260hp to 245hp conversion

[WOT77]

I didn't get your comment until I took the photos🤣😂 Thank you!

[WOT77]

I do have another set as well but can't get to them until tomorrow. Will post them when I get the chance.

[pkstv]

Don’t forget about the bleed lines needed . Here’s my 245

[25two.stroke]

I thought that the 260s and 245s had the same porting. 15 HP from changing to EFI seemed like a lot. Was it that much?

5 to 7 petal front...dont forget that. It was not as simple as carbs vs efi and everything else the same.

Sorry, what was I thinking yeah they all had 7 petal fronts...I guess I was thinking of promaxes with 5 petal fronts

[WOT77]

Don’t forget about the bleed lines needed . Here’s my 245

Thanks for pointing this out. What carbs are on this setup? Is it a kk block?

[mach351]

5 to 7 petal front...dont forget that. It was not as simple as carbs vs efi and everything else the same.

245’s were 7peddle nic motors with identical porting to a 260

[mach351]

Don’t forget about the bleed lines needed . Here’s my 245

If he has a 260 block it won’t have bleed fittings on the cylinders. They can be installed but that’s usually more trouble than it’s worth. A better option for a carbs (or any wet-reed system like laser efi) is to connect all the bleed lines together into one line and run that back to the fuel tank. 1/8” line is sufficient. I’d recommend your “#1” set of carbs. Again, this is pretty easy to do…..your only real issue where you will have to design something is the throttle linkage. And efi linkage won’t work, and a carb linkage won’t fit an efi front half. If I remember right (it was a while ago) I spaced a carb throttle bracket out about 3/8” and then made a custom rod to the carbs out of 1/8 round stock.

[mach351]

Put #72 jets in the mains of those whm-21’s to start and you’ll be good. You’ll probably end up going down to a 70 or 68 eventually.

[mach351]

And you’re going to need a 2.5 7peddle carb intake if you don’t have one already.

[WOT77]

Thank you for all of your input Mach351! That is very helpful! I'll definitely be using your input 👍!