L92 Sectioned Head Pics.....Porters beware!
L92 Sectioned Head Pics.....Porters beware! I got a chance to section cut a semi raw head casting and thought I'd share some pics with the board. I started out with a head casting number 5364. BTW does anyone know how many different casting numbers GM made for these heads? I have at least 2 different casting number cores.
Here's a shot of the unfinished chambers.
Note that there are no spark plug holes.
The main purpose of this exercise is to determine how much casting thickness there is in some critical areas of an unported head.
This is a shot of the intake port cross section.
This shot shows the deck thickness.
Note that this casting was not machined to the finished deck height. It was .055" thicker than the finished heads I have. As you can see there's a bit less than 1/2" of material supporting some of the head gasket sealing surfaces.
The back wall of the the chambers seem to be thick enough as evidenced in this shot. It looks like a little over 3/8" wall thickness here.
Several thin spots surrounding the intake and exhaust ports are evident. This shot is looking at the back of the intake bowl on one side of the guide boss.
And heres a look at the as cast exhaust port section.
Note the lack of roof section thickness here:
If I come up with any more relavent pictures I'll post 'em up.
Richard
Here's a shot of the unfinished chambers.
Note that there are no spark plug holes.
The main purpose of this exercise is to determine how much casting thickness there is in some critical areas of an unported head.
This is a shot of the intake port cross section.
This shot shows the deck thickness.
Note that this casting was not machined to the finished deck height. It was .055" thicker than the finished heads I have. As you can see there's a bit less than 1/2" of material supporting some of the head gasket sealing surfaces.
The back wall of the the chambers seem to be thick enough as evidenced in this shot. It looks like a little over 3/8" wall thickness here.
Several thin spots surrounding the intake and exhaust ports are evident. This shot is looking at the back of the intake bowl on one side of the guide boss.
And heres a look at the as cast exhaust port section.
Note the lack of roof section thickness here:
If I come up with any more relavent pictures I'll post 'em up.
Richard
Very informative. Thanks Richard. Do you have some comparison measurements from GM and aftermarket LS1 style heads? Do GM LS7 heads (and aftermarket variants) share the thin issues?
Thanks,
Bill
Thanks,
Bill
When I got my heads we noticed that the valve seat seemed to have a lot of extra material in it. Could you take material out of the areas I circled to improve flow? The opening appears to be smaller than the valve right there, and not by a little.
-Geoff
-Geoff
This example is pretty standard for factory parts including the LS7 heads. I'll try getting some shots of other heads to post up in the near future.
No doubt there's working room to improve airflow in these heads, but I wanted to note the ultimate short coming of these heads. That being said, they're still an impressive part from a major automaker.
Richard
No doubt there's working room to improve airflow in these heads, but I wanted to note the ultimate short coming of these heads. That being said, they're still an impressive part from a major automaker.
Richard
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Originally Posted by White_Hawk
When I got my heads we noticed that the valve seat seemed to have a lot of extra material in it. Could you take material out of the areas I circled to improve flow? The opening appears to be smaller than the valve right there, and not by a little.
-Geoff
-Geoff
Richard
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Teching In
Joined: Nov 2006
Posts: 37
Likes: 0
From: Nevada
Thanks Richard,
Great info. I agree I wonder how they compare in strength i.e. thickness to Ls6, Ls2, and Ls7 heads. I'm glad there are sponsors/vendors like yourself that are willing to do the homework and share tech. knowledge with the rest of us. Many don't. Can't wait till you offer different L92/L76 packages.
Great info. I agree I wonder how they compare in strength i.e. thickness to Ls6, Ls2, and Ls7 heads. I'm glad there are sponsors/vendors like yourself that are willing to do the homework and share tech. knowledge with the rest of us. Many don't. Can't wait till you offer different L92/L76 packages.
Those unfinished chambers are nasty. You might not be able to go crazy on the runners, but you sure as hell can there. Definetly could pick up some major flow there.
Staging Lane
Joined: Apr 2006
Posts: 62
Likes: 0
From: Saint Clair Shores Mi
Originally Posted by Juiced
Ricahrd
do you see any issues with th head being able to handle a solid roller spring with 300+ seat pressure
do you see any issues with th head being able to handle a solid roller spring with 300+ seat pressure
Last edited by deputydog; Dec 14, 2006 at 05:26 PM.
Originally Posted by deputydog
I building a max effort F2 blown motor and was going to switch from my LS6 heads to the L92 heads. The main reason I cannot is they dont make aftermarket rockers for the head. I called W2W, Jesel,T & D and SDPC no rockers. At SDPC they havent even heard of any talk of rockers any time soon. W2W siad they would not recommend the stock rockers with anything over 200psi on the seat
Staging Lane
Joined: Apr 2006
Posts: 62
Likes: 0
From: Saint Clair Shores Mi
Originally Posted by dhdenney
Jesel e-mailed me a few months ago on the L92 rockers. The thread is here https://ls1tech.com/forums/showthrea...ight=jesel+l92
Side note...How do you like that TDI Volkswagen?
Originally Posted by deputydog
I'll call them back with that info, but as of yesterday they dont have a set. Jesel and T & D can both make a one-off custom set if you send them your head, but i dont want the L92 head that bad.
Side note...How do you like that TDI Volkswagen?
Side note...How do you like that TDI Volkswagen?
That has been several months ago so maybe they've changed their plans. On the VW, it's a great car. I'll probably never own another car for a DD. It'll get 50 mpg if you'll leave your foot out of it, but believe it or not, it's got some power. The turbo really gives it some oomph. I hope to put half a million miles on it before I have to have any major overhaul on the engine.
Originally Posted by WKMCD
Thanks Richard. This info is one of the reasons I didn't rush to have the L92's ported for my build. I'm waiting for a proven CNC product.