Re: Steel shim gaskets?
[Re: polkat]
#283212
04/10/09 03:42 AM
04/10/09 03:42 AM
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Joined: Jan 2003
Posts: 9,826
las vegas
70AARcuda
master
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master
Joined: Jan 2003
Posts: 9,826
las vegas
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good deal..cause the new ones would not be a cost effective deal...
Tony
70 AARCuda Vitamin C
71 Dart Swinger 360 10.318 @ 128.22(10-04-14 Bakersfield)
71 Demon 360 10.666 @122.41 (01-29-17 @ Las Vegas)
71 Duster 408 (10.29 @ 127.86 3/16/19 Las Vegas)
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Re: Steel shim gaskets?
[Re: DusterKid]
#283215
04/10/09 07:57 AM
04/10/09 07:57 AM
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Anonymous
Unregistered
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Anonymous
Unregistered
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This swap was worth a tenth in the eigth on my boys car when i switched with no other changes. 
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Re: Steel shim gaskets?
[Re: polkat]
#283216
04/10/09 08:22 AM
04/10/09 08:22 AM
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Joined: Mar 2003
Posts: 1,102
Melbourne, Florida
Florida_70Bee
super stock
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super stock
Joined: Mar 2003
Posts: 1,102
Melbourne, Florida
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Quote:
I have a set that's about 10 years old and never been out of the package. How much will these raise compression above stock? Also, if I use them, will I have to shorten the pushrods? These gaskets are about .020" thinner then the stock gasket, can I shorten the pushrods that much? Thanks!
I currently have a set of old Fel Pro 8280 SH-1's (steel shim) gaskets on my 383 Bee with no issues. They compress to .020 and have been on the motor for 5 years with no issues.
The key to using them I found is to make sure both the head and block deck are completely flat (a pass or 2 on a milling machine would true both surfaces up). I my case I milled the block to the point where the pistons are .006 below the deck (they were .040 down in the hole from the factory) and the heads I had milled down to 80cc (they were 88cc from the factory) this combined with the steel shim gaskets give me a CR around 10.2. I did however compensate for the milling on the heads and block by adding shims under the rocker arm shafts (I think .050) to get the lifter preload right with the hydraulic cam.
Also before installing them I would coat the gaskets with copper coat spray.
Hope this helps
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Re: Steel shim gaskets?
[Re: Florida_70Bee]
#283217
04/10/09 08:52 AM
04/10/09 08:52 AM
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Joined: Nov 2006
Posts: 196
West Central Indiana
Mr.Runum
member
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member
Joined: Nov 2006
Posts: 196
West Central Indiana
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Find an engine calculator like the one on Chenoweth Racing Enterprises LLC. Just plug in your spec change around the gasket thickness and it will show you changes in compression. Without guessing.  Mr.Runum
69 RoadRunner 383 4spd coupe, 06 Hemi Daytona Charger, 08 6.7 RAM QC short bed 3/4 4X4
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Re: Steel shim gaskets?
[Re: Cab_Burge]
#283223
04/10/09 01:54 PM
04/10/09 01:54 PM
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Joined: Jan 2003
Posts: 75,043
U.S.S.A.
JohnRR
I Win
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I Win
Joined: Jan 2003
Posts: 75,043
U.S.S.A.
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Quote:
Quote:
and it is the stock gasket.
Randy
 There where two different thgicknesses on the gaskets depending on the motor and the year and vendor, .017 and .022 usually on the B&RB. I have measured some used 426 Hemi gaskest that where .020
X3 , that motor should have steel shim gaskets it its STOCK so changing will net you alot of work and a big GOOSE EGG for compression increase .
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Re: Steel shim gaskets?
[Re: polkat]
#283225
04/10/09 02:24 PM
04/10/09 02:24 PM
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Joined: Jan 2003
Posts: 75,043
U.S.S.A.
JohnRR
I Win
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I Win
Joined: Jan 2003
Posts: 75,043
U.S.S.A.
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Quote:
Okay. Well, in this case I was thinking about using them on a 400 from a '73 truck (original engine). But if that engine came stock with the steel gaskets (doesn't seem to have ever been apart), then there wouldn't be any compression advantage to using them...right? Or am I missing something here? Thanks!
No you aren't missing a thing , I have never seen anything but steel shim gaskets on original BB mopars , the first with a composite gasket was my crate hemi .
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Re: Steel shim gaskets?
[Re: polkat]
#283226
04/10/09 02:29 PM
04/10/09 02:29 PM
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Joined: Mar 2003
Posts: 1,102
Melbourne, Florida
Florida_70Bee
super stock
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super stock
Joined: Mar 2003
Posts: 1,102
Melbourne, Florida
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Quote:
Okay. Well, in this case I was thinking about using them on a 400 from a '73 truck (original engine). But if that engine came stock with the steel gaskets (doesn't seem to have ever been apart), then there wouldn't be any compression advantage to using them...right? Or am I missing something here? Thanks!
That is correct. the original motors came with the steel shim gaskets in those years. Mine was steel shim when it was pulled apart the for first time. For that engine you could gain compression by either a different set of pistons, milling the heads and or the block deck.
But since this a low compression 400 you would probably have mill a ton off the block and heads (and intake) to get the compression anywhere useful. Those pistons are probabily .090 to .100 down below the deck. So if it were me a another set of pistons (higher compression pistons that is) is what I would consider.
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Re: Steel shim gaskets?
[Re: polkat]
#283228
04/13/09 12:48 PM
04/13/09 12:48 PM
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Joined: Jan 2003
Posts: 75,043
U.S.S.A.
JohnRR
I Win
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I Win
Joined: Jan 2003
Posts: 75,043
U.S.S.A.
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Quote:
How about a closed chambered head? I assume that a '73 400 came with open chambered heads like the 906 or similar. What kind of compression increase could I get with...say, 516 heads? Thanks!
not enough
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used to use them on all my engines with iron heads...never had any problems, always sprayed them with silver high temp paint. No pushrod change was ever made...never calculated the compression change, just knew it raised it and back in those days that's all I was after... 
