Topic: No stroke all bore?? On an fxr (Read 11832 times)

Frisco kid · « **on:** December 10, 2012, 01:01:40 AM »

No stroke all bore?
This is what i have been pondering on my fxr.
My bike has 32k miles and stage 2.
I want to go with more (10 to 1) compression and was thinking of increasing bore at same time.
My thought was to have my guy open her up.
If bottom end looks good just bore and go to bigger higher compression pistons.
No need to open up the bottom and save some money.
Same time do some head work and get it all matched up.
I plan to keep my EV27 cam as i like the way it comes on, just want more to come on.
So if bore no stroke, what size to bore to. I would like 88+ inches.
I figure all things being equal 10% more cubes means 10% more tq.
Add to that the higher compression pistons my bike might go from 70 something hp to close to 90.
That would keep me happy for a while.
So who agrees and who doesnt?
And why?
Thanks all!

SHRADER · « **Reply #1 on:** December 10, 2012, 10:35:26 AM »

I don't think that the evo cases, or any others for that matter, will allow but so much bore without machining the spigots for larger cylinders. So in reality what you are wanting to do is not possible. You cannot increase the CI by 10% without going into the bottom end.

Regards
Shrader

Landshark · « **Reply #2 on:** December 10, 2012, 01:30:17 PM »

I put a S & S big bore sidewinder kit on my FLHTC Evo and to do it the cases had to be bored to take the larger cylinders. Someone else might make something but I don't think so. Good luck.

HILLSIDECYCLE.COM · « **Reply #3 on:** December 10, 2012, 08:42:24 PM »

Yep.
97" with 3.812" bore cylinders.
The 27 cam will be fine.
Matter of fact built this combo in an FXR for a Special Forces Weapons Instructor not that long ago.
Built quite a few 97" Shovels, and Evo's over the years.
Always a home run.

Scott

Frisco kid · « **Reply #4 on:** December 11, 2012, 04:59:00 PM »

Hey Hillside can you really get 97" without splitting cases?
Can all the clearences be made with the engine in the chassis?

Also does anyone think more than 10 to 1 or less?
I am looking for a great combo that will be relaible trouble free with great power.
As it is a lighter bike, I donb't see the need for a huge engine with more that 100hp.

prodrag1320 · « **Reply #5 on:** December 12, 2012, 07:31:57 AM »

like scott,we`ve also done tons of the 4.25x3.812 builds (a VERY nice shovel or evo build),you`ll have to split the cases and bore the holes.the 4.25 cylinders are no taller than stockers so fitment isnt a problem & compression can be set pretty much where you want.even with very mild headwork your looking at 105+HP/TQ.the biggest you can go will bolt on cylinders is our 85" kit

HILLSIDECYCLE.COM · « **Reply #6 on:** December 16, 2012, 01:19:46 PM »

Quote from: Frisco kid on December 11, 2012, 04:59:00 PM

Hey Hillside can you really get 97" without splitting cases?
Can all the clearences be made with the engine in the chassis?

Also does anyone think more than 10 to 1 or less?
I am looking for a great combo that will be relaible trouble free with great power.
As it is a lighter bike, I donb't see the need for a huge engine with more that 100hp.

No.
The cases need boring, and we re-balance the crank here, when doing those also.
Cylinder spigot dimension is 4.000", an the cases are bored to 4.005-4.010".
Cam, compression, and cylinder head air flow will all dictate the output of these.
Scott

ltank · « **Reply #7 on:** January 06, 2013, 09:41:55 PM »

I would avoid going more than 10:1 compression on a everyday rider. You need to consider that even the premium gas is not what it used to be. Do you always want to have fuel additives in your back pocket? Pinging or Detonation is bad on wristpins/bearings etc..going with 9.75:1 woulld be a good compromise. I have bee on many major bike events. Sturgis, Daytona, Bike Blues &BBQ and LoneStar rallies. Some gas stations had completly run out of premium gas! and your motor will run hotter. But being a EVO motor you will probably be OK. Be glad you have a EVO and not a TC motor. Alot of Harley shops would be out of busseness if they had not made the TC motors. EVOs are alot more durable, less money to get good HP gains, run cooler. The FI motors just dont sound a good a the carb motors. A few more CI you may want a different cam. just make sure it turns on at the rpm you want ex: 2800 -3200 rpm. The EV 27 has fast ramps that it harder on you lifters and other valve train parts.
Just my two cents,
Ltank

HILLSIDECYCLE.COM · « **Reply #8 on:** January 07, 2013, 08:39:27 AM »

Quote from: ltank on January 06, 2013, 09:41:55 PM

I would avoid going more than 10:1 compression on a everyday rider. You need to consider that even the premium gas is not what it used to be. Do you always want to have fuel additives in your back pocket? Pinging or Detonation is bad on wristpins/bearings etc..going with 9.75:1 woulld be a good compromise. I have bee on many major bike events. Sturgis, Daytona, Bike Blues &BBQ and LoneStar rallies. Some gas stations had completly run out of premium gas! and your motor will run hotter. But being a EVO motor you will probably be OK. Be glad you have a EVO and not a TC motor. Alot of Harley shops would be out of busseness if they had not made the TC motors. EVOs are alot more durable, less money to get good HP gains, run cooler. The FI motors just dont sound a good a the carb motors. A few more CI you may want a different cam. just make sure it turns on at the rpm you want ex: 2800 -3200 rpm. The EV 27 has fast ramps that it harder on you lifters and other valve train parts.
Just my two cents,
Ltank

The cams intake closing number will dictate where the compression, of the given engine combination, needs to set at.
Surely would not want a Wood 9B, or 9F, for instance, set at only 10.0 cr, as it'll be a stone turd, and on the flip side of that, if you set a Crane 300-2B, at 10.0 and your going to have problems.
Scott

Snakebyte · « **Reply #9 on:** March 07, 2015, 11:44:54 PM »

Quote from: Frisco kid on December 11, 2012, 04:59:00 PM

Hey Hillside can you really get 97" without splitting cases?
Can all the clearences be made with the engine in the chassis?

Also does anyone think more than 10 to 1 or less?
I am looking for a great combo that will be relaible trouble free with great power.
As it is a lighter bike, I donb't see the need for a huge engine with more that 100hp.

10-1 compression are we talking static?
At any rate I had helped out a friend build his EVO and we set his compression to 10.65:1 with a wood6. CCP and weisco flat tops. Ended up 204 each cylinder. He runs it in a ElectraGlide. Had to weld the chamber. He runs 92 octane no problems with SE ignition.
Anyway shoot for at least 195 CCP.
As far as splitting the cases, its not a big deal if you do decide to go that route. Bigger bore is way more fun than stroke. Took me a lot of builds to figure this out. Stroke is overrated. If you don't want to take my word for it just look at all the shootout winners and racers. Over square is a lot more fun in a light bike.

HILLSIDECYCLE.COM · « **Reply #10 on:** March 12, 2015, 10:26:07 AM »

97" Evo's are not news, nor are 97" Shovels. Been there, done that yeeeeeeeeeeeeears ago.
Built a lot of those over the years, and several local ones are still in service, including 88" all-bore XL's.
We fluidly move from something along those lines to 2015 models and all points in between............."the pay is the same, if your fighting or marching".
Scott

Ridgerunr · « **Reply #11 on:** March 23, 2015, 07:55:05 AM »

Stock Evo cases are questionable IME with big bore cyls., tend to weep, especially the rear. I don't know what the cost is to rebuild your stock motor into a big bore. Might look into the S&S 111" crate motor, square motor=smooth power and a warranty.

ltank · « **Reply #12 on:** March 23, 2015, 01:18:00 PM »

I have a S&S V111. It is smooth, has really great power for a touring motor. I can run it all day in 100 degrees and oil temp is never over 190. No leaks, no problem. Got 60,000 on this motor and a tappet just starting to make a slight ticking noise. I am very satisfied. Smokes HD 110, taken several 3500 mile trips with average interstate speeds 80 mph. Love it.

Rooster · « **Reply #13 on:** March 23, 2015, 02:56:10 PM »

Quote from: ltank on March 23, 2015, 01:18:00 PM

I have a S&S V111. It is smooth, has really great power for a touring motor. I can run it all day in 100 degrees and oil temp is never over 190. No leaks, no problem. Got 60,000 on this motor and a tappet just starting to make a slight ticking noise. I am very satisfied. Smokes HD 110, taken several 3500 mile trips with average interstate speeds 80 mph. Love it.

Pipes look like she's runnin good.

ltank · « **Reply #14 on:** March 23, 2015, 09:55:30 PM »

She Runs Great! Pipes are custom S.S. Stepped 2 into 1 pipes.
There is moderate discoloration the 1st two inches. A lot of S.S.
Pipes turn purple/black about a foot due to excessive heat telling you bike is out of tune. I get 50 MPG on the highway at speeds 70 to 85. Past 85 will the GPM takes a hit to 38 or so.

Rooster · « **Reply #15 on:** March 24, 2015, 03:39:38 PM »

Quote from: ltank on March 23, 2015, 09:55:30 PM

She Runs Great! Pipes are custom S.S. Stepped 2 into 1 pipes.
There is moderate discoloration the 1st two inches. A lot of S.S.
Pipes turn purple/black about a foot due to excessive heat telling you bike is out of tune. I get 50 MPG on the highway at speeds 70 to 85. Past 85 will the GPM takes a hit to 38 or so.

Old Thunderheader without shields on my 96 WG looks about the same at 54k. The most dependable bike I have owned.

HILLSIDECYCLE.COM · « **Reply #16 on:** March 30, 2015, 07:20:25 AM »

Quote from: Ridgerunr on March 23, 2015, 07:55:05 AM

Stock Evo cases are questionable IME with big bore cyls., tend to weep, especially the rear. I don't know what the cost is to rebuild your stock motor into a big bore. Might look into the S&S 111" crate motor, square motor=smooth power and a warranty.

Contact Axtell Sales, Des Moines, Iowa, or S&S Cycle in Viola, Wis. in regards to stock case integrity.
Only cases we see here that were problematic, even in OEM trim, were the family of 1992-94 Evo's. Only.
The 90* machined corner behind the rear tappet block sets the stage for a fracture point right out of the gate, and that is where they'll break, stock, or bored.
Scott

Ridgerunr · « **Reply #17 on:** April 15, 2015, 07:38:30 AM »

I've seen enough 88' - 93' cases with issues that I'd definitely get aftermarket cases if increasing power. I owned a 1988 and a 1993, both rear cylinder bases leaked, the 1988 bone stock. The 1993 started when I got it to 86 hp, with heads and cams, no overbore. The 1992 FXR I owned with the S&S 80" Hot Set Up made the same horsepower (86) and didn't leak a bit. Point is it's a crap shoot IME when pumping up an Evo with stock cases. S&S, Delkron, STD, Jims, House of Horsepower made their replacement cases beefier in that area for a reason.

HILLSIDECYCLE.COM · « **Reply #18 on:** May 12, 2015, 07:21:15 AM »

Those Evo's always would leak on the primary side, rear cylinder, particularly with the ancient paper gaskets.
No fault of the engine case integrity.
Those cases mentioned really cannot be thicker in that tight area.
They are/were, however, manufactured from 356-T6 aluminum alloy of a much higher tensile yeild than the OE cases.
The years of the cases I mentioned are the ONLY ones we have ever seen any issues, in the 70 hr/6 day a week/30 years of HD enging building enviroment.
Scott

prodrag1320 · « **Reply #19 on:** May 12, 2015, 07:30:55 AM »

we`ve done too many big bore motors with stock cases to count,never had a problem because of case integrity (pan,shovel or EVO),in our early years of drag racing,we used stock cases.never had any problem there either

HILLSIDECYCLE.COM · « **Reply #20 on:** May 15, 2015, 06:21:26 AM »

Had a 97" Shovel hurt the cases once..............client did not have the upper motor mount in place when he installed the engine in the chassis............

Scott

Classic Beast · « **Reply #21 on:** June 06, 2015, 04:50:16 AM »

S&S makes a great 126" 4 3/8" bore 4 3/8" stroke 150 Hp with twin cams (has evo or twin cam mounting) I would bet this motor with the shorter stroke would be a good one I run a 127" with 4 1/4 bore and 4 1/2 stroke and it's been good to me. Running the aftermarket cases they are 1/4" wider and stronger so a big bore isn't an issue, stock cases, are ok within limits I ran a 3 5/8" bore 96" shovel for years with stock cases (1975) didn't have any issues with that.

Author Topic: No stroke all bore?? On an fxr (Read 11832 times)