high compression 2.7RS engines?

[Neunelfer]

Why not re-bush the end of the rods... doesn't Harry Bieker do that for cheap?

Timing chains aren't an issue then...

[swisscheese]

ok, so after an absence of 15 years, I'd like to pick-up this thread, as I still haven't made a decision yet. Are there any "new insights" on the High Compression 2.7RS engine, making from a 2.4S engine? Read a lot about the 2.7RS HC engine, but no hands-on experiences...

[Mr9146]

ok, so after an absence of 15 years, I'd like to pick-up this thread, as I still haven't made a decision yet. Are there any "new insights" on the High Compression 2.7RS engine, making from a 2.4S engine? Read a lot about the 2.7RS HC engine, but no hands-on experiences...

Chuck Miller's car has been running a high comp 2.7L RS spec motor for the last decade (or longer) and over 90,000 HARD miles.

Ask him...

[RSTarga]

are the Andial 9.5 pistons Chuck runs still available from Mahle?
The 2.2 S was 9.8 so for street gas that would be about the max safe compression I would think.

[sithot]

EBS sells JE pistons. 9.5:1 to 10.5:1

https://www.ebsracing.com/products?c...20&clev=1&fc=1

[Chuck Miller]

Chuck Miller's car has been running a high comp 2.7L RS spec motor for the last decade (or longer) and over 90,000 HARD miles.

Yep...……. 15 years, and 93,000 mile....
Was at the track with it on Monday, about 30 laps on the small track, over 50 10/10ths (for me) miles...

It's a GREAT option... The 9.5's are actually about 9.7 c/p

This has just come up with an old ESR member from Holland that is thinking about going that way... And I'm now trying to find a retailer for him...

I am told that the only difference between the set I put in 15 years ago and the new sets that are (hopefully) available now; is that the older sets had the old type ring thickness, and the new sets are cut to use the modern (supposedly more efficient) thinner rings...

I've only had about 1/2 hour homework on this search.... Please help with the search and post here....

Looking online or calling the U.S. Mahle distributor is kind'a useless...
These were/are made for Porsche Motorsports venders … like Andial ….was.

BTW - Arnold at Andial sold me the complete set (P's & C's/rings/pins/clips) with a $100 PCA discount, and a friend's resale number for over $2600 over 15 years ago.... Have no idea what they would cost today....

BTW - Harvey W. had these h/c sets way back when he was at the SoCal dealership back in the '70's

- Here's a crappy pic of what they look like.... They kind'a look in between an 8.5 2.4 or 2.7RS, and 2.2S...
- And a pic from 2 days ago....

[swisscheese]

hey Chuck, thanks man! I was Googling on the subject, when I came across this thread; Seems it was mine! I totally forgot about this (getting old, I guess..). I'm checking with Mahle Motorsport about a high-compression set they seem to have. Trying to get an idea of the overall effort/cost (and if I want to cut my matching numbers cases..).

[RC70SCoupe]

In another thread, the question of increasing the compression of a 2.4S engine was discussed. Using 2.2S pistons seem to be the (relative) easy solution.

In 2006, Scotts Independent completely rebuilt my 2.4S. They used 2.2S pistons.
I've been VERY happy with that vs. the days when its was just 2.4S

First 2 dyno graphs were on the bench. Second 2 were dyno pulls in the car at John Willhoit's Open House.

[sithot]

In 2006, Scotts Independent completely rebuilt my 2.4S. They used 2.2S pistons.
I've been VERY happy with that vs. the days when its was just 2.4S

First 2 dyno graphs were on the bench. Second 2 were dyno pulls in the car at John Willhoit's Open House.

That's what was done to my 73-S (T conversion). I wouldn't hog out the spigots if it were mine.

[Chuck Miller]

I wouldn't hog out the spigots if it were mine.

Well THAT'S the question isn't it?…
And I agonized over it 15 years ago, and went in the 2.7 direction...
I did consider a 2.2S piston rebuild first... trust me

AND - BTW - The question and measured consideration I'm talking to my Dutch friend about now...

Part of my decision was by '02 I had tracked (not raced, but time trialed) and 'drove the hills' in my 911 for 13 years and felt that I really didn't need to go faster where my old 2.4S was already pretty fast... what I needed was to go faster where the car wasn't very fast... out of slow corners... I needed the torque.

Yeah, yeah, I know even back then 2lt. 911 race cars were go'n MUCH faster then me...(over 5 seconds a lap on the big track... ) But mine was a mixed purpose 6000 mile a year 'street car' that needed to last for a long time...

Then about the same time I drove Randy Wells' '72S 2.7 rebuild up in the hills, with Randy coach'n 'try this next turn one gear up'... and I was in love...

There's also other decisions I made about cams, head work, and a bunch of other stuff..... All and all, through lots of homework, a very good engine builder, and a little luck... just for me, I feel I made the right decision...

Now - If I was to do it all over again today??? … I'd probably take the 2.4S engine out and put it on a pallet complete... and start the 2.7 h/c project on an old aluminum or turbo case.... But who had the money? ….
......…. If wishes were fishes....