Im sure many of you have seen the stroker kit from flatlander racing, my question is if you increase the stroke of an engine does that lower the rpm you can safely run? If say you increased the stroke on the 7m, will you have to lower the rpm limit lower than stock?
Stroker kit
- Thread starter juggy61
- Start date
This post by Supracentral does a pretty good of answering your question.
http://www.supramania.com/forums/showpost.php?p=180719&postcount=18
Bits and peaces taken from the post:
Using the formula above, we can see that the Flatlander kit hits the “Very Short Life” barrier at 6,249RPMs. Can you exceed this RPM with Flatlander’s kit, with out flying apart. Yes, however the engine life will be greatly reduced.
Hope that answers your question
http://www.supramania.com/forums/showpost.php?p=180719&postcount=18
Bits and peaces taken from the post:
Supracentral said:
Using the formula above, we can see that the Flatlander kit hits the “Very Short Life” barrier at 6,249RPMs. Can you exceed this RPM with Flatlander’s kit, with out flying apart. Yes, however the engine life will be greatly reduced.
Hope that answers your question
Free bump. As I am also wondering,
And once it gets answered correctly, has anyone gone the other way and destroked a 7m to increase rpm's??
sorry dirgle, didn't see ya there.
And once it gets answered correctly, has anyone gone the other way and destroked a 7m to increase rpm's??
sorry dirgle, didn't see ya there.
The only people I've heard of destrokinig the 7M is HKS on there MKIII drag supra. They have had great success destroking the 7M to 2.89 liters, hitting 800+hp and revving it to 9,000 RPMs. This gave them an 8.09 second 1/4 mile pass on their tube chassis MKIII, with mufflers and on wet track conditions.
the 5m crank (~85mm stroke) can be used (same bore-stroke ratio as the 1jz but 2.8ltr) its no weaker then the 6m crank, but still not as good as a late 7M crank.
you can also go the M-EU crank for 75mm stroke and get your hands on some M-TEU rods! but your going to need a SERIOUS valve train to make power!
you can also go the M-EU crank for 75mm stroke and get your hands on some M-TEU rods! but your going to need a SERIOUS valve train to make power!
sorry but I am going to disagree with Mike. At 94mm stroke Ryan woon is pushing the 3.4l engine to 9500 rpm.
BMW in their S54 redlines that engine at 8000 rpm from factory. and that is with a 91mm stroke
and btw the piston speed in both those engines exceed the "recommended" limits.
BMW in their S54 redlines that engine at 8000 rpm from factory. and that is with a 91mm stroke
and btw the piston speed in both those engines exceed the "recommended" limits.
figgie said:sorry but I am going to disagree with Mike. At 94mm stroke Ryan woon is pushing the 3.4l engine to 9500 rpm.
BMW in their S54 redlines that engine at 8000 rpm from factory. and that is with a 91mm stroke
and btw the piston speed in both those engines exceed the "recommended" limits.
cause there are made to do that
NashMan said:
Ditto...
Rods break under deceleartion, under exhaust stroke... because it has to stop the piston from moving up..... and start it down... Both the 2j, and these other engines mentioned have lighter pistons... when you pair the piston wieght to piston speed, thens when too high of a rev coms to play.
MK III supra people tend to be cheap. Very cheap, meaning they'll go with Ross pistons. Ross pistons are great pistons, but tend to weigh almost 100grams more per piston then other pistons, which is where your problems tend to start..
You can also trust people who have minimal experince, have read a bunch of posts and made their own unsupported theories. You know, the guys who are saying "This company has done it, and so has this one, the 2j does this" Who gives a flying fuck? This is the 7M... and in the 7M it DOES NOT REV!!!! Piston speed and mass create problems. Do what HKS did, you have to DESTROKE, and then you can rev it.
figgie said:
The vast majority of Supra owners on this board use the car as a daily driver. Additionally, quite a lot of them rely on it as the ONLY car they have.
I didn't say it couldn't be done. I said is isn't a good idea. Go back an re-read my original post. I'm not sure what you disagree with.
figgie said:BMW in their S54 redlines that engine at 8000 rpm from factory. and that is with a 91mm stroke
and btw the piston speed in both those engines exceed the "recommended" limits.
Woons car is a marketing tool for WOTM. Ryan is always going to push the limits of what can be done, just as I did when crew chiefing the AAP drag car (which by the way ran two full seasons on the same motor without a rebuild).
I'm talking about sane engine design for a streetable motor with long life. Run the numbers on a Top Fuel motor and you'll find they run some insane piston speeds too.
And (if you read my original post) I've stated that manufacturers do sometimes go outside these guidelines for exotics & high end cars. The s54 that you mention is the powerplant for the BMW e46 ///M3, the flagship performance car for an auto manufacturer obsessed with high performance & engineering.
I'm certain BMW engineered that motor to withstand it.
What exactly do you disagree with?
Mike,
we are talking the stroker kit for the 7m.
So I can tell you that this stroker kit can infact be revved to 8000 rpm. Hell I am going to put my motor on the line and see what it can be the "grenade" limit.
Of course me along with adjuster are the only two running this kit. I can tell you with utmost confidence that if anything were to fail on this kit I would lean towards the crank grenading first before the rods or pistons fry.
we are talking the stroker kit for the 7m.
So I can tell you that this stroker kit can infact be revved to 8000 rpm. Hell I am going to put my motor on the line and see what it can be the "grenade" limit.
Of course me along with adjuster are the only two running this kit. I can tell you with utmost confidence that if anything were to fail on this kit I would lean towards the crank grenading first before the rods or pistons fry.
Raven97990 said:
I suggest you go looking for melloyellow for how a 7m
can in fact rev! As a matter of fact search for a post that I posted about this particular "myth" (i.e the 7m can not rev). IJ also contributed on that particular thread, But the short response is it CAN rev, you will run out of head flow first though but nothing a pnp job will not fix.
figgie said:
Figgie..
Your entire post is non-sequiter.
I'm aware of the topic we are discussing. I'm aware that the two of you are running this kit.
We're talking about sane engine design, not what "you feel" or what can be done.
I've already stated multiple times that revving these motors is possible, just not suggested.
Let us know how it does over time, it may be a well engineered kit - only time will tell.
mike,
my bad, for some reason I understood that the scope of thevdiscussion had changed hence me stating the 7m stroker.
bah not enough sleep.
my bad, for some reason I understood that the scope of thevdiscussion had changed hence me stating the 7m stroker.
bah not enough sleep.
On a side note, do any of you guys have the crank throw numbers for that kit?
I'd like to the full blown stress analysis calcs on this setup rather than the quick & dirty numbers we've been using.
I'd like to the full blown stress analysis calcs on this setup rather than the quick & dirty numbers we've been using.
Again, you refer to a "race" built engine, is the topic a daily driven vehicle being revved that high, or a full race engine revved that high?
Supracentral said:
Mike
the crank throw is 97.5mm for the crank specialist/flatlander racing kit. Rods are 6.00 Inch length, pauters.
hmmRaven97990 said:
you can call it what you want, the kit is no diffrent considering the pauter rods and the option for either ross or JE. The only thing not forged is the crank. That is a moddified OEM crank.
Adjuster
Supramania Contributor
Well, after running the "Stroker" as delivered from Flatlander for about 350 miles, it crapped out, and I ended up re-building it again. (Combination of a soft set of pin bushings, and Flatlander's total screw up on ordering the parts, and then not owning up to their screw up's...)
So, with the crank re-worked again, and the journals hard chromed and then ground true, and Pauter using hard bronze pin inserts, the motor has now held up to some regular abuse and use with not too many problems.
If I was going to do it all over again? I'd either just do something simple like convert this car to a LS3 based V8 with twins and standalone ECU, or get lighter pistons from JE, still do the coatings, and the oil system and all the other mods since the 7M Stroker motor is really fun to drive on the street, and make's silly amounts of tourqe on a mid sized turbo. (Spell that tire smoke at will in the lower 3 gears.)
I'm in the process of going to a larger turbo and fuel injectors, and ditching the whole MAF thing for the Maft Pro to control the fuel and air calc's.
Should be good for nearly 600rwhp when I'm done, but I'm not going to claim any HP or Tq figures untill it's up and running and strapped to a dyno.
So, with the crank re-worked again, and the journals hard chromed and then ground true, and Pauter using hard bronze pin inserts, the motor has now held up to some regular abuse and use with not too many problems.
If I was going to do it all over again? I'd either just do something simple like convert this car to a LS3 based V8 with twins and standalone ECU, or get lighter pistons from JE, still do the coatings, and the oil system and all the other mods since the 7M Stroker motor is really fun to drive on the street, and make's silly amounts of tourqe on a mid sized turbo. (Spell that tire smoke at will in the lower 3 gears.)
I'm in the process of going to a larger turbo and fuel injectors, and ditching the whole MAF thing for the Maft Pro to control the fuel and air calc's.
Should be good for nearly 600rwhp when I'm done, but I'm not going to claim any HP or Tq figures untill it's up and running and strapped to a dyno.