Back in the day, wasn't Sifton the cam (Interstate 143-EV) to have in a stock Evo for low/mid range power?

 

I have used the 510 in Twin Cams and it is a fantastic cam, my favourite.

 

I wonder if going with a different ratio rocker arms might accomplish what you are after with your existing cam.

 

I run an ev 3010 an it's rated for 1500-5800... I really like it. the 3020 is rated 1800-6000 rpm's. their next cam up needs better valve springs an higher compression is recommended.

 

From the cam profile, the 510 should be a decent cam. I have a 508 in a box that goes in my evo this month. You can get decent prices by shopping around. My friend had a leinweber cam in his evo years ago. Hot cam. Ramps are really aggressive. Make sure the valve train is in top shape. Too much cam is worse than too little. Clay those valves.

 

Buddy of mine had the 510 in a Dyna,I loved the way it sounded and ran,so I put the same cam in my 93 Classic. Great cam!!

 

Thanks.
Any other engine mods?

 

THC,

Is your engine 80" or is it bigger? How much cranking pressure does it currently have?

How many rpm and how much mph is it running out of steam?

 

It's still an 80"er.
Currently not enough cranking pressure but things are underway to solve that.

It's the roll on at hwy speed that I don't think is strong enough.

 

The EV27 reduces your cranking pressure. Since Evo's are marginal psi when stock, any reduction is going to be detrimental.

One of these days I need to check to see what I am running at.

I took .025 off my heads, went with .030 cometic gaskets, and an EV13 cam. The EV13 is good with stock compression but I wanted a little more and it paid off.

Since you have an EV27, you could take more off the head if there is enough clearance or simply run higher compression pistons. You need to be at least 180psi if you are interested in performance. Also check the variance between the cylinders.

I think that combined with a little tweaking of your carburetor afterwards would be the first place I would start, then if that doesn't do it, then change the cam.

The higher compression will broaden the torque curve and increase the responsiveness and it sounds like that is what you need.

I have to run 91 octane or higher. I was in a remote area one time and the only gas available was 87. I found I had to keep it in one gear lower than normal for the speed I was going to prevent pinging until I could get some higher octane gas.

I remember back in the day, Jerry Branch of Branch Flowmetrics was the super guru of heads.