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Author Topic: Camshaft ID  (Read 2959 times)

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Offline mick7504

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Camshaft ID
« on: October 09, 2009, 11:29:48 PM »
I pulled this from a motor that had been sitting around for ever and a day and was wondering if anyone would know what this cam might be from the stamping on the end. (SM369)
The lobe lift on the intake and exhaust measures 1.415".
[IMG]http://i582.photobucket
This motor has had some reasonably extensive work done to it at some stage of it's life and I am suspecting that it may have spent some time on the strip.
« Last Edit: October 10, 2009, 06:30:49 AM by mick7504 »
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Offline Jerry Rxman Griffin aka MuthaF'er

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Re: Camshaft ID
« Reply #1 on: October 10, 2009, 09:41:45 AM »
Don't know but that mofo sure has some serious duration!
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Offline mick7504

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Re: Camshaft ID
« Reply #2 on: October 10, 2009, 05:31:44 PM »
Thanks Jerry - It certainly is a lumpy one.
It remains a mystery as to what it is and where it originated from so I think the only way is to dial it up and get some sort of a reference on it.
The crank has been lightened, pistons are 67mm with stock rods bored to take 16mm pins.
Pretty certain that the pistons are early 70's CB360.
The head has been opened right up internally and shaved down to it's limit - or not too far from it and the fins have been ground away around the exhaust ports to take some big OD header pipes.
The motor is a K1 and has been in storage for many years complete with wasp nests.
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Offline 754

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Re: Camshaft ID
« Reply #3 on: October 10, 2009, 07:06:35 PM »
To me it looks  builtup or hardfaced? that should narrow it down a bit..
 Had a mystery cam years ago, very revvy, nothing down low.. >: marked Luther I think?
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Offline mick7504

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Re: Camshaft ID
« Reply #4 on: October 10, 2009, 09:53:27 PM »
Quote from: 754 on October 10, 2009, 07:06:35 PM
To me it looks  builtup or hardfaced? that should narrow it down a bit..
 Had a mystery cam years ago, very revvy, nothing down low.. >: marked Luther I think?
Yes it has been welded and reground.
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Offline Ace

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Re: Camshaft ID
« Reply #5 on: October 10, 2009, 11:40:26 PM »
Since it is in Oz, one of the only cam grinders that I know of to stamp 369 into the end was Ivan Tighe.  Can't help you with the SM.  The 369 grind will be an interesting choice of good top end power.  I'm about to put the Ivan Tighe 369 cam in my engine......when it goes back together.
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Offline mick7504

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Re: Camshaft ID
« Reply #6 on: October 11, 2009, 12:05:15 AM »
Quote from: Ace on October 10, 2009, 11:40:26 PM
Since it is in Oz, one of the only cam grinders that I know of to stamp 369 into the end was Ivan Tighe.  Can't help you with the SM.  The 369 grind will be an interesting choice of good top end power.  I'm about to put the Ivan Tighe 369 cam in my engine......when it goes back together.
Thanks for that info.
That sheds a bit of light on the "mystery"
I'll contact Tighe Cams and ask if they can confirm anything.
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Offline mick7504

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Re: Camshaft ID
« Reply #7 on: October 11, 2009, 09:31:38 PM »
Tighe Camshafts said that this is one of theirs from way back.
He said the grind is a factory HRC and would be streetable with a big bore.
Lift - .370
Ex - 6636
In - 3659
I don't know what these last 2 figures relate to ???
Does anyone have any clues about this or is it another weird terminology that leaves the mind wondering??

Mick
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Offline Jerry Rxman Griffin aka MuthaF'er

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Re: Camshaft ID
« Reply #8 on: October 11, 2009, 11:55:19 PM »
660/360 & 360/590 are opening and closing degrees that tell you when/at what position the valves open & close and give you the measurement of duration.

Number wise and appearance wise that is a seriously long duration cam that keeps the valves open extremely long allowing more time to fill the chambers. You can have only so much valve lift (before you lift valves into pistons) to fill chambers then you have to increase duration of valve opening to increase filling/emptying. Probably more important for BIG bore 750 engines. Of course one other method of increasing flow is larger valves and porting.  

I don't think I'm a cam guru and there are better guys here. Any thoughts from you cam gurus? Correct me if I'm wrong.  
« Last Edit: October 11, 2009, 11:59:16 PM by Jerry Rxman Griffin »
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Offline mick7504

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Re: Camshaft ID
« Reply #9 on: October 12, 2009, 12:07:39 AM »
Thanks for that Jerry.
It is starting to make a bit of sense to me now.
The guy who I spoke to spun these numbers off and went.
He was helpful and knowledgable for sure but he left me right at the back of the pack with this one.
You've been a great help.
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Offline Ace

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Re: Camshaft ID
« Reply #10 on: October 12, 2009, 03:54:31 AM »
Mick7504, I'm putting that cam in my big bore F2 engine, port and polished head.  I do have problems with valve to piston clearance do due a few different reasons.  I dialed in the cam the other day and thought the 59 degree was out, more like 66 degrees.  Can't remember now it was over a week ago and I was more concerned about the .021' clearance I had left.  All I need now is a dial gauge to find out a bit more accurately how much clearance I do have.

What engine are you going to put it in if any?
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Offline mick7504

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Re: Camshaft ID
« Reply #11 on: October 12, 2009, 05:40:15 AM »
The guy I was speaking to at Ivan Tighe's said to run this cam with .012 > .014 clearances.
The pistons that were pulled from this motor had been intersecting with the valves and the head had previously been shaved right down to the max.
These pistons I am fairly sure are CB360 pistons (ART) with 16mm pins and no offset on the valve pockets.
The stock rods had been bored to accomodate the larger pins.
Initially the plan was to rebuild with 67mm RC pistons but this cam got the better of me not knowing what it's behaviour would be.
In the meantime the idea is to run it with some 72mm MTC pistons when time allows and see what happens then.
The picture shows the 67mm ART piston at the front, the RC 67mm on the right rear and the MTC next to it.
Mick
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Offline Ace

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Re: Camshaft ID
« Reply #12 on: October 12, 2009, 02:37:26 PM »
Quote from: mick7504 on October 12, 2009, 05:40:15 AM
The guy I was speaking to at Ivan Tighe's said to run this cam with .012 > .014 clearances.
The pistons that were pulled from this motor had been intersecting with the valves and the head had previously been shaved right down to the max.
These pistons I am fairly sure are CB360 pistons (ART) with 16mm pins and no offset on the valve pockets.
The stock rods had been bored to accomodate the larger pins.
Initially the plan was to rebuild with 67mm RC pistons but this cam got the better of me not knowing what it's behaviour would be.
In the meantime the idea is to run it with some 72mm MTC pistons when time allows and see what happens then.
The picture shows the 67mm ART piston at the front, the RC 67mm on the right rear and the MTC next to it.
Mick
I'm checking those figures today so will hopefully see if those clearances 0.12 and 0.14 are correct.  Those would be the valve lash.
I've also got a different valve lift of .385/.385.  I'm running 67mm pistons.
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Offline mick7504

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Re: Camshaft ID
« Reply #13 on: October 12, 2009, 04:18:16 PM »
Ace
Just an update on those figures I posted last night.
I was running on memory then and should've known better!!
At work now with them in front of me.
Intake - .012"
Exhaust - .010"
Lift is .370"
Measurements are taken at .040" (1mm) lift.
Hope this helps.
Contact details if you need more info on this one - www.tighecams.com.au/
Mick
« Last Edit: November 02, 2009, 01:33:12 AM by mick7504 »
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Offline bryanj

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Re: Camshaft ID
« Reply #14 on: October 13, 2009, 08:13:04 AM »
On an asside rather than try and measure a 40 thou gap one full turn of the adjuster screw is 1mm or 40 thou
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Offline mick7504

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Re: Camshaft ID
« Reply #15 on: October 13, 2009, 07:38:30 PM »
Quote from: bryanj on October 13, 2009, 08:13:04 AM
On an asside rather than try and measure a 40 thou gap one full turn of the adjuster screw is 1mm or 40 thou
Good one.
I had never thought about it that way before.
It's amazing how the mind thinks along one set of tracks sometimes. (Old habits)
If the thread pitch is 1mm it makes perfect sense.
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