1.5 or 1.6 rockers?

[Art Jett]

I am getting ready to start putting my 383 together and need some advise. I am building a TPI stroker with Edelbrock performer rpm heads. It should be 10:1 compression. I have Sanderson headers and a new 700R-4. At this point I'm not sure if I should use 1.5 or 1.6 rockers. The valve springs will handle the extra lift from the 1.6s but I'm not sure how much I would gain in performance. I'm not going to race the car but at this stage of construction if I can gain a little for not much more cost, why not? I have a Comp cams extreme energy 262H cam. With 1.5 rockers it will have .462I and .469E lift. w/218I 224E duration and 110 degrees lobe separation. I had to go somewhat mild on the duration because of the computer. I have a set of 1.5 roller tip rockers that I got with the heads now but wouldn't object to spending a little more now as opposed to after I get it all together.
Thanks

 

[Jack]

Art:
With 1.6 ... valve lift will increase to about .493"I/.500"E ... duration will increase about 2 degrees to about 220*I/226*E ... lobe separation remains about 110* ... roughly thirty thousandth's more lift & two more degrees ... not so much. Pretty sure OE RPM setup can handle more than that. Frankly, if it were me and I were building this mild street-only combo ... and I already had a set of 1.5 in real good shape ... I would use them. IMHO the potential gain on this mild motor ain't worth the time & expense of more rockers. XE cams have somewhat aggressive ramp angles & have been getting plenty of bad rap on failures. Jury's out if due to poor process control at CC or fact that today's motor oils formulated w/ less wear additive packs or improper valvetrain prep/setup/break-in ... maybe some combo?

Insurance: Do use a dollop of moly grease/paste on bottom of each lifter and slathered around each lobe. Also, a pint bottle of EOS (engine oil supplement stinks a lot like gear oil) from local GM dealer parts dept ... pour some over cam just before install and lube block's lifter bores just before you install lifters ... pour the rest in w/motor oil. Do change oil & filter immediately after initial 20-30 min cam break-in ... & pour in another bottle of EOS w/ fresh motor oil. G'Luck!
JACK:gap

 

[Art Jett]

Jack, Thanks for the advice. I'd kinda figured the increase wouldn't be worth it, besides the chip is already programmed for the 218,224 duration and the increase would probably screw it up. I also saw a thread advising Shell Rotella-T motor oil. It said this oil has Zinc in it like most used to to help lubricate the cam lobes. Heard this? I'm going to let a race engine builder here locally put my engine together and do the initial startup and break in so hopefully, any set-up problem would fall on his shoulders.
Art

 

[Jack]

Yep ... I've switched to RotellaT 15-40 and DelVac1300 15-40 ... both readily available at decent price. In addition to the 71 ... I've just begun trying it in a "modern" V8 gas FI car w/ lotsa sensors ... so far so good ... so far no fouled O2 sensors ... fingers crossed ... 71 OK but the new car's valvetrain's a bit noisier on startup ... will try lighter weight next go'round.
JACK:gap

 

[Art Jett]

I just got off the phone with the guy who's going to get me going and he said the Rotella-T is what he uses. He's going to assemble the engine, set up the valvetrain and spin it to check the oil pressure and get it to the point that when I get it back, all I have to do is put it in the car and assemble the upper fuel injection stuff. GREAT! There might actually be a light at the end of the tunnel after all.

 

[kiwi vet]

VeTec 350?

Just something else to look at, saw these!

http://www.hotrocker.com/index.html

Has anyone used them? A VTec Chev? something to ponder on!!

Cheers Grant