I'm building an iron-block L33 clone with 241 heads, hyper flattops and 10:1 compression. I'm going to be running a small Cam Motion HR cam.

I need an education on LS valvetrain parts. Most valvetrain threads I see are on big cams and expensive rocker systems. I'm need to know what basic upgrades will live long-term on the street.

What would be the best lifter for the application? When do you run a .750 vs a .700" lifter wheel? Stock tray vs linkbar? $450 or less price range for the lifters.

Who makes a good budget rocker arm? I was going to use stock rockers but I see the stock rockers can spit out their rollers. Is the Comp trunnion upgrade for stock rockers reliable enough for a DD?

The goal is a reliable street engine that can go 100K miles before major service is required.

 

No comments? I figured this stuff would already be covered but didn't find anything with the search function. tnx

 

I'm going with the trunion upgrade myself. It seems like popular mod especially for DDs.

 

I just installed the Comp trunnions with my new cam in my DD.
and a set of good push rods and springs

 

What rod and main bearings are you guys using?

For a mild street motor, do I go back with a stock aluminum bearing or the old-school tri-metal type? What are the pros/cons of the new aluminum bearings? I'm used to the old style bearings in muscle car engines. This engine will use stock floater rods with ARP bolts. Stock 5.3 GM crank.

 

Trunion upgrade for the stock rockers are fine. Ive seen too many failures with the ls7 lifters.

 

Here's the update on the build-

The 216 casting crank needed metal added to balance with the floater rods and Speedpro flattop pistons. Bobweight was 1790 or therebouts. King AL bimetal bearings, STD size. Mahle moly rings.

I've got a cam from cam motion coming. They recommended their 205/210 115+4 cam for this motor with 10:1 compression. They recommended a spring with 140# seat, 325# at 502" lift, so I went with the PAC1219 springs. Stock 241 heads with valvejob.

Would it be worth going to 1.8 ratio Comp Pro mag rockers, or is the comp trunnion upgrade to stock rockers good enough?

If not LS7 lifters, then what?

 

I'd say go with the trunion kit and the comp 850-16 lifters. I know a little pricier than the ls7s but that's what I'm running and my valve train is actually quieter than my stock dod/afm valve train.

 

What cam lobes are you running? 1.8s don't like a high ramp rate.

Did you just have the 241s laying around?

 

Their description was XA 205/295. 205 duration at .510" lift doesn't sound that aggressive, and CM is known for being conservative with their cams. I can only assume it's not a harsh lobe. I was actually surprised they suggested running so much spring, 140 seat, 350 on the nose seems kinda high for a mild street cam. But roller lifters are heavy I suppose.

I was really wondering if the small increase in duration and lift from the 1.8 rockers would show power gains with stock 241s? And yes, I got the 241s super cheap off Fleabay. They are the non-notched ones that can use MLS gaskets. Why do people bag on the 241s? 243/799s were a lot more expensive online and I'm not hunting huge numbers.