Currently in the process of upgrading the engine from my drag car ( The Jagerbug)
I’m changing the 2276 (82x94) engine from Cb 044 heads to some secondhand superflo heads I picked up a while back
The Superflos have been flycut somewhat so have a chamber volume of 30cc which is pretty small, I want a final cr of about 12:1
Current deck height is 0.90 mm
My calculations so far take me to using a 1.5mm copper head gasket (gives another 11cc according to my maths) which gives a top end volume of 41cc
Using a 0.5mm cylinder spacer drops the deck to 1.4mm
According to the Jmr calculator this gives a CR of 12.2
Does this sound correct ?
Engine runs FK89 , 48 Ida’s and is not street driven - just want to up the breathing with the bigger valve better flowing heads
Cheers Alex
Head upgrade from 044 to Superflow
- FJCamper
- Moderator
- Posts: 2901
- Joined: Wed Nov 14, 2007 2:19 pm
Re: Head upgrade from 044 to Superflow
Hi Alex,
I understand you have an estimated 30cc combustion chambers Which is small. The smallest we run is 39cc on an 11:1 engine.
There is no practical power gain in anything over 11:1, especially in an air-cooled engine.
Set your deck to 60 thousanths to allow for 94mm piston rocking at high RPM. You want as tight a deck as possible. You get this by shimming the cylinder, not adding copper spacers between cylinder and head.
044 heads are not going to flow enough to exceed 7500 RPM even with the right cam. You'll need 48 Webers with at least 40mm venturis.
Good luck
I understand you have an estimated 30cc combustion chambers Which is small. The smallest we run is 39cc on an 11:1 engine.
There is no practical power gain in anything over 11:1, especially in an air-cooled engine.
Set your deck to 60 thousanths to allow for 94mm piston rocking at high RPM. You want as tight a deck as possible. You get this by shimming the cylinder, not adding copper spacers between cylinder and head.
044 heads are not going to flow enough to exceed 7500 RPM even with the right cam. You'll need 48 Webers with at least 40mm venturis.
Good luck
- WickedWagens
- Posts: 775
- Joined: Fri Sep 02, 2005 9:33 pm
Re: Head upgrade from 044 to Superflow
Yes, that would give you 12.4:1, but that is also .114" or 2.9mm of deck height which is pretty big. With it being a drag car I would't worry about getting it up into the 13's on compression to keep the deck smaller.
1968 Karmann Ghia land speed
G/CFALT 106.643 MPH G/CGALT 113.131 MPH
G/CBGALT 169.462 MPH G/CBFALT 146.715 MPH
G/CBGC 158.242 MPH H/CBGC 94.334 MPH
H/CPRO 93.383 MPH H/CBFALT 101.282 MPH
H/CBGALT 120.591 MPH
Top Speed 174.2 MPH
G/CFALT 106.643 MPH G/CGALT 113.131 MPH
G/CBGALT 169.462 MPH G/CBFALT 146.715 MPH
G/CBGC 158.242 MPH H/CBGC 94.334 MPH
H/CPRO 93.383 MPH H/CBFALT 101.282 MPH
H/CBGALT 120.591 MPH
Top Speed 174.2 MPH
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- Posts: 5
- Joined: Sun Jun 06, 2004 12:47 am
Re: Head upgrade from 044 to Superflow
Ok - so rather than increasing the deck, if I machine a 70mm dish 1.5mm deep in the piston crowns then it will gain 5.6cc into the combustion chamber, then keeping the deck at 1.4mm that gives 13.4 compression - sounds more reasonable ?
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- Posts: 2399
- Joined: Fri Dec 07, 2001 12:01 am
Re: Head upgrade from 044 to Superflow
13,4 static requires race gas, even with the FK89.
On 93 pump gas I´m more in favour of ,118" deck and 12-1, along with a GOOD ignition system (MSD or similar)
On 93 pump gas I´m more in favour of ,118" deck and 12-1, along with a GOOD ignition system (MSD or similar)