1100w 750w compatible cams / engine bits

[iamhiding]

Alrighty guys,

Been lingering here for a while now. running/building a WP 1100 and I've been offered any engine bits that are of use from a water boiler 750 engine getting broken down from a member

so info online is pretty vague on the cams but it has been done, anyone able to comment on gains?

any other bits like casings etc compatible does anyone know?

 

thanks,

 

 

[almostthere]

think the 750 cams give a bit more lift, casings are the same as are crankcases, alternator & starter motor are the same

Edited April 28, 2016 by almostthere

[iamhiding]

2 hours ago, almostthere said:

think the 750 cams give a bit more lift, casings are the same as are crankcases, alternator & starter motor are the same

 

good to know man! cheers, sounds like i might have a thorough raid of it.

really curious about a cam swap as the earlier wc 11 cams like mine weren't as hot as the later ones or so I've read. if I've got access to the 750 cams its a free gain if its worthwhile doing.

[Gammaboy]

Yeah, 750 cams on Wn-WR 1100s is a common thing, they're the same as what alot of people sell as "Stage 1" cams for 1100s. Topend gains to be had with them, slight loss of bottom end. With some swapping of bits around, you can slot in the 750 6 speed box. I vaguely recall it requires putting the 1100 gear onto the 750 clutch basket.

[iamhiding]

17 hours ago, Gammaboy said:

Yeah, 750 cams on Wn-WR 1100s is a common thing, they're the same as what alot of people sell as "Stage 1" cams for 1100s. Topend gains to be had with them, slight loss of bottom end. With some swapping of bits around, you can slot in the 750 6 speed box. I vaguely recall it requires putting the 1100 gear onto the 750 clutch basket.

noted, the 750 cams are meant to be hotter than the later 11 ones, thanks man. any builds or documentation that you know of worthwhile checking out? I'm usually on the ball with finding stuff but no real luck with anything cam related. found a reference to some magazine build talking about them being usable but not much more than that.

 

funny you should say about the 6 speed box, i was thinking about it earlier, literally was just about to look it up haha that could be really interesting to do. 

[Kristjan]

750 cams never had more lift... I don't know where this came from but check your sources. I have some in my shed and can prove it wrong. They do have a couple of degrees more duration though.

I wouldn't bother with the 6 speed swap, it probably won't last long.

Cams... I'm too lazy to write, si I'll copy some info I've copied from manuals. Just a baseline, not exact measurements.

IN 275
EX 278

95-on 1100:
ign. 7* BTDC <1500rpm
IN 275* 36.692 - 8.7mm
EX 278* 36.222 - 8.2mm

93-94 1100:
ign. 13* BTDC <1500rpm
IN 275* 36.692 - 8.7mm
EX 278* 36.612 - 8.6mm

 

92 750:
ign 13* BTDC <1500rpm
IN 278* 36.592 - 8,6
EX 282* 36.222 - 8,2

[iamhiding]

On 30 April 2016 at 9:48 PM, Kristjan said:

750 cams never had more lift... I don't know where this came from but check your sources. I have some in my shed and can prove it wrong. They do have a couple of degrees more duration though.

I wouldn't bother with the 6 speed swap, it probably won't last long.

Cams... I'm too lazy to write, si I'll copy some info I've copied from manuals. Just a baseline, not exact measurements.

IN 275
EX 278

95-on 1100:
ign. 7* BTDC <1500rpm
IN 275* 36.692 - 8.7mm
EX 278* 36.222 - 8.2mm

93-94 1100:
ign. 13* BTDC <1500rpm
IN 275* 36.692 - 8.7mm
EX 278* 36.612 - 8.6mm

 

92 750:
ign 13* BTDC <1500rpm
IN 278* 36.592 - 8,6
EX 282* 36.222 - 8,2

theres a few sources saying very different things to be fair, thanks for backing it up rather than adding to all the speculation out there  definitely interesting to see a side by side comparison in cam specs. thanks dude.

I'm sure i had read up on the 6 speed swap ages ago and longevity problems when used hard isn't going to be worth the hassle is it. that was off the table pretty quickly.

//

so my knowledge on cams is pretty basic having never really dealt with them hands on and I'm not going to pretend otherwise but in terms of comparative figures the 92 750's EX is a close match to to the 95 onwards EX except it looks to have a much longer duration like you said, actually both in and ex have longer duration. 

this stuff is slightly beyond me, will have to get my head wrapped round it. initially i was looking at it thinking i could use the 750 EX alone in the 93-94 but I'm not sure about overlap or any other factors that may be of issue. if both 750 cams are longer duration it could be worthwhile looking at using both at the loss of 0.1mm lift on the IN side in comparison to the later 11 setup I'm aiming for if my understanding is correct. 

i'll need to figure out what engine exactly it is thats sitting as I suspect the cams were probably changed at some point in the 750 W's production.

//

any known matches/setups or well educated speculation is welcome though 

[Kristjan]

I would bet my money on using two intake cams on 1100 motor, but this will need modified cam clamps for exhaust side.

Longer exhaust duration is not really something I would like to see. Both durations could be equal and it'll probably work very well. Long duration exhaust means either a big overlap or tighter piston to valve clearance on exhaust side... and the last one has blown many 1100W's.

I don't have a spare intake cam, and too much hassle finding one quick and cheap enough to try, otherwise I would have put one in my motor already. Currently running stock WS cams and ecu, 1146 cm3, +1mm valves both sides and ported head. Plenty of torque, but I think top end somewhat flattens out...