I hadn't actually thought about the firing order, but I figured Theoretically at lest the lobes should be Oversize that that they can be ground down to profile desired by the designer...
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Cams & cam regrind discussion as a performance adder
- Thread starter buddy
- Start date
I hadn't actually thought about the firing order, but I figured Theoretically at lest the lobes should be Oversize that that they can be ground down to profile desired by the designer...
randomid25
Rattle-Trap Cap'n
Excellent point. I forgot the LSX engines shared the same firing order. Whats even cooler is that, according to all data, the LS series engines also have the same cam journal size as the 6.2/6.5. The 6.5 uses an undersized journal on the number 5 bearing that the lsx doesn't share but that could be dealt with easily with a few minutes on a lathe. If someone could get their hands on a cam from both engines, we could find out for sure if lsx cam blanks would be compatible with the idi diesels. We need measurements of overall length, seperation of the cam journals, lobe width, etc.
3500GMC
What T F, over
So the LSX cam shares the same journal size? Exact? What about the length?
Hmmm. This could be a first for a wildcat cam experiment.
You saw it here first...:thumbsup:
Hmmm. This could be a first for a wildcat cam experiment.
You saw it here first...:thumbsup:
randomid25
Rattle-Trap Cap'n
I just remembered that the LS series engines are all distributorless. There would be nothing on the end of the camshaft to drive the oil pump. The ls engines use a gerator style oil pump that's crank driven.
iamdave0887
Here Comes Chaos.....
Wow. Talk about not knowing any of the story at all and spinning it totally into the wrong direction. I've sent you a PM with the truth Jim, as i don't want to air it on the open forum and dilute this thread any.
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turbonator
Member
x-2 dave... when i seen this, i almost posted but i just let it go.... it is not my place to air somebodys dirty laundry...
3500GMC
What T F, over
Ah, no gear... Oh well. Getting a reliable pump drive setup would be tough. Unless one were to get crazy and go dry sump, with an external pump. A lot of detours just to get a cam that 'might' work...
randomid25
Rattle-Trap Cap'n
My thoughts as well.
buddy
Active Member
Here are the specs of the grind I got. I am not in any way recommending it, as it will have piston interference without some other modifications. I did not want to get it as big as it is, but to get the lift I wanted had to use longer duration. thats where a billet could be made superior. I got the specs I wanted at TDC, and settled on what it gave me around BDC to give it a try unless I could get a billet. I have custom Rhoads lifters that will decrease lift and duration a little at low RPM, and reach max lift/duration around 3000rpm.
Lobe Separation: 111
Lobe Centerline: intake 106, exhaust 116
Duration @ .05" lobe lift
intake: 202 w/ 0.297" lift
exhaust: 220 w/ 0.297" lift
Cam Timing @ .05" lobe lift
intake open: 5 ATDC
intake close: 27 ABDC
exhaust open: 46 BBDC
exhaust close: 6 BTDC
Ground in advance: 5 degrees
I actually wanted a tad more lift on the lobe, but best I could get on a grind. And I could have used about 10 degrees less on the intake valve closing after bottom dead center (ABDC), and maybe a couple less on the exhaust valve opening BBDC, which it was supposed to be 2 degrees less than I ended up with but the guy said the lobes were so big thats the closest he could get it. It cost $160 to grind and ship it back, plus the $15 or so to send to him.
I would like to use 1.6 ratio roller rockers with some new springs but havent picked these components yet or how to get them on the head. If peninsular offers a bolt on application with 1.6 ratio rockers then I wont have to worry about how to do it I guess and have to select a set of springs. It would be nice if the rockers had the pushrod adjustment. Looks like they cut about 0.3" off the lobe diameter to get the lift, so I may need 0.15" longer pushrods if not an adjustable rocker.
Lobe Separation: 111
Lobe Centerline: intake 106, exhaust 116
Duration @ .05" lobe lift
intake: 202 w/ 0.297" lift
exhaust: 220 w/ 0.297" lift
Cam Timing @ .05" lobe lift
intake open: 5 ATDC
intake close: 27 ABDC
exhaust open: 46 BBDC
exhaust close: 6 BTDC
Ground in advance: 5 degrees
I actually wanted a tad more lift on the lobe, but best I could get on a grind. And I could have used about 10 degrees less on the intake valve closing after bottom dead center (ABDC), and maybe a couple less on the exhaust valve opening BBDC, which it was supposed to be 2 degrees less than I ended up with but the guy said the lobes were so big thats the closest he could get it. It cost $160 to grind and ship it back, plus the $15 or so to send to him.
I would like to use 1.6 ratio roller rockers with some new springs but havent picked these components yet or how to get them on the head. If peninsular offers a bolt on application with 1.6 ratio rockers then I wont have to worry about how to do it I guess and have to select a set of springs. It would be nice if the rockers had the pushrod adjustment. Looks like they cut about 0.3" off the lobe diameter to get the lift, so I may need 0.15" longer pushrods if not an adjustable rocker.
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Woody35
Active Member
let us know how it goes.
buddy
Active Member
The only thing I really wanted was more lift and bring the valve events closer to TDC, and open the exhaust valve a tad earlier. I Reduced the negative overlap to just -11 degrees, vice stock is about -22 degrees.
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3500GMC
What T F, over
It'd be super if you could get it to the dyno before and after...
I mapped a late 80's 6.2 cam but it was done @ .006 lift. I did observe a .281 lobe lift and a LSA of 111.., which happens to be the same as a '93 6.5. It would appear that the grinders took .016" from the heel of your cam. You should net .446" lift with your grind.
Definitely get out the clay and test valve springs and check out the valve clearence.
I mapped a late 80's 6.2 cam but it was done @ .006 lift. I did observe a .281 lobe lift and a LSA of 111.., which happens to be the same as a '93 6.5. It would appear that the grinders took .016" from the heel of your cam. You should net .446" lift with your grind.
Definitely get out the clay and test valve springs and check out the valve clearence.
buddy
Active Member
It will be a while before I have this put together, and since it will be a whole new build with other mods, wont really be able to do a before and after, but if it runs good when its done I would get it dyno'd.
On this grind, the duration at .006" lobe lift is intake: 260; exhaust: 274
On my grind sheet the lobe diameters of the intake and exhaust is listed as 1.8" and then below it, is written 1.5" and I went to measure and the base diameter is 1.5" now, so to get the higher lift and the duration and smooth it out right I guess they took off 0.3" diameter, unless I am misreading the sheet. Do you have a bace circle diamater measurement of the stock camshaft? Or maybe someone could measure it if they have one laying around?
Its odd that stock lobe lift is 0.281 but I have seen the valve lift referenced as 0.40x" in a few places. Thats what CIL6 measured his as, and a site I have for spring compression from closed to open is only 0.4", and I'd swear I have seen it referenced elsewhere as well. So I suppose there is some imperfect translation from lobe lift multiplied by the rocker ratio, with a loss just under 0.02", from rocker deflection or lifter compression or otherwise.
I already know there is valve interference using stock pistons and compression ratio. Thats why I intend to machine valve reliefs into the pistons, which will also drop the CR to about 19:1 with the depth of reliefs about 0.07". Thats about 1/16". It will look kind of like Kennedy's low compression pistons, but just circular spots blended in. Together with the valve drop at TDC of about 0.055" should give me the clearance at TDC while the valves are closing and opening, and a bit of margin for a lagging exhaust valve with the approaching piston. At 0.05" lobe lift and 1.6 ratio rocker my theoretical lift at 6 BTDC will be 0.08", and I just consider 6 BTDC to be TDC, with the crank journal and connecting rod at its peak and turing over to the other side to begin going down. About 10 degree sway there at TDC. The .055" valve drop plus a 0.07" relief being 0.125" of space for the valve at TDC.
The valve drop CIL6 measured was about .056", but I have specs that the valve is supposed to be recessed in the head about 0.042", and with a .045" gasket squished down a little, valve drop should be at least 0.055", but maybe a little more closer to 0.07" itself for a tad more clearance. That is with a piston protruding about .005" out of a standard deck.
On this grind, the duration at .006" lobe lift is intake: 260; exhaust: 274
On my grind sheet the lobe diameters of the intake and exhaust is listed as 1.8" and then below it, is written 1.5" and I went to measure and the base diameter is 1.5" now, so to get the higher lift and the duration and smooth it out right I guess they took off 0.3" diameter, unless I am misreading the sheet. Do you have a bace circle diamater measurement of the stock camshaft? Or maybe someone could measure it if they have one laying around?
Its odd that stock lobe lift is 0.281 but I have seen the valve lift referenced as 0.40x" in a few places. Thats what CIL6 measured his as, and a site I have for spring compression from closed to open is only 0.4", and I'd swear I have seen it referenced elsewhere as well. So I suppose there is some imperfect translation from lobe lift multiplied by the rocker ratio, with a loss just under 0.02", from rocker deflection or lifter compression or otherwise.
I already know there is valve interference using stock pistons and compression ratio. Thats why I intend to machine valve reliefs into the pistons, which will also drop the CR to about 19:1 with the depth of reliefs about 0.07". Thats about 1/16". It will look kind of like Kennedy's low compression pistons, but just circular spots blended in. Together with the valve drop at TDC of about 0.055" should give me the clearance at TDC while the valves are closing and opening, and a bit of margin for a lagging exhaust valve with the approaching piston. At 0.05" lobe lift and 1.6 ratio rocker my theoretical lift at 6 BTDC will be 0.08", and I just consider 6 BTDC to be TDC, with the crank journal and connecting rod at its peak and turing over to the other side to begin going down. About 10 degree sway there at TDC. The .055" valve drop plus a 0.07" relief being 0.125" of space for the valve at TDC.
The valve drop CIL6 measured was about .056", but I have specs that the valve is supposed to be recessed in the head about 0.042", and with a .045" gasket squished down a little, valve drop should be at least 0.055", but maybe a little more closer to 0.07" itself for a tad more clearance. That is with a piston protruding about .005" out of a standard deck.
ak diesel driver
6.5 driver
be interesting to see Bill's specs
Woody35
Active Member
will he include it with the purchase of the cam? It would be nice to know if you plan on modifying the pistons or heads.
turbonator
Member
X-2.....
Mike K3500
Member
I had quite a lengthy, in depth conversation with Bill last night... He has had these cams around for quite a while but just never thought the interest would be there for them. After the info / knowledge gained from him, I am probably going to be making another purchase before too long.... AND of course, some more re-work.
Mike
Mike
turbonator
Member
do you think anyone gets dizzy doing 180* turn-arounds?.....
http://www.thetruckstop.us/forum/sh...formance-adder&p=322920&viewfull=1#post322920
i wonder why it did not work then, but works now?
http://www.thetruckstop.us/forum/sh...formance-adder&p=322920&viewfull=1#post322920
as long as people have money to spend, there will be stuff to buy....
Mike K3500
Member
Yes I am aware of getting dizzy doing turnarounds.. I just don't like rework, kinda a perfectionist in some ways, just like to go the extra mile and do things right and once.
Are you saying that you don't have faith in these cams ??.. I guess I'm just not understanding the point of the statement of it "not working then, but does now", unless I have missed something. I don't think I have read anything that Bill has posted about it working well or not working well, just second or third hand stuff posted on the forums. From what I had gathered from talking to him last night was both his towing (HT-3) and his higher performing (HP-4) were both better all around in all aspects with no ill side effects, very smooth idle, more power, better fuel economy. The HT cam being stronger to maybe 3,000 rpm then stock and the HP cam working well to 4,800 RPM. Bill did recommend the HP cam for my application and says I would see a significant increase over the stocker, but says I would really notice the difference if I could get my pump governed another 1,000 rpm higher (the tag on it now says 3,600).
I do like to spend money.. it gets moldy if it sits around too long and you cant take it to the grave with ya. Not to mention, this will probably be one of my last vehicle projects so I want it to count a lil.
turbonator
Member
i am not pointing at you, just stating that it did not work for him last year, and the gains were no better than stock, so why does it work now? i am saying it is kinda wierd the coincidence that it just popped up now.... cams have been talked for years, so there was a market then.... how long did he say he has been "sitting" on them? 2 months, 5 months, 10 years....?