Hey guys. I have a Velocity 280 with a hp 500. I am currently having the heads redone, new cam, and adding a 256 blower. I hear alot of people talking about reversion when going to more aggressive cams. What do I need to look for when making my cam selection? The last thing I want to worry about is sucking water back into the motor. Any guidance would be appreciated! Also, We are looking at running a solid roller cam and it has I believe Gill exhaust?

Overlap causes reversion. With a blower you don't need much- 110 to 112. The 256 might not be the best choice- it spins too fast and adds alot of heat to the intake charge. Also, you probably won't get the benefit from a solid roller since you'l probably not be spinning much more than 6,000 and your lift shouldn't be much over .600

There were just some complete 420 blowers in the classified section with chillers. This set up will give you 700hp easy. I've heard the 500hp cams work very well in this set up. But I'm sure there are many better ones out there.



Darrell.

My problem with running a chiller or a larger blower is height. I want it to be low profile so that I don't lose my sun pad. I know it's not the ideal setup but if I can pick up 5-7 mph I will be happy.

Have you already purchased a blower?



Darrell.

IMO, a solid roller is not needed and will be more trouble than its worth. You should be able to make close to 650hp with a 250 blower @5lbs and a Crane 741 or 525efi cam. You should gain 7-10mph.

I already purchaced the blower from a friend of mine.

Hey Griff. What are the troubles with running a soild roller opposed to running a hydraulic roller?

You will need to adjust the valve lash at least every 50hrs and the valve springs will wear out faster.

Solid rollers are needed to spin higher rpms, 6000 rpms or more. If you don't plan on spinning it to 5800rpms or more then a hyd roller is the way to go.

Solids often have more aggressive ramp profiles as well. This is taxing on everything in the valvetrain.