Topic: which stock cam should i run

[BIG AL 202]

REALLY

[NH Mowster]

These cams are for a splash lube. I haven't got into my pressure lube yet till I get this engine done. Going to run splash till I get the pressure lube built then swap them out. Pressure lube will have custom cam, billet rods, AVS piston etc...just need a good engine to start next season off with since I don't have the parts for the pressure yet. The pressure lube is a 42 cid engine

[BIG AL 202]

OK THE CAM IS DIFFERENT FOR THE PRESSURE LUBE. IT HAS A SLOT IN ONE OF THE ENDS. I DO BELIEVE YOU CAN SLOT A NON PRESSURE CAM AND MAKE IT WORK. I HAVE NOT DONE IT BUT I HAVE BEEN TOLD YOU CAN.

[NH Mowster]

Yeah the picture of the 2 cams are splash and will be going back in a splash lube engine.

[SinisterRacing]

because 4000 rpms got me around our track pretty good this year and I could pass ungoverned oppys that was turn somewhere near 4500-5000. Its all in the gearing.

I am curious as to what class you are running. From what I uinderstand all oppy's need to run the same gearing at 8:1. Mod X.

I would love to use an oppy in a class where I can change the ratio.

[Rooster]

OK THE CAM IS DIFFERENT FOR THE PRESSURE LUBE. IT HAS A SLOT IN ONE OF THE ENDS. I DO BELIEVE YOU CAN SLOT A NON PRESSURE CAM AND MAKE IT WORK. I HAVE NOT DONE IT BUT I HAVE BEEN TOLD YOU CAN.

And a hole through the center.....

I am curious as to what class you are running. From what I uinderstand all oppy's need to run the same gearing at 8:1. Mod X.

I would love to use an oppy in a class where I can change the ratio.

Mod-X does not have a gear ratio rule, the only classes that do are Super Stock(ARMA) or IMOW(USLMRA) and neither class allows an oppy.

[NH Mowster]

Yeah I run ARMA ModX. This year I think I ran somewhere around 6:1 running at 4000 rpm in 3rd gear. I wasn't the fastest but I could get them off the corner because I could get on the gas faster and as soon as they were down the straights they ran me over  I think I will run 6.5:1 next year and that should hit the sweet spot around 4500 rpms

[Johnson Mowersports]

Try 5.8:1 or somewhere in that range and turn it too 4500 then it will be way faster than it was this year

[NH Mowster]

OK thanks. I thought that I was going the wrong way with it    been working on the chassis and engine work and haven't crunched numbers on ratios yet.

[Zippy 13N]

Try 5.8:1 or somewhere in that range and turn it too 4500 then it will be way faster than it was this year

That will depend on the track.  You can't really say use 5.8:1 will put you at 4500 cause the track may be longer or shorter.

NH Mowster, you will just have to play with the ratio to get it to your liking.  Weight, engine all kinda of things effect how many rpms you will turn.  Good luck!

[NH Mowster]

Thanks Zippy. The track is close to 1/5 mile with slight banking in the corners. We get around there pretty quick. I will have to crunch numbers later to figure ratio but it will take time to get the setup perfect. I have a digitron tach  so I know how long to hold it and if its not fast enough when I let off at that rpm then I will keep tweaking it

[Rooster]

Yeah I run ARMA ModX. This year I think I ran somewhere around 6:1 running at 4000 rpm in 3rd gear. I wasn't the fastest but I could get them off the corner because I could get on the gas faster and as soon as they were down the straights they ran me over  I think I will run 6.5:1 next year and that should hit the sweet spot around 4500 rpms

So your lugging it off of the corner?

[NH Mowster]

The way I had it was since they had more speed in the straights they had to stay off the gas longer in the cornets and all I had to do was let off to setup up to enter the turn then I was back on it just short of halfway through the turn when they were getting back on it coming out of the turn. It worked for me and I even carried enough speed to pass going in and out of the turn. Straights killed me because I didn't have the rpms they did

[NH Mowster]

The main issue I had running like that was when we were pace lapping under yellows while everybody was just idling I was riding the brakes and clutch to stop running over other mowers. But that will be fixed for 2013