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Stroker
https://slantsix.org/forum/viewtopic.php?t=42617
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Author:  Dart270 [ Mon Nov 22, 2010 5:22 am ]
Post subject: 

If you are trying to make power, across the board, spend money/time on the cylinder head rather than stroke. The 225 is already a bigtime stroker motor. However, if you just have a hankerin', then go for it!

Lou

Author:  ceej [ Mon Nov 22, 2010 6:38 am ]
Post subject: 

Paul, if you decide to build the stroker for a truck application using the K-1 build, don't go hog wild with cutting the deck and head like I did.
You are not going to want that kind of compression. A nice 9:1 is more than adequate.
By jacking the compression way up, you will loose bottom end torque.

The stroke number that is recommended is 4.440" to avoid the extreme clearancing for rods and such. It's still a gob of stroke. With the K-1 pistons and rods, you will have more compression than you will want with a stroke of this size.

My engine is not a K-1 Build, and the pistons from Wisco would not fit with my stroker crank! A little clarification there.

CJ

Author:  Dart270 [ Mon Nov 22, 2010 8:10 am ]
Post subject: 

Quote:
By jacking the compression way up, you will loose bottom end torque.
CJ
I have never understood statements like this, and believe it is one of those erroneous things that gets repeated so often everyone believes it (exhaust "backpressure" is another).

My experience (and basic understanding of engines) is that higher compression increases torque and efficiency across all ranges. However, if you have to back off timing or richen mixture to stop pinging, it could indirectly cause low end torque drop. Having the right combo is important.

I am happy to be shown wrong...

Did I just sound like Dan there??? :wink: :lol:

HOWEVER, CJ is correct that you won't want super high compression for your truck build, and his suggestion to not cut block/head is a very good one. 9:1 is a good target.

Lou

Author:  Polara1974 [ Tue Nov 23, 2010 3:49 pm ]
Post subject: 

I'm just going the opposite direction with my new engine. I'm using 7,65" center to center rods with 2" big end (Chevy?) and will offset gring the rod journal to reduce the stroke to 3,93" and the bore size will be aroung 90mm (3,54").
This way I'll have 500-700++ RPM, that along with the long rods will make a slant turn 6800RPM with no problem.

For me the bigger the bore, the shorter the stroke and the longer the rod can be is the best for performance.
Quote:
One thing that you have to remember about a Slant, no matter what stroke you have the crappy small ports and bore make RPM somewhat irrelevant anyway. :lol:
Why? I have seen ACTC Slant Sixes turning 7800RPM (with the stock head ported, NOT the ACTC Race Head) and had no problem about cfm flowing trough the ports!!!

Author:  slantzilla [ Tue Nov 23, 2010 3:51 pm ]
Post subject: 

Quote:
Why? I have seen ACTC Slant Sixes turning 7800RPM (with the stock head ported, NOT the ACTC Race Head) and had no problem about cfm flowing trough the ports!!!
I've turned mine over 7000 a couple times. Yes, it will rev, but it did not make any power.

Fortunately for me, it did not make a hole in the block either. :lol:

Author:  1974duster kev [ Tue Nov 23, 2010 4:02 pm ]
Post subject: 

I'm not trying to step on any toes but i just dont see the point of stroking an already stroked motor (besides because you just want to or you want a 4x4 monster) but say a street strip car there are guys all who are going faster with non stroked slants their just seems more to gain from longer rpm sweeps in stead of flooring it then the motor being outa ooomf by 4500rpm not to mention you could run a better gear becasue rpm would help out your top speed. Just my opinion but it also seems someone could build a faster non stroked motor for less money then a stroked motor. What ever happend to brens 258cube slant six didn't he sell it? and if so did that new owner ever get it running right?
I'm no guru but the way to go would head towards a sqaure motor equal bore to stroke or even bigger bore than stroke ( generally speaking for any motor).
Just my 2 cents i've never built a stroker motor so i could be wrongo
Kev

Author:  Polara1974 [ Tue Nov 23, 2010 5:14 pm ]
Post subject: 

Quote:
I'm no guru but the way to go would head towards a sqaure motor equal bore to stroke or even bigger bore than stroke ( generally speaking for any motor).
Just my 2 cents i've never built a stroker motor so i could be wrongo
Kev
Thats my point. If I have the chance I'll never build an engine with longer stroke than bore. With the slant six this is almost impossible (unless running on 170 crank)

Author:  Rick Covalt [ Tue Nov 23, 2010 5:32 pm ]
Post subject:  Lou's Truck

I believe that is the motor in Lou's Slantkota truck he uses for towing? Runs 15's too! :D

Author:  sandy in BC [ Wed Nov 24, 2010 6:52 am ]
Post subject: 

The Slantkota not only will turn 15s.....but it will do it with me behind the wheel.

Author:  /6 Matt [ Thu Nov 25, 2010 10:20 pm ]
Post subject: 

Quote:
i just dont see the point of stroking an already stroked motor
It is indeed an already stroked motor. That's exactly why I've always fancied building a turbo diesel slant someday. But man would that require some $$$!

Author:  Dart270 [ Fri Nov 26, 2010 11:48 am ]
Post subject: 

Kevin and all,

Bren's 258" Slant is alive in the 1990 Slantkota, yes. 4.250" stroke X 3.592" bore (no typo). Needs rings - lots of oil smoke (crappy total seal rings). 15.39 @87.7 MPH fastest 1/4 mile yet. Pulled Project V to the track through the mountains too on that weekend (Clay City, KY). Very docile motor. With rings and a better suited cam, should run 14s next year.

Lou

Author:  1974duster kev [ Sat Nov 27, 2010 7:55 am ]
Post subject: 

Thats what i'm saying right there lou, those 33 extra cubes seem to not make any huge benefit of bigger is better.

Thanks for conversating opinions guys i just like those hypothetical what would work better kinda topics.
Kev

Author:  Rick Covalt [ Sun Nov 28, 2010 12:39 pm ]
Post subject:  ??

Kev,

I think that Lou's 258 is proof of what can be done. Not what most of us are going to do or can afford to do. I think those extra 30+ cubes definitely help. Lou's truck is set up to tow (and he towed clear up to Mason Dixon back in July) and it still runs a low 15 second time slip. It is an automatic without low gears and tows dependably. I am impressed with that, and I think the extra 33 cubes are definitely worth 20-25 more horsepower. It takes some doing to get an A-Body street car into the 14's with a 225. To do it with a truck is even more impressive. A tow truck makes it super impressive. Just my 2 cents. :D

Rick

Author:  sandy in BC [ Sun Nov 28, 2010 1:20 pm ]
Post subject: 

The Slantkota engine begs for the right head/cam combo. You can tell there is more in it.

Right now it makes excellent midrange torque. .....the kind that is associated with no fuss. It just pulls.

We have the same truck here in V6 form....the Slantkota is a much better balanced truck . It is also quiet, well behaved and intuitive to drive.

That much torque would really be fun with a 5 speed.

Its the Dakota Dodge should have built.

Author:  ceej [ Sun Nov 28, 2010 2:48 pm ]
Post subject: 

Something a tad nastier than the RV15M RDP I've got would likely work. For towing, this cam works flawlessly. (Yes I towed a trailer with the Valiant to several races, dropped the trailer, and raced it.)

I also went with gapless rings. It'll get Iron before I'm through. Just not worth the hassle for "Improved sealing" that doesn't seem to work with such a long stroke.

4.475" x 3.445" in my build.
Best of 15.02 1/4.
There are things to be said for getting all the power in well under 5000 rpm, and it will turn that engine speed pretty easily with the lightened 198 rods and dainty little pistons from the Toyota.

CJ

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