BC

[QUOTE=Mike Simard][QUOTE=blown 87]I think it was in A. Grham Bell or Corky Bell's book talk about how much that reverse cooling and flow make in controlling detonation.
He means A. Graham Bell, the author of Four Stroke Performance Tuning.

svp928

Nice work, Mike! Can you give us some detail as to why you are using Nikasil?

Steve

blown 87

[QUOTE=Mike Simard][QUOTE=blown 87]I think it was in A. Grham Bell or Corky Bell's book talk about how much that reverse cooling and flow make in controlling detonation.

They are good books, if you are into that sort of thing.
So, no on the reverse cooling.
It was just a thought, you have went so far with this.
What kind of drive train and mods are you going to do?

Mike Simard

Here's how I came to Nikasiled steel:

An important consideration was to keep as much structure in the block as possible so step #1 is to set the block on the machine and cut away the existing cylinders just deep enough to reach full material beween them and no further. By stopping there the register surface that the sleeve would sit on is cleaned up in between sleeves but not 90 degrees from that point. I believe a large register surface area is desired and too little could possibly cause settling so an o-ring will not be there. After that depth is determined, it's time to bore where the sleeve will fit into down to the bottom. Keeping maximum block material is still considered and now the width of the register surface makes itself known. At this point the sleeve material and sealing are dictated. I didn't want to open the bore enough to have a sleeve thick enough for an o-ring groove on the sleeve so I want a thin sleeve at the bottom. That also makes an aluminum sleeve less appealing. By putting the o-ring groove inside the block I was able to go with a beefier size o-ring, keep more meat in the block and the most register surface available. it is more diffucult to place the o-ring groove in the block, all tooling must be carbide on the Alusil so there were special cutting tools made.

BC

Thanks. So the sleeves are steel but will be coated with Nikasil?

Mike Simard

Thanks for the book ideas, now my wife will have Valentines gift ideas
Drive train? Oh, that's right. I wonder what will break. In other projects the axles have been a weak link and I've machined stronger alloy ones, I really don't know what would be the area to concentrate on this car, any ideas? I would love to have a dog-ring box for the track, ahh!

BC

Your cuts seem similar to this:

https://rennlist.com/forums/showthre...ight=Green+Bay

Mike Simard

OK, so the sleeves would like to be steel. Here's how it snowballed: The easy way would be to have LAsleeve supply some from a good ductile iron. Probably better than the iron blocks of old and they would be able to supply blanks but I'd still want to do some cooling fin machining. Since I've already put alot of machining time into this project why not just order raw material and handle all of the sleeve? OK, if I'm going to order material and do a heap of machining on why not just use 4140 and heat treat them? If 4140 is used it's strong and can be made very thin, the sleeves are made from a similar material and heat treat to shotgun barrels. Then it will have great cooling and be lightweight too! 4140 isn't an ideal material for having things slide against it, a hard chrome would be nice! OK, but there are alternatives to hard chrome, in fact the latest technology in racing is Nikasil which is considered superior to chrome. there are also many companies that specialize in Nikasil as well as shops that can hone it. Since this is truly my dream engine even more so than others I've built, it's easy to keep saying yes to the 'why not's
Here's some 4140 tubing about to become sleeves.

Mike Simard

Similar in that both have been machined for sleeves but different strategies and sealing methods.

BC

Can you expand on that? Have you talked to Todd?

blown 87

With that much power you are going to need some good brakes, thats for sure.

You should be able to get 450-500 FT/LBS of torque out of this build, so I am sure you will be able to find the next weakest link, if you can get it to hook-up with the pavement.

I will have to say that the depth of knowldge here on the 928 forum, dwarfs some of the other forums I have been on.

BC

Exactly. With all this machining people can do I was hoping someone could maching a new transmission case that would control the angles better and not expand, which some people think causes the gear breakage.

Next is a thicker TT shaft, but I think thats been done.

JEC_31

In my intraweb experience this is very true, even for other sections here on Rennlist. The only deeper forum on the 'net that I've found is the drivetrain engineer's forum that suddenly I cannot find my link to, where deep math and physics are tossed about casually. And where did I hear about it? Here.

Mongo

Question regarding your choice of pistons; Porsche had coated the skirts of their pistons with an iron composition for it to travel smoothly in the bores. If you have steel sleeves, would it be necessary to do the same thing to your new pistons that will go in?

Never heard of a German V8 with an American displacement. This should be interesting..

Mike Simard

Our o-rings are in different places. Anything beyond that would only be noticable to the guy doing the work and not of any interest to anyone else. For all practical purposes we're doing the same thing. I've never talked to Todd, I did ask Hacker once to put me in touch but never heard back. He may not be interested in talking to a hobbiest when he's in the business. I understand that and certainly don't hold that against him, I sometimes get strangers that email me about past projects I've done and wouldn't respond to a stranger asking out of the blue for my CAD models etc. which has happened. On the other hand, Erkka or you could ask me to help with your build and I would enjoy it and make time for it and encourage it! Todd seems to have done admirable work and I don't want to compare our projects, I admire his work and that's that.