Couple Q's... Valve spring lift rating. Dual vs. 918.. Valve tick, also.
 

918's are apparenly rated good to .600 lift. Are these ratings cam or valve lift? The reason I ask is a mild cam would produce more than .600, therefor making the beehives no good. -Explain...

2nd question... We got my buddy's SS fired up after the MS4 cam and stage 1 LS6 head install. We have an intermittent valve tick now. It's loud enough to be concerned about. How normal is a valve tick w/ in the first 2 hrs of the car running after a cam install? Here's a vid of the valve tick...
http://s96.photobucket.com/albums/l1...t=P1040627.flv

Last question. Cam install on stock springs. .... Can it be done? I'm thinking about the milder cams, first then get heads eventually. 224/224 .581 .581 or 228/228 .588 .588 both w/ either 12LSA or 114. I like the 112 lope.

1) Cam lift. Go with PRC duals or some other type of dual spring on cam swaps.

2) You may have to readjust the valve lash. Pop the covers and make sure nothing is visually broken.

3) No. LS6 springs on LS6 cam and that's about it for the factory stuff.
Stick with a proven grind like the Futral stuff and you can't go wrong.

Valve lash. We TQ'd the stock rockers to the specs... I thought there should have been a lash adjustment spec for the rocker to valve tips.. but he said there wasn't one... :confused:.. There should have been. It sounds like the drivers side. We used molybdenum grease to install the cam. I figured it might have been the grease working thru the system or maybe air pockets in the oil system due to a new oil pump.

Ok... Gotcha on the stock springs and cam... No problem switching springs on stock heads. I found a good idea on LS1howto.com. I really want a cam now. But I have to find a DD for fuel mileage concerns. He used 1/4 tank on a couple mile cruise around town. We were also breaking 'em loose at 45mph in 2nd... :devil:.. That cam IS Nuckin FutZ, but the narrow powerband is sluggish at lower RPM's. Would be good for the track.

There isn't a lash adjustment on any hydraulic cam ever. Lash is a gap between the valve stem and the tip of the rocker.
There is however a certain amount of preload required for the lifters to work properly. When right the lifter plunger will be in the center of it's travel.
Did he check piston to valve clearance?
Did he check for proper pushrod length?
Aparently he didn't check for lifter preload as you said that he just bolted them down.
Any of these could cause problems. If the ticking was sporatic and went away it was probably oil/air related and nothing to worry about. If it's still doing it, well then he's got a problem

stock springs are only good to .525" lift i beleive....so not many cams on the market fall under that.

as for the ticking...did he get the right pushrods?

He duplicated another install on a stock 02 LS1. Same parts, same gaskets, PR's... etc.. We spun the engine over by hand a couple times before we fired it.

IS there a lifter preload walk thru anywhere? I'm not too familiar w/ it. It's been a number of years since school, so I probably forgot some of my theroy.

Here's an article describing valve lash and lifter preload.

http://shbox.com/1/4th_gen_tech2.html#adjust_valves

Dude, that's not for LS1 cars. That's for small block chevy motors.

Ben T.

:(

Damn the Gen III/IV :(

Hey, Ben. You didn't respond in your GOI Racing thread, but what size did those runners and combustion chambers spec out to?

Approximately 230cc and +1 on the chambers. Kraest, keep in mind these are for a larger than stock motor and with 11/1 compression.

Ben T.

Ahhh.. yes... I think with a little more trickery and time put into them, you could have coaxed the same numbers with the runners ending up at 205cc. I guess we'll see how it all works out :) Those GOI guys are giving you alot of flak :lol:

Didn't want to mill them down any to decrease the chamber size?

Mike

Yeah, I wanted to get them to around 67-68cc. They will be milled accordingly. Yes, we will see how they perform, but I'm playing against a stacked deck- his car has never ran the numbers it should have since it was a bolt-on car.

Also, you should see the 853 LS1 heads I'm working on! Flow results will be posted soon.

Ben T.

We figured out the valve tick... ... He needed longer pushrods. We installed 7.400, he needs 7.425. He has them on the way...

And we also found out that you can't adjust preload on stock LS1 lifters. You TQ the rockers, and w/ the correct length PR's, the lifters SHOULD be at a correct load.

Yes you can. You can mill the pedestal bases for more preload or you can shim the pedestals for less preload.

Well.. I mean for basic adjustments. I was told that by a reputable source. He should have it fixed now.