Topic: ohv porting

[bountyhunter]

how much of the port(hump) are you guy removing on the ohv single exhaust port? and are you guy using same lenth and size exhaust as flat head?

[300xdeere]

Rule of thumb i like to use for exhaust tubing size...I.D= diameter of your exhaust valve. As for the porting not really to sure, but i'm sure some one will jump it to give you a hand.

[bountyhunter]

is the 28 cu ohv head have a smaller camber and if so will it fit on my 31 to raise com.?are the valves same size!!

[Old Goat]

A 28 head and a 31 head both have the same valves. As far as the chamber goes they look the same, but I never CC'd any to tell for sure.

[bountyhunter]

hows race season going old goat?

[Old Goat]

Hi, Bountyhunter. I'm dissapointed that I didn't get to go to Delaware, Ohio. We had a local race at the Port Royal Fair and I had to be there. Other than that it's going pretty good. I've had my Bolens to 9 races, so far. I broke down during 3 of them, but I won all the rest! How is your season going?

[bountyhunter]

not bad!! best feature 2 place, won a couple heats. now moved up a couple classes running basicly stock 31 ohv against a built 31 a couple of oppossed twins a v twin kawasaki and a v twin kohler need a lttle more hp will have it net year last race was a bad one teched in and than got back to pit place and broke rocker

[Old Goat]

Yup, I know how that feels! I broke one at the ARMA national points race in Forrestville during warm-ups. Luckily the D & B Motorsports gang had a spare one (they are a pretty good bunch) and I changed it and ended up winning the feature! Then I went out for a 5 lap shoot out and broke the crank just putting around the track going over to get lined up for the start! Seems like there's always something, but I still always have a lot of fun. It's a great sport & great people! (I got a set of E.C. roller rockers on her now)

[bountyhunter]

if I stick with ohv single will have to get the rockers!!! What happened to the crank or what caused it to brake?thats one reason considering a motor change next year!

[Old Goat]

I think I had the timing advanced too far. It was on the 4th notch above zero (ARC flywheel), but dang it, it REALLY ran good that way. I got it set on zero now and it doesn't have quite as good top end, but at least it's still running.