Head improvements anyone?
#1
Staging Lane
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Hey,
I had to remove the driver side head on my LS1 to extract a bolt. Now that the head is off (the other side will be easy) is there something I should do to the heads? Also, I'm looking for any performance improvements that I can do to it before I put it back on. The criteria is that I dont want to spend a lot of time (weeks) but money is not an issue. Maybe new rocker arms? or push rods or porting? Any suggestions here would be greatly appreciated.......
I had to remove the driver side head on my LS1 to extract a bolt. Now that the head is off (the other side will be easy) is there something I should do to the heads? Also, I'm looking for any performance improvements that I can do to it before I put it back on. The criteria is that I dont want to spend a lot of time (weeks) but money is not an issue. Maybe new rocker arms? or push rods or porting? Any suggestions here would be greatly appreciated.......
#3
TECH Apprentice
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Is this really a fact? Reason I ask is cause I just got into a discussion about this very subject yesterday. IF your putting the same head back on the same aluminum block, I believe common sense is that that head has formed to the shape of tht block and to resurface it is to make it have to conform all over again. I've never resurfaced unless it's going on a diferent block or it's an aluminum head going on a iron block.
#5
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Andy, Yes, check out AGearHead4Life's porting vids. If you try opening up the runners where they meet the manifold, you might run in to flow differences. Control of porting in those areas can be inexact, without some kind of measurement of the runners. Your most gains will come inside the bowls, short-side radius, and the "speed bumps".
As far as flow differences created from home porting....stock manifolds already do not flow equally between runners.
Here's one of the porting episodes...
As far as flow differences created from home porting....stock manifolds already do not flow equally between runners.
Here's one of the porting episodes...
#6
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How many miles does your engine have?
Don't know if you've done a compression test before the heads cam off.
In order...home port, a valvejob & bath of the heads, trunion upgrade to the rockers (unless you're going with new rockers), upgrade to the springs, locks/keepers, seals.
Comp 918 springs work just fine, as long as the cam is not too aggressive.
Also, depending upon mileage, you might consider changing the lifters.
You can skip the porting, if need be. It's one of those 'extras'.
Don't know if you've done a compression test before the heads cam off.
In order...home port, a valvejob & bath of the heads, trunion upgrade to the rockers (unless you're going with new rockers), upgrade to the springs, locks/keepers, seals.
Comp 918 springs work just fine, as long as the cam is not too aggressive.
Also, depending upon mileage, you might consider changing the lifters.
You can skip the porting, if need be. It's one of those 'extras'.
#7
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I'd open the bowls to 90% of valve diameter blending to the port and then remove the step around the guide. You could port match and smooth the port with flappers. Goodman sells some nice home porting tools.
The previously mentioned valvetrain upgrades too. I have the trunion kit to install before spring.
Surfacing the heads? Did you check with a straight edge? If you have more than .002 gap I would have then cut. Otherwise prep them properly before you install with 100grit emery paper wrapped around something flat. I use a coarse machinist/honing stone with WD40 after, Norton makes them. Surfacing the head lowers the CC size so you get a slight boost in compression which would't hurt.
The previously mentioned valvetrain upgrades too. I have the trunion kit to install before spring.
Surfacing the heads? Did you check with a straight edge? If you have more than .002 gap I would have then cut. Otherwise prep them properly before you install with 100grit emery paper wrapped around something flat. I use a coarse machinist/honing stone with WD40 after, Norton makes them. Surfacing the head lowers the CC size so you get a slight boost in compression which would't hurt.
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#8
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okay guys,
First of all, I absolutely appreciate all the attention to my post but I have to admit it is all foreign to me and a lot of information. Although I am a garage junkie, and aside from my electrical genius most of the work i have done to her is pretty straight forward. I know nothing when it comes to tearing down an engine. Flapper? bowl? trunnion? step around guide? With all this said I am willing to learn all there is to know about getting these heads prepared. I had a high performance cam put in and an LS7 clutch set-up and thats all the mods. After pulling the head she looks like she has got a lot of miles and probably needs a complete re-build but I would like to concentrate on the top end for now. The first step is what I need in getting these heads prepared. @Gmag: you mentioned a valve job and a bath first right?
First of all, I absolutely appreciate all the attention to my post but I have to admit it is all foreign to me and a lot of information. Although I am a garage junkie, and aside from my electrical genius most of the work i have done to her is pretty straight forward. I know nothing when it comes to tearing down an engine. Flapper? bowl? trunnion? step around guide? With all this said I am willing to learn all there is to know about getting these heads prepared. I had a high performance cam put in and an LS7 clutch set-up and thats all the mods. After pulling the head she looks like she has got a lot of miles and probably needs a complete re-build but I would like to concentrate on the top end for now. The first step is what I need in getting these heads prepared. @Gmag: you mentioned a valve job and a bath first right?
#9
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About a valvejob...if a compression test showed valve leakage, then it would be a definite. Mileage would be a factor, too.
If the engine has 80>100k, or more, I'd recommend it and have them change the valveguides, as well.
When changing worn valvetrain components, it makes sense to change them all, as a set.... springs, lifters, locks, etc, especially with your cam change.
The stock rocker arm trunion upgrade is a good way to go. An alternative is to buy new rockers.
It's good to know whether compression is up to specs. After the heads go back on, it's possible that, because of piston ring wear, that the rings might have to be replaced. Just putting that out there/might not be an issue at all.
If the engine has 80>100k, or more, I'd recommend it and have them change the valveguides, as well.
When changing worn valvetrain components, it makes sense to change them all, as a set.... springs, lifters, locks, etc, especially with your cam change.
The stock rocker arm trunion upgrade is a good way to go. An alternative is to buy new rockers.
It's good to know whether compression is up to specs. After the heads go back on, it's possible that, because of piston ring wear, that the rings might have to be replaced. Just putting that out there/might not be an issue at all.
#10
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I guess you have to ask yourself what you wish to accomplish and how long do you intend to use the motor. What's the budget? Timeframe? If you aren't sure you can do the work yourself on the cheap then just put the motor back together. If it ran well before then it stands to reason it will still run well after you get it together. Still check to be sure the head is flat and there are no visual concerns.
In the mean time you can do some research and educate yourself on rebuilding heads, porting and maybe even rebuilding the whole motor. By porting I mean minimal cleanup, bowl work and guide blending. I'd suggest buying a book on the LS1 by Chris Werner: How to Rebuild GM LS-Series Engines, item SA147. It explains complete teardown and rebuilding the LS1 with some performance mods too. Very good book.
Find a donor LS1 longblock and rebuild it in the meantime. When it's done you can swap it over a weekend with a couple friends. Sell your old motor to someone looking to do the same. This brings use back to your budget and timeframe.
In the mean time you can do some research and educate yourself on rebuilding heads, porting and maybe even rebuilding the whole motor. By porting I mean minimal cleanup, bowl work and guide blending. I'd suggest buying a book on the LS1 by Chris Werner: How to Rebuild GM LS-Series Engines, item SA147. It explains complete teardown and rebuilding the LS1 with some performance mods too. Very good book.
Find a donor LS1 longblock and rebuild it in the meantime. When it's done you can swap it over a weekend with a couple friends. Sell your old motor to someone looking to do the same. This brings use back to your budget and timeframe.