GM L31HD and cam choice

[Supercharged111]

By the standards I'm accustomed to, the stock L31 springs are inadequate for an L31, so there surely inadequate for a warmer version of the same motor, and I'm not calling you Shirley. When you have to warranty a motor for however many miles, you look at a slight performance drop for valvetrain longevity as an advantage, not a disadvantage. I'll take GM engineering's stance on a lot of things, but not this, or the gov-bomb, or the 4L60E. I don't care which springs GM put in which motor. I'm concerned with open/close pressures, rates, and valve control, with anything "LS" out of the considerations.

I won't argue there, my main concern was coil bind on the stockers. All I had to do for clearance on the seals was put the new ones all the way down.

 

[98 Nitro]

What stinks is GM use to sell L31 short blocks, you could save $800 over the crate engine and pick your cam/springs/heads.

 

[davkenrem]

What stinks is GM use to sell L31 short blocks, you could save $800 over the crate engine and pick your cam/springs/heads.

Now they pick them for you and mark it up.

 

[GMTMark]

I’m assuming you guys are using stock torque converter and not a lot of gear? My plan is a Yank 3200 stall which is supposed to be very streetable and a custom grind from Bullet cams. Ill use their recommendations on springs, retainers and seals. My stock L31 has 162,000 miles and is very healthy according to compression and leakdown tests. If I need to cut guides I plan to purchase a cutter and do so. IMHO if you’re going for performance you need to be willing to do some extra work and really raise hp and torque. This all depends on how you use your vehicle. I Don’t plan to do towing so that opens up a lot. A smaller cam shop with knowledgeable people can beat the factory to death yet not cost much if any more money. This applies to mild or aggressive cams. I realize I’m doing more work here but check into a custom grind. The possibility of a little extra money could pay off. I’ve been drag racing since 1976 so I hope I’ve learned a little bit. Just my $.02.

 

[GMTMark]

I should add that I’m going to build a strong 4L60E and install.410 gears with a posi and Moser axles. The best way to add much power is plan from the back end forward. All this depends on your budget and expectations.