Replacement SBC heads...????
Thread Starter
Melting Slicks
Joined: Nov 2005
Posts: 3,323
Likes: 142
From: Green Valley Arizona
Originally Posted by Little Mouse
If you have pistons above the deck and use a .020 gasket you can kiss your heads goodby in a hurry.
But I will be using the standard FelPro head gasket, not any steel shim or anything like that.
Also I posted a new question regarding other damage I found upon removing the pistons....which was caused by the machine shop not turning the crank properly. Turns out that my mistake was going to last longer than the machine shop's mistake. Oh and gee...that machine shop is out of business....wonder why.
Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
Originally Posted by LannyL81
I thought that was what the valve reliefs were for? Comparing the valve reliefs to the divets that the intake valves made; the reliefs are more than 3x as deep and 2x as wide, lots of clearance there.
But I will be using the standard FelPro head gasket, not any steel shim or anything like that.
Also I posted a new question regarding other damage I found upon removing the pistons....which was caused by the machine shop not turning the crank properly. Turns out that my mistake was going to last longer than the machine shop's mistake. Oh and gee...that machine shop is out of business....wonder why.
But I will be using the standard FelPro head gasket, not any steel shim or anything like that.
Also I posted a new question regarding other damage I found upon removing the pistons....which was caused by the machine shop not turning the crank properly. Turns out that my mistake was going to last longer than the machine shop's mistake. Oh and gee...that machine shop is out of business....wonder why.
Originally Posted by jackson
If your pistons are sticking above deck 0.006" ... you'd better not use a gasket as thin as 0.020" ... that equates to 0.014" quench ... later, if not sooner, piston will slam into combustion chamber's wedge.
With that huge deck cut ... If you haven't experienced it already, and unless there's been some fancy-dancing done with intake gasket/ machining of intake ... I fully expect problems with intake leaking outside air/motor oil into ports & leaking water ports.
Maybe a shorter piston would suit better ... one that's not 1.560". With that huge deck cut, you're not dealing w/ the same thing everyone else has ... it's a bastard. Red-headed stepchild it is, but not a total loss by any measure ... it is manageable. But if you don't get a good grasp on exactly what's been done & what it means ... and take correct actions ... heartbreak & budget woes will surely escalate. Does this sting? ... maybe so pal, but I'm only trying to spur you into helping yourself do the right thing.
Instructor
Joined: Oct 2005
Posts: 240
Likes: 0
From: Banbury Oxfordshire
6 thou out isn't that bad. A decent set of 40thou gaskets and you're fine. The machine shop probably decked it hard because the block was totally out of shape. My shop warned me this can happen before they went near my block - then went on to tell me once on a properly trued and decked block, he found a crank which was so out of whack one of the pistons was 15 thou out while another was 6 thou down!
If you want to minimise squish on a street engine, aim for 30thou, but that means a 36 thou gasket - not common in my (limited) experience.
A bit of careful top end assembly and checking your intake fit and you're away. Good luck finding some new heads or getting yours sorted.
Mark.
If you want to minimise squish on a street engine, aim for 30thou, but that means a 36 thou gasket - not common in my (limited) experience.
A bit of careful top end assembly and checking your intake fit and you're away. Good luck finding some new heads or getting yours sorted.
Mark.
Racer
Joined: Jan 2006
Posts: 395
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From: Orange massachusettes
I know this thread is about replacement/repairing your heads, but I noticed your running a 2.78 rear gear. Doesn't seem to be enough gear to run w/268 cam. Something like 3.70's would really make a big difference. If it was me, I'd go w/ above mentioned Dart or World products Iron heads as they are affordable, and with the money saved from passing on the better, but much more expensive AFR's, I would change rear gears. You will get more "Bang for your buck" w/gear swap than w/ the better flowing AFR's. Just my .02
Thread Starter
Melting Slicks
Joined: Nov 2005
Posts: 3,323
Likes: 142
From: Green Valley Arizona
Jackson:
I am the first to admit that I have much to learn about engine parameters.....so I am not taking any offense to your comments...I am open to learning.
I do not know how much the machine shop took off the block when he deck'ed it....he was not one for much communicating. I only found out about the 0.006" above, when I go the block home.
Yes the intake had to be cut down to seal. Also had to go to a shorter push rod to say on the valve stem. The original problem I had was high oil usage...a quart in 150 miles or so. I though it was the intake gasket not sealing in the lifer valley and was sucking oil. But found no problems with the gasket...that was when I did a leak down test and heard a problem and took one of the heads off. You know the rest of the story.
72LT1:
Yeah that 2.73 rear end really needs to go. That was my plan for next summer; send the trailing arms out to be rebuilts and take the diff out and have the gears changed out. Doubt that is going to happen now with this engine problem using all the funds up.
I am the first to admit that I have much to learn about engine parameters.....so I am not taking any offense to your comments...I am open to learning.
I do not know how much the machine shop took off the block when he deck'ed it....he was not one for much communicating. I only found out about the 0.006" above, when I go the block home.
Yes the intake had to be cut down to seal. Also had to go to a shorter push rod to say on the valve stem. The original problem I had was high oil usage...a quart in 150 miles or so. I though it was the intake gasket not sealing in the lifer valley and was sucking oil. But found no problems with the gasket...that was when I did a leak down test and heard a problem and took one of the heads off. You know the rest of the story.
72LT1:
Yeah that 2.73 rear end really needs to go. That was my plan for next summer; send the trailing arms out to be rebuilts and take the diff out and have the gears changed out. Doubt that is going to happen now with this engine problem using all the funds up.
