My opinion - get rid of the copper head gasket. Others swear that you should use it.
Do a mock up and once you have the piston and barrel on, measure the deckheight. Distance between piston crown and top of barrel. Adjust using the spacers under the barrel, adding or subtracting. Cut your own from shimstock if needed.
Once you have all the bits and you put it all together you will see. If not, then read the article again
Just hoping for the best leads to tears
Deck height. What is it and how to adjust it...
- Tony Z
- Donor
- Posts: 14999
- Joined: Wed Sep 14, 2005 8:33 am
- What model do you have?: 2.3L 69; 1302; P/Van
- Location: Klipheuwel (near Durbanville), Cape Town or working at sea
- Has thanked: 192 times
- Been thanked: 487 times
Re: Deck height. What is it and how to adjust it...
ANGRRR
http://www.aircooledvwsa.co.za/viewtopi ... 23&t=14775
1302S
http://www.aircooledvwsa.co.za/viewtopi ... 23&t=33521
Panel Van
http://www.aircooledvwsa.co.za/viewtopic.php?p=288723
http://www.aircooledvwsa.co.za/viewtopi ... 23&t=14775
1302S
http://www.aircooledvwsa.co.za/viewtopi ... 23&t=33521
Panel Van
http://www.aircooledvwsa.co.za/viewtopic.php?p=288723
vader wrote: The Force is strong with you young Sith Lord Z!
-
- Oil Stain
- Posts: 162
- Joined: Tue Apr 14, 2009 3:16 pm
- What model do you have?: 1973 VW Type 2
- Location: Canvey Island, Essex, England
Re: Deck height. What is it and how to adjust it..
Perform a trial assembly (without sealants) of the crankcase, crankshaft, connecting rods, cylinder barrels, pistons and associated components, omitting the barrel shims. Then check your deck-height clearance, for each of the pistons at TDC, using either a straight-edge & feeler gauges or a dial-gauge micrometer. Once you have knowledge of these measurements, one can then consider the next step.Blitzkrieg wrote:How do I set the deckheight?
My 1700 Type 4 has shims under the barrels, and the original factory head gaskets.
Common advice to type 4 owners is to remove the gasket and lap the barrels into the head with valve grinding compound.
Now, do I simply do that or just reassemble everything as stock, including the head gasket?.
Or should I dispose of the head gaskets, leave the barrel shims and just reassemble and hope for the best - apparently this would increase the comp ratio slightly -BUT what about the deckheight?
Advice from experienced folk would be appreciated...
-
- ACVWSA Junkie
- Posts: 10784
- Joined: Wed Mar 07, 2007 10:41 am
- What model do you have?: none
- Location: Johannesburg
- Has thanked: 91 times
- Been thanked: 44 times
Re: Deck height. What is it and how to adjust it..
Will attempt this and if I can't come right, will take it to someone who can do it. Good to learn new things.Nigel A. Skeet wrote:Perform a trial assembly (without sealants) of the crankcase, crankshaft, connecting rods, cylinder barrels, pistons and associated components, omitting the barrel shims. Then check your deck-height clearance, for each of the pistons at TDC, using either a straight-edge & feeler gauges or a dial-gauge micrometer. Once you have knowledge of these measurements, one can then consider the next step.Blitzkrieg wrote:How do I set the deckheight?
My 1700 Type 4 has shims under the barrels, and the original factory head gaskets.
Common advice to type 4 owners is to remove the gasket and lap the barrels into the head with valve grinding compound.
Now, do I simply do that or just reassemble everything as stock, including the head gasket?.
Or should I dispose of the head gaskets, leave the barrel shims and just reassemble and hope for the best - apparently this would increase the comp ratio slightly -BUT what about the deckheight?
Advice from experienced folk would be appreciated...
If I screw it up, I can only blame myself
If it's too low, you're too old
- louisvr45
- Valve
- Posts: 1085
- Joined: Wed May 20, 2009 3:24 pm
- What model do you have?: VW SC fleetline 1600
- Location: pta
- Has thanked: 1 time
- Been thanked: 1 time
Re: Deck height. What is it and how to adjust it...
tony how would one increase you cr? Like to 10:1 and how do one calculate it?
- Tony Z
- Donor
- Posts: 14999
- Joined: Wed Sep 14, 2005 8:33 am
- What model do you have?: 2.3L 69; 1302; P/Van
- Location: Klipheuwel (near Durbanville), Cape Town or working at sea
- Has thanked: 192 times
- Been thanked: 487 times
Re: Deck height. What is it and how to adjust it...
start a new topic and I'll answer it therelouisvr45 wrote:tony how would one increase you cr? Like to 10:1 and how do one calculate it?
ANGRRR
http://www.aircooledvwsa.co.za/viewtopi ... 23&t=14775
1302S
http://www.aircooledvwsa.co.za/viewtopi ... 23&t=33521
Panel Van
http://www.aircooledvwsa.co.za/viewtopic.php?p=288723
http://www.aircooledvwsa.co.za/viewtopi ... 23&t=14775
1302S
http://www.aircooledvwsa.co.za/viewtopi ... 23&t=33521
Panel Van
http://www.aircooledvwsa.co.za/viewtopic.php?p=288723
vader wrote: The Force is strong with you young Sith Lord Z!
-
- Fuel Injection
- Posts: 2112
- Joined: Sat Sep 30, 2006 10:25 pm
- What model do you have?: Aircooled, various
- Location: Kaapstadt
- Has thanked: 42 times
- Been thanked: 207 times
Re: Deck height. What is it and how to adjust it...
A comment from Aircooled.net's John:
"I had one engine that the pistons just kissed the heads,
.028" Deck (0.711mm)
84mm stroke
8500 RPM"
That was a type 1 application where he was testing the limits of deck height.
In another example, a prominent guy on STF ran 0.65mm deck height in a type 4 engine- 914 for well over 200 000 kilos without issues. The bulletproof strong type 4 bottom end probably helped here.
Comment by those who ran tight decks was that no space is necessary to provide for carbon build up. The squish will blow this area clean, and this was confirmed when heads were removed for inspection. Problem may be when small parts like loose accelerator jets fall down the intake manifold.
Piston speed around tdc is not as fast as we would think. Between 3 degs btdc and 3 degs atdc it is quite slow.
For long term reliability i would be careful and not go below 1mm. But, more than 1.2mm is not optimum and wasting fuel. However, this is assuming that deck on all 4 cylinders were measured, and not a crude "volume rebuilt" application.
Some people do not understand the efficiency of squish. Some rebuilders will even cut a large step in the chamber when not asked to do so, or shim the cylinder for much larger deck height than even standard specs. The thinking there probably that ultra low compression engines have a better chance to survive their guarantee period.
"I had one engine that the pistons just kissed the heads,
.028" Deck (0.711mm)
84mm stroke
8500 RPM"
That was a type 1 application where he was testing the limits of deck height.
In another example, a prominent guy on STF ran 0.65mm deck height in a type 4 engine- 914 for well over 200 000 kilos without issues. The bulletproof strong type 4 bottom end probably helped here.
Comment by those who ran tight decks was that no space is necessary to provide for carbon build up. The squish will blow this area clean, and this was confirmed when heads were removed for inspection. Problem may be when small parts like loose accelerator jets fall down the intake manifold.
Piston speed around tdc is not as fast as we would think. Between 3 degs btdc and 3 degs atdc it is quite slow.
For long term reliability i would be careful and not go below 1mm. But, more than 1.2mm is not optimum and wasting fuel. However, this is assuming that deck on all 4 cylinders were measured, and not a crude "volume rebuilt" application.
Some people do not understand the efficiency of squish. Some rebuilders will even cut a large step in the chamber when not asked to do so, or shim the cylinder for much larger deck height than even standard specs. The thinking there probably that ultra low compression engines have a better chance to survive their guarantee period.
Staying Aircooled is so much nicer.
Do'nt assume anything- (While doing fault-finding).
Do'nt assume anything- (While doing fault-finding).
- retrovan
- Donor
- Posts: 8710
- Joined: Mon Feb 07, 2011 8:51 pm
- What model do you have?: 52T1,68FB,72Bay,75FL
- Location: Eich! no, in Jefferys Bay
- Has thanked: 421 times
- Been thanked: 541 times
- Contact:
Re: Deck height. What is it and how to adjust it...
Here is a site that has most info you need,
very helpful for spec's.
http://www.headflowmasters.com/helpful- ... iUIVH87n3A
Herman
very helpful for spec's.
http://www.headflowmasters.com/helpful- ... iUIVH87n3A
Herman
1952 Split Beetle 1835cc
1968 Fastback 2Lt.type4
1972 Low Light Bay Panel Van 2Lt type 4
1975 Fleetline Panel Van 1914cc
2020 MeFusco Beetle Truck 2Lt type 4
1972 FT Hahn SP 1776 cc
1968 Fastback 2Lt.type4
1972 Low Light Bay Panel Van 2Lt type 4
1975 Fleetline Panel Van 1914cc
2020 MeFusco Beetle Truck 2Lt type 4
1972 FT Hahn SP 1776 cc
- riaanj
- Exhaust Pipe
- Posts: 1665
- Joined: Wed Oct 06, 2010 8:17 pm
- What model do you have?: None ATM, oneday...
- Location: Germiston
- Has thanked: 6 times
- Been thanked: 41 times
Re: Deck height. What is it and how to adjust it...
Awesome, thanks Hermanretrovan wrote:Here is a site that has most info you need,
very helpful for spec's.
http://www.headflowmasters.com/helpful- ... iUIVH87n3A
Herman
Just keep on BUGGIN'
Protect the endangered, say NO to exporting our AirCooled spares & cars..
T6 Ranger 2.2TDCi D/Cab
307E Anglia panel-van
Honda CBR600RR
Honda CBR600F4
Honda CBR1100XX SuperBlackbird
Protect the endangered, say NO to exporting our AirCooled spares & cars..
T6 Ranger 2.2TDCi D/Cab
307E Anglia panel-van
Honda CBR600RR
Honda CBR600F4
Honda CBR1100XX SuperBlackbird