Bill Ball

The debate over technically what is best to do with what parts can be a healthy thing. I think you have stated the key point - in the final analysis, it's up to Mark to get what he feels he needs. I donated the money to Mark's racing effort. I knew with only $5K and with the questions about the specific motor, this was not going to be a simple button-it-up-drop-it-in-and-go-racing project. That it doesn't go as originally planned is not important to me. I never thought it would. I appreciate that Todd and Tim and others are involved and that it isn't completely clear what to do yet with which motor. Ultimately it should be up to Mark.

mark kibort

Im glad the group is back talking like family again. (oh wait, thats what families do, they argue!)

Looks like we are back on track.

I think the main issue here is that no one but the Tim and Erik show knew about the details of the original engine. Sure, a freshly built engine is attractive,and certainly better than what i have now (as far as power), but if you are going to go through all the steps of an engine transplant, is a 6 liter the way to go? Since the goal is to make the Holbert car more competitive, and there is a dyno result of a GT with a 6 liter running 360rwhp, one can only guess that a 6 liter with 9:1 compression would make less.

The team is really rallying together to put the right engine together. I think its fantastic, and again, im still in awe of the support the list is giving me and the Holbert machine. I hope the car and I can live up to the expectations!!! Believe me, with 400rwhp, the "driven to the track" Holbert 928 will surpise a lot of big money racers!

I did like the idea of still running pump gas on the engine, so can we do this with 11:1 or should we stay at the near stock levels of 10.5:1 for compression ratios? one thing we dont know right now, other than my compression tests and cam set up, is what the holbert heads look like. i think we should shoot for 10.5:1 compression , just in case the holbert heads have less volume. either way, we will be in good shape. worst case, i have to buy $7 a gallon gas for the races, right?

Thanks again everyone!

Mk

Fastest928

400 NA rwhp on pump gas for $5K

Whos is smoking what happy juice?

RAce gas is under $6 per gallon at the highest point this year...is SCCA gas different?

atb

Sorry for going slightly off topic on the fund drive for Mark's motor, but I do have some questions since I was intending on running these same pistons in my stroker.

Is there any chance of getting a pic of the scuffed Mahle Motorsport pistons? Were the cylinders scuffed as well?
Was motor was built to OEM tolerances and then boosted or was it built looser in anticipation of boost.

My intent isn't to question anyone's engine building ability, so please don't go there.
I'm just curious as to the conditions present when the scuffing occurred.

BC

Labor, knowhow, and a good work ethic are less expensive in Wisconsin. Noone said anything about the total being 5k. Thats the money that was raised.

100 unleaded was 6 bucks at willow springs last weekend. The 91 octane was 4 bucks, but locked off.

The only koolaid we are drinking here is the stuff labeled:

"It ain't rocket science, or anything special - its just an engine that needs to last,"

I know how most 928s are used - and its nowhere CLOSE to what Mark K, or Mark A or Joe Fan puts thier engines through.

I have seen several comments here about 968 pistons. Its a good plan when you are yet to get custom rods. Custom, Well-built carillo rods are already part of the picture.


As a side point, the pistons that Matt mentions Greg Grey having had ordered and recieved Do look coated normally:




But this is an exception, as I mentioned to Matt privatley, to the rule that Mahle has never really come up with the original solution that made the 928 and 944 engines 200k mile engines.

hacker-pschorr

When the person doing all of the machine work is in house with his own (paid for) equipment - anything is possible.

When I was at Todd's house last night I told him Mark was shooing for 400rwhp
His response: "Why so low?"
I dunno, coming from a guy who's daily driver is a VW powered motorcycle with over 400hp - I have a feeling he can pull it off.

Anyway - we are starting with a $10,000 motor being sold for $7,500. The overall cost if you started from scratch is well beyond $5k. We are not starting from scratch here, so the numbers will reflect that.

BC

I think 968 valves would be a great idea. They are supported by the S3 cams from Mark's heads.

I honestly think that closer to 475 is a good goal for the engine. 6.1L or more, reving to 7000rpm? 400 IS low.

Larry928GTS

Adam,

It may not be exactly what you're looking for, but the information below might be of interest to you. It's a response I got from one 928 owner in regards to the scuffing he experienced with the coated pistons that he had, and which were supposed to work but didn't. His new engine has been running sucessfully for a while now.

"My pistons were KS pistons coated w/chrome… apparently Porsche was exploring/looking for some alternatives to the ferrostan coating mahle was using at one point. They were pretty hacked up. I pulled my motor apart cause of oil leaks, was running well. After pulling it apart, I saw all the scuffing, found metal in the pan and decided to do a complete OH. One thing led to another, ie – new mahles were $3k alone and a new Porsche crank was the same, so I decided to go w/nicom and JE”s. course at that point boring it out wasn’t a big deal… heads needed to be cleaned up, so 968 valves were a minor add-on, etc, etc. and I ended up w/my current “tuned” car. A slippery slope indeed!

The 911 and 968/944 gangs have been using nicom w/AL pistons for years, and I’d used it on some race bikes of mine, so I felt pretty comfortable w/the technology. Most of the builders I talked to claimed that friction coatings simply didn’t last on pistons due to expansion and heat issues. Cams, and other bearings seemed to work fine though."

GlenL

Hacker,

Thanks for the detailed response.

With Tim's response I'm free to plan being at RA next Labor Day weekend.

Tim Murphy

Adam, I'll get you some pictures. The coating failed on the pistons and scuffed the bores. We changed the honing procedure a little with my engine and all seemed good when it went together. Today I would be more comfortable with a plated bore.

hacker-pschorr

I'm hoping for a record turnout next year for the PCA event. Get the rest of the twin cities gang to come over.

Bill Ball

This is a great thread. People are expressing opinions and proposing options, and when things get heated, one of the parties tries to calm it back down and stay focused. Every so often it looks like it will explode, but then, like the last bunch of posts, it gets back to trying to work this out when somebody wisely shows some emotional control. I don't have any dogs in this hunt, as I wouldn't know Nikasil from Shinola. I am just supporting Mark getting the HP he needs and anxious to see where this goes. It's up to Mark to sort through all this and pick his way through to the end - a tough task. I'll just be there to turn a wrench as needed when we get to that stage. Congrats to Andrew, Hacker, Tim, Todd and all the other contributors for getting it this far and trying so hard to keep the project moving along.

hacker-pschorr

Well Bill, like it was mentioned above, this is family. Sometimes, this is what families do. I’m in the middle, some how quietly nominated to run this parade. So far so good, no death threats.

Gretch

Hacker, you know of course that "no good deed goes unpunished"............especially in "families"...........

THAT........ is why I am a recluse.

hacker-pschorr

If you some how orchestrated all of this as some revenge plot for the picture……my God man, you are a master.

Time to mess with the other pics you posted.