Building a high rev. motor, what would it take?
07-01-2007, 01:18 AM
#16
Banned
Join Date: Nov 2003
Location: En La Boca Del Raton
Posts: 1,341
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by Steve Weiner-Rennsport Systems
Contact Porsche Motorsports,........be prepared to spend really BIG money,........
07-02-2007, 05:31 PM
#17
Racer
Join Date: Apr 2007
Posts: 296
Likes: 0
Received 0 Likes
on
0 Posts
I can tell you that a 996GT3RS engine in the UK is £56,000 plus v.a.t. for 450bhp ish. 997 do not know. Will only rev to from memory 8700rpm and will require stripping down regularly. Every 12 hours is advised. Chances are it will have broken something. Good luck with your quest for revs.
07-24-2007, 10:27 PM
#19
Instructor
Join Date: Jul 2004
Posts: 110
Likes: 0
Received 0 Likes
on
0 Posts
Got to Japan and find the guys the built this 10k RPM Honda
http://www.youtube.com/watch?v=nj2nlF1hkEc
http://www.youtube.com/watch?v=nj2nlF1hkEc
07-29-2007, 07:57 PM
#21
Racer
Thread Starter
Originally Posted by m42racer
The limiting factor for high engine speed in these opposed engines is the Crankshaft.
I assume this means the crank is not balanced enough or strong enough, "throwing a rod, etc."
then how about using a 3.6 short block and putting in some 2.0 pistons and liners, machine some adapters to make up the difference in piston sizes where cyclinders mate with the case, this would reduce the load on the rod bearings way below design assumptions. Could we then turn up over 10k reliably?
How does F1 do it? The goal is the RPM without breaking the motor, the power will be whatever it is, I realize we can make power other ways, I am simply after the project for challenge of it. (and the sound)
07-29-2007, 09:02 PM
#22
The issue is the counterweight mass or lack thereof. These engines have little to no counterweight mass, and no dampener. At this sort of engine speed the harmonics have to be controlled or the crankshaft will reach or get very close to its natural frequency. I am not sure if its second or third order harmonics, but whatever they are they will cause the crank to break. Adding mass to the Crank and running a dampener will allow this sort of speed. The reciprocating masses have top be taken into account here to figure out the counterweight mass required. If I remember correctly its somewhere around 39% of the reciprocating mass in a V type engine with a 90^ Cylinder angle. I'm sure it changes with many factors not considered here. It would have to be calculated, but most Porsche cranks do not have enough counter weight to run up in the 10K Revs. I have seen cranks that have failed when run up and over 9000K. Best to get someone who knows this stuff to advise. I see you are in Costs Mesa. Call Neil @ Performance Developments. 949 646 7461. He's in that town and would know. As it's been stated, it will be expensive. Are you sure a Porsche engine at 10K sounds good?
08-04-2007, 05:18 PM
#24
check out www.rudtnersracing.com
Look at the videos of the Watkins Glen race. Speed at the exit of the esses is 154 in fourth gear.
exit rpm out of most turns is 8600
The engine is in an older 1979 turbo. Picture of the car is on the web site entry page. We are building a very similar engine now for a guy in Atlanta.
Enjoy the ride
Look at the videos of the Watkins Glen race. Speed at the exit of the esses is 154 in fourth gear.
exit rpm out of most turns is 8600
The engine is in an older 1979 turbo. Picture of the car is on the web site entry page. We are building a very similar engine now for a guy in Atlanta.
Enjoy the ride
08-05-2007, 11:23 AM
#25
Rennlist Member
Originally Posted by sparetireless
Could a semi-reliable 10k RPM motor be built? Seems like the main weak points are rod bolts, and valve float, is there anyway around these week points.
I would like to build a motor like this just for the challenge of it. Any suggestions ?
I would like to build a motor like this just for the challenge of it. Any suggestions ?
find a copy of the Jun 1999 Excellence.
There's a 3 page article on just this subject.
(it all depends on your definition of "semi-reliable").
craig
08-17-2007, 12:28 PM
#27
Pro
Join Date: Nov 2006
Location: Tibet
Posts: 563
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by sparetireless
How does F1 do it? The goal is the RPM without breaking the motor, the power will be whatever it is, I realize we can make power other ways, I am simply after the project for challenge of it. (and the sound)
when you have such tiny moving parts its easier to make it spin fast.
08-18-2007, 08:38 AM
#28
Track Day
Join Date: Sep 2006
Location: Richfield Ohio during the warmer seasons and Bonita Springs Florida when cold
Posts: 15
Likes: 0
Received 0 Likes
on
0 Posts
"Howabout putting a certain 4-cylinder engine up to 8000RPM without breaking? Anyone know who could make a head good for that?"
Sure, been doing that with our 944 SCCA GT2 car for several years. Head is not a big problem. PM me if you would like more detail.
Al
Sure, been doing that with our 944 SCCA GT2 car for several years. Head is not a big problem. PM me if you would like more detail.
Al
09-02-2007, 06:11 PM
#29
Drifting
Peripheral port 20B.
I wonder why they spell Tsuchiya's name Shichiya or whatever it is in that youtube video.
Could go with a 20v 4a-ge too lol. I guess it would be a sin to put a Japanese engine into a German car, especially a Porsche.
Good luck.
I wonder why they spell Tsuchiya's name Shichiya or whatever it is in that youtube video.
Could go with a 20v 4a-ge too lol. I guess it would be a sin to put a Japanese engine into a German car, especially a Porsche.
Good luck.
