97" build specs and check list

[838]

I did a 570 at 10.3:1 in a 117. It can run all day on 89 octane CA pump gas... though it gets 91 mostly... with 98 octane readily available I doubt 10.4:1 will even be an issue.

[Adam76]

I did a 570 at 10.3:1 in a 117. It can run all day on 89 octane CA pump gas... though it gets 91 mostly... with 98 octane readily available I doubt 10.4:1 will even be an issue.

thanks

[Adam76]

I think you will find the pistons down the hole a little more than you have allowed and average 1000ft for altitude in OZ and you are pretty well set for compression.

   I think you will just love it , have fun with the build and remember clean clean then clean again can never be to clean on a engine.   Bob

Thanks Bob, 

[Adam76]

I think you will find the pistons down the hole a little more than you have allowed and average 1000ft for altitude in OZ and you are pretty well set for compression.

Thanks Scotty, just wanted to make sure I didn't end up with a ping monster.   

[Scotty]

I did a 570 at 10.3:1 in a 117. It can run all day on 89 octane CA pump gas... though it gets 91 mostly... with 98 octane readily available I doubt 10.4:1 will even be an issue.

Different fuel US vs Australia so US uses AKI we use RON so
94 US is 98 AUST
91 US is 95 AUST
89 US is 92 AUST

Have to be careful when comparing fuels between a world forum as not everyone lives in the USA

[Adam76]

I did a 570 at 10.3:1 in a 117. It can run all day on 89 octane CA pump gas... though it gets 91 mostly... with 98 octane readily available I doubt 10.4:1 will even be an issue.

Different fuel US vs Australia so US uses AKI we use RON so
94 US is 98 AUST
91 US is 95 AUST
89 US is 92 AUST

Have to be careful when comparing fuels between a world forum as not everyone lives in the USA

😁 Funny you mention that Scotty. I was just comparing all the 97" and 98" big bore  pistons - KB,  Wiseco and CP  and there's quite a discrepancy and variance in the  stated dome sizes and the advertised compression ratios. Since I was thinking of a way to slightly reduce my compression....

Wiseco pro like lite 97" pistons are advertised to give 10-1 compression (stock heads) but actually have a 6.5cc dome and give me more like 10.4 on the calculator and  200ccp.
Where as the CP  98" pistons that are actually advertised as 10.25:1 only have a 6cc dome and therefore give me an actually slightly less compression ratio of 10.35.... and 9.5 dynamic

John Sachs was right when he said don't trust just what you read  about piston domes and compression without measuring.

CP also do a 98" 10.1 piston with an even smaller 3cc dome which is the one in going with so I can mill the heads and use the .030 HG to get me right on 195-197ccp. 👍

[Adam76]

With a 97"/98" piston,  I need the cometic head gasket with the 3.937" bore, obviously the cylinder bore has to exactly match the gasket bore right?
Not many suppliers are showing stock of the Cometic #10034 top end kit...
Cheers.

[kd]

Before trimming the head, mock up the pistons and barrels.  If your quench (squish) is below the deck you can take advantage of a clean-up and true the barrels at the same time. It may be a better option so your heads can be repurposed without the restriction induced by trimming them.  Replacement barrels are much less money and more available as used and seasoned.  Also, remember that Cometic has a .027 gasket that will get you there or closer if you are only in the .003ish below deck range.  It sounds like you will have a great build.  IMO the extra care in planning you are taking will pay big dividends going forward. 

[04rkryder]

Those are CP Bullet Pistons with a C\H of 1.265. Theoretically a C\H of 1.270 will get a zero deck height on a TC88 with 4" stroke. So like KD said, a little trimming on top and bottom and you'll have nice flat surfaces on those cylinders.

[Adam76]

Before trimming the head, mock up the pistons and barrels.  If your quench (squish) is below the deck you can take advantage of a clean-up and true the barrels at the same time. It may be a better option so your heads can be repurposed without the restriction induced by trimming them.  Replacement barrels are much less money and more available as used and seasoned.  Also, remember that Cometic has a .027 gasket that will get you there or closer if you are only in the .003ish below deck range.  It sounds like you will have a great build.  IMO the extra care in planning you are taking will pay big dividends going forward.

Thanks kd, I agree.
On my last build I did trim the base of the cylinders to get close to zero deck height. 

[Adam76]

Those are CP Bullet Pistons with a C\H of 1.265. Theoretically a C\H of 1.270 will get a zero deck height on a TC88 with 4" stroke. So like KD said, a little trimming on top and bottom and you'll have nice flat surfaces on those cylinders.

👍 thanks

[Adam76]

Before trimming the head, mock up the pistons and barrels.  If your quench (squish) is below the deck you can take advantage of a clean-up and true the barrels at the same time. It may be a better option so your heads can be repurposed without the restriction induced by trimming them.  Replacement barrels are much less money and more available as used and seasoned.  Also, remember that Cometic has a .027 gasket that will get you there or closer if you are only in the .003ish below deck range.  It sounds like you will have a great build.  IMO the extra care in planning you are taking will pay big dividends going forward.

Thanks kd.
If I end up using the CR575 std cams (not S&S easy starts) what's the general ccp that you can go up to before needing compression releases?
Thanks.

[kd]

If I'm not mistaken, your 2010 heads may be set up for ACR's.  If so, lots of guys here are using them tied into their starter solenoid (green wire?).  I have a friend using the CR575 cams and he may be at 10.5 to one. It was done at Cycle Rama including headwork.  He has manuals in it but doesn't need them all the time.  A heat soaked engine at the pumps or a weak 07 up compensator can cause kick backs on his. In your climate you may want to consider either option. The ACR's don't burn your fingers if you're day dreaming.  The manuals might be less expensive but machining is required for install.

By the way, my buddies street glide goes like a scalded cat and makes me work with my 120.  He also occasionally pulls a camper trailer w/cooler while 2 up on trips (including mountains) and has a sidecar rig attached on occasion too.  IMO the CR575 is a great all around cam that serves many masters.

[Adam76]

If I'm not mistaken, your 2010 heads may be set up for ACR's.  If so, lots of guys here are using them tied into their starter solenoid (green wire?).  I have a friend using the CR575 cams and he may be at 10.5 to one. It was done at Cycle Rama including headwork.  He has manuals in it but doesn't need them all the time.  A heat soaked engine at the pumps or a weak 07 up compensator can cause kick backs on his. In your climate you may want to consider either option. The ACR's don't burn your fingers if you're day dreaming.  The manuals might be less expensive but machining is required for install.

By the way, my buddies street glide goes like a scalded cat and makes me work with my 120.  He also occasionally pulls a camper trailer w/cooler while 2 up on trips (including mountains) and has a sidecar rig attached on occasion too.  IMO the CR575 is a great all around cam that serves many masters.

Yep, great cam, I just didn't consider it at first because I don't have compression releases in my 2010 heads and I will have to get them machined and fitted... This option might actuality work out better for me as it's easier in my situation to get to 10.1 compression with just pistons that it is to get to 10.2 / 10.3 that the s&s570 likes. Just another option to consider. 
Cheers

[kd]

Larger battery cables are a good start. They are much overlooked as a remedy for cranking issues with higher compression and hot start types of issues. I use them and noticed better performance starting with them. You can buy them or make a set.

[Adam76]

Larger battery cables are a good start. They are much overlooked as a remedy for cranking issues with higher compression and hot start types of issues. I use them and noticed better performance starting with them. You can buy them or make a set.

Any suggestions on a good set of cables? 

[HogMike]

Any suggestions on a good set of cables? 

I bought some Terry Cable years ago at a show for the green bike with the S&S motor.
Worth the $$ IMHO.
Heavy duty and very flexible.
He's in SoCal.

[FSG]

Any suggestions on a good set of cables? 

visit your local auto electrician and get them made

[kd]

Any suggestions on a good set of cables? 

I bought some Terry Cable years ago at a show for the green bike with the S&S motor.
Worth the $$ IMHO.
Heavy duty and very flexible.
He's in SoCal.

I know you folks down under get hosed on shipping buying in the US like us poor Canucks but the Terry Cable kits are pre-made including the extra leads if any. They were great to deal with.  I use them too and like HogMike says, they are worth it.  Check the cost before you go to a local shop. It may be a better deal.

[Adam76]

Any suggestions on a good set of cables? 

I bought some Terry Cable years ago at a show for the green bike with the S&S motor.
Worth the $$ IMHO.
Heavy duty and very flexible.
He's in SoCal.

I know you folks down under get hosed on shipping buying in the US like us poor Canucks but the Terry Cable kits are pre-made including the extra leads if any. They were great to deal with.  I use them too and like HogMike says, they are worth it.  Check the cost before you go to a local shop. It may be a better deal.

[Scotty]

I built my own cables very flexible cable and ends I bought from Jaycar.
Crimped the ends and soldered as well and was good to throw the stiff stock ones in the bin.

[98fxstc]

What gauge are we talking for these cables ?

[PC_Hater]

On my 99 FLTRI I used the fattest heavy duty flexible marine quality cable that I could find.
It stops being defined by wire gauge and becomes mm2.

This is what I bought:-
912/0.3, 70mm², 485A, cable OD 15.5mm, available in red or black at £15.63 per metre

I also bought heavy duty crimp terminals, and a nice crimp tool.
For the 'normal' bike wiring to the fuses etc I used 80Amp rated 10AWG silicone very flexible cable. The copper core is 4mm diameter - 12.56mm2.

The voltage drops are very low and the stock starter spins the little 88" motor like the plugs are out!
      

[rigidthumper]

Stock plate will be fine if it isn't damaged.

[Adam76]

Stock plate will be fine if it isn't damaged.

👍 thanks