Head work or pistons?
Thread Starter
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Tourer
Joined: May 2009
Posts: 401
Likes: 19
From: Middleboro, MA USA
Thanks bagger. That info helps. I have been checking out the calculator. I'm still learning about duration, lift, valve timing, etc and how everything works together with different combustion ratios. Interesting stuff but not a quick read.
Seasoned HDF Member
Joined: Aug 2008
Posts: 5,070
Likes: 2,115
From: Ohio
This stuff can turn your brain into Jello and lose sleep, simple base setup for steet is intake valve timing affecting compression, the higher the intake valve timing, the more compression needed because late intake timing lets some air out for base compression but cylinder fill comes in with large lifts and duration - confusing as hell
Made a mistake with too much compression and early intake closing resulting in starter eater, detonation, hot temperatures affected runabiltiy but boy would your teeth slide back when you rolled into it but costed a heated cylinder. Trying to relay the school of hard knocks and already went thru the Jello brain stage plus with my current engine I had a hall of fame engine builder that did my heads in my corner spewing knowledge of targeted real world compression in any conditons, learned alot by asking questions and then listening to experiance
Made a mistake with too much compression and early intake closing resulting in starter eater, detonation, hot temperatures affected runabiltiy but boy would your teeth slide back when you rolled into it but costed a heated cylinder. Trying to relay the school of hard knocks and already went thru the Jello brain stage plus with my current engine I had a hall of fame engine builder that did my heads in my corner spewing knowledge of targeted real world compression in any conditons, learned alot by asking questions and then listening to experiance
Last edited by 1997bagger; May 12, 2013 at 09:48 AM.
Cruiser
Joined: May 2012
Posts: 144
Likes: 2
From: Chicago, IL
Nothing wrong by raising the mechanical compression ratio, via surfacing the heads.
A great combo we've used here for waaaaaaaay over 15 years is to remove .065", with a .030" head gasket, and install a Wood 6.
Must've built 80-100 Evo's over the years with that set-up.
It'll hover at 80 hp, and 90 ft/lbs.
Scott
A great combo we've used here for waaaaaaaay over 15 years is to remove .065", with a .030" head gasket, and install a Wood 6.
Must've built 80-100 Evo's over the years with that set-up.
It'll hover at 80 hp, and 90 ft/lbs.
Scott
Would removing .065" on the heads, with .030" head gaskets - work as well with the EV27 cam, as it would with the Woods 6?
Thread Starter
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Tourer
Joined: May 2009
Posts: 401
Likes: 19
From: Middleboro, MA USA
Here's what I ended up doing-
98 FXD with stage one bolt ons installed. I just had killer cycles do up my CV too. I have an Ultima ignition ready to go in.
I just got back from talking to the shop doing the headwork and this is what we decided on.
I'm having .050 shaved off the heads along with a competition valve job, bowls blended, D-cut in the combustion chamber and porting. I'm not touching the cylinders or pistons. They will stay stock for now. I'm installing an EVL-3010. My compression should be 9:1 according to the shop doing the heads. I'm sticking with the stock cometic MLS head gaskets which if I remember right measured .043. I brought up using the .030 gasket and he cautioned me against it because he was afraid I might get some pinging.
We have it set up like this so that later on if I decide I hate the EVL-3010 and want another compression bump to accommodate a different cam I can have him open up the cylinders by .005 or .010 and put in some KB domed pistons.
Once I measure my deck height I am going to bring the cylinders down to the shop to make sure the bases are square. I did some dremelling with a scotch brite wheel to get the baked on gasket material off so in hind sight I decided to have them checked.
Now I just need to get some ez-adjust rods and I should be good to go.
Then I just have to wait for Avon to get's its *** in gear and ships my 2 replacement tires.
I just got back from talking to the shop doing the headwork and this is what we decided on.
I'm having .050 shaved off the heads along with a competition valve job, bowls blended, D-cut in the combustion chamber and porting. I'm not touching the cylinders or pistons. They will stay stock for now. I'm installing an EVL-3010. My compression should be 9:1 according to the shop doing the heads. I'm sticking with the stock cometic MLS head gaskets which if I remember right measured .043. I brought up using the .030 gasket and he cautioned me against it because he was afraid I might get some pinging.
We have it set up like this so that later on if I decide I hate the EVL-3010 and want another compression bump to accommodate a different cam I can have him open up the cylinders by .005 or .010 and put in some KB domed pistons.
Once I measure my deck height I am going to bring the cylinders down to the shop to make sure the bases are square. I did some dremelling with a scotch brite wheel to get the baked on gasket material off so in hind sight I decided to have them checked.
Now I just need to get some ez-adjust rods and I should be good to go.
Then I just have to wait for Avon to get's its *** in gear and ships my 2 replacement tires.
Seasoned HDF Member
Joined: Sep 2012
Posts: 6,570
Likes: 590
From: almost there
I was always told if you have the heads off and have them built you might as well drop some 10.1 pistons in there so the builder can work up a ballanced total package. Cheaper to do it once since it's already open. I have built heads and 10.1 CR and it starts very easily with no compression releases no ping ding but it does have ZING. No since in doing it twice for mo money. Evo motors need all they can get without over building them. Im very glad I choose my set up. Just my 2 nickles.
Last edited by aces&8s; May 13, 2013 at 05:44 PM.
Dirt don't hurt
Joined: Jan 2011
Posts: 21,062
Likes: 4,547
From: Haslet Texas
98 FXD with stage one bolt ons installed. I just had killer cycles do up my CV too. I have an Ultima ignition ready to go in.
I just got back from talking to the shop doing the headwork and this is what we decided on.
I'm having .050 shaved off the heads along with a competition valve job, bowls blended, D-cut in the combustion chamber and porting. I'm not touching the cylinders or pistons. They will stay stock for now. I'm installing an EVL-3010. My compression should be 9:1 according to the shop doing the heads. I'm sticking with the stock cometic MLS head gaskets which if I remember right measured .043. I brought up using the .030 gasket and he cautioned me against it because he was afraid I might get some pinging.
We have it set up like this so that later on if I decide I hate the EVL-3010 and want another compression bump to accommodate a different cam I can have him open up the cylinders by .005 or .010 and put in some KB domed pistons.
Once I measure my deck height I am going to bring the cylinders down to the shop to make sure the bases are square. I did some dremelling with a scotch brite wheel to get the baked on gasket material off so in hind sight I decided to have them checked.
Now I just need to get some ez-adjust rods and I should be good to go.
Then I just have to wait for Avon to get's its *** in gear and ships my 2 replacement tires.
I just got back from talking to the shop doing the headwork and this is what we decided on.
I'm having .050 shaved off the heads along with a competition valve job, bowls blended, D-cut in the combustion chamber and porting. I'm not touching the cylinders or pistons. They will stay stock for now. I'm installing an EVL-3010. My compression should be 9:1 according to the shop doing the heads. I'm sticking with the stock cometic MLS head gaskets which if I remember right measured .043. I brought up using the .030 gasket and he cautioned me against it because he was afraid I might get some pinging.
We have it set up like this so that later on if I decide I hate the EVL-3010 and want another compression bump to accommodate a different cam I can have him open up the cylinders by .005 or .010 and put in some KB domed pistons.
Once I measure my deck height I am going to bring the cylinders down to the shop to make sure the bases are square. I did some dremelling with a scotch brite wheel to get the baked on gasket material off so in hind sight I decided to have them checked.
Now I just need to get some ez-adjust rods and I should be good to go.
Then I just have to wait for Avon to get's its *** in gear and ships my 2 replacement tires.
Thread Starter
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Tourer
Joined: May 2009
Posts: 401
Likes: 19
From: Middleboro, MA USA
Aces, I don't have the cash flow for pistons and cylinder boring right now. Im way over budget now. This was just supposed to be a cam swap/gasket replacement. When I yanked the heads and tested them I found the needed a valve job. If you're gonna get a valve job you might as well get the heads done up. Doing the heads killed my budget. Also, the 10:1 wouldnt work well for the cam I choose according to the head guy.
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Road Master
Joined: Jun 2012
Posts: 1,088
Likes: 2
From: Mo
Well, I'm glad its coming back together for ya tearra. BUT, if I was you I would wait and save up a little more green backs, and get forged pistons.I wouldn't put KB's in my lawn mower...just me though.Also hear nothing but bad news from the guys at the track too!