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About 5 or 6 months ago, I asked the board about bigger valves and head work to improve flow in my heads. I was to do the work myself.

http://www.v-twinforum.com/forums/showthread.php?t=58017&highlight=Flong

Since then, I've bought 3 sets of take off Twin Cam heads off eBay and a diy style flow bench:

http://www.diyporting.com/flowbench.html

I already have hand tools to r/r valves and guides and have since bought porting tools, mainly from Mondello, Goodson and AV&V.

Its been an interesting compulsion and I now have a head I'd like some comment on. First, I've just purchased a 98 inch Revolution cylinder kit and Andrews 37G cams from HDWrench so that is the set up I'm looking at. My bike is a '05 Softail Nighttrain with RB Racing Black Hole pipes (1.75 inch diameter pipes, bung for O2 sensor) SE aircleaner and stock EFI with a Techno Research brand of SERT.

My first set of heads ('04 take offs) have become my "mules" mainly because I botched the job - the cost of experience I guess. These were to have 1.9 inch intake valves and stock exhaust valves. My current set that I listed below are '05 take offs.

HD 2005 heads, ported and flowed,
stock '05 valves and valve guides,
stock intake manifold port diameter.
5 cc of material removed from intake port.
about 1 cc from exhaust port.
no porting to the valve guides bosses or the roof.
standard factory 3 angle seat.
The short radius was not lowered - still measures the same distance from the head gasket surface as when I started.
I haven't even blasted the "paint" off the combustion chamber or exhaust port but I did clean up the valves and valve seats of carbon.


Flowed at 28" SCFM with clay radius on intake and no radius on exhaust.

Lift - Stk Int - Stk Exhaust - Prtd Int - %- Prtd Exht -%

.100 - - 80 -- 26 -- 80 -- 0 -- 28 -- 7
.200 --133 -- 86 -- 135 -- 1 -- 91 -- 6
.300 -- 185 -- 120 -- 189 -- 2 -- 130 -- 8
.350 --201 -- 132 -- 206 -- 3 -- 145 -- 10
.400 --207 -- 139 -- 214 -- 3 -- 152 -- 9
.450 -- 205 -- 143 -- 219 -- 7 -- 155 -- 8
.500 -- 203 -- 146 -- 224 -- 10 -- 157 -- 8
.550 -- 203 -- 146 -- 224 -- 10 -- 159 -- 9
.600 -- 205 -- 147 -- 223 -- 9 -- 160 -- 9

What I did in the intake port was widen the floor - made it look more like the letter "D". Removed the aluminum from the valve seat underhang and slightly round the bowel, especially on the sides of the port. Then, and what made the most difference (by about 20 SCFM increase) was reradius the short side radius from the valve seat back to the apex of the short side.
The exhaust port was opened slightly on the short side radius at the exhaust gasket surface but not greater than a 1.5 inch diameter I drew on the exhaust gasket seating surface. Slightly egg shaped. Then I took off some metal to shape the short side apex more like a "D" and lowered the floor from the apex of the short radius to the outlet.

My questions are:

How am I doing? I can't find any listed porting numbers or % increase for commercially available ported '05 heads with stock valves , especially on '05 heads with their smaller intake valve.

Is this a significant increase in flow and is it helpful for my 98" Andrews 3G build?

How much gain is there from radiusing the valve guide bosses and/or changing to more streamlined valve guides? Different valves? Raising the roof?

Different valve seat radius will take an expensive tool (A hand driven Serdi with holding fixture is $3500.00). The only available cutter I know of for this tool and HD heads is made by Mondello and available from Goodson. What kind of gains am I leaving behind using the stock valve seat radius'?

Opinions welcomed.

Thanks.

Frank


http://mondello.com/

http://www.av-v.com/Introduction.htm

http://www.goodson.com/
 

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Hello flong, so you followed through with your project.........good job in doing that.

Guess you are going to be doing quite a bit of experimentation to obtain optimum results.

No doubt you will end up with the right amount of velocity and balanced with an additional amount of flow..............only trial and error will get you there bro.
Some of the top guys will help you out.

All the best, Ozzie
 

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Just remember,80% of the air flow is controlled by the valve and the seat ! Think about this ,you have a big hole {port} and what is it that stopped the airflow ? The valve ,yes. The type of valves you use and how you modify them and how you cut your seats will determine your airflow. I will tell you a secret,I took a stock set of twin cam heads and milled them .030 and put in a set of Manley valves that I modified . I don't want to tell you the dyno's #s because it will shock you !! No porting,none.
 

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OK what you have accomplished is get a stock head to flow equivalent to a SE performance head. About 10 to 12% better than stock. Stock= [email protected]" yours are [email protected]" and flatten after .500 lift similar to the SE part. No opinion just what I see and the SE part has the equivalent of .050 milling to bring up compression which yours don't. Now that you know the flow you can adjust compression and camming appropriately.
 

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SILVER BULLET said:
Just remember,80% of the air flow is controlled by the valve and the seat ! Think about this ,you have a big hole {port} and what is it that stopped the airflow ? The valve ,yes. The type of valves you use and how you modify them and how you cut your seats will determine your airflow. I will tell you a secret,I took a stock set of twin cam heads and milled them .030 and put in a set of Manley valves that I modified . I don't want to tell you the dyno's #s because it will shock you !! No porting,none.
Dewey,
Have you tested the Kibblewhite valve p/n 20-20322 with the improved R1.700 tulip?
 

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I have tested every valve in the business. I used to run kibblewhite and then I went to Ferrea ,but they only worked better after I modified them. Cheaper too ! I used Manley {nailheads} on some heads years ago and they are within 2-3 hp and the same tq. as the Ferreas. You have to cut your seats different for a nailhead. Just remember that a motor acts different than a flow bench. On a flow bench you have DRY air being pushed thru the port with a vaccum cleaner motor. On a motor it is WET air {gas+air} and SWIRL is very important. The best way the check heads is on a dyno,see what worked ,then you can go from there.
 

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Discussion Starter #9
Doc and all,

The flow bench uses a Sears Craftsman shop vac. At 100 SCFM (converted to 28"), the inches of water vacuum is about 23". At 230 SCFM, the inches of water pulled by the shop vac is about 7". The setup is suppossed to compensate for the varous pressures.

While playing around, I got my intake flow on one head:(all at 28"SCFM)

.450 lift --- 224
.500 lift---231
.550 lift ---236
.600 lift ---235
Going to try to get the other head to match.

I guess one of my important questions is:

Where do I stop?-- For my set up of 98" Rev cylinders and Andrews 37G cam, is this "enough" or should I continue to try and get more are flow?

Thanks for the replies,

Frank
 

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Very cool to read this and watch Frank have at this :corn:

What is very nice is the information that has been shared by guys who truly know what they are doing.{salute(

Hey, one of you guys don't have one of those 100 mile to a gallon carburetors off that V8 Ford Galaxy from back in the day, just like laying around do ya :whistle:
 

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Yes where to stop?
Your heads will support 110hp with everything else optimized right now, but not with that low compression and mild cams. That said I would think getting the heads to match perfectly is a little futile as it is just not required. A carbed motor will be unequal anyway unless you build your own custom intake.
One advantage of EFI in the hands of a competent tuner.
 
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