Big Bore

[WideBoy04]

Anybody here do a big bore on a 88" and run stock heads? I have my EG
rocker boxes off and was wondering if I would gain much by installing a
big bore and maybe doing heads later to keep cost down for now. I already
have HQ34 cams in, Ness Big Sucker, and V/H 1 3/4" True Duals w/Bassani
slip-ons. Would the torque gain be worth it without doing the heads now?
Have my cylinders bored? Buy a Kit?

                                                    Jim

[moose]

done it both ways the best bet is to have the heads done while it is apart. just make sure the porter knows what combo your running. the heads are the best to do for real performance

imho

moose

[Sonny S.]

you would gain more by doing head work, bump CR and leaving it 88", than 95" w/ stock heads.
But if your going to do that, 95" is not that far away..... one thing leads to another huh ?

[JOS]

I am currently doing a big bore on my 88 and am keeping the stock heads ('01 FLHT). The good folks at AMS (see the list of head porters on this site) have my cylinders and heads right now. They are taking the cylinders out to 96" matched with KB pistons and are "cleaning up" my cylinder heads (5-angle on intake valve seats, smoothing out and ceramic coating the exhaust ports). Like you, I was contemplating either cutting my cylinders or just buying a kit. I was leaning towards buying a kit 'cause I just thought it would be less hassle, less time waiting for parts, etc. I would just be able to purchase an HD SE BB95 kit, pull off old-put on new and be done! But, I knew that having your cylinders cut to match your pistons was truly the best way to go and common sense prevailed, lol. After talking to the guys from AMS at a local swap meet about a week ago, I then decided that I would let them clean up the heads and just do a "mild" port job...so to speak. Not looking for any big HP #'s, I ride my bike every day and do a lot of long rides so reliability/rideability is/was a lot more important to me then heavy HP #'s.

[crazycalvin]

you would gain more by doing head work, bump CR and leaving it 88", than 95" w/ stock heads.
But if your going to do that, 95" is not that far away..... one thing leads to another huh ?

Does doing head work really effect the entire RPM range?  I can understand a really hot build wanting or needing head work and the head work doing things for a high lift cam.  But what about cams that have "normal" lift and if you don't plan on stretching it past 6000 rpms?  Do the same principles that work on car/truck heads work on H-D heads (80 grit finish on intake port, radius, etc).  I might start a new thread about headwork.  Thanks, Calvin.

[moose]

you do big bore, I'll do the heads and not big bore.

I win hands down

moose

[crazycalvin]

Even with stock or short duration cams?

[WideBoy04]

Moose, you win where? High rpm range, low to mid torque, HP?
I'm looking for a bump in the low to mid range torque only.

                                      Jim

[L-]

Wideboy,

When I got my brand new 88" FLHR I started immediatley to work on the engine.  I ran a big bore with bone stock heads and a Mikuni 42.  Very nice and power off idle all the way up. I then started with cams like the Andrews 21, 26, 37 and then I got the heads done by Head Quarters with a 0039 cam.  You may like it enough to leave it alone.   There is nothing wrong with a big bore and stock heads and a mild cam.  There are a lot of them out there and they run pretty damn good.

[03deuce]

Another low buck option would be to pick up a set of low mileage 06 and up TC heads, use a thinner head gasket and have your cylinders bored to fit the new SE cast flat top pistons.  A final tune by a competent dyno operator should make you a happy man! 

[Valley]

Anybody here do a big bore on a 88" and run stock heads? I have my EG
rocker boxes off and was wondering if I would gain much by installing a
big bore and maybe doing heads later to keep cost down for now. I already
have HQ34 cams in, Ness Big Sucker, and V/H 1 3/4" True Duals w/Bassani
slip-ons. Would the torque gain be worth it without doing the heads now?
Have my cylinders bored? Buy a Kit?

                                                    Jim

Do the bore kit. Set your deck, use a .030hg and shave alittle off those heads.Get a good tune and you should be happy!
Do the bore kit. Set your deck, use a .030hg and shave alittle off those heads.Get a good tune and you should be happy!

[Faast Ed]

Have my cylinders bored? Buy a Kit?

I bought the jugs and pistons from one of the discount on line HD Dealerships, delivered to my door for around $440.
Never had any problems with it.  But theoretically it is better and slightly less costly to have yours bored to match your pistons. (I did not want to wait).

[PoorUB]

Moose, you win where? High rpm range, low to mid torque, HP?
I'm looking for a bump in the low to mid range torque only.

                                      Jim

I wonder too!
I don't care about HP over 3500 RPM as I rarely ride there so what bennifit is head work to the heavy bagger cruising down the highway??
Not all of us want a kazillion HP at 6000 RPM!!

For the OP, I plan on using my stock heads on my 95" build this winter. I may clean up the ports a bit, and blend in the valve seats, but that is all.

[Faast Ed]

You can always add the heads later, for another nice addition.

One thing I have noticed over the years is that I get used to my last change after time goes by, and enjoy adding something that repeats the rush I got during the previous change.
Enjoy your jugs, then when you get bored with them, add the heads for another boost.

[hotbo]

you will notice a nice torque gain with the big bore,leaving the heads stock is okay if you dont have the money.you will be happy :wink:then later do the heads and you will be happier

[Deye76]

If you don't mind paying for gasket sets......twice, then wait.
IIRC there was a saying......something about you can pay now or pay..........

[WideBoy04]

Say I go with the big bore, what piston would be the choices, and why. I've been
spoiled and been running 87 octane for a long time but guess I could spring for some
better fuel . Thanks for all the input so far.

                                              Jim

[Faast Ed]

Pistons depend some on the rest of your build, but I used the SE cast flat tops.  Cheap cost and acceptable, but there are better choices out there.

When I mentioned earlier about paying $440 shipped, that was with the low cost flat tops.  They worked plenty fine in my build.

[Scurvy]

All that work to disassemble, might as well do the heads while they're off (thats how I justified it for me, hehe).

Hey JOS - when AMS does your heads, ask Steve to check cc and deck them to 85cc's or less, not sure they do it as a matter of business, but I had to ask them to do it.

[WideBoy04]

I was looking around a come across the AMS site. Anyone ever
use their 96" kit? How about Short Block Charlies work?

                                            Thanks, Jim

                               

[Bakon]

Use flat tops with stock heads. That way you might keep them when the heads are done. I would take a 95 with stock heads over an 88 with just head work, especially for your riding. Mild cam in both, 95 still wins. Performance cam, maybe the 88.

[HarleyCharley]

When I went to 95" on my '02 ultra, I used SC 1550 jugs, Keith Black flat top pistons, Andrews 26g cams, and found a low mileage (10 mi.) set of '06 heads. I used the .030 Cometic gaskets with the stock '06 heads. Haven't had it on a dyno but my seat-of-the-pants gauge gives the build a passing grade. Good torque from 2200 up allows easy passing even hauling the wife.

[03deuce]

The SE cast flat top pistons should be more than adequate for a mild street big bore project.  If you order them from one of the 20% discounters, hard to beat the price.  Concerning the 96 cu in, not sure one more cu in is worth the additional cost?  but you could compare prices and then decide.

[WideBoy04]

I came across a set of 95" cylinders in black like I wanted w/KB 9.5:1 flat top piston kit for $290.
I'm leaving the heads alone for now. Should I use the Cometic .030 hg and how much would it help?
I'm by know means a engine builder and don't know what alot of this means, thats why I'm here. I do
as much as I can but think I'm going to let a trusted HD Service manager pull the cylinders and heads.
The heads are ready to come off but don't have the tools to do the pistons.

                                         Thanks for all input, Jim   

[Faast Ed]

Should I use the Cometic .030 hg and how much would it help?

Besides being a real durable gasket, the Cometic .030 will add a little bit of compression to your build (.2-.3 aprox) and will also optimise your squish band.

[frito1]

WideBoy
Back when I started reading HTT Sort Block Charlie was the builder of the month.  Based on that, last Fall I bought a set of jugs & SE flat tops, 95" +.005, fresh bored & new pistons.  $198 delivered.  I dropped them on with a set of '06 heads, 800 mile pull offs.  $202 delivered.  Cometic Gaskets (.030) $50 or so.  I already had 21G cams.  It was cheap ~$450.  I'm happy.  It's quite the tractor.  7500 or so miles & no issues.  I'd use SBC again.

s-r-t

[WideBoy04]

Short Block Charlies was my first choice until I ran across the set I got.
Sounds like your set up is kinda like what I'm looking at. When I run across
a set of heads I'll probably switchem out. I talked to my builder and he says
he's seen mid 90's and up torque with my choices. I'm at 88 at 3300 now.
I'll post results in a few weeks when I'm done, dang work gets in the way .
                             
                                                     Jim

[Ghost Rider]

Nothing wrong with SE cast flattops. They should last 100k or more.

[Lovetoride007]

Jim
How many miles are on the heads now, If you have them off you may want to have them gone through maybe new seals and ck the guides ,cant see it being to much for a mild street port , It would save you a bunch of money to do it now,
JMHO

[Eglider05]

I was looking around a come across the AMS site. Anyone ever
use their 96" kit? How about Short Block Charlies work?

                                            Thanks, Jim

                               

I did a AMS 96"/37g build on my friends 00 RK last spring and he still has a grin on his face. The quality of work and the support is excellent.

Rick

[waskier01]

warranty-----  My '03 Ultra is still under warranty, so, I have the big bore and am waiting till the warranty expires to do anymore work to it.  Five years now and I still haven't decided what to do to it.

[WideBoy04]

The heads got a little under 40,000 miles. Short Block Charlie is offering some head work on ebay,
might look into that.

                                                     Jim

[Twincam-Iron]

I've been watching these posts, and the info I have seen is like gold to me.  Been getting much info for my 01 Deuce for future mild engine work on stock engine.. Some of you guys have done exactly what I want to do.
Than Short Block Charlie pops up.  I just talked to Him Monday about rebuilding my Custom sporty Iron heads.
Very nice fellow over the phone with much info and a nice shop with the latest machines.

[03deuce]

Wideboy,
Check out this webpage.  http://www.harleyhog.co.uk/1550/bbonline.htm
Good info about what's involved in a Big Bore upgrade.

[Lovetoride007]

With 40,000 mi on those heads I would definatly go through them, before I put them back on,