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New 95" kit with low power gain

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  #11  
Old 04-19-2009, 07:34 PM
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Originally Posted by MikeinCR
Steve...That's a nice looking bike. I like the Doherty A/C. Did you see any gain going to an open filter? I have the SE stage I and the guy who did the dyno tune said the SE Stage I was not adequate for my build...
I like the looks of the open element..........it just screams "power". It also allows it to suck in cool air from all over, not warm air from the engine side like with the stock cover on it.

If I was you, I would have your heads cc'ed and have your deck height measured........that will tell you exactly what CR you are at. Then have your heads milled to set your CR at 10:1 to 10.2:1 with a .030 head gasket. Stick with the Woods cams......they are some of the best out there.

Steve
 
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Old 04-19-2009, 09:29 PM
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"It also allows it to suck in cool air from all over, not warm air from the engine side like with the stock cover on it." On my FXDF the air inlet was right behind the fwd exaust, when I posted about changing the system for more of a cold air induction I had some knowitall tell me it wouldn't bother it, I felt like telling him to reach down and grab the pipe and then tell me it doesn't get hot.
 
  #13  
Old 04-19-2009, 09:51 PM
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Originally Posted by MikeinCR
Thanks for all the info guys....

SEDeluxe...Not sure what he did to heads. He said ported and polished but kept the stock valves and springs.

Sounds like all agree that the CR is on the low side. When we first discussed this, we talked about the 10.5:1 pistons, but builder said Woods recommended the 9.5:1...

At this point, if I go back to builder, would it be better to change cams to better work with the 9.5:1, or change pistons to better match cams???

Mike i know a few builders around that deal with Bob wood every day. there is absoluty no way that bob suggested 9.5 compression for that cam
he knows them cams like 10.0 and up.
.
i bet you that if you tighten the quench you will gain a few more tq.
even a bare basic build should be making 1hp/tq per cubic inch.
10.5 is where i would put it maybe 10.3
 
  #14  
Old 04-20-2009, 06:00 AM
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As far as the compression on that cam, set it at 10.25. That is where it'll want it. 9.5 is not enough. That engine size with that cam(and a good set of heads) will historically show 105/105 easily, tuned correctly.
Scott
 
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Old 04-20-2009, 10:59 AM
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I read somewhere that due to the different stroke the cams (although they are interchangeable physically) for the 88 and the 96 are cut differently. If this is correct that could be part of your problem. The other thing can be the head porting. There is much more to head porting than just making the hole bigger and smoothing it out. The shape has more to do with it. This is why 883 head will make more power than 1200 heads even though the runner volumes are smaller on the 883 head (the port shape just has a better venturi shape which increases the intake charge speed at a higher rate). It might be that the mechanic has no idea how to actually shape the ports and is just making the hole bigger. That 's why it's best to shell out the extra cash on a port job from a reliable source. If that's so, most reputable head porting places wont take previously worked on heads as exchange for this exact reason. Hope this helps
 

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  #16  
Old 04-20-2009, 12:56 PM
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Originally Posted by critter_catcher74
I read somewhere that due to the different stroke the cams (although they are interchangeable physically) for the 88 and the 96 are cut differently. If this is correct that could be part of your problem. The other thing can be the head porting. There is much more to head porting than just making the hole bigger and smoothing it out. The shape has more to do with it. This is why 883 head will make more power than 1200 heads even though the runner volumes are smaller on the 883 head (the port shape just has a better venturi shape which increases the intake charge speed at a higher rate). It might be that the mechanic has no idea how to actually shape the ports and is just making the hole bigger. That 's why it's best to shell out the extra cash on a port job from a reliable source. If that's so, most reputable head porting places wont take previously worked on heads as exchange for this exact reason. Hope this helps
i agree with you on the heads but before we throw stones at the porter we must get the other parts up to working order first.
if the cam is not in the proper compression zone the heads cannot do their part and flow. if the heads canot flow the exhaust cannot work if there is a sock stuck in the t/b then it does not matter what cam , heads and exhaust you have on there .
first thing first lets do the checking of the ccp first and get thje proper compression so the cam can work.
if the # do not move after the compression is corrected then move on to the heads.
now we are all under the impression the cam and motor was assembled correctly.
one thing at a time....
 
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Old 04-20-2009, 01:52 PM
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On my Andrews 37H they say stock to 9.5:1, I'm waiting on an adapter for my comp. gauge to see where I'm at because I'm thinking about advancing it until I change the topend. The intake closes at 38 now, if I move it to 34 would that be too much?
 
  #18  
Old 04-20-2009, 03:08 PM
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Guys, thanks for the info...
SEDELUXE...you seem very knowledgeable about this stuff and I appreciate your advice.

Question...If you shave your heads by .040 or .050 to get the 10+:1 compression, won't you need to do something with the throttle body to get it to fit up...?
 
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Old 04-20-2009, 05:10 PM
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Originally Posted by SEDELUXE
i agree with you on the heads but before we throw stones at the porter we must get the other parts up to working order first.
if the cam is not in the proper compression zone the heads cannot do their part and flow. if the heads canot flow the exhaust cannot work if there is a sock stuck in the t/b then it does not matter what cam , heads and exhaust you have on there .
first thing first lets do the checking of the ccp first and get thje proper compression so the cam can work.
if the # do not move after the compression is corrected then move on to the heads.
now we are all under the impression the cam and motor was assembled correctly.
one thing at a time....
good point. Do you know about any difference between the 88 cams and the 96 cams due to the crank stroke? I threw that in because I had heard that but it just seems like BS. They dont sell different cams for each and every SBC just because they have a different stroke (283/327/350 doesn't matter, all the same cam). Just asking because you seem to know what you are talking about.
 
  #20  
Old 04-20-2009, 06:01 PM
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Originally Posted by MikeinCR

Question...If you shave your heads by .040 or .050 to get the 10+:1 compression, won't you need to do something with the throttle body to get it to fit up...?
When you put the TB back in, you'll have to test fit it to make sure it will seat without binding up. If it's too tight, you just take some material off with some fine sandpaper on a flat surface. It normally doesn't take much to make it fit right.

I have my heads shaved a lot to get to 10:1 with flat top pistons, and I had to do some sanding to get my TB to fit. My chambers are at 78cc which is quite a bit smaller then the stock size of 86-90.

Steve
 


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