cross flow to looper

[jjmalkow]

Can I use a V-4 cross-flow gearcase on a V-4 looper? It would be 80's crossflow going on a 1995 130 Rude. Only thing I can think of is prop shaft size, or am I not thinking clear? Anything else I should be looking at?? Thanks guys!!!!

[bigbore]

i'm thinking no,those are'nt innerchangable:cool:

[BenKeith]

I think you're biggest problem you run into is the drive shaft length's not being compatable on that later model looper. Gear ratio and shift rods might also be a problem but if the drive shafts don't interchange, that other stuff is not a player.

[Dhadley]

Yep, no problem. Use the shift shaft from the motor (130) you're putting the 80's unit on. Set the shift rod height to whatever the 130 calls for.

The unit you have now is a V6 "style" which uses the larger diameter props. 14 1/4" is typical for a 3 blade. The 80's V4 unit uses the 13 1/4" type diameter 3 blade props.

The gear ratio you have is 2.25:1, the 80's V4 unit is 2:1. Somewhat of a difference but the 80's case is smaller (less resistance).

Just keep in mind you'll not have an O ring on the driveshaft. On the 1995 130the O ring is in the bottom seal plate on the crank.

[racer]

Drive shaft length is different.

[jjmalkow]

Thanks for the info guys! I have props for both gearcases, so I'll give it shot.

[SRP71]

Would this work? Looking at a 225 Looper power head, would it bolt up to a 235 Big block mid? Both are V6 but from a glance it looks like the Exh cavity/tuner would be different. Has anyone done this? Would like to keep the cowling I have as it is custom painted to match the boat. Like the idea of a slightly newer motor that is prop shaft rated HP not flywheel.

[Dhadley]

The looper p/h will not bolt up to the 235 cf mid. Nor would the hood fit.

[Forkin' Crazy]

Yep, no problem. Use the shift shaft from the motor (130) you're putting the 80's unit on. Set the shift rod height to whatever the 130 calls for.

The unit you have now is a V6 "style" which uses the larger diameter props. 14 1/4" is typical for a 3 blade. The 80's V4 unit uses the 13 1/4" type diameter 3 blade props.

The gear ratio you have is 2.25:1, the 80's V4 unit is 2:1. Somewhat of a difference but the 80's case is smaller (less resistance).

Just keep in mind you'll not have an O ring on the driveshaft. On the 1995 130the O ring is in the bottom seal plate on the crank.

:confused:

I thought that if it was a V4, it would take a V4 size prop. Unless it was a commercial model and then it would be a V6 case???

[bigbore]

Drive shaft length is different.
Thats all ya need to know right there.:cool:

[Dhadley]

The larger V6 "style" cases on V4's do indeed use the V6 props. Some recreational V4's do come with the V6 type case. IE - if the unit has a 13 spline prop shaft it'll use the "V4" type props which are typically 13 1/4" diameter 3 blade props. If the case has a 15 spline shaft it'll use the V6 type prop (14 1/4" 3 blade). We've done this many times, swapping V4 cases from looper to cf, put V4 units on a V6, put V6 units on a V8, put V6 propshafts in a V4 unit etc.

[BarryStrawn]

put V6 propshafts in a V4 unit etc.

You should post a how to on this. I think many people here would be interested in having a 15 spline shaft in their 4 1/8" V4 case.


From your earlier post, it appears you have good results running the early style short driveshaft into late cranks. You don't have problems with the grease seal or spline wear?

[Dhadley]

We didn't have any spline problems but we pulled the unit every year and checked the splines. Putting the earlier driveshaft (with an O ring groove) into the later crank (with the O ring in the seal plate) obviously wasn't a problem because the O ring was there in the seal plate. I've see it done with leaving the O ring on the d/shaft and it just pushed the O ring down the shaft.

I've seen it done the other way -- newer shaft with no O ring into an older crank with no O ring. I told the guy I wouldn't do it that way but he did. He kept an eye on it and didn't have any trouble for a couple of years that I know of. He sold the boat and I lost track of it.

[Forkin' Crazy]

put V6 propshafts in a V4 unit etc.

Don't you have to turn it down for a bearing? Or is that on an early case?


The gear ratio you have is 2.25:1

Is that what a V6 case on a V4 Commercial is?

[Dhadley]

Yes, a bearing surface has to be turned down. When I decided to do this I had started to lay things out to see what had to be done. It just so happened that I was talking to Ron Baker Sr. one day and he mentioned he had one for sale so I bought his. We never had any trouble with it so I never opened it up. It was still on the motor when I sold it.

Yes, the V6 style unit on a V4 is 2.25:1.