how to increase r100 power

Nath87 · 10-19-2012, 06:23 AM

I'm thinking about making a cafe racer out of a r100/7. I would like the bike to have more than stock 60 hp and 54 lbft torque is it possible to get much more horsepower out of the old air heads with out making them over heat?

mykill · 10-19-2012, 07:15 AM

Yes, it is possible.

Airhead Wrangler · 10-19-2012, 07:23 AM

Quote:

Originally Posted by Nath87

is it possible to get much more horsepower out of the old air heads with out making them over heat?

Don't worry, your wallet will overheat before the bike does.

KhaoSanMan · 10-19-2012, 08:52 AM

I stumbled across this article yesterday and found it interesting to read: http://www.ibmwr.org/r-tech/airheads/336cam.shtml

chasbmw · 10-19-2012, 09:29 AM

Note the costs.............and this was done a number of years ago!

The variety of cams, pistons, ignitions that are available now is very wide and if you are not careful we will end up with a repeat of the great 336 flame war................look at posts by RG gregor and pommie john for some ideas and interesting threads.

You cant go far wrong with a high compression dual plugged engine with a slightly more spritely cam and some port work, if done properly, by someone who knows what they are doing, you will be pleasantly surprised.

And if you are going to improve the engine, you might want to consider brakes and handling, in which areas BMW were somewhat lacking when new, let alone after 35 odd years!

Charles

mykill · 10-19-2012, 09:39 AM

Really good point.
The best money spent to go the fastest is suspension and diet for both you and the bike. After that cam, compression, porting, carbs and a well designed exhaust will free things up. The number of combinations will rival oil threads in opinions.

Rob Farmer · 10-19-2012, 11:17 AM

Quote:

Originally Posted by Nath87

I'm thinking about making a cafe racer out of a r100/7. I would like the bike to have more than stock 60 hp and 54 lbft torque is it possible to get much more horsepower out of the old air heads with out making them over heat?

Step this way young man. Look at the pretty things and see how they sparkle

http://www.moorespeed.co.uk/moorespeed/bmw-tuning

supershaft · 10-19-2012, 01:58 PM

Most agree the biggest bang per buck is either a new cam or carbs. I think the cam wins out simply because most people aren't very good at jetting. I put just a 336 in my bike first and loved the results. Other inmates here really like their 336's too. The very first hot rod part(s) I got was a close ratio gear set. Personally, if I were you the first hot rod parts I would get would be Brembo brakes forks and a late model ('81 on) clutch and flywheel. Start at the beginning I always say. Good luck!

bikerfish · 10-19-2012, 05:47 PM

buy a K100

bmweuro · 10-19-2012, 06:55 PM

Quote:

Originally Posted by mykill

Really good point.
The best money spent to go the fastest is suspension and diet for both you and the bike. After that cam, compression, porting, carbs and a well designed exhaust will free things up. The number of combinations will rival oil threads in opinions.

I agree. Once everything else is done and you are outriding the power you have then go bigger and better.

robtg · 10-19-2012, 09:18 PM

Lighter throttle springs......

supershaft · 10-19-2012, 09:48 PM

Lighter springs? But still be careful cranking that thing wide open. A freind of mine from back home came out here and broke a throttle cable trying to get his bike to run with mine. He said he kept hoping there was more. There wasn't.

supershaft · 10-19-2012, 09:50 PM

Quote:

Originally Posted by bikerfish

buy a K100

I think I've done better than that.

orangebear · 10-19-2012, 10:29 PM

my dad use to run a 79 r100/7 and said he use to sit at 90mph on long runs and said the top speed was great even tho the bike handle bad. i thought the book top seep for one was like 130ish mph

Rob Farmer · 10-19-2012, 10:40 PM

Quote:

Originally Posted by orangebear

i thought the book top seep for one was like 130ish mph

You're thinking of the RS or CS machines. These came in around 125Mph

The early 100/7 was much slower with a soft engine and small carbs. I have one, it used to rev it's nuts off at 90 until I fitted a 33/11 final drive. If you want top end performance you need to get the compression up and it breathing better.

We don't know what year the machine is that the OP owns but if he's quoting 60Bhp it's probably a 81-84 machine.

10-19-2012, 06:23 AM	#1
Nath87 ^OP Adventurer Joined: Feb 2012 Location: Bedford, NH Oddometer: 47	how to increase r100 power I'm thinking about making a cafe racer out of a r100/7. I would like the bike to have more than stock 60 hp and 54 lbft torque is it possible to get much more horsepower out of the old air heads with out making them over heat?

10-19-2012, 07:15 AM	#2
mykill odd Joined: Feb 2008 Location: Los Angeles Oddometer: 1,092	Yes, it is possible. __________________ Never underestimate the laxative properties of motorcycling.

10-19-2012, 09:29 AM	#5
chasbmw Beastly Adventurer Joined: Feb 2006 Location: Bath Uk Oddometer: 1,005	Note the costs.............and this was done a number of years ago! The variety of cams, pistons, ignitions that are available now is very wide and if you are not careful we will end up with a repeat of the great 336 flame war................look at posts by RG gregor and pommie john for some ideas and interesting threads. You cant go far wrong with a high compression dual plugged engine with a slightly more spritely cam and some port work, if done properly, by someone who knows what they are doing, you will be pleasantly surprised. And if you are going to improve the engine, you might want to consider brakes and handling, in which areas BMW were somewhat lacking when new, let alone after 35 odd years! Charles __________________ Charles http://i46.photobucket.com/albums/f1...ps6e61ae2e.jpg R90s 1070 replica, R90/6 1971 Commando Fastback

10-19-2012, 09:39 AM	#6
mykill odd Joined: Feb 2008 Location: Los Angeles Oddometer: 1,092	Really good point. The best money spent to go the fastest is suspension and diet for both you and the bike. After that cam, compression, porting, carbs and a well designed exhaust will free things up. The number of combinations will rival oil threads in opinions. __________________ Never underestimate the laxative properties of motorcycling.

10-19-2012, 05:47 PM	#9
bikerfish flyfishandride Joined: Aug 2010 Location: western pa Oddometer: 970	how to increase r100 power buy a K100

10-19-2012, 08:52 AM	#4
KhaoSanMan Airhead Joined: Apr 2009 Location: Chico, CA Oddometer: 507	I stumbled across this article yesterday and found it interesting to read: http://www.ibmwr.org/r-tech/airheads/336cam.shtml

10-19-2012, 01:58 PM	#8
supershaft because I can Joined: Sep 2010 Location: San Francisco Bay area Oddometer: 6,060	Most agree the biggest bang per buck is either a new cam or carbs. I think the cam wins out simply because most people aren't very good at jetting. I put just a 336 in my bike first and loved the results. Other inmates here really like their 336's too. The very first hot rod part(s) I got was a close ratio gear set. Personally, if I were you the first hot rod parts I would get would be Brembo brakes forks and a late model ('81 on) clutch and flywheel. Start at the beginning I always say. Good luck!

10-19-2012, 09:18 PM	#11
robtg Gnarly Adventurer Joined: Jun 2007 Location: san jose Oddometer: 359	Lighter throttle springs......

10-19-2012, 09:48 PM	#12
supershaft because I can Joined: Sep 2010 Location: San Francisco Bay area Oddometer: 6,060	Lighter springs? But still be careful cranking that thing wide open. A freind of mine from back home came out here and broke a throttle cable trying to get his bike to run with mine. He said he kept hoping there was more. There wasn't.

10-19-2012, 10:29 PM	#14
orangebear Studly Adventurer Joined: Aug 2010 Location: dumfrie scotland Oddometer: 707	my dad use to run a 79 r100/7 and said he use to sit at 90mph on long runs and said the top speed was great even tho the bike handle bad. i thought the book top seep for one was like 130ish mph __________________ bmw r100gs i ride it all year round bmw r100/7 sold bmw r1oo/7 sold road legal stomp pitbike sold

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