Biggest Crank in a Type4

[wrenchnride247]

Let me rephrase my earlier post... 86mm is the biggest you can go SAFELY and RELIABLY (knew about the 90mm, but didn't think the OP wanted to go extreme $$$)

[Type 4 Unleashed]

Let me rephrase my earlier post... 86mm is the biggest you can go SAFELY and RELIABLY (knew about the 90mm, but didn't think the OP wanted to go extreme $$$)

Actually, one of the customers EMW had made the 90mm cranks for had previously had EMW make him a 88mm crank that he had ran for about 2 years before having them make him the 90mm one. And from that 88mm crank he was able to determine that he could run a 90mm crank.

And he's been running the 90mm crank going on 2 years.

And anyways sooner or later parts break, that's what happens when you double & triple the hp on these motors.

[Wally]

Question is also: will you make more hp with the 90mm crank then with a 86mm or a 82mm...?

[Type 4 Unleashed]

Question is also: will you make more hp with the 90mm crank then with a 86mm or a 82mm...?

Then how about we continue the question, will you make more HP with a Pauter 96mm crank than you would with a 86, 88 or 90mm crank ?

I will seeif I can get the answer too: Was it worth it going from the 88 to the 90mm crank ?

[Wally]

Yeah, when do the diminishing returns go backwards?

Would be a much deeper discussion on flow inside the case and through the heads.
I guess if your heads would flow enough and then some, the extra displacement could surely help boost torque across the range.

[fusername]

yeah but you would probably need god's own heads to really take advantage of the work. taht said, I would really like to see these cranks inside a case. can't have a thread like this without some engine porn.

[Type 4 Unleashed]

yeah but you would probably need god's own heads to really take advantage of the work. taht said, I would really like to see these cranks inside a case. can't have a thread like this without some engine porn.

Actually heads won't be too much of a problem, most people other than myself don't run a cam large enough to need anything over a stock 2.0 ltr valved head anyways...

And with a 90mm stroke & 105mm bore or larger, velocity in the ports will never be a problem, it will be volumne that will be lacking from small ports & valves. And I have the heads to just take care of that problem...

I have a set of 5.4" Rabbit jrl Carrillo rods that I will throw on my 90mm Rabbit jrl crank tomorrow and mock it up in a case. Do to the fact I am very curious as to clearance issue's. And anyways I am already thinking about having a set of Cunningham rods done in Rabbit jrl's...

[fusername]

man you get to have all the fun. tommorow I am only going to chop my keepers and wash my heads a bit more.

[Type 4 Unleashed]

man you get to have all the fun. tommorow I am only going to chop my keepers and wash my heads a bit more.

I don't know about having all the fun, who knows what issues I will find.

And I hate chopping keepers, untill just recently, I would just go to Gene Berg's and spend the $20 something dollars and get their pre-clearance, hardened & black oxided keepers, that they don't bother to black oxide them any more... ... just to keep from having to grind keepers.

[fusername]

I used to have a notch in my finger nail from doing them all the time. When i'm finally done, whats so exciting about a good set of keepers? when your done, you get the excitment of taming a 90mm crank!

[Type 4 Unleashed]

There was a power outage, so finished mocking this up in the dark, and was how the pics were taken.

This is going to be fun, it hits every where... ... It's not really a fair mock up, the 2.0 ltr H beams compared to these carrillo rods I used for the mock up, have the clearancing where it's need and would provide far more clearance than these did.

And the cam was a bad choice for a clearance mock up, it had a fairly large B/C along with a large lobe lift of .430".
And I didn't put the drive gear on so the cam lobes were not where they were suppose to be when the rod came around.