Casting numbers ground off head - help identifying
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Casting numbers ground off head - help identifying Hi,
I have an LS1 swapped Porsche 951 with the engine from a 99(?) f body. The heads have had the casting numbers ground off and no additional numbers stamped in as far as I can tell. Is this a good indicator that the heads have been reworked or CNC'd or whatever? All I can see is a worn label on the face of one head saying something like "WHA" and a barcode and the number 12 with a circle around it. Does that tell us anything? I don't know what 325 horsepower or so should feel like but this car does feel very fast to me.
I'll probably post another thread with questions about my top end rebuild and upgrades while I'm in there but here's a quick preview of why:
I recently let the pro comp autometer coolant temperature gauge get out of sight for a little too long and right as I notice it I lose power and believe the head gasket let go. The temp gauge maxed out which means over 250 degrees.
BTW, TONS of great information on this site. Thank you to everyone!
I have an LS1 swapped Porsche 951 with the engine from a 99(?) f body. The heads have had the casting numbers ground off and no additional numbers stamped in as far as I can tell. Is this a good indicator that the heads have been reworked or CNC'd or whatever? All I can see is a worn label on the face of one head saying something like "WHA" and a barcode and the number 12 with a circle around it. Does that tell us anything? I don't know what 325 horsepower or so should feel like but this car does feel very fast to me.
I'll probably post another thread with questions about my top end rebuild and upgrades while I'm in there but here's a quick preview of why:
I recently let the pro comp autometer coolant temperature gauge get out of sight for a little too long and right as I notice it I lose power and believe the head gasket let go. The temp gauge maxed out which means over 250 degrees.
BTW, TONS of great information on this site. Thank you to everyone!
Last edited by TurnerJ; Mar 30, 2015 at 07:13 PM.
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Update OK well I definitely need some help now. Can't make any meaning of these casting numbers and new engraved serial numbers after some time searching. The number on the inside is 691H. Serial number is one end of the head is 992351(8?)262229855 and on the other end of the same head is 9235N7070856
My main question is whether or not there is any work done to these heads. What's the bottom line about them? All I wanted to do is get a simple, reliable, budget bump in horsepower because I thought everything was stock. Maybe, say, LS6 intake, 243/799 heads, baby cam (maybe ls6 or something like 212/218 114, and GM performance valve springs: http://www.ebay.com/itm/391107527341?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AITMain thing about the cam is I want it to sound just like it did before I took it apart. Not lumpy, but stealthy until I open it up. I have a nice flowing exhaust if it matters; headers, y-pipe to 3 inch, no cat.
Now here's the kicker. The pushrods that I just took out of this engine are Texas Speed 7.40"! So someone's been in here! And who would upgrade the pushrods if he hadn't done something to the valvetrain to require it? So, for the seasoned professionals what doesn't look stock here? Head gasket was MLS which I guess is normal for a '99 and runners do not look polished or anything. Probably doesn't mean anything but I couldn't get the springs to compress by hand. How can I tell if the cam or lifters have been done? I said earlier that this engine feels very fast but again I don't know what I'm talking about.
Thanks a ton everyone! I really enjoy learning so much about this.
My main question is whether or not there is any work done to these heads. What's the bottom line about them? All I wanted to do is get a simple, reliable, budget bump in horsepower because I thought everything was stock. Maybe, say, LS6 intake, 243/799 heads, baby cam (maybe ls6 or something like 212/218 114, and GM performance valve springs: http://www.ebay.com/itm/391107527341?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AITMain thing about the cam is I want it to sound just like it did before I took it apart. Not lumpy, but stealthy until I open it up. I have a nice flowing exhaust if it matters; headers, y-pipe to 3 inch, no cat.
Now here's the kicker. The pushrods that I just took out of this engine are Texas Speed 7.40"! So someone's been in here! And who would upgrade the pushrods if he hadn't done something to the valvetrain to require it? So, for the seasoned professionals what doesn't look stock here? Head gasket was MLS which I guess is normal for a '99 and runners do not look polished or anything. Probably doesn't mean anything but I couldn't get the springs to compress by hand. How can I tell if the cam or lifters have been done? I said earlier that this engine feels very fast but again I don't know what I'm talking about.
Thanks a ton everyone! I really enjoy learning so much about this.
Appears they might be 856 casting ls1 heads with some aftermarket beehive springs. Don't appear to be ported.
Springs could be stock but my first instinct says they look a little beefier and coated in a different finish than stock GM springs (but it's been a LONG time since I've seen a stock spring that was low mileage and not covered in oil stain)
Springs could be stock but my first instinct says they look a little beefier and coated in a different finish than stock GM springs (but it's been a LONG time since I've seen a stock spring that was low mileage and not covered in oil stain)
They look like stock castings. If they started life as 799/243/317 heads they would have d port exhaust outlets. I tend to lean towards what thunderstruck thinks on these.
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All good info, thanks!
Why would the numbers be ground off and given new serial numbers though? The heads must've made their way to a machine shop at some point, right? Or is it possible a salvager that maintains an inventory could have done this? Any way to tell if they have been milled?
Seems like it'll be easier to look at the cam from the front than the rear plate. Ugh, this sounds like more gaskets I'll have to buy.
Why would the numbers be ground off and given new serial numbers though? The heads must've made their way to a machine shop at some point, right? Or is it possible a salvager that maintains an inventory could have done this? Any way to tell if they have been milled?
Seems like it'll be easier to look at the cam from the front than the rear plate. Ugh, this sounds like more gaskets I'll have to buy.
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Verdad Gallardo On the casting number I have no idea why they might be ground off......especially on stock heads. As far as the deck being milled maybe just measure the chamber volume and compare......here's a list of casting numbers and a good read pertaining to stock heads.
http://www.performancetrucks.net/for...g-info-434396/
This info is on here also but I had the link saved to pt which is a sister forum.
http://www.performancetrucks.net/for...g-info-434396/
This info is on here also but I had the link saved to pt which is a sister forum.
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AHA! It dawned on me that I might try texting the previous owner. Well what do you know, he had a torquer v2 cam installed until he returned to the the stock cam! So the springs are .625 lift along with new pushrods and lifters. Needless to say, I'm glad that I texted him.
So now I am looking at the following mods:
1. Factory LS6 or Dorman LS6 intake <-- Any estimate in hp difference between the two?
2. Comp Cams 212/218 <-- What's the up and downsides to high vs low lift options? Noticeably different sound? Wear and tear?
3. Stock LS6 Heads
So now I am looking at the following mods:
1. Factory LS6 or Dorman LS6 intake <-- Any estimate in hp difference between the two?
2. Comp Cams 212/218 <-- What's the up and downsides to high vs low lift options? Noticeably different sound? Wear and tear?
3. Stock LS6 Heads
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