Stroker Cranshafts
08-08-2002, 11:03 PM
#31
So Jay,
At what point in climbing Horsepower Mountain does the TT give it up and twist off?
We never really had a long sit down for shooting the breeze, the twisty's were the source of an enormous amount of fun, but consumed to much of our limited time in Sharkansas.
I have been wondering for some time now at what point HP and new found gobs of torque start breaking things. Are you in touch with even the club racers to see what trends in breakage developed? Of particular concern is the toss-up between wether torque tube wind-up or converter balloning - both - is causing the crank to walk and turn into a hidden machine shop. Do the big hp guys manufacture a double bolt setup like Snow mentioned or just re-torque daily? Same for the short shafts , what happens there?
OR...
Are you going to be a dare-devil risking your current marital status
as parts let go one by one.
I would love to have the torque of a locomotive engine and 425 HP or better when I build a sHARk... someday... . But there are threshholds I'd just as soon have someone else document - including the many small sadnesses. <img src="graemlins/crying.gif" border="0" alt="[crying]" />
John S. and Pattycakes
At what point in climbing Horsepower Mountain does the TT give it up and twist off?
We never really had a long sit down for shooting the breeze, the twisty's were the source of an enormous amount of fun, but consumed to much of our limited time in Sharkansas.
I have been wondering for some time now at what point HP and new found gobs of torque start breaking things. Are you in touch with even the club racers to see what trends in breakage developed? Of particular concern is the toss-up between wether torque tube wind-up or converter balloning - both - is causing the crank to walk and turn into a hidden machine shop. Do the big hp guys manufacture a double bolt setup like Snow mentioned or just re-torque daily? Same for the short shafts , what happens there?
OR...
Are you going to be a dare-devil risking your current marital status
as parts let go one by one. I would love to have the torque of a locomotive engine and 425 HP or better when I build a sHARk... someday... . But there are threshholds I'd just as soon have someone else document - including the many small sadnesses. <img src="graemlins/crying.gif" border="0" alt="[crying]" />
John S. and Pattycakes
08-09-2002, 05:05 AM
#32
Hi John and hi Mike, John in regard to the TT and I'll say this first my direct knowledge is limited, but what about this for an idea. What if you put a slip joint at the engine end of things, The slip joint would be similiar to the joint that rear wheel drive cars have, that don't have independant suspension like any early Chevy or Ford.
The slip joint on these cars is located just behind the transmission. It's needed on these cars because of the changing relationship of the rear suspension to the drivetrain.
So this could allow for a bit of movement without any damage. I know I will have to deal with this problem when I build my new motor and would be interested to get some feedback on this idea.
Mike I don't think the bearing sizes would be a problem because those chevy race motors put out enormous power, and don't seem to have reliability problems.
As point of interest what is the difference in the bearing sizes? All the best
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" /> <img src="graemlins/drink.gif" border="0" alt="[cherrsagai]" />
The slip joint on these cars is located just behind the transmission. It's needed on these cars because of the changing relationship of the rear suspension to the drivetrain.
So this could allow for a bit of movement without any damage. I know I will have to deal with this problem when I build my new motor and would be interested to get some feedback on this idea.
Mike I don't think the bearing sizes would be a problem because those chevy race motors put out enormous power, and don't seem to have reliability problems.
As point of interest what is the difference in the bearing sizes? All the best
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" /> <img src="graemlins/drink.gif" border="0" alt="[cherrsagai]" />
08-09-2002, 01:32 PM
#33
There was someone that was working on what I think was a slip joint for the front of the torque tube. I haven't heard anything about it in a while though, so I don't know what the status of that is.
I don't know what the sizes of the bearings are, or even for sure if they really are different or not. That is something I've heard though. I didn't mean to imply that the Chevy size bearings were inherently unreliable, just that if all other things were equal, the wider bearings should last longer. The engineered life expectancy of a 928 engine is 300,000+ miles. Not so with a Chevy engine. Just trying to add more for thought and discussion.
I don't know what the sizes of the bearings are, or even for sure if they really are different or not. That is something I've heard though. I didn't mean to imply that the Chevy size bearings were inherently unreliable, just that if all other things were equal, the wider bearings should last longer. The engineered life expectancy of a 928 engine is 300,000+ miles. Not so with a Chevy engine. Just trying to add more for thought and discussion.
08-13-2002, 03:06 AM
#34
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[quote]Originally posted by Mike Schmidt:
<strong>There was someone that was working on what I think was a slip joint for the front of the torque tube. I haven't heard anything about it in a while though, so I don't know what the status of that is.</strong><hr></blockquote>
It is Constantine (in Florida) that is doing this. My understanding is that he is trying a custom-machined front coupler that uses a "sliding spline" to allow some "float" at the connection. I haven't heard of any recent update on how this is working out.
Brad
'78 euro 5 speed
928 Owners Club
Rennlist #020804-2937
<a href="http://www.p-caronline.com/directory/showngo/" target="_blank">928 euro</a>
<strong>There was someone that was working on what I think was a slip joint for the front of the torque tube. I haven't heard anything about it in a while though, so I don't know what the status of that is.</strong><hr></blockquote>
It is Constantine (in Florida) that is doing this. My understanding is that he is trying a custom-machined front coupler that uses a "sliding spline" to allow some "float" at the connection. I haven't heard of any recent update on how this is working out.
Brad
'78 euro 5 speed
928 Owners Club
Rennlist #020804-2937
<a href="http://www.p-caronline.com/directory/showngo/" target="_blank">928 euro</a>
09-02-2002, 04:02 AM
#35
[quote]Originally posted by show'n'go:
<strong>
Mike, even if this thread is buried in the "back pages" by then, please let us
all know the latest on this car/engine. Hope you get a chance to talk to the KMR
guys!</strong><hr></blockquote>
I went to Road America Sunday, and the Kelly-Moss 928 engined car was there. It was standing out in front of the trailer that they had there, with the front section off of it. I did some looking, and also talked to a couple of the Kelly-Moss guys that were there. The car that the engine is in is a 944GTR, which is a factory built race car. The engines originally in them were four cylinder turbos. The front section of the car was cut off, and a new one was made to accomodate the 928 engine. Because of the rarity and history of the car, this was done so that the original front end could be put back on at some time in the future if desired, to return the car to original condition.
Now for the stuff that you probably only really care about. The engine is 6.6 liters. It has the eight individual throttle bodies on it. The engine management system is from EFI Technology (www.efitechnology.com), and it has individual coil on plug ignition. The dry sump pump is made by Barnes Systems. The engine dynoed at 711 hp, and 680 ft/lbs of torque. Since Kelly-Moss has an engine dyno, and not a chasis dyno, I'm assuming that these are the crankshaft power numbers.
I was hoping to see the car out on the track, but unfortunately that didn't happen. The only day that I was there was Sunday, and the car had been out on the track for only a short time on Thursday. Apparently the clutch wasn't very happy with all that torque, and developed a problem after only the first two laps of testing. The other big problem that they discovered was the lack of traction. Even with the big racing slicks on the car, there would be wheel spin anytime the gas pedal was floored in third gear. The next things to be done are to find a solution to the clutch problem, and to try to get larger tires on the rear. Overall they said that they were extremely happy with the 928 engine so far.
Want one? The figure that I heard mentioned for the cost of the engine was $80,000.
<strong>
Mike, even if this thread is buried in the "back pages" by then, please let us
all know the latest on this car/engine. Hope you get a chance to talk to the KMR
guys!</strong><hr></blockquote>
I went to Road America Sunday, and the Kelly-Moss 928 engined car was there. It was standing out in front of the trailer that they had there, with the front section off of it. I did some looking, and also talked to a couple of the Kelly-Moss guys that were there. The car that the engine is in is a 944GTR, which is a factory built race car. The engines originally in them were four cylinder turbos. The front section of the car was cut off, and a new one was made to accomodate the 928 engine. Because of the rarity and history of the car, this was done so that the original front end could be put back on at some time in the future if desired, to return the car to original condition.
Now for the stuff that you probably only really care about. The engine is 6.6 liters. It has the eight individual throttle bodies on it. The engine management system is from EFI Technology (www.efitechnology.com), and it has individual coil on plug ignition. The dry sump pump is made by Barnes Systems. The engine dynoed at 711 hp, and 680 ft/lbs of torque. Since Kelly-Moss has an engine dyno, and not a chasis dyno, I'm assuming that these are the crankshaft power numbers.
I was hoping to see the car out on the track, but unfortunately that didn't happen. The only day that I was there was Sunday, and the car had been out on the track for only a short time on Thursday. Apparently the clutch wasn't very happy with all that torque, and developed a problem after only the first two laps of testing. The other big problem that they discovered was the lack of traction. Even with the big racing slicks on the car, there would be wheel spin anytime the gas pedal was floored in third gear. The next things to be done are to find a solution to the clutch problem, and to try to get larger tires on the rear. Overall they said that they were extremely happy with the 928 engine so far.
Want one? The figure that I heard mentioned for the cost of the engine was $80,000.
09-02-2002, 01:29 PM
#37
Jay,
But what about in town mileage? I'm sure the 6.6L is a mere sipper compared to the 'Chebbey'.
There are many of us who prefer our docile 700HP grocery getters to be tree and porpoise friendly
And properly muffled most State Troopers won't get an erection when we cruise by at 142mph in 4th - I wonder, what are these other two gears for? - <img src="graemlins/bigok.gif" border="0" alt="[thumbsup]" />
Well, if I hit the Lotto... You are all welcome to join me at 'The Salt Flats', my treat, for one or two passes at the 250 club in a natually - sort of - aspirated 928.
Anyone know what happened to the factory engine molds?
Jay, any Idea, at all, why they were having clutch problems?
Well gotta go ... lotto tickets awaiting ...
Pattycakes says she'll watch from the tent...
But what about in town mileage? I'm sure the 6.6L is a mere sipper compared to the 'Chebbey'.
There are many of us who prefer our docile 700HP grocery getters to be tree and porpoise friendly
And properly muffled most State Troopers won't get an erection when we cruise by at 142mph in 4th - I wonder, what are these other two gears for? - <img src="graemlins/bigok.gif" border="0" alt="[thumbsup]" />
Well, if I hit the Lotto... You are all welcome to join me at 'The Salt Flats', my treat, for one or two passes at the 250 club in a natually - sort of - aspirated 928.
Anyone know what happened to the factory engine molds?
Jay, any Idea, at all, why they were having clutch problems?
Well gotta go ... lotto tickets awaiting ...
Pattycakes says she'll watch from the tent...
09-02-2002, 03:38 PM
#38
[quote]Originally posted by Jay Wellwood:
<strong>Wow...and to think I passed on a 924 with a Chebby motor in it for $4K.</strong><hr></blockquote>
There's a guy that lives about a block and a half from me that's selling his mid '70s Camaro. He drives it regularly on the street, but I don't know about the gas milage on that one. It's got a fuel injected big block Chevy engine, with twin intercooled turbos in it, that makes 1100hp. Only $10,000 and you can get your groceries in record time.
<strong>Wow...and to think I passed on a 924 with a Chebby motor in it for $4K.</strong><hr></blockquote>
There's a guy that lives about a block and a half from me that's selling his mid '70s Camaro. He drives it regularly on the street, but I don't know about the gas milage on that one. It's got a fuel injected big block Chevy engine, with twin intercooled turbos in it, that makes 1100hp. Only $10,000 and you can get your groceries in record time.
09-03-2002, 07:50 AM
#39
Hi Guys, I'm starting on a basic engine package this week. The starting point is a 310 s2 engine and the mods it will get are as follows;
Headers which are of my own design.
The exhaust from there back will be duel 2.5 inch with the variable backpressure option. The heads will be flowed.
I'm also designing custom camshafts for this system. With variable backpressure I will be able to run a decent overlap due to better low speed scavenging.
A rising rate fuel pressure regulator.
The headers and intakes port matched to the head.
What am I hoping for? Well I would hope to get close to 400 flywheel hp. Or about 330 rear wheel hp we'll see as the steps along the way will be dyno tested. A trip to the drag strip wouldn't go astray either. Food for thought, all the best.
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" /> <img src="graemlins/jumper.gif" border="0" alt="[jumper]" /> <img src="graemlins/yltype.gif" border="0" alt="[typing]" /> <img src="graemlins/bigok.gif" border="0" alt="[thumbsup]" />
Headers which are of my own design.
The exhaust from there back will be duel 2.5 inch with the variable backpressure option. The heads will be flowed.
I'm also designing custom camshafts for this system. With variable backpressure I will be able to run a decent overlap due to better low speed scavenging.
A rising rate fuel pressure regulator.
The headers and intakes port matched to the head.
What am I hoping for? Well I would hope to get close to 400 flywheel hp. Or about 330 rear wheel hp we'll see as the steps along the way will be dyno tested. A trip to the drag strip wouldn't go astray either. Food for thought, all the best.
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" /> <img src="graemlins/jumper.gif" border="0" alt="[jumper]" /> <img src="graemlins/yltype.gif" border="0" alt="[typing]" /> <img src="graemlins/bigok.gif" border="0" alt="[thumbsup]" />
09-03-2002, 08:50 PM
#40
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What is the accepted drivetrain loss quotient for the 928? 15% or 17% or something else??
Is 330HP at the wheels with a 17% loss 386 HP? Am I doing the calculations correctly (1.17 X 330)?
Is 330HP at the wheels with a 17% loss 386 HP? Am I doing the calculations correctly (1.17 X 330)?
09-04-2002, 04:38 AM
#42
I don't see anything wrong with your calcs. I used a 20% loss because my car is auto. All the best.
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" /> <img src="graemlins/bigok.gif" border="0" alt="[thumbsup]" />
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" /> <img src="graemlins/bigok.gif" border="0" alt="[thumbsup]" />
09-04-2002, 01:36 PM
#43
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I think a good way to do it would be to gather a data base of 5sps and autos through various years. we know the book values. For example,316hp for an S4...take the average data and figure and average loss. <img src="graemlins/yltype.gif" border="0" alt="[typing]" />
09-06-2002, 02:36 AM
#44
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[quote]Originally posted by Mike Schmidt:
<strong>
I went to Road America Sunday, and the Kelly-Moss 928 engined car was there.
Now for the stuff that you probably only really care about. The engine is 6.6 liters. It has the eight individual throttle bodies on it. The engine management system is from EFI Technology (www.efitechnology.com), and it has individual coil on plug ignition. The dry sump pump is made by Barnes Systems. The engine dynoed at 711 hp, and 680 ft/lbs of torque. Since Kelly-Moss has an engine dyno, and not a chasis dyno, I'm assuming that these are the crankshaft power numbers.
Want one? The figure that I heard mentioned for the cost of the engine was $80,000.</strong><hr></blockquote>
Thanks for the update and the details Mike!
Some pretty serious numbers.... 711, 680, 80000
I checked out that EFI Technology website. Those people aren't shy about their prices either, LOL.
Brad
'78 <a href="http://www.p-caronline.com/directory/showngo/" target="_blank">928 euro</a> 5 speed
928 Owners Club
<strong>
I went to Road America Sunday, and the Kelly-Moss 928 engined car was there.
Now for the stuff that you probably only really care about. The engine is 6.6 liters. It has the eight individual throttle bodies on it. The engine management system is from EFI Technology (www.efitechnology.com), and it has individual coil on plug ignition. The dry sump pump is made by Barnes Systems. The engine dynoed at 711 hp, and 680 ft/lbs of torque. Since Kelly-Moss has an engine dyno, and not a chasis dyno, I'm assuming that these are the crankshaft power numbers.
Want one? The figure that I heard mentioned for the cost of the engine was $80,000.</strong><hr></blockquote>
Thanks for the update and the details Mike!
Some pretty serious numbers.... 711, 680, 80000
I checked out that EFI Technology website. Those people aren't shy about their prices either, LOL.
Brad
'78 <a href="http://www.p-caronline.com/directory/showngo/" target="_blank">928 euro</a> 5 speed
928 Owners Club
09-11-2002, 12:14 AM
#45
Rennlist Member
The uniquely "DEVEK" 8 counterweight, center drilled cranks are shipping and we are preparing for the next order. This order for 8 is gone, and two are going into 500 rwhp street monsters, one into a 800 hp racer, and the rest, inot nice and easy 400+ rwhp streeters!
Look for a writeup in the future on these newly developed einges in the future.
Yeehah!
Let me know if anyone is interested.
Marc
DEVEK
Look for a writeup in the future on these newly developed einges in the future.
Yeehah!
Let me know if anyone is interested.
Marc
DEVEK