Street porting a 1.9 big valve head

[neuropel]

Yeah...even with Bob's skills I don't think that size valve will fit...
Duly fixed...

[Hiro]

Originally Posted by hrcollinsjr Hiro, Some of us (me) may be metrically challenged in that we (I) understand the metric system but "think" in inches and feet. Would it be too much trouble for you to do a graph for the metrically challenged. Harold

OK I will make the plots both metric & imperial,
I understand it's not comfortable when the unit is not the one we use daily.
Hiro

[Hiro]

Originally Posted by RallyBob Harold, does this help? I suspect it may be tougher for Hiro than us to convert things. We use both metric and 'standard' measurements here in the US, but in most of the rest of the world it's been nothing but metric for many years. In fact the first country to adopt the metric system was France in 1791! Any apparently there are only three countries left in the world who have not officially adopted the metric system as their standard of measures. Guess we're stubborn, huh? Bob

I'm getting familiar with imperial units little by little,
still difficult for me to convert torque m.kg into lb.ft
and very difficult for me to remember tool/spanner size order! (1/4 3/8 1/2 etc)
I better improve this fast because this winter I'm building my first SB,
plan to race this big piece of cast iron in one of my CommodoreB...
Hiro

[Hiro]

Originally Posted by neuropel Harold, I quickly remade the graphs using the SAE numbers. Hope this is what you were looking for. Todd

thanks Todd!
Hiro

[hrcollinsjr]

Originally Posted by Hiro OK I will make the plots both metric & imperial, I understand it's not comfortable when the unit is not the one we use daily. Hiro

Thanks Hiro, I figured if you were smart enough to do the graphs you could do them to order. When I want to perform conversions I use a program on my Palm Pilot.

Thanks again,
Harold

[RallyBob]

Originally Posted by Hiro Go ahead Bob! I'm back from holidays so I have some time now. Post your data & comments here on this forum, I will make/post the plots & update your webpage @ RROC. Cheers, Hiro

I found some more flow charts for various head types. Now you have work right up until winter...

1.9 competition-ported, 1.85" intake valves, 1.50" exhaust valves

Intake port:..... Exhaust port:
.100" - 37.5 cfm..... 31 cfm
.150" - 53 cfm..... 46 cfm
.200" - 71 cfm..... 54 cfm
.250" - 86.5 cfm..... 68 cfm
.300" - 99 cfm..... 76 cfm
.350" - 110.5 cfm..... 86.5 cfm
.400" - 120 cfm..... 96 cfm
.425" - 122 cfm..... 100 cfm
.450" - 124.5 cfm..... 103 cfm
.475" - 126 cfm..... 105 cfm
.500" - 126 cfm..... 106 cfm
.525" - 126 cfm..... 106.5 cfm
.550" - 128.5 cfm..... 107.5 cfm
.575" - 128.5 cfm..... 108 cfm
.600" - 128.5 cfm..... 108 cfm

[RallyBob]

Here was a 1.6 litre head I built for a friend.

5/16" stems, 1.80" intake valves, 1.55" exhaust valves
Bowls blended, valves guides trimmed only.

Intake port:.... Exhaust port:
.100" - 31 cfm.... 31 cfm
.150" - 42 cfm... 42 cfm
.200" - 53 cfm... 51.5 cfm
.250" - 67 cfm... 61 cfm
.300" - 78 cfm... 66 cfm
.350" - 88 cfm... 71 cfm
.400" - 95.5 cfm... 75 cfm
.425" - 99 cfm... 78 cfm
.450" - 100 cfm... 79.5 cfm
.500" - 102 cfm... 81 cfm
.525" - 102 cfm... 82 cfm
.550" - 102.5 cfm... 83 cfm
.575" - 103.5 cfm... 83.5 cfm
.600" - 104 cfm... 83.5 cfm

Same head, but with competition porting done.

Intake port:... Exhaust port:
.100" - 35.5 cfm... 32 cfm
.150" - 52 cfm... 43.5 cfm
.200" - 65 cfm... 53 cfm
.250" - 78 cfm... 62 cfm
.300" - 90.5 cfm... 72.5 cfm
.350" - 103.5 cfm... 81 cfm
.400" - 109 cfm... 90.5 cfm
.425" - 115 cfm... 93 cfm
.450" - 119 cfm... 95 cfm
.475" - 121 cfm... 96 cfm
.500" - 124 cfm...97.5 cfm
.525" - 125 cfm... 100 cfm
.550" - 125.5 cfm... 101.5 cfm

[RallyBob]

Here is a stock 2.2 head head flow.

Intake port:... Exhaust port:
.100" - 42 cfm... 33 cfm
.150" - 57 cfm... 45 cfm
.200" - 75 cfm... 56 cfm
.250" - 89 cfm... 65 cfm
.300" - 102 cfm... 72 cfm
.350" - 109 cfm... 75 cfm
.400" - 113 cfm... 75 cfm
.425" - 115 cfm... 75 cfm
.450" - 118 cfm... 75 cfm
.475" - 119 cfm... 77 cfm
.500" - 119 cfm... 77 cfm
.525" - 120 cfm... 77 cfm
.550" - 120 cfm... 77 cfm

Now here is a high performance street 2.2 with 1.94" intake valves and 1.60" exhaust valves.
Intake port:... Exhaust port:
.100" - 40 cfm... 31 cfm
.150" - 57 cfm... 43.5 cfm
.200" - 74 cfm... 53 cfm
.250" - 89 cfm... 65.5 cfm
.300" - 101 cfm... 76.5 cfm
.350" - 115.5 cfm... 86 cfm
.400" - 128 cfm... 95 cfm
.425" - 134 cfm... 99 cfm
.450" - 139 cfm... 101 cfm
.475" - 143.5 cfm... 102 cfm
.500" - 146 cfm... 102 cfm
.525" - 146 cfm... 102 cfm
.550" - 146 cfm... 103.5 cfm
.575" - 146 cfm... 103.5 cfm
.600" - 146 cfm... 105 cfm

[RallyBob]

Stock 2.4 litre head.

Intake port:... Exhaust port:
.100" - 36 cfm... 28 cfm
.150" - 50 cfm... 42 cfm
.200" - 68 cfm... 54.5 cfm
.250" - 84 cfm... 68.5 cfm
.300" - 99 cfm... 78 cfm
.350" - 110.5 cfm... 86 cfm
.400" - 109 cfm... 89 cfm
.425" - 110 cfm... 91 cfm
.450" - 110.5 cfm... 93 cfm
.475" - 110.5 cfm... 94 cfm

High performance street ported 2.4 head with 1.94"/1.60" valves.

.100" - 36 cfm... 31 cfm
.150" - 53 cfm... 46 cfm
.200" - 68.5 cfm... 58.5 cfm
.250" - 84 cfm... 72.5 cfm
.300" - 100 cfm... 83.5 cfm
.350" - 112.5 cfm... 90.5 cfm
.400" - 126.5 cfm... 100 cfm
.425" - 132 cfm... 103.5 cfm
.450" - 136 cfm... 106.5 cfm
.475" - 138 cfm... 108 cfm
.500" - 139 cfm... 110 cfm
.525" - 140 cfm... 112 cfm
.550" - 141 cfm... 113 cfm
.575" - 143 cfm... 115 cfm
.600" - 144 cfm... 115.5 cfm

You'll note that when modified, both the 2.2 heads and 2.4 heads both don't really start 'coming alive' until about .400" valve lift. What that means is if you are running a typical .430" lift street cam you're not letting the head make any power! A prepped 1.9 head is a better choice with low valve lift.

[Hiro]

Originally Posted by RallyBob I found some more flow charts for various head types. Now you have work right up until winter... 1.9 competition-ported, 1.85" intake valves, 1.50" exhaust valves Intake port:..... Exhaust port: .100" - 37.5 cfm..... 31 cfm .150" - 53 cfm..... 46 cfm .200" - 71 cfm..... 54 cfm .250" - 86.5 cfm..... 68 cfm .300" - 99 cfm..... 76 cfm .350" - 110.5 cfm..... 86.5 cfm .400" - 120 cfm..... 96 cfm .425" - 122 cfm..... 100 cfm .450" - 124.5 cfm..... 103 cfm .475" - 126 cfm..... 105 cfm .500" - 126 cfm..... 106 cfm .525" - 126 cfm..... 106.5 cfm .550" - 128.5 cfm..... 107.5 cfm .575" - 128.5 cfm..... 108 cfm .600" - 128.5 cfm..... 108 cfm

thanks for the data Bob!
I'll work on it back home this evening,
back to work today with lots of paperwork sh... to deal with!
Hiro

[RallyBob]

Okay, more data gathering occurred today!

I ported a street 2.4 head last week, and wanted to flow-test the bare head, as well as the Dbilas DSD intake manifolds which were port-matched to the head. Then it occured to me I had never flow-tested the cut-down 3.0 litre EFI intake I had prepared for another engine with a 2.4 head, so here was my chance to compare a ported big-valve 2.4 head (bare port), the DSD intakes, and the EFI intake on the same day, minimizing the variables.

So, here are the results on the intake port with a 1.94" valve:

Bare port........Dbilas intake.....EFI intake

.100" - 33.5 cfm... 32 cfm... 32 cfm
.150" - 50 cfm... 47.5 cfm... 46 cfm
.200" - 68.5 cfm...65.5 cfm... 63.5 cfm
.250" - 88 cfm... 83.5 cfm... 80 cfm
.300" - 106.5 cfm... 100 cfm... 93.5 cfm
.350" - 123 cfm... 115.5 cfm... 105 cfm
.400" - 132 cfm... 124 cfm... 113 cfm
.425" - 137 cfm... 128.5 cfm... 116.5 cfm
.450" - 137 cfm... 131.5 cfm... 119 cfm
.475" - 137 cfm... 134 cfm... 121.5 cfm
.500" - 137 cfm... 134 cfm... 123 cfm
.525" - 138 cfm... 134 cfm... 121.5 cfm
.550" - 138 cfm... 134 cfm... 120 cfm

Years ago I tested a ported 2.2 head, and it flowed a peak of 136 cfm through the bare intake port. I then bolted a stock 2.2 EFI intake manifold to that head, and the flow peaked at 99 cfm! I had another 2.2 intake on loan from Gil (OGTS) that had been Extrude-Honed, and it peaked at 100.5 cfm....only 1.5 cfm more! So you can see how bad the 2.2 intakes truly are...

And for posterity, the cylinder #1 exhaust port with a 1.60" valve:
.100" - 32 cfm
.150" - 47.5 cfm
.200" - 60 cfm
.250" - 71 cfm
.300" - 81 cm
.350" - 88.5 cfm
.400" - 94 cfm
.425" - 96 cfm
.450" - 97.5 cfm
.475" - 98 cfm
.500" - 99 cfm
.525" - 100 cfm
.550" - 100.5 cfm

[Hiro]

Originally Posted by RallyBob Okay, more data gathering occurred today! I ported a street 2.4 head last week, and wanted to flow-test the bare head, as well as the Dbilas DSD intake manifolds which were port-matched to the head. Then it occured to me I had never flow-tested the cut-down 3.0 litre EFI intake I had prepared for another engine with a 2.4 head, so here was my chance to compare a ported big-valve 2.4 head (bare port), the DSD intakes, and the EFI intake on the same day, minimizing the variables. So, here are the results on the intake port with a 1.94" valve: Bare port........Dbilas intake.....EFI intake .100" - 33.5 cfm... 32 cfm... 32 cfm .150" - 50 cfm... 47.5 cfm... 46 cfm .200" - 68.5 cfm...65.5 cfm... 63.5 cfm .250" - 88 cfm... 83.5 cfm... 80 cfm .300" - 106.5 cfm... 100 cfm... 93.5 cfm .350" - 123 cfm... 115.5 cfm... 105 cfm .400" - 132 cfm... 124 cfm... 113 cfm .425" - 137 cfm... 128.5 cfm... 116.5 cfm .450" - 137 cfm... 131.5 cfm... 119 cfm .475" - 137 cfm... 134 cfm... 121.5 cfm .500" - 137 cfm... 134 cfm... 123 cfm .525" - 138 cfm... 134 cfm... 121.5 cfm .550" - 138 cfm... 134 cfm... 120 cfm Years ago I tested a ported 2.2 head, and it flowed a peak of 136 cfm through the bare intake port. I then bolted a stock 2.2 EFI intake manifold to that head, and the flow peaked at 99 cfm! I had another 2.2 intake on loan from Gil (OGTS) that had been Extrude-Honed, and it peaked at 100.5 cfm....only 1.5 cfm more! So you can see how bad the 2.2 intakes truly are... And for posterity, the cylinder #1 exhaust port with a 1.60" valve: .100" - 32 cfm .150" - 47.5 cfm .200" - 60 cfm .250" - 71 cfm .300" - 81 cm .350" - 88.5 cfm .400" - 94 cfm .425" - 96 cfm .450" - 97.5 cfm .475" - 98 cfm .500" - 99 cfm .525" - 100 cfm .550" - 100.5 cfm

very interesting data Bob!
I will make the plots tomorrow.
Hiro

[neuropel]

So what's the source of restriction on the top side for the 3.0L EFI? It actually starts going the wrong way...

Todd

[Hiro]

Originally Posted by Hiro thanks for the data Bob! I'll work on it back home this evening, back to work today with lots of paperwork sh... to deal with! Hiro

OK some plots using Bob's flow data,
first here are the merged plots for all intake & exhaust respectively:

[Hiro]

the two previous plots are quite messy,
so now let's go head by head separately,
here are the "low intake cast" port heads:

[Hiro]

and here are the "tall intake cast" heads:

[Hiro]

now comparing the two 1.6 heads both intake & exhaust on the same plot,
or the three 1.9 heads intake or exhaust separately:

[Hiro]

all 2.2 head data on the same plot,
all 2.4 head data on the same plot: