1100R motor

Posted: Thu Jul 06, 2017 12:58 am

I noticed a post recently on Larry Conlins 1100R bike. I bought an 1100R motor from Matt for Larrys estate.
Does anybody know of anything I can use from it in my 1100F build or does anyone need an 1100R engine?
It turns over fine but is missing the clutch, alternator and side covers

Hawk Joined: Aug 17, 2013 Posts: 302 Location: Devon. UK

As I understand it, and I may be wrong, the main difference between an 1100F motor and the 1100R motor is that the R was based on the 900, and shares the same Crank dimensions, so has the narrower primary chain drive. This is thought to result in a stronger Crank than the 1100F has with its wider primary chain.
I could also be wrong here, but I believe accepted wisdom has it that the strongest 1100 motors get built using the 1100 cases with a 900 Crank and primary drive system.
There are many detail differences with the rods, pistons, head etc, but all the R components will work in an F motor, and will be better.
The alternator rotor, stator and cover were unique to the R, they're smaller and lighter. As long as you fit all 3 matching components then they are interchangeable between the R and F.
The R clutch was again based on the 900, so a 900 clutch and cover will fit and work fine, the other outer covers, starter and ignition, and the sprocket cover are interchangeable with the 900's & 1100's.
The main cases are different in that the R uses solid mounts to the frame, the F has different mounts for the rubber mountings.
Personally in your situation, I'd be rebuilding the R motor components, barrels and head etc into your 1100F main cases to go in the F. The cost will be the same but you'll end up with the best motor Honda produced.

Somebody much more knowledgable then myself may be along shortly to point out all the errors in what I've said, if so then I apologise now and advise you listen to them instead if me 😂😂

CB1100F Joined: Jun 18, 2006 Posts: 2525 Location: UK

Stueecat wrote:

As I understand it, and I may be wrong, the main difference between an 1100F motor and the 1100R motor is that the R was based on the 900, and shares the same Crank dimensions, so has the narrower primary chain drive. This is thought to result in a stronger Crank than the 1100F has with its wider primary chain.
I could also be wrong here, but I believe accepted wisdom has it that the strongest 1100 motors get built using the 1100 cases with a 900 Crank and primary drive system.
There are many detail differences with the rods, pistons, head etc, but all the R components will work in an F motor, and will be better.
The alternator rotor, stator and cover were unique to the R, they're smaller and lighter. As long as you fit all 3 matching components then they are interchangeable between the R and F.
The R clutch was again based on the 900, so a 900 clutch and cover will fit and work fine, the other outer covers, starter and ignition, and the sprocket cover are interchangeable with the 900's & 1100's.
The main cases are different in that the R uses solid mounts to the frame, the F has different mounts for the rubber mountings.
Personally in your situation, I'd be rebuilding the R motor components, barrels and head etc into your 1100F main cases to go in the F. The cost will be the same but you'll end up with the best motor Honda produced.

Somebody much more knowledgable then myself may be along shortly to point out all the errors in what I've said, if so then I apologise now and advise you listen to them instead if me 😂😂

The 1100R has the same Crank and primary chain as the CB1100F, The CB1100RB has the non-donut Crankcases cases whereas the RC/D has the stronger donut cases
The R has a closer ratio gearbox than the CB1100F
The R has hotter Cams and Forged pistons
The Head is very similar just the R head has a small amount of machining to clear the cam chain tensioner
The R uses a similar main cam chain tensioner but the CB1100F one is an improved version of the R one

Keith

CB1100F Joined: Jun 18, 2006 Posts: 2525 Location: UK

Hondo57 wrote:

I noticed a post recently on Larry Conlins 1100R bike. I bought an 1100R motor from Matt for Larrys estate.
Does anybody know of anything I can use from it in my 1100F build or does anyone need an 1100R engine?
It turns over fine but is missing the clutch, alternator and side covers

I would use it in the CB1100F, you would loose the rubber engine mounts thats all

All your CB1100F covers Clutch will fit straight on, you will get a good power increase, With a jetting change and your CB1100F twin snorkel airbox you will have 120bhp

R engines are quite valuable and rare to see for sale if you decide to sell it

Keith

Posted: Thu Jul 06, 2017 11:33 am

I have an 1100f motor already. I bought the R as a spare and to help out with the estate. If anyone is interested in the motor, send me a PM. Pretty sure I won't be using it.

Hawk Joined: Aug 17, 2013 Posts: 302 Location: Devon. UK

krgood0 wrote:

Stueecat wrote:

As I understand it, and I may be wrong,

Somebody much more knowledgable then myself may be along shortly to point out all the errors in what I've said, if so then I apologise now and advise you listen to them instead if me 😂😂

The 1100R has the same Crank and primary chain as the CB1100F, The CB1100RB has the non-donut Crankcases cases whereas the RC/D has the stronger donut cases
The R has a closer ratio gearbox than the CB1100F
The R has hotter Cams and Forged pistons
The Head is very similar just the R head has a small amount of machining to clear the cam chain tensioner
The R uses a similar main cam chain tensioner but the CB1100F one is an improved version of the R one

Keith

See, told you my knowledge was sketchy... 😂😂😂

Posted: Thu Jul 06, 2017 1:02 pm

Hondo57 wrote:

I have an 1100f motor already. I bought the R as a spare and to help out with the estate. If anyone is interested in the motor, send me a PM. Pretty sure I won't be using it.

PM sent