Which heads would you pick?
Club Member
Joined: Apr 2011
Posts: 5,816
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From: SE Louisiana
Was that test with the throttle wide open?
Also with the amount of work on the heads, they may be set up to handle higher lift cams.
The W6H is a higher lift version of the W6 (.590) and will get you closer to your goal with the right compression.
Also with the amount of work on the heads, they may be set up to handle higher lift cams.
The W6H is a higher lift version of the W6 (.590) and will get you closer to your goal with the right compression.
Seasoned HDF Member
Joined: Mar 2010
Posts: 21,116
Likes: 7,638
From: Poolville
Combustion chambers
Depending on the configuration of the build it is necessary to reconfigure the combustion chambers to accept larger valves and higher compression pistons. I have not heard of a 1.925 intake most likely a 1.90 with 1.63 exhausts and depending on the porting they should flow upwards of 180 cfm. They sound very familiar to what I have in my build. Hillside Stage II heads. The changed combustion chamber can still accept a higher compression piston but most likely the dome might have to be milled to fit the chamber to maintain the proper clearance. I would bring them to your indy have them flowed and cc'd and then have him reccomend a higher compression piston that can be fitted. Hopefully they are around 84 cc. If so you will have a great start to a 90/90. Especially with a w6. However I don't care much for the Mikuni... good luck. will be following the thread to see the outcome..
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Intermediate
Joined: Jun 2007
Posts: 40
Likes: 1
Thank's Bagger, I was just on their web site and it looks correct to me. They look like the #4 heads and show 8.9-1 for the Evo. The .030 should get me to 9.4. Anyone know if substituting the cylinder base gasket with Three-Bond 1104 works as a good sealer and if it will help bring the compression up to 10 - 1 or is it not worth the possible leaking that will come a year down the road?
Road Captain
Joined: Jul 2014
Posts: 717
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From: San Dimas
Thank's Bagger, I was just on their web site and it looks correct to me. They look like the #4 heads and show 8.9-1 for the Evo. The .030 should get me to 9.4. Anyone know if substituting the cylinder base gasket with Three-Bond 1104 works as a good sealer and if it will help bring the compression up to 10 - 1 or is it not worth the possible leaking that will come a year down the road?
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Intermediate
Joined: Jun 2007
Posts: 40
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No. 10 turns of the starter for the 145lbs . I will take a look at the W6H but I have the w6 now so it it is close I will stay with it. Just depends on the cost/output. I will do it if I can get to 100hp without breaking the bank. A little extra info: I put the old heads up against the new .050 decked heads and they have the same deck hight. Thanks again for the info guys, Lots of good comments.
Road Master
Joined: Feb 2014
Posts: 913
Likes: 5
From: indiana
145 is way to low it should be closer to 200. at 145 your compression ratio is around 8:1 optimum static ratio for a W6 is 10.38:1
those head gaskets are probably on there for a reason when I use .060 head gaskets its because I trued the cylinders and the pistons now come out of the hole .010- .030 if they are like that and you put .030 head gaskets on it you will smash the pistons into the heads
show me picture of the combustion chamber and find out the cc of the heads and the bore and deck height of the pistons. with that information I can point you in the right direction.
those head gaskets are probably on there for a reason when I use .060 head gaskets its because I trued the cylinders and the pistons now come out of the hole .010- .030 if they are like that and you put .030 head gaskets on it you will smash the pistons into the heads
show me picture of the combustion chamber and find out the cc of the heads and the bore and deck height of the pistons. with that information I can point you in the right direction.
Last edited by D_gyver; Dec 26, 2014 at 12:35 AM.
Banned
Joined: Apr 2014
Posts: 678
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From: LA
Yah, I was thinking the same ... you didn't tell us the squish, did you?
Club Member
Joined: Apr 2011
Posts: 5,816
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From: SE Louisiana
Two things need to be measured to know what's going on here.
1)Head deck height off the fins won't tell you anything, combustion chamber volume has to be measured.
Get a piece of plexiglass or lexan, drill a hole in it, place it over the chamber with grease around the deck to seal it, and a means to measure how much liquid(rubbing alcohol) it takes to fill the chamber.
http://www.motorstate.com/CCHeads.htm
2)To measure piston deck height, drop the jugs on with no piston rings or base gaskets, get a straight edge and a feeler gauge to measure how much the piston is above or below the deck.
Measure this inline with the wrist pin, not like the picture below, because the piston will rock, and give inaccurate reading.
This will determine what thickness base gaskets and head gaskets could be used.
1)Head deck height off the fins won't tell you anything, combustion chamber volume has to be measured.
Get a piece of plexiglass or lexan, drill a hole in it, place it over the chamber with grease around the deck to seal it, and a means to measure how much liquid(rubbing alcohol) it takes to fill the chamber.
http://www.motorstate.com/CCHeads.htm
2)To measure piston deck height, drop the jugs on with no piston rings or base gaskets, get a straight edge and a feeler gauge to measure how much the piston is above or below the deck.
Measure this inline with the wrist pin, not like the picture below, because the piston will rock, and give inaccurate reading.
This will determine what thickness base gaskets and head gaskets could be used.
Last edited by Schex; Dec 26, 2014 at 06:44 AM.
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Club Member
Joined: Apr 2011
Posts: 5,816
Likes: 7,847
From: SE Louisiana
No. 10 turns of the starter for the 145lbs . I will take a look at the W6H but I have the w6 now so it it is close I will stay with it. Just depends on the cost/output. I will do it if I can get to 100hp without breaking the bank. A little extra info: I put the old heads up against the new .050 decked heads and they have the same deck hight. Thanks again for the info guys, Lots of good comments.
I was checking out a stuck auto compression release problem on my 111 the other day, and I get a 40lb difference in compression with throttle open compared to closed.
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Intermediate
Joined: Jun 2007
Posts: 40
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I see you point on the tall head gasket guys, I will need to do the tests that Schex3x has suggested. Where did you get that measuring tube thingy? I want one 
I am going to use some puddy on the piston to find out what the valve clearance is. Also going to talk to Woods on Monday about the w6h. I really would like to get to 100hp now that Im in it. Many Thanks to all!
I am going to use some puddy on the piston to find out what the valve clearance is. Also going to talk to Woods on Monday about the w6h. I really would like to get to 100hp now that Im in it. Many Thanks to all!
Last edited by Jerrysounds; Dec 26, 2014 at 11:11 AM.