Just wondering if anyone happens to have any flowbench numbers on a 94-97 1.8L head with/without headwork? I've seen the 99 head numbers from FM's site as well as the pics of the better port placements, but curious as to the actual flow rates. Thanks.

 

Here's what I have found so far, but more numbers would be great.

Fully ported 1.8 with stock valve sizes....lots of work. IRTB manifold, stock exhaust manifold. Measured at 28" average.

Intake Exhaust
.050 43.2 32.5
.100 84.3 65.4
.20 158.3 131.9
.25 183.1 151.7
.30 197.4 164.3
.35 205.8 171.4
.40 211.9 176.6
.45 213.8 183.1

Stock 1.6, stock intake manifold, stock exhaust. Measured at 28" average.

Intake Exhaust
.050 37 35
.100 67.8 63.7
.20 128 118.5
.25 146 137
.30 160 147
.35 166 152
.40 169 154
.45 172 156

 

99 head from FM at same 28" intake is 1st picture and exhaust is 2nd.

 

Looks like the 1.8 head numbers you posted basically matches the 99 numbers with back cut/unshrouded stock valves.

 

My old boss is the owner of M2 Race Systems, fancy 5 axis cnc heads and stuff. He said he'd like to do a miata head, I have a spare '94 head that he or I can digitize and recreate. But we need to find a person (me?) to hand port one cylinder first. I dont' want to pay anyone who's good at it, and I don't know if it's worth the time on a non-99-00 head. But the source is there...

But looks like you got the info you were looking for anyway.

 

Problem is that I'm not sure how much "work" was really put into it. I found it from an old post of gibb's from around 2002 or something like that.

 

Oh, will if it was his then I'm sure everything was touched. What does a stock na 1.8 head flow I wonder.

 

Yeah, me too which is why I asked, I hope someone has the info. Did you happen to get your head flowtested? Would be interesting to compare to the stock 1.6 test I posted.

 

I've got a spare 01 head that's gonna get ported.... is that useful?

 

why are these flowed at 28" of water.

we all know based on Randy's flows of the 1.6 AFM that all measurements need to be taken at 15" of water. Therefore rendering the AFM a huge restriction in the intake that's barely able to flow enough to support the HP output to the wheels.

cause 28" of water is only used when measuring for forced induction purposes. it's not a standard of measurement or anything....


sorry, too many debates about that on m.net. just had to

 

I have a spare 1.6L head too.

 

I have a 99 head

 

I stole this from an m.net search


Hear are the flow number from my 96 head, done at the same shop Gibb's head was done at.
LIFT Stk-In Port-In Stk-EX Port-EX
0.050 36.8. 41.2 32.3 34.8
0.100 71.4. 82.4 63.8 72.2
0.150 115.0 122.2 92.9 102.0
0.200 148.5 157.4 124.3 130.2
0.250 173.8 184.2 143.1 157.6
0.300 191.0 206.0 152.8 177.0
0.350 195.4 214.1 158.6 188.8
0.400 201.8 223.7 160.8 196.7
0.450 203.9 227.5 163.1 201.2
0.500 206.0 231.2 165.8 205.7

 

I have before and after flow numbers for my '99 head. Think the numbers are on my website, not got time to look as I am about to go out to pub. If not I can post them up later.

 

OK. The values are not on my website, yet another of those items on the to do list that I do not have time for right now. Anyway here are the figures:

Exhaust flow (cfm) using 110 Flow Bench, using 10" water
Lift 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45
Stock 16.90 36.17 54.55 72.97 84.40 91.94 95.54 97.70 99.86
Fully modded 20.00 47.95 71.26 91.58 102.69 111.12 115.16 118.04 120.20
% imp 18.34 32.57 30.63 25.50 21.67 20.86 20.54 20.82 20.37

Inlet flow (cfm) using 110 flow bench and 10" water.
Lift 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45
Stock 21.80 43.28 66.72 87.84 103.29 113.13 118.75 122.47 124.50
Fully modded 23.42 47.16 71.40 94.71 114.53 128.59 137.02 141.49 144.26
% imp 7.43 8.96 7.01 7.82 10.88 13.67 15.39 15.53 15.87

I only have the post-modification figures for measurements made with a 600 Flow Bench, at 25" water:
Inlet
38.50 79.50 120.75 153.40 185.85 206.50 221.25 227.15 232.46
Exhaust
34.97 80.86 112.26 141.93 156.69 167.48 173.80 180.12 184.86


Reason for using the 110 flow bench is that it provides more accurate than the 600 at 28".