Heads

APE Jay wrote:

Duck wrote:

Jay-
Does APE sell the 30t sprockets so I can use the J camshafts?

No. Never any demand for that combo. We used to do a 32T when funnybikes used to run those cams, but that died also.

Jay

Wonder why. The cam profile looks better than the stock 900. Guess it doesn't make sense if buying all new parts. But, a new APE 1175 'J' piston kit with 1100 sleeves recycled to a KZ, 900 or 1000, and the 'J' head with cams would make a relatively inexpensive yet significant upgrade at about $800-$900 total.

It would not compete with the 1075 kit with .410 cams that APE sells because the guy who is gonna do it is not the guy who is gonna buy the kit.

-Duck

there are 2 things I'd consider.

1. 34mm flat slide smoothbore carbs
2. APE's K410 cams [can you say mid-range;) ]

can you explain how the k4io cams give more mid compaired to my RC400's?
RC400 = in. 45 to 85
ex. 85 to 45
lift .429
total duration 310

K410 = .410 lift
duration @ .03 =266

You can use J cams with KZ sprockets. It required drilling holes, slotting the sprockets and using allen bolts with the heads slightly machined down to clear the cam chain.. Also you must remove all the rubber from the sprockets.

I did 83 GPz11 cams in a 10.25:1 1015 motor like that with a ported head and 29 smoothbores. The motor liked 106 lobe centers and with top shim buckets.

It's the only J cam worth the effort of using in my opinion.

I'm going to be working on that bike again in the near future. I'll post some pics of the cam sprockets when I do.

mark1122 wrote:

there are 2 things I'd consider.

1. 34mm flat slide smoothbore carbs
2. APE's K410 cams [can you say mid-range;) ]

can you explain how the k4io cams give more mid compaired to my RC400's?
RC400 = in. 45 to 85
ex. 85 to 45
lift .429
total duration 310

K410 = .410 lift
duration @ .03 =266

Based on your posts on this forum and some others, I get the impression your bike is over cammed for the type of riding you do. Now I agree, numerically speaking the RC cams look good. Might be perfect in a 1260 motor with a good head. I've never run one of their cams. That grind looks very similar to a couple of others but their duration must be advertised at .020 or something because it's quite high. If you happen to degree them, I'd appreciate a .050 duration number with zero lash. It would also help you in comparing apples to apples.

Anyway, the APE K410 cams appear to be and Andrews 8x grind that Andrews doesn't do any longer. They were a hell of a cam. I just have a gut feeling that your motor would like those cams more than the RCs you're currently running. The newer 34mm flat slides are leagues better than those old 33 mics and would work really nice with that .410 cam from APE.

If it were me, I'd buy the carbs first and try them with your current cams. If you still have acceleration problems, then I'd move to APE's K410 cams. Might be a step down in lift and a step up in drivability.

larrycavan wrote:

Mark,

Back in that mid 80's I had a conversation with a guy that had a couple of the heads that came off Eddie Lawson's factory superbikes.

The heads flowed suprisingly small amounts over a stock GPz11 head [the head that was modeled around those championship winning heads]. Regardless of the unimpressive CFM number, the heads made good power because it was the total package that worked.

V&H got their hands on some of those "special" parts too that were developed for that roadrace effort. At some point Kaw made an 8-plug head that had cast-in bosses for that purpose. There were also some titanium rod roller cranks that were produced. Neat stuff!

ok, since we're throwing idea's out, here's a hypothetical engine build, that has a pretty good chance of coming to fruition.

900 crank/cases/bottom end, bored for large sleeves...

900 block, set up for big sleeves, and 1197 pistons.

1197 pistons, crowns are relieved a bit for lower c/r

900 head, ported(going to be MILD port, CSA TBD, bowl work, STOCK valves)

.435 cams, shim under buckets, good springs.

vm29 mikuni's.

dyna s and coils... maybe a few other bits.

what do you think about that setup larry? under-carbed or over cammed?

my guess, is that it will make all of it's power under 6k rpm, and have the overall power limited by the size of the carbs, small valves, and limited porting that i am planning to do. also, i am worried the cams are going to move the power band higher than where i want it.

my goal is a stump-pulling engine to eat up some miles next summer. not a max power effort, durability is my #1 goal. the bike's gonna do over 3K miles for next summer's motogp at laguna.

--r

29's Will work on that combo but I would suggest 34's or Pro-Flow DFI throttle bodies with a microsquirt computer.

I'll run you some numbers later today for required CFM and CSA....What's your peak HP RPM target?

LarryC

i've got vm29's, or flat slide 38's.

my goal for this engine is for a tq monster, rather than peak hp, so the 29's are gonna be the way i'll be going.

HP RPM targets will peak below 7500 rpm. this engine will see some in town bombing, but mostly gonna be two-lane highway cruising. power spread will *hopefully* be between 2200 to 7000 rpm. early peak is ok.

--r

I see your situation with the carbs. Neither set is ideal. The 29's should yield excellent throttle response on that setup. IMO, 38's are entirelly too big for 900 port runners.

With those cams, you've got enough curtain area and flow with a stock head for roughly 7800RPM Peak HP RPM.

Now, unless you plan on going with more carb later on, there's not really much port work needed. It sounds to me like you've ported before. You could clean up the casting lines, shape the bowl a tad bit and match the seats to the ports. I'd definitely go 90% on the throat size. IMO, you could actually get away with less cam for what your goal is for the motor. K410's are about perfect for your goal.

I guess it's getting to sound like I'm a K410 fanatic or something. It's not the case. There are 2 primary reasons I've been coming back to that grind.

1. It's the right cam numerically for the application.
2. APE has been around a good long while and I hope they continue to be. There's still life in these old 2V KZ motors, there's still a market for performmance parts.

Anyway...that's how I see it.....I'd love to take the bike for a ride when it's finished...should be lots of fun.

Larry C

larrycavan wrote:

I see your situation with the carbs. Neither set is ideal. The 29's should yield excellent throttle response on that setup. IMO, 38's are entirelly too big for 900 port runners.

With those cams, you've got enough curtain area and flow with a stock head for roughly 7800RPM Peak HP RPM.

Now, unless you plan on going with more carb later on, there's not really much port work needed. It sounds to me like you've ported before. You could clean up the casting lines, shape the bowl a tad bit and match the seats to the ports. I'd definitely go 90% on the throat size. IMO, you could actually get away with less cam for what your goal is for the motor. K410's are about perfect for your goal.

I guess it's getting to sound like I'm a K410 fanatic or something. It's not the case. There are 2 primary reasons I've been coming back to that grind.

1. It's the right cam numerically for the application.
2. APE has been around a good long while and I hope they continue to be. There's still life in these old 2V KZ motors, there's still a market for performmance parts.

Anyway...that's how I see it.....I'd love to take the bike for a ride when it's finished...should be lots of fun.

Larry C

its being copied basically off of the motor that was in this bike,yeah it was a riot to try and keep in straight line!

larrycavan wrote:

You can use J cams with KZ sprockets. It required drilling holes, slotting the sprockets and using allen bolts with the heads slightly machined down to clear the cam chain.. Also you must remove all the rubber from the sprockets.

I did 83 GPz11 cams in a 10.25:1 1015 motor like that with a ported head and 29 smoothbores. The motor liked 106 lobe centers and with top shim buckets.

It's the only J cam worth the effort of using in my opinion.

I'm going to be working on that bike again in the near future. I'll post some pics of the cam sprockets when I do.

Larry-
Thanks. I'll keep an eye out for some sprockets and 83 cams. Have some 87 KZP cams which appear to be the same as the 82 GPz1100.

900 crank/cases/bottom end, bored for large sleeves...

900 block, set up for big sleeves, and 1197 pistons.

1197 pistons, crowns are relieved a bit for lower c/r

900 head, ported(going to be MILD port, CSA TBD, bowl work, STOCK valves)

.435 cams, shim under buckets, good springs.

vm29 mikuni's.

dyna s and coils
that sounds a lot like my bike when i got it.[see sig below].Now it has 1mm. over intakes and vm33's.That setup feels much the same as it does now.I find that the motor came on then and now the same,at 7000rpm.I think it must be the cams,so i think larry is right with the k410 cams.I would like more bottom end as well..(mine are .429 lift 310 total duration,)