dr_whigham

iTrader: (49)

Question guys,

Where I live, we have a great machine shop (30+ years), but they don't have much experience with LS based engines. They don't have an LS torque plate, but they feel confident they can give me a good valve job / clean-up in the neighbordood of $300

I bought some used 243's off ebay. Extremely clean heads, low mileage, but before I throw them on, I wanted to get a valve job. They'll eventually go to AI for the 226 program, but I'll be sending LS6 valves with them when I do that, so this VJ on the stock valves is simply to get me by and be a bit better than stock until that happens.

What are the recommended / best degrees to get the valves cut? This is a 100% street car.... I've heard something about 3 angle for drag and 5 angle for street?

I just didn't know if there were any good and proven degree #'s out there that work well.

I hope you guys understand what I mean. I was hoping to carry a bit of experience with me in there and just be able to tell them what #'s to cut... like 30* on the back cut or whatever.....

Thanks again

01ssreda4

iTrader: (96)

I wouldn't sink anymore money into them then you already plan on. I think the stock valves will be fine and don't necessarily need the sodium filled exhaust valves from a Zo6. I also wouldn't install them if you plan on having them ported anytime remotely soon. No reason to install them twice. I'd just hold out till you get the money for the CNC work.

crainholio

iTrader: (2)

If they're telling you that torque plate use has anything to do with cylinder head work...run away.

bww3588

iTrader: (49)

They aren't. He is saying they don't have much experience with ls engines so they don't have a torque plate to do the block...BUT...they can do the heads.

And I agree, leave the heads alone until you send them to AI. They can do a valve job also and will probably charge you less since they are doing it all at once.

dr_whigham

iTrader: (49)

Well, it may be 9 months to a year before I can send them to AI, but the Ed Curtis cam and the heads are going on within the next month or so. I just thought I could benefit from a decent valve job for the time being, and that there were some good proven #'s out there that these valves like to be cut at and respond well to.

Thanks so far, and yes, I meant they can't do the block, but CAN do the heads.

KCS

iTrader: (20)

Proven valvejobs aren't exactly something that gets out on the Internet. It's one of those things cylinder head guys like to keep proprietary.

Since they are not familiar with LS engines, ask if they're familiar with SBF stuff. The ports are pretty close and what works well on the SBF will likely work well on the LS.

thunderstruck507

iTrader: (18)

If they are low mileage I would lap the valves and run them for now.

dr_whigham

iTrader: (49)

I just figured there was some ideas that maybe you home porters / machinists knew or could share. I know the full blown VJ's from named companies aren't getting out, but figured it was worth a shot to see if I could get any tips or ideas.

studderin

iTrader: (28)

with the port stock, any port really. Its also can be more important some sizes of the VJ then the angles. The intake your gona be bolting on, and how fast and high you move the valve ... not a competition class setup, lets say you stick with the 45 seat. It's all about whats under AND above that, as your asking. But you can have the same angles, one heads is a turd. Another head makes a lot more power. Its all depending on how you use them. The seat size is the limit.
I've blended stock worn VJ 241, and 853s, and made more power then a budget cnc ported head with a bigger intake valve.

dr_whigham

iTrader: (49)

LS6 intake, Shaner S3, Chrs1313 non AC R/A
Cam is Ed Curtis- 229/236 .631.631 112+2


Stock 3.42's, but WILL be getting 3.90's (M6)

Just wanting a good peppy street car that can surprise some folks

01ssreda4

iTrader: (96)

Again, I would not throw them on. Remember, when they go off for CNC work your car will be down. If they are not installed it won't cost you a running vehicle while they are away. Plus I did the same thing with mine and wish I woulda waited. A .025 cut 241 felt the exact same or better then a stock 799 casting. No BS. I went from 241, to 799, to .025 cut 241, back to the 799s worked from AI.

studderin

iTrader: (28)

ya Im with 01SS, If you can't do the VJ yourself I wouldn't pay to have them cut if you dont know what you want anyway. Plus you might mess them up for what AIs port is blending to. Do you port or grind on heads? If you want to mess around do this with a LS1 head, you dont have to have a $200-400 VJ done. If you have arps and a HG you can reuse. (comedics) and just want to spend you time. I kinds do this, got some used arps that were around the shop, I shouldn't even post how many times they have been used. I'm up to 4 times now using the same HG over too. So its free for me to change heads the last 4 times. when normally I think retail is $80 a HG and GM bolts are $30-40? So it $200 is parts.

dr_whigham

iTrader: (49)

Kinda neat information... I had no idea a .025 241 would be about the same as a stock 243/799.

I know I have to at LEAST get a clean-up mill done. There a few little knicks around a few corners from shipping.

Yeah, I'm no porter by any means. I just figured I could get a back cut or something done for the time being, since I plan to find and install actual LS6 valves when they go to AI, but I forgot they'd prob mess with the valve seat also, and could potentially screw my future CNC job.

Thanks for the advice, guys. I'm actually going to listen. I'll just get a clean-up mill for a true surface and throw them on with some ARP studs and cometics.

01ssreda4

iTrader: (96)

Seriously, I wouldn't even waste the time installing them. I really don't think its worth the 2x head swap for what you are gaining. Leave your stockers on there and put the heads up and start saving for your machine work. If I could go back and do it over and was not planning on porting there is no way I woulda sunk the money in the 799s to just throw them on there stock. I woulda cut my heads .030 and stuck them right back on for 1/5 the price. I wanted the better castings and actually needed a set of cylinder heads at the time so I sprung for the 799s. Shoulda just bought some $100 241s and threw them on to get me by.

dr_whigham

iTrader: (49)

Understood. I wasn't worried about down-time being that I only work 2 weeks a month. I was just thinking that if I even picked up 10rwhp going from stock 241's to stock 243's, to me it would be worth it. It's only a half days work.

But yeah, I guess I should just let them sit till I have the $$ for the CNC.

Thanks guys

01ssreda4

iTrader: (96)

I'd pull the 241s, shave em .025-.030 and re-install. Then you can let your 243s sit while you gain 10-15hp from the compression jump. Win/win for you.

dr_whigham

iTrader: (49)

I'm already wondering though with the cam lift if I'm going to have PTV issues even at stock cc's

01ssreda4

iTrader: (96)

My cam is very similar, and I'm not having PTV issues with my 799s milled .040. I say, check your PTV before you pull the heads (dial indicator method) then subtract your mill amount from your measurement. I bet you will find it is more then acceptable. With my heads cut 40, I still had no less then .105 on the intake or the exhaust. I would consider 60-70 a safe limit for a street engine.