Author Topic: different sleeves? (Read 13638 times)

JoeCooley · « **Reply #25 on:** February 20, 2018, 05:37:50 PM »

Thank you for the information. This build is sort of mothballed for now. My 836 is running good and I might try the cam on it.

BPellerine · « **Reply #26 on:** February 20, 2018, 05:48:12 PM »

just make sure you have no valve to piston contact,not trying to discourage you just passing some stuff on.bill

PeWe · « **Reply #27 on:** February 21, 2018, 03:50:49 AM »

Quote from: BPellerine on February 20, 2018, 05:35:11 PM

..... a 315 or something like that would be more in order if you hoped to lose a little compression,just my thoughts.bill

DP315 has some overlap. I run it with 1000cc, appr CR 10:5-1 (Maybe a little bit less). I had it with 836 for a while too.
It has the recommended valve lash of 0.12" (0.3mm).
The overlap will increase some degrees more if you reduce valve lash to 0.04/0.05" as many hot cams have.
315 cam does not feel wild, the power is applied very smoothly and has a fantastic calm idle in my engine. Very strange

Overlap: IN open + EX close

I measured overlap
@ 0 lash: 68.5°
@ 0.3mm lash: 54.5°
0.15mm (0.059") must be in the middle
I do not know how much it will change the Dynamic compression.
Many other hot cams have 40-50° overlap

I saw 2 good things with more lash (recommended according to Russ Collins), easier for oil to lubricate rocker arm/cam, longer valve cooling time in seat and less overlap increasing dynamic compression which is OK for my engine, CR probably around 10:1. I can use thinner gaskets.
Compression was 175PSI with the 315 cam. Checked after some idling sessions direct after install of new 71.25mm pistons.

754 · « **Reply #28 on:** February 21, 2018, 10:40:45 AM »

Yes I was talking about the 315, I really liked it. Ran it at .012, and it was quieter than I expected.
And it had good bottom end. Maybe the Webers helped.
I put an A grind Andrew's cam in a stock motor, nothing under 3 k rpm,then it starts to work.

PeWe · « **Reply #29 on:** February 21, 2018, 01:02:52 PM »

I'll see later coming season how the DP315 will provide with a Hindle 4-2-1. I'll compare the dyno runs with my 4-4.

JoeCooley · « **Reply #30 on:** February 21, 2018, 02:41:05 PM »

What do you guys think about the DP327 with a 12:1 890cc build? It has more lift and duration than the DP315.

Edit: oops got confuse with the 325° duration.

gschuld · « **Reply #31 on:** February 21, 2018, 03:12:14 PM »

Minor edit: it’s DP327 not DP325😉. It’s Dynoman’s clone of the RC Engineering RC327 cam.

The 327 cam is generally the go to drag racing cam, especially if your into vintage grinds.

Bill Benton and Frankie(Dragracer) have LOTS of experience with that cam. Less street friendly than a 315 in a 890 motor, but at 12:1 compression, not thinking streetable is a top priority for you.

George

JoeCooley · « **Reply #32 on:** February 21, 2018, 04:22:29 PM »

Meh, not real concerned with streetability. Mostly just want the right cam for the hi comp 890.

gschuld · « **Reply #33 on:** February 21, 2018, 04:39:27 PM »

Sounds like a great combination as long as you run race gas...

Pump gas, I’d be concerned about detonation.

George

dragracer · « **Reply #34 on:** February 21, 2018, 07:54:27 PM »

I think I would stick with a 315 for a hot street/strip engine. The 327 won't really come at a useable range on the street in my opinion unless you gear it up. My plan is to eventually build a 970 for the street but I'll definitely be installing the 315 I have on hand.

754 · « **Reply #35 on:** February 21, 2018, 08:35:52 PM »

Overcammed bikes are a drag to ride.. no fun..

JoeCooley · « **Reply #36 on:** February 21, 2018, 09:05:06 PM »

Thanks for all the info guys! This has been one of the most information threads that I've been apart of. 😎🤘

I think I will stick the HO284 in my 836 and see how it performs. The 12:1 890 is in the works but backburnered due to other (life) things in the works. I will build it tho. In due time...

Terry in Australia · « **Reply #37 on:** February 21, 2018, 10:27:19 PM »

Dammit, I just pulled my garage apart looking for a hot cam that a mate gave me a couple of years ago, it looks like the Tardis has swallowed it? Oh well, Ebay is my friend...........

PeWe · « **Reply #38 on:** February 22, 2018, 11:05:06 AM »

Terry, CB750 cams are interesting to collect.
CycleX has a new cam for sale CX-11. Interesting description http://www.cyclexchange.net/camshaftpage.htm
I wonder which old cam profile this is?

slikwilli420 · « **Reply #39 on:** February 22, 2018, 04:49:44 PM »

Quote from: PeWe on February 22, 2018, 11:05:06 AM

Terry, CB750 cams are interesting to collect.
CycleX has a new cam for sale CX-11. Interesting description http://www.cyclexchange.net/camshaftpage.htm
I wonder which old cam profile this is?

That's the one going in my road racer. Apparently popular with midget racers. Kenny said it pulls like a freight train out of the corners.

PeWe · « **Reply #40 on:** February 22, 2018, 09:53:14 PM »

Quote from: slikwilli420 on February 22, 2018, 04:49:44 PM

Quote from: PeWe on February 22, 2018, 11:05:06 AM
Terry, CB750 cams are interesting to collect.
CycleX has a new cam for sale CX-11. Interesting description http://www.cyclexchange.net/camshaftpage.htm
I wonder which old cam profile this is?

That's the one going in my road racer. Apparently popular with midget racers. Kenny said it pulls like a freight train out of the corners.

Feels like a perfect street cam!

Terry in Australia · « **Reply #41 on:** February 22, 2018, 11:01:53 PM »

Ahhh, dunno about that boys, the specs look close to my Megacycle 125/75 and while it was good at WOT, it was a sh1t street cam.............

slikwilli420 · « **Reply #42 on:** February 23, 2018, 04:12:09 AM »

Quote from: Terry in Australia on February 22, 2018, 11:01:53 PM

Ahhh, dunno about that boys, the specs look close to my Megacycle 125/75 and while it was good at WOT, it was a sh1t street cam.............

Not sure but it's the cam Kenny and Mike Rieck choose for my racer. I guess we'll see.

livefast_dieold · « **Reply #43 on:** February 23, 2018, 07:21:39 AM »

Since we are on the subject, DP315's absurd valve lash of 0.3 mm makes absolutely no sense to me.
What's the rationale behind changing valve lash to change performances?

PeWe · « **Reply #44 on:** February 23, 2018, 01:24:02 PM »

Quote from: Terry in Australia on February 22, 2018, 11:01:53 PM

Ahhh, dunno about that boys, the specs look close to my Megacycle 125/75 and while it was good at WOT, it was a sh1t street cam.............

125-75 has higher lift. Duration and overlap numbers are measured different, @ 0.04 lift vs 0.05" lift
Maybe 4 degrees can be subtracted on each for the Megacycle to come closer to 0.05" lift?
(I measured a cam (RC295 copy) at 0.04" lift and 0.05" and got about 4 degrees less at the higher lift.)
That gives 22/52 49/20
CX-11 19/57 62.5/22.5
Numbers can be balanced different by retarding the 125-75 or advancing CX-11 3 degrees, CX11 has still very different exhaust. Maybe for better cooling as KHD?

CX-11 reminds me about my Megacycle 125-20 cam I measured
Lift: 0,377 / 0,329 @ 0 lash
dur: 269/278 IN 30,5/ 58,5 EX:76/22 @0lash and 0.04 lift
(maybe 26.5/54.5 72/18 at 0.05"lift? This depends on how steep the cam lobes are)

@ 0.04" lift
125-75 .400 262 105 High performance street/road w/big 26/56 .005
.375 257 104.5 bore kit. Use racing pistons & 53/24 .005
springs. Mini sprint 3/8 and 1/4
mile. More top-end power than our
#125-65. Lobe clearancing needed

CX-11
VALVE LASH (INCH): .004" / .005"
VALVE LIFT (INCH): 0.385/ 0.330
DURATION @ 0.050: 256° / 265°
LOBE CENTER: 109° / 110°

INTAKE OPENS 19° BEFORE TDC
INTAKE CLOSES 57° AFTER BDC
EXHAUST OPENS 62.5° BEFORE BDC
EXHAUST CLOSES 22.5° AFTER TDC
VALVE TIMING IS CHECKED WITH ZERO VALVE LASH @ 0.050 INCHES OF VALVE LIFT.

CX-11 look interesting!
I'll also try less valve lash on my DP315, like half.
The hammering rockers might dent the lash caps on my valves?

754 · « **Reply #45 on:** February 24, 2018, 10:08:47 AM »

Did you try one ? I did and am more than happy.
It's not as loud as I expected either, I think part of the reasoning is better lubrication and perhaps a bit of cushioning.

PeWe · « **Reply #46 on:** February 24, 2018, 02:02:31 PM »

Yes, the DP315 has been running the recommended lash most of the time, 0.3mm blade is what I have (0.00118").
I started it today, idled maybe 2 minutes. First start since middle of October. Needed to burn up the old fuel in the carbs.

Terry in Australia · « **Reply #47 on:** February 24, 2018, 03:26:45 PM »

I wish I could find a nice "drop in" street cam like the one I installed in my K1 just before I swapped it for my RC51, pretty much same profile as the stock cam, but a couple more mm lift. It was in a box with some other CB750 parts I bought and was already bolted to it's cam sprocket, so I just dropped it in, and with the JMR head and Cruizin image 836cc kit, would happily lift the front wheel under hard acceleration, unlike the 125/75 which would bog down.

I had an Andrews street cam in my first K1 with stock everything, and it felt really nice too. Its a pity they only make Harley cams nowadays.

754 · « **Reply #48 on:** February 24, 2018, 04:13:08 PM »

Which Andrew's ? I put in an A last year after I came back from Dolores.
It sort of likes to be revved to be noticeable, it's flat under 3 K..
Must be me I don't rev the piss outa them anymore..like I used to
836 with the 315 was far more fun.

JoeCooley · « **Reply #49 on:** February 24, 2018, 04:18:21 PM »

Quote from: Terry in Australia on February 24, 2018, 03:26:45 PM

I wish I could find a nice "drop in" street cam like the one I installed in my K1 just before I swapped it for my RC51, pretty much same profile as the stock cam, but a couple more mm lift. It was in a box with some other CB750 parts I bought and was already bolted to it's cam sprocket, so I just dropped it in, and with the JMR head and Cruizin image 836cc kit, would happily lift the front wheel under hard acceleration, unlike the 125/75 which would bog down.

I had an Andrews street cam in my first K1 with stock everything, and it felt really nice too. Its a pity they only make Harley cams nowadays.

Maybe a DP295 or CX1 is what your looking for. Both seem to be good for low and middle grunt... 🤔

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Author Topic: different sleeves? (Read 13638 times)