2.2/2.5 Cylinder head flow

All the heads on this page are flowed at 28" except where noted in red.

Most of this information is several years old and will be updated with hands on information in the future.

Numbers from Dave St Louis-

 Head type  Intake  Exhaust  Lift
 Lotus 16V  244 cfm  182 cfm  350"
 Maserati 16V  237 cfm  213 cfm  350"
 Neon DOHC  237 cfm  195 cfm  350"
 Swirl SOHC  156 cfm  135 cfm  500"

Dave's numbers are converted from 10" with a 2.6 conversion factor and using the swirl head as a baseline. 

Notes- Well I have been going to do this for awhile now and I finally got it done although not the way I wanted to but a good comparison anyway. I compared these on a decent flow bench all in one day. I flowed the 4v ones at .350 in lift as this is very close to what they all come with for cams (.335in for the Lotus and .330in for the Maserati) and the 2v at.500in lift assuming the S60 cam. There was not alot of increase in flow in the 2v head by going from .350in to .500in so I guess that's why the cams don't seem to make a huge difference in power in these. All are stock with the exception of the Maserati which has had a good valve job and some mild port cleanup done. Thanks to Don Dulmage for the help and use of the flowbench, Dean Stille for the use of the DOHC Neon head ,and Marc Young for the Maserati head. The SOHC 2v head is a 89 T2. Some of the results suprised me, judging by looking at the heads before I started .These figures are at 10" of water, with the head on a 2.2 deck plate on the bench. I wanted to flow all these at .100 increments but the time and money involved turned out to be too much. This was done just for comparison and not the last word. The figures are rounded up. 

I thought that by looking that the Lotus would have the lowest (of the 4v) flowing intake and the neon would have the lowest flowing exhaust but I guess you can't go by looks. The neon port looks tiny compared to the rest ,but flows well. All the 4v heads showed noticeable improvements by going with more lift although I didn't measure it exactly .The 2v ,the flow just got turbulent above .550in. I'm having my Lotus head professionally ported and I will check it again after its done and see how it looks.

Barry Goodall

 S-60 Head  Intake 400"  Exhaust 400"  Intake 500"  Exhaust 500"
 Before  159.5  119.3  177.6  128.4
 After  165.4  147.9  188  162.2

Notes- In response to Gary's post looking for information, the head on my Omni started out as an MP fully ported race head, which was a G-head with the oversize valves and was what MP referred to as "fully ported."  I then had it ported again as it looked like there was still needed work.

For this porting, the head was optimized for the S60 cam which has a max of about .500 lift.   While the intake only increased a touch over 6%, the exhaust saw a 20% increase over the MP fully ported head (both at .500 lift).   Notice that there are gains at .300 and .400 lift (especially on the exhaust) where the cam spends a lot more time than at .500.    The head was ported by Total Flow Products in Troy Michigan. Also, they told me they could do more with a head that had not been "screwed up" by MP first.

As received from MP, the head had two exhaust valves that never completely sealed, the valve job was THAT bad.   Since this discovery, my advice to anyone looking for performance from their cylinder head is to avoid the overpriced MP heads (mine listed for $1300 when new) and get a good porting job from someone that understands the requirements of turbocharged heads.   They will save money and get better performance in the long run.

As an aside, Total Flow Products is a premier head service shop that has a national reputation as one of the best.   Just about every head you see damaged when a Top Fuel car blows an engine is repaired by Total Flow as the repair is only about 1/2 to 2/3 the cost of replacement.  They repair heads that have the combustion chambers completely burnt or blown away, amazing stuff they do, they make them like new again.

Danny Fazzina

 Ported Swirl  Intake 400"  Exhaust 400"  Intake 500"  Exhaust 500"
 CFM  159  131  181  153


Swirl head 90 casting, chamber polished like a mirror, ported by Ned at Rolling Thunderz, bowls were fully ported for a stock valve, runners were reshaped, roofs were raised and the floors were barely touched. Swirl marking in the bowl was reshaped, valves were stock, no backcut, no valve job...and valve wasn't even polished still had carbon on it.. I will send more info as soon as I can.

Randy Hicks (AT 25 INCHES)

 Head  Intake 400"  Exhaust 400"  Intake 500"  Exhaust 500"
 S-60 Head  166  116  182  126
 Swirl  140  96  151  105

Notes- I had my stock M.P. Super 60 head flowed when I bought it about 3 years ago. It was flowed at 25" H20. For comparison I had the stock 1988 TII swirl flowed at the same time by the same guy/machine. For what it is worth the S60 graph is still pointing upward at .600 lift and the stock swirl is starting to point down on the intake and level on the exhaust.

Steve Menegon

 Ported Swirl  Intake 400"  Exhaust 400"  Intake 500"  Exhaust 500"
 CFM  164  129  185  143

I've been dabbling with cylinder head porting on my own as I like the work. I've wondered if I was screwing up the heads and overcoming the inadequacies with excess boost or if I was onto something decent. So, I ported a cylinder and took it to have it checked. All the work was done on a Superflo bench and the head has stock T2 valves. I also unshrouded the valves  slightly.

Todd Nelson

 Head  Intake 400"  Exhaust 400"  Intake 500"  Exhaust 500"
 Ported G  167  122  179  138
 Ported Swirl  157  121  177  132
 Peters Swirl  161  117  163  131
 Stock Swirl  145  121  157  127

Ported G- Stock 1.60/1.39 valves, multi-angle valve job, back-cut valves, 58 cc chamber. 

Ported Swirl-  Stock valves, multi-angle valve job, ports raised, 48 cc chamber.

Ed Peters Swirl- Radically ported, stock valves, 50 cc chamber (.70 milled from head?) 

Stock Swirl- No valve job, no milling, 50 cc chamber.

F.M. Ported Swirl Head

Purchased Aug 18, 1995- Oversize valves, interlocking valve seats, ported, polished runners & reworked combustion chambers.  Head is currently at skilled cylinder head shop where they are trying to rectify flow issues and replace four defective M.P. exhaust valves at owners expense. 

Thanks for visiting Donovan's Dodge Garage