Specialist II camshaft specs.

[Robert Hellmer]

I have a brand new set of Specialist II performance camshafts. I have them and new springs and a head ported and clearanced for the camshaft swing, 33mm smoothbores. (3 1216cc 12to1 Spec II pistons) The parts list is a novel in itself. Anyway, I considered putting a fresh engine together (yes I have a complete, rebearinged, balanced, good cam chained, good second gear shift forked bottom end too). I bought these cams in something like 1983, I never installed them. I did remove them from the original package and of course lost the spec sheet for the cams. I would like an idea where to time them and what the recommended clearance should be.
I have 3 of the 1216 pistons here too, I suppose there's no hope of finding one such piston.
I found Spec II on the web. Turns out to be a RD/RZ specialized site. I will call there but I'm not holding my breath on their having 20 year old parts or specs.
Is there anyone out there who can help me?
Oh yea, I used the xs1100 engine in a small race car (mini sprint) so I have a chain drive set up here too. This set up opens up numerous opportunities, way more than my time (or wife) will allow.

Bob

[chevy45412001]

chain conversion

hook a man up were is it and how much? that is a hot topic here .many have wanted fat tires for the XS-XJ me included. any info on were to get or how to do it would be a god send.tia.

[Robert Hellmer]

I hadn't really considered selling it, the chain drive that is. I did build it, It uses a sprocket shaft and sprockets from a KZ. I don't know that I'd have time to build any right now. I'd have to remove it from the last engine it was on, out in the garage I think, I don't know I've got a few complete engines around. It would need to be duplicated, I just don't have the time right now. Sorry.

[pgg]

Robert, heres a spec sheet for a stock 78E inlet cam. Maybe it's of some use? Your hotted cams must have more lift and duration though.

lift dur open close runout - .0017
(btdc)

.002 428.5 204.2 44.3 abdc centreline .8 atdc
.006 352.9 165.7 7.3 abdc
.008 317.8 149.4 11.5 bbdc .050 lift c/l .6 atdc
.012 280.2 137.7 37.6 bbdc peak open acc .000696
.016 269.5 133.6 44.1 bbdc peak nose acc .000184
.020 263.7 130.9 47.2 bbdc peak close acc .000699
.040 247.1 122.9 55.8 bbdc lift @ tdc .3429
.050 241.0 119.9 58.9 bbdc
.200 162.8 80.8 98.0 bbdc
.250 131.0 64.9 113.9 bbdc
.300 89.2 43.9 134.7 bbdc
.343 - peak lift -

[Robert Hellmer]

Thanks,
I don't have the original stock specs, with the local cam guru we'll try to get something figured out. I guess I'm just as concerned about lash as I am timing. Like I said we'll try to figure something out.
These cams measure to have about .410 lift built into the cam. The base circle measures 1.105'' and heel to toe the cam measures 1.515''.
I'm going to try to get in touch with Spec II again today. I haven't been able to talk to anyone there yet. I haven't given up all hope there just yet.
It seems I've lived a whole lifetime since I shelved this project. My 78 has some 66000 miles on it. Unfortunately it's been sitting idle for probably the last 10 years (marriage, house, children.......). I lived on that bike (as much as one can in Wisconsin). My son is big enough to ride with me so it's time to resurrect old faithful. I don't really need a zoom motor right away but I'd like to put one together. This bike and I have been together since I found her in 1979.
I inherited a 1980 XJ too. I like the ergo's of the 80 but I've still got a soft spot for the old 78.

Thanks again,
Bob

[TopCatGr58]

Hey there Bob,

The only stock specs I can find in the Clymer's is Lobe Height, with Intake = 1.449" and Exh. =1.429", so with your 1.515" you're getting a 0.066" boost Int. and 0.086" with Exh. !
T.C.

[TopCatGr58]

I just did a search for "Camshaft timing" and found a thread started last year by Clarknobb from the UK, was asking about the cam timing specs, was told that the shop manuals didn't provide that info, he was very eager to find the info, but never posted back as to whether he found it or not. Chopper provides a great description on timing cams with slotted sprockets. Not sure if the Email addy to Clarknobb thru his profile will still work, might give it a try and ask if he found the info!?
T.C.

[Robert Hellmer]

Well, thanks for the reply.
I did the same and found a couple different links. There are several good explanations of cam timing, Comp cams has some useful information. This was still information more related to a single cam, not dual.
I don’t think a further education in camshafts 101 is going to hurt. I went into this with the pipe dream that someone might have purchased similar cams from Spec II and might be able to provide the necessary information. I did call Spec II only to find that they’re only open for a few hours each weekday. They open at 1:00 California time; I’ll try again today.
You know we used stock cams when we used the XS engine in the mini sprint. I changed the cam timing to provide more top end (I got the tuning information from a drag race buddy). I’d have to look into my feeble records to see if that meant tipping the cams together of tipping them further apart. That was what that simple information suggested. I do remember there had to be consideration given to crankshaft direction of rotation.
It was just too bad that oiling issues weren’t addressed before that old Yamaha got voted out and we went to the norm of a Suzuki GSXR engine. I never got one good, complete engine put together. I didn’t have time, we either ran lean or lacked oil pressure in the corners and woofed (there was a lack of communication between myself and the driver, seems he didn’t feel it necessary to tell me of the oil light being on in the corners until there were 3 engines hurt). I will tell you one thing; I will always wish we’d have gotten things figured out. Sure the old 2 valve would have never made the power of the 4 valves. It did have nice racetrack power. It pulled very well off the corners and pulled the length of the small ¼ mile track.

Sorry, there I got to rambling.
Thanks again,
Bob

[pgg]

Bob, your bike with ported head, hot cams, pistons and badass smoothbores is going to be a snarling monster. Yeah! I'd be serious about modifying the stock valve train components though. If your machine is going to rev that old heavy valvetrain over 9000 the friction and strain is going to be dicey for reliability.

The valves, springs and shims are gonna vibrate shudder and float like crazy. Inevitable something will give. I for one wouldn't like to risk an engine lockup at plus 140 mph. It wouldn't be thrilling! Powerpoles tend to be unforgiving to soft mushy humans!

On my hotted up 78E, I went with a set of later model stock XS11 cams to keep the extra grunt below 8500. Good on the road. The later model cams with less duration but extra exhaust lift. The performance 'gurus' told me the next stage would to increase the lift to around the .420 range for even more low down torque, but valve mods are needed.

They also said an increase in both duration and lift will give more top end power at the expense of low down torque loss. (not so good for the road) I wouldn't take any notice of the stupid claims coming from merriam cycles of 160 mph on stock gearing with stock engine components. In my opinion B.S. statements like that are misleading and dangerous for the uninitiated.

Good luck with your project.

[Robert Hellmer]

Well, these cams only lift .410. I would probably do what I could to keep the H.P. rpm down to a comfortable number, between 8500 and 9000. I discussed the lift with a drag racer friend, who builds his own KZ 1000 (13??cc) engines. He said the worries really started with lift of more than .430-.440. He said he used stock cam train components (other than springs) until he got to the .440 lift range. I do have the new aftermarket springs that I purchased with the cams. Thanks; I will try to be cautious.
By the way I helped my friend last night at the track. He qualified and dialed 9.15 - 9.17. It was an interesting evening. His is a drag bike right down to the 10’’ rear tire. Trouble with the fancy centrifugal clutch shortened the evening though, breaking a spring stud in the second round. I might be interested in making a pass or 2 just to say I did it but I don’t know if that whole scene is in my future. We’ll see.