883 to 1200 heads flow test

[BB]

Here is some flow numbers on a 883 to 1200 convertion we are building . The heads are not done yet , will try to get more out of them .It shows good increases with just a valve size change and a little port work .All flow numbers are at 28 in depression.Stock valve sizes are int 1.585 , exh 1.350. Throat sizes increased to exh 1.242 , int 1.427. I will open the throat of the ports on my next step.Would like to know from other head porters if this is all I can get or is there more in the heads yet.Never tested sportster heads before.Thank you.

lift CFM (stock int valve) CFM with 1.720 valve
.050 25.5cfm 43.3cfm
.100 51.75cfm 75.65cfm
.150 80.28cfm 103.5cfm
.200 107.2cfm 131.3 cfm
.250 133.3cfm 156.2cfm
.300 152.7 cfm180.8cfm
.350 163.7cfm 198.7cfm
.400 171.cfm 202.4cfm
.450 174.4cfm 205.8cfm
.500 176.3cfm 208.3cfm
.550 174.6cfm 209.9cfm
.600 176cfm 210.8cfm
.650 173.9 cfm211.5cfm

CFM (stock exh valve) CFM with 1.480 valve
.050 21.5cfm 36.7cfm
.100 41.7cfm 60.cfm
.150 59.8cfm 83.cfm
.200 73.1cfm 102.7cfm
.250 81.8cfm 121.8 cfm
.300 87.8cfm 139.cfm
.350 92. cfm152.6cfm
.400 93.9cfm 161.4cfm
.450 96.3cfm 164.9cfm
.500 97.9cfm 166.9cfm
.550 99.7cfm 167.5cfm
.600 100cfm 167.5cfm
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[mayor]

what years does these heads respresent (casting number)? 

btw, thanks for posting.  this is very good info.   

[Hillside Motorcycle]

Just sent a set to Prince George, BC, for a clients, wifes, 1200 XL.
Had an S/E cam in it we had never worked with.
It popped 101 hp SAE, on the local H-D store's dyno, and they actually did not run the rpms off until it "curled".
Those heads were running 269 cfm.
Scott

[BB]

what years does these heads respresent (casting number)? 

btw, thanks for posting.  this is very good info.   

They 86B at rhe end of the casting number.

[BB]

Just sent a set to Prince George, BC, for a clients, wifes, 1200 XL.
Had an S/E cam in it we had never worked with.
It popped 101 hp SAE, on the local H-D store's dyno, and they actually did not run the rpms off until it "curled".
Those heads were running 269 cfm.
Scott

Thanks Scott , it looks like I have a lot of work to do.Can you tell me what size valves you used?

[prodrag1320]

we use the 1.720/1.480 conversion valves on most regular 883-1200 conversions and get 150/120 cfm @ 10" (around 75hp),but on the hotrod conversions,we`ll go with 1.850/1.485 valves,flowing 160/125 & have also topped 100 hp with these heads

[BB]

we use the 1.720/1.480 conversion valves on most regular 883-1200 conversions and get 150/120 cfm @ 10" (around 75hp),but on the hotrod conversions,we`ll go with 1.850/1.485 valves,flowing 160/125 & have also topped 100 hp with these heads

Kirby , did some more work on this heads.Got the cfm to 220 @ .600 lift . Opened the throat and worked on SSR .I think with out increaseing valve size to 1.850 , these old casting may land short . To install the 1.850 do I need to install new seats?And already having some valve to valve issues . I have the valve stem protrution at 2" now , that is from spring pad to valve tip .Have to be at or under .190 TDC lift on cam to fit.If I install bigger valve the valve to valve will be worse , won't it?

[strokerjlk]

Subscribing ...... Nice info BB not much goes on in this section.

[BB]

Subscribing ...... Nice info BB not much goes on in this section.

Yep I know . I did a search before I posted this and didn't find much . This bike is going to run on the salf flats this year so I want to push it a little .Never did much more then a normal convertion before . And I have a new flow bench so I'm trying to build  new data for my own library . These are the reasons I'm ask question .When this is done I will post dyno runs also .

[strokerjlk]

 

Subscribing ...... Nice info BB not much goes on in this section.

Yep I know . I did a search before I posted this and didn't find much . This bike is going to run on the salf flats this year so I want to push it a little .Never did much more then a normal convertion before . And I have a new flow bench so I'm trying to build  new data for my own library . These are the reasons I'm ask question .When this is done I will post dyno runs also .

I hope to be there this year also. Maybe not until next year.
You though about a set of Buell heads?

[BB]

Strokerjlk , I don't know much about the Buell heads or any sporty heads , that why I'm asking question .LOL !! :idunno:I did talk to Kirby today and he said more air flow . So I'm try to find it now . :scratch:I'm going to widen the SSR  and see if I can pickup some more .

[strokerjlk]

Strokerjlk , I don't know much about the Buell heads or any sporty heads , that why I'm asking question .LOL !! :idunno:I did talk to Kirby today and he said more air flow . So I'm try to find it now . :scratch:I'm going to widen the SSR  and see if I can pickup some more .

I am with you man. I am learning the sporsters myself.
I don't have any idea what  mine flow . I have a 1.900 In and 1.615 ex in buell XB heads.
SE 575 HO cams . 3.563 30 deg .500 dome pistons.
I am told the 575 cam with its low TDC lift is often used in this combo  if there are clearance problems.

[saltcaveminer]

i might suggest a call to zippers performance and pick their brains.they know the drill when it comes to evo sporty heads.Salty

[sfmichael]

 

[WhipLash96]

I hope that this isn't the end of this thread, I am subscribing anyways... 

[strokerjlk]

You still around BB ?

[prodrag1320]

been doing some work on a florida guys 74" XL drag bike,did some porting on his 1200 heads,he`s about to break into the 8`s,ran a 9.02 a couple weeks ago

[strokerjlk]

been doing some work on a florida guys 74" XL drag bike,did some porting on his 1200 heads,he`s about to break into the 8`s,ran a 9.02 a couple weeks ago

he's fast for sure.
I will get mine out to you when I get the pistons and cylinders