then we custom-order a cometic MLS gasket to match, but we do not groove the sleeve for an o-ring.

Maximum bore size for this process is 4.125". That still leaves enough of the stock cylinder wall to properly locate the sleeve.

A 4.125" bore fitted with one of our steel stroker cranks makes a 6.57 liter motor.
http://www.928motorsports.com/parts/stroker_crank.php

IcemanG17

Looks great!!!! 6.57L......damm that would be NICE

Carl Fausett

I have experience welding up and re-boring deep scratches in the 928 Alusil block.

The reason some who do this create a block that fails is either: the block was not properly heated prior to the welding or did not receive controlled cool-down after the welding; and/or, the assembler felt that the welding rod materials would behave like the Alusil. It wont. The welding rod material is softer, and the rings will eat it up if allowed to contact it.

The proper way to do this, then, is to weld up the crack, bore it down, and then coat the bore with Nikasil like this:
http://www.928motorsports.com/services/uschrome.html
or sleeve the repaired engine, like we are discussing here.

atb

Awesome Carl! Thanks for devising another method for improving longevity and performance enhancement for our engine blocks. I've got a squirterblock collecting dust waiting for just this kind of breakthrough.

john gill

Hello Carl

great work Carl , we have a gts block here that was sleeved by the porsche factory in the 90s to cure the obvious oiling issues that some of the gts s had , this block has cracked & failed , I would assume that the sleeves were made of alusil ,am I right /
can anyone confirm this?
as I sure that there are more of these blocks around , this block developed a crack in the bore & failed , can this one be reused ? if so this is a wonderful solution that you have developed.

thank you very much.

tailpipe

Is this just a newer engine mod or can the older 4.5 lt blocks be punched out larger also? what would it cost to bore an older block ?

918-S

Same question.

slate blue

Carl I'm glad you have had excellent results with your sleeving, given you have also got other engine performance products, stroker crank, cams coming etc, are you planning to offer a aftermarket damper?

Greg

Carl Fausett

Yes, we can sleeve the "sleeved" GTS block.

Yes, you can punch out a 4.5 motor a bit, we can go to about a 4.8 Liter with it, after that the cylinder walls get pretty thin. Usually, if you are going to spend the money boring and sleeving a block, most guys will start with a 5.0 L block. Boring a 5.0 block is same cost as boring a 4.5 block, so why not start bigger to begin with?

No plans on developing an aftermarket harmonic dampner at this time. Thats challenging and expensive to do it right, and if you get it wrong, you ruin the engine. Porsche has engineering resources the likes of which i will never see - I prefer their harmonic dampner. In all my racing and rebuilding, I have only had one fail and that was the very early aluminum harmonic dampner.

Mark Anderson

Both Joseph and I have had a few balancers fail so Greg Brown made a conversion for us using a Chevy fluid dampner. You might check with him if you are interested.

tailpipe

what is a ballpark figure to bore and sleeve a 4.5 motor?

IcemanG17

My guess is its about the same as the 5.0L engine...since the blocks aren't a whole lot different