Printable Version of Topic
Click here to view this topic in its original format
914World.com _ 914World Garage _ Deck Height Q
Posted by: sdoolin Mar 28 2016, 11:05 AM
I have read as much as I can stand on measuring deck height in preparation for doing just that as part of my 2056 build (different thread). While I am comfortable with the process once set-up, I can't tell from all of my reading if I should begin with a shim/gasket between jug and case, or if I should begin naked (no shim/gasket)?
I would think that I'd want to use the 4 metal gaskets (VR P/N 17-00121-01) that came with the gasket set as a crushable seal to keep oil in the engine, and so as-such would think I'd begin my deck height and CR measurements with these in place.
However, I have seen many suggestions to do the set-up without "shims". Do we consider the "shims" different than the "gaskets"?
As always all help appreciated.
Posted by: r_towle Mar 28 2016, 11:08 AM
measure without shims, do math to add the correct amount of shims.
They deform when torque is applied, even though they are supposed to be hardened.
I do it this way, just my opinion and I know others like to do things differently.
rich
Posted by: sdoolin Mar 28 2016, 03:35 PM
measure without shims, do math to add the correct amount of shims.
They deform when torque is applied, even though they are supposed to be hardened.
I do it this way, just my opinion and I know others like to do things differently.
rich
Thanks for this. But - I am still unclear - if I measure without the "gasket" then won't I be wrong from the git-go as the gasket adds a bit of height to the cylinder (and thusly affects deck-height)? I can't imagine final assembly without at least the crushable gasket between jug and case.
Shims (I am hoping) are different than gaskets?
Apologies if I am being a little dense.
Posted by: r_towle Mar 28 2016, 03:47 PM
Measure without, subtract cylinder base gasket thickness from deck height measurement ( do the math) and use that final number in your compression ratio calculation
Posted by: sdoolin Mar 28 2016, 03:56 PM
Measure without, subtract cylinder base gasket thickness from deck height measurement ( do the math) and use that final number in your compression ratio calculation
Got it! Even makes sense.
Posted by: r_towle Mar 28 2016, 04:40 PM
There are different thicknesses of cylinder base shims to help you achieve your target compression ratio
Posted by: rdauenhauer May 24 2018, 07:53 PM
I recently tore down a engine that was found set up w/o base gaskets/shims on one bank and a single (.008 compressed) shim on the other bank.
The bare bank showed clear signs of marring of the registers that wasn't present on the opposite bank. Both banks probably had a equal amount of oil leakage / grime present.
Shouldnt some shim always be used between jug & register?
Posted by: 914Sixer May 24 2018, 08:41 PM
Paper gasket goes on case where cylinder touches case.
Posted by: cgnj May 24 2018, 08:41 PM
I have read as much as I can stand on measuring deck height in preparation for doing just that as part of my 2056 build (different thread). While I am comfortable with the process once set-up, I can't tell from all of my reading if I should begin with a shim/gasket between jug and case, or if I should begin naked (no shim/gasket)?
I would think that I'd want to use the 4 metal gaskets (VR P/N 17-00121-01) that came with the gasket set as a crushable seal to keep oil in the engine, and so as-such would think I'd begin my deck height and CR measurements with these in place.
However, I have seen many suggestions to do the set-up without "shims". Do we consider the "shims" different than the "gaskets"?
As always all help appreciated.
Hi,
This is how I proceed.
Assemble without gaskets or shims.
Measure deck.
Heads already Done?. CC the chambers.
Now calc and see the raw static compression. Add in gaskets and calc required flycut or base shim to hit your number.
Good luck
Carlos
Posted by: Mark Henry May 24 2018, 09:35 PM
The base shims don't crush, they're steel not aluminum.
If you don't believe me put a magnet on them.
You can use a maximum of 3 shims, after that you need custom size shims from T4store or EMW. Minimum deck .040" but do the math.
I use loctite SI 5900 flange sealant on the cylinder bases.
Posted by: Mark Henry May 24 2018, 09:48 PM
Are you talking about the base shims or the head gaskets?
I don't use the head gaskets and you shouldn't use them on 96mm cylinders.
Posted by: rdauenhauer May 24 2018, 09:58 PM
Base shims. No paper gaskets present, Cast steel cylinders directly on aluminum case/register. The other bank had only a single shim
I didnt mention bore but in this case it is an OE 94mm 2.0L that from appearances had never been messed with.
Powered by Invision Power Board (http://www.invisionboard.com)
© Invision Power Services (http://www.invisionpower.com)