Big bore build 88" to 95"
Road Captain
Joined: Jun 2008
Posts: 572
Likes: 6
From: Ft. Worth, Texas
I agree with "gibbyflhx" I think you should just buy parts as money allows and when youve got it all, then tear it apart and do it all at once. You will not see a big gain with just the pistons alone. In addition you will need to get a fuel managment or rejet if your carburated.
Tourer
Joined: Jan 2010
Posts: 473
Likes: 0
I do alot of 95 inch builds. I use Wiseco forged pistons, S+S 570 gear drive cams and use the stock heads with porting and polishing along with high lift valve springs and new valves. This combo has always yielded around 110HP and 110ft lbs or torque when using a good set of pipes and aircleaner.
I do not like the SE flat top pistons for a couple reasons. They are not high enough compression as i like to use either 10:1 or 10.5:1 pistons, and they are cast and not forged.
I do not like the SE flat top pistons for a couple reasons. They are not high enough compression as i like to use either 10:1 or 10.5:1 pistons, and they are cast and not forged.
Road Captain
Joined: Jun 2008
Posts: 572
Likes: 6
From: Ft. Worth, Texas
In fact i have never had one single bike built with this combo that has ever blown up or had any reliability issues. Usually they come back in for stickier tires... Hahaha
Last edited by texas_speed_freak; Jan 13, 2010 at 02:44 PM.
Thread Starter
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Advanced
Joined: May 2009
Posts: 85
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Thanks to all for your input !!...after all is said and done..im gonna get the big bore kit to 95 "..put me at about 9:4 compr....and sit on the kit till i find a cam to go with it..so atleast i will have those two done..
And can do heads next year...any suggeetions on cams..chain drive..its the $ issue,,typically ride ***** to the walls...and 2 up alot...thanks to all..dd
And can do heads next year...any suggeetions on cams..chain drive..its the $ issue,,typically ride ***** to the walls...and 2 up alot...thanks to all..dd
Road Captain
Joined: Jun 2008
Posts: 572
Likes: 6
From: Ft. Worth, Texas
Thanks to all for your input !!...after all is said and done..im gonna get the big bore kit to 95 "..put me at about 9:4 compr....and sit on the kit till i find a cam to go with it..so atleast i will have those two done..
And can do heads next year...any suggeetions on cams..chain drive..its the $ issue,,typically ride ***** to the walls...and 2 up alot...thanks to all..dd
And can do heads next year...any suggeetions on cams..chain drive..its the $ issue,,typically ride ***** to the walls...and 2 up alot...thanks to all..dd
Road Warrior
Joined: Jan 2009
Posts: 1,489
Likes: 23
From: East of Tulsa
If money is an issue the SE 255 cam is supposed to perform well in stock "96iners. You will need the kit to change to the new cam drive style which is something you will probably want to do. Geared cams are goin cost. The 255 goes for fairly low prices on eBay. If you are going with 9.4 comp keep your cam choices to what will work with it.
Tourer
Joined: Sep 2009
Posts: 276
Likes: 0
From: Tampa Fl
Find you a good Indy, have your cylinders bored to 95, there are a number of good cams, get one gear drive,heads ported and polished ( thats my next move ) a fuel mngtment system and a good tune. SWEET.
OHH, exhaust make a huge differnce also. MY 2 Cents.
OHH, exhaust make a huge differnce also. MY 2 Cents.
Elite HDF Member
Joined: Apr 2007
Posts: 4,919
Likes: 23
From: Seattle, WA
Not to differ with the professional opinions ... especially because I tend to agree with them for the most part about doing it all (Big Bore, cams heads) at once ....
But, I have kept hearing the same old refrain "there's no replacement for displacement" ... that if you can only do one thing to add the cubes and it will increase your TQ and HP numbers across the board ....
Yeah, ideally to get the most out of your build you should do cams and if you go high-lift over about .570" you will need to get valve springs which will accommodate your cam ... and if you either get performance heads or have your heads ported you will (can) get heavy duty valve springs that will work with your cams ....
Note that I have also had mechanics who advised me that the lift numbers for heads (valve springs) are conservative--that you can exceed the lift by a little without doing any harm to the motor (as long as you have clearance between the piston and the valve at top dead center) ....
Bottom line ... and I'll caveat this by saying I am not a licensed mechanic ... I think you will increase your performance by bolting on the big bore kit without anything further ... and, if wrenching on your bike is something you get satisfaction from, you will have it apart at a later date when you get some bread to install the heads and cams ... there ya have it ... good luck!
R/
'Chop
But, I have kept hearing the same old refrain "there's no replacement for displacement" ... that if you can only do one thing to add the cubes and it will increase your TQ and HP numbers across the board ....
Yeah, ideally to get the most out of your build you should do cams and if you go high-lift over about .570" you will need to get valve springs which will accommodate your cam ... and if you either get performance heads or have your heads ported you will (can) get heavy duty valve springs that will work with your cams ....
Note that I have also had mechanics who advised me that the lift numbers for heads (valve springs) are conservative--that you can exceed the lift by a little without doing any harm to the motor (as long as you have clearance between the piston and the valve at top dead center) ....
Bottom line ... and I'll caveat this by saying I am not a licensed mechanic ... I think you will increase your performance by bolting on the big bore kit without anything further ... and, if wrenching on your bike is something you get satisfaction from, you will have it apart at a later date when you get some bread to install the heads and cams ... there ya have it ... good luck!
R/
'Chop
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Road Captain
Joined: Jun 2008
Posts: 572
Likes: 6
From: Ft. Worth, Texas
I will disagree with you on that point. The best dollar for dollar upgrade will be without a doubt cams. The bolt in 510 S+S cams either chain driven, or gear driven will be the biggest increase in power you will achieve of any mod on a stock Twin Cam. Think of it this way, what are you going to gain with higher compression and more bore if you dont have a cam opening up the valves more or longer to get more air and fuel into the engine?
Elite HDF Member
Joined: Apr 2007
Posts: 4,919
Likes: 23
From: Seattle, WA
Well ... I do not take offense, since it is not my point (I, frankly, have been contemplating doing a bunch of work to squeeze more power out of my 88 without increasing the CID) ... I just thought I would pass on what seems to be 'common wisdom' among forum members ... yourself excluded, obviously ....
My counter would be that the additional lift of the S&S 510 cam over the stock cam is not significantly greater--given that the lift of the stock cams is .510 intake and .483 exhaust ... duration is 234 / 239 respectively ... the S&S duration figures are 234 / 252 ...
Now one thing the MoCo's cams do not feature is any overlap of int/exh cycles which is a common feature of most aftermarket cams ... also, the opening and closing are timed a little different ....
My observation is that while the 510 cam will be a modest improvement over stock (as would the SE 203 cam or Andrews 26, etc) ... he would still get a boost in performance given the big bore kit, even with the rest of the motor stock ....
Just my $0.02 ... and I do not claim to be an expert ... just a relatively well-informed lay person ....
R/
'Chop
My counter would be that the additional lift of the S&S 510 cam over the stock cam is not significantly greater--given that the lift of the stock cams is .510 intake and .483 exhaust ... duration is 234 / 239 respectively ... the S&S duration figures are 234 / 252 ...
Now one thing the MoCo's cams do not feature is any overlap of int/exh cycles which is a common feature of most aftermarket cams ... also, the opening and closing are timed a little different ....
My observation is that while the 510 cam will be a modest improvement over stock (as would the SE 203 cam or Andrews 26, etc) ... he would still get a boost in performance given the big bore kit, even with the rest of the motor stock ....
Just my $0.02 ... and I do not claim to be an expert ... just a relatively well-informed lay person ....
R/
'Chop