atb

DK wrote:
I'll probably hold up on this and let my wallet recover a bit. My understanding is that the H-beam rods may need more clearancing that I-beams, and I'm as of yet not totally decided which way I'm going.


Erik wrote:
[QUOTE]1. What diameter before and after?
2. What pistons will you use?
3. Budget cost for that project?
4. Are you doing the assamplly yourself?
5. What is your estimated HK and Nm?
Kind regards from Erik in Denmark
PS: You said (weeks ago) that the new issue of 928 Forum is sent - Still not arrived Denmark!

1. I haven't had a chance to look at any of the paper work or specs. I'll post after I've had a chance to look overy everything.
2. Used Mahles with HPC coating
3. Budget??? Whatever it takes to finish.
4. Yes.
5. If I get in the 390HP/415ft.lb neighborhood, I'd be happy.
PS: I'll follow up on the overseas shipments and get word back to you.


Everyone else:

Thanks for all of the fine compliments. I'm personally suprised about the integrity of the bores. I was expecting wafer-thin appearing walls, with a very inconsistent finish on the cylinder surface due to the depth of the overbore, but the walls look nice and thick and the consistency looks good.

Rob, I would be interested in what ever rod infor you can provide on the Carillo's. I'm looking at the Oliver's right now, as they appear to have minimal clearancing issues.

Thanks all for the encouragement.

Lagavulin

Adam,

Are you saying that the Mahles were used and that you coated them?

Do you have any details on what the 'HPC' coating is and how much it cost?

The block looks beautiful!

BTW, did you ever dyno your GTS cams yet?

John..

Nice work, brings back memories of last summer for me. Man, I need to drive the Bastard more often, she has been sitting for 4 weeks now....no time as of late.

atb

Lag wrote:

Yes, I went with used pistons. After seeing what my options were, and discussing with the folks at Powerhaus, I decided this was the route that was right for me. They had stated that based upon what they had seen, that this was the best and most cost effective solution for my application.

I'm not dissing anyone who is using coated/nikasiled blocks with domestic pistons, etc., so let's not open that discussion. Just stating what decision went with.

Below is the response I got from HPC:



My machinest wasn't comfortable with HPC's recommendation of sizing the piston to it's running clearance, and so my block was honed .0007" larger than minimum running clearance to allow for installation of the piston with the coating. In this way, after the coating burnishes, the piston to block clearance will still be in the middle of Porsche spec, although it will be looser than if I had run the pistons straight. He thought it would be no problem if running a domestic engine, but the Porsche specs are so tight to begin with, he didn't want to me to damage the motor on start up.

I just got back from Wichita last night, but will be picking up the block tonight. I'll get it cleaned up and put on the stand, very much looking forward to getting a closer look.

I have not dynoed the GTS cams because my flappy isn't functional. I'll be fixing that not too far down the road and will post the graph when done. After that, I'll probably drop in the S4 exhaust cams just for kicks and see if I get some of the bottom end back. The way it runs now, it seems like it will be a big mid-range motor. Softer on the bottom than the S4 with a little less run out over 5500, but from 3K to 5.5K it should be a power hitter. I'm not a big believer in SOP impressions, so I'll stop there and let the dyno do the talking.

Lagavulin

Adam, thanks for sharing!

Did HPC mention whether their coating would work on a 'domestic' piston in an Alusil bore?

rob rossitto

still looking for receipt, but think it was EPW at 502 937 7258, $1150.02 delivered ground to LA....$1596 list...they are one of carillo's top volume dealers, hence better pricing...hope I find it before the wife...

lots of ways to skin a shark, don't think block needs notching w/these, they have a low bolt/mounting profile similar to olliver and pauter... 5.85" was designed as an SBC stroker rod for taking 350cheby to 383/390ci...

had some ollivers, but wrench wouldn't put them in....some parts seem to have religous significance w/some folks.... just parts to me, as long as it won't blow up, I'm happy....carillos do have rep for being a top rod (this month anyway)....I suspect there are many good choices however, just stay away from aluminium rods - they are super light, but stretch as much as .040"... a bit much for street use...

you might have to make a piston mod to clear the bottom of the block w/the stock 968 piston skirts....also you'll have to ck wrist pin sizing - the 928 is a bit different than the SBC .927" spec, might get by w/some light machine work I think, but unless you are going custom rod$, you'll need to stay on top of that one... might want to clearance everything before you coat them....

also the mahles are a bit heaver than aftermarket stuff 750g vs 450g...something to keep in mind, as many aftermarket rods are designed for less wt....depends on rpm you'll be spinning her at, too....I've been told as long as we're under about 7400rpm, life is good....

I agree, it does need an altar....

atb

Lag wrote:

I didn't even ask because I didn't want to get a self-serving answer. I did ask Powerhaus, and they said they haven't found a coating that works on a domestic piston running in an alusil bore. (Hence I went with used Mahles).

Rob, thanks for the info. Yup, gotta enlarge the small end of the rod for the mondo porsche wrist pin. The carillos are awesome, just kind of overkill for my motor. But at that price, I could definitely deal with it.

fst951

It looks like a nicely done job, Adam. I hope that everything works out well. Check out Oliver's Rods. Nice pieces. No cracks in the upper H-beam design to worry about either. Not that in your application you would ever notice this problem. Nice looking project.

Hope Wichita was fun. Good luck with the tickets!

atb

fst951 wrote:

Thanks fst. I cleaned up the block last night (man there was a s@!%tload of shavings when I pulled off the girdle), popped in the new bearings and laid the crank. I'll be taking measurements soon for the rods and will call you to get a quote on some Oliver rods.

The boring/honing job looks first rate. Now I need to confirm that the clearances are right (.0015 +) If the machinest nailed that, I'll be able to pass along the Birnbaum seal of approval to my 928 brethren.

Must say, that stroker crank looks nice sitting in the 928 block. Hmmm....should the altar have gold guilding or ruby encrusted sterling silver accents? Maybe both?

Fastest928

Adam,
One test I always do is check the bore for roundness, at three different heights...have you done that to the block? If so, what are the numbers.

And, any check on the piston to wall clearance at room temp? I know how incredibly difficult it is to hold .0008" max.

See you a DEVEK day, maybe even compare notes...

Good luck.....yeehah!!!

Regards,
Marc
DEVEK
Regards,
Marc

atb

Hi Marc,

I'm not going to be able to check for roundness at this point, since the torque plates have found their way back home. (I personally dropped them off in Utah on my way to the OCIC) I would guess since the holes were honed with the plates, that they wouldn't be round without them?

I went beyond the .0008" clearance to allow for the coating on the pistons. It didn't make sense to me hone to .0008", and then have a piston with a coating potentially .0015" thick, and try to assemble it. I may still run into some issues as my cylinders are .0015", which assumes the .0008" piston clearance and the .0007" minimum coating thickness prior to burnishing. It could end up being a little loose if everything is on the big end of the tolerances and the coating does burnish to zero. But that's all part of the experiment here.

I am totally bummed that I probably won't get down to San Fran next month. Heaven knows of all the times I've been down, now is the time I need to be able to talk with you the most. But I'm pretty sure I've maxed out my kitchen pass for the year with Wichita trip. Never say never, but this time around will be tough to pull off.

Regarding internal measurements, do you use in internal micrometer? I've been trying to locate a set of these and no one knows what I'm talking about. Do you just use calipers? Do you have a source for tools to measure internal diameters? (cylinders, main line, rod ends, etc.)

John Veninger

http://www.thetoolwarehouse.net/shop...2-646-300.html

Fastest928

Adam,

I would measure the bores and the pistons. Maybe it is just that I like to measure to extreme tols...our tools can get to .000005, or maybe I just want to know the effects of the tols on engine performance. Maybe it makes a difference....well, we know it does!

Too bad you won't make it down, maybe we could actually do a tech session on measuring blocks....jsut the basics.

Anyway, i am sure it will work fine with the extra tols, but ring wear will be a bit higher, the looser the piston.

Having coated many a piston for 928s, and with considerable experince in coatings, thicknesses, piston material, i would want to know so that when I pull it apart, I will know what has changed and by how much. Do you know the spread of thickness on the pistons? Are some at .0007 and some at .0015? Or are they all the same.....??

And the same is true for the bores....in reality, each bore will be a tick different...even if it is only by .00005 or .0001. It is impossible to bore closer due to heat issues. We did some experimenting for controlling the temp of the block during the honing process....learned alot.

Anyway, keep up the good work.....it looks like the poly dyn type coatings seem to be working...only time will tell.


Hope to see you...if youcan make it to DEVEK Days,
Regards,
Marc

Erik - Denmark

[QUOTE]Originally posted by atb
DK wrote:


Erik wrote:

Quote:

1. What diameter before and after?
2. What pistons will you use?
Adam wrote:
1. I haven't had a chance to look at any of the paper work or specs. I'll post after I've had a chance to look overy everything.
2. Used Mahles with HPC coating

Thanks all for the encouragement.

Adam;
I think you misunderstood my question 1. and 2

I try again:
1. I think you have 100 mmØ as start and now you are going up to f.ex. 104 mmØ?
2. If you went up to 104 mmØ you cannot get original Porsche/Mahle pistons
Regards from Erik in Denmark

John Veninger

Marc,

What brand/model measuring tool do you use that is that accurate!?
It must cost thousands of dollars.