Problem with Cam purchased from Mike at FSPS?
- Thread starter Ronn
- Start date
Because the more feedback I can get the better. I put the cams side by side to compare and see no difference. What should be noticably different? I measured from the log to the tip of the lobe. Both are 5/16".
I'm about to take these both to my machine shop and have them measure it for lift and duration for me. I hope it's right but I doubt it.
I'm about to take these both to my machine shop and have them measure it for lift and duration for me. I hope it's right but I doubt it.
Maybe your right. This block was rebuilt fresh before I got it but where and how they got this cam that was in there is beyond me. It even has the yellow paint on one spot towards the back..they both have this paint....hmmm. Mike, did you ever send a cam to Rose Engine service in Dover Delaware? say about 5 years ago? If this is the case, then I want to know if I can send this new cam back and get it refunded or swapped for a full set of new valve springs? 80#?
How are you measuring lobe lift? With a ruler? You need to check lobe lift between the two cams with a dial indicator.
The difference in lobe lift between the stock cam, which could be .232", .240", .245", or.248", and the one you bought, can be as little as .054" and as much as .07" depending on which stock cam you have. In any case, measuring hundredths of an inch with a ruler and your eye is pretty tough to do. :roll:
You should confirm your measurements with precision tools first, then, if your new cam doesn't measure up, IMO, you really should contact Mike @ FSPP directly to resolve the issue and not air it out here.
The difference in lobe lift between the stock cam, which could be .232", .240", .245", or.248", and the one you bought, can be as little as .054" and as much as .07" depending on which stock cam you have. In any case, measuring hundredths of an inch with a ruler and your eye is pretty tough to do. :roll:
You should confirm your measurements with precision tools first, then, if your new cam doesn't measure up, IMO, you really should contact Mike @ FSPP directly to resolve the issue and not air it out here.
OK, went and bought a dial caliper. And I measured both. I measured the whole lobe from the back where the lifter rest at lowest position to tip of lobe.
Old cam measures; 1.523
New cam; 1.494
The measurement without the lobe tip is,
old cam; 1.281
new cam; 1.210
When I subtracted each I should have whats left over;
old cam; 242
new cam; 283
Number on new cam is bigger but meat on backside of lobe is smaller as noted by the side measurements. WHY? I don't get it. That 7 hundreths smaller than the old cam...would'nt this create slop at the rockers?
Old cam measures; 1.523
New cam; 1.494
The measurement without the lobe tip is,
old cam; 1.281
new cam; 1.210
When I subtracted each I should have whats left over;
old cam; 242
new cam; 283
Number on new cam is bigger but meat on backside of lobe is smaller as noted by the side measurements. WHY? I don't get it. That 7 hundreths smaller than the old cam...would'nt this create slop at the rockers?
Your cam lobes are also ground on a slight taper. This assists in the rotating motion of the lifters. They have a base radius equal to about 40". Doesn't sound much but check it. You'll be surprised. I'm not sure of the angle of this "matching" taper, but it will affect your measuring.
Only way to measure a cam in most situations is to slap it in a block with a NEW solid lifter and make sure your test pushrod and dial gauge are square to the lifter top.
One reason the base circles may be smaller on a performance cam is that lift = (lobe peak-base circle). Remember that the billets from which they're ground, are pretty standard. To achieve this extra lift, it is thus necessary to reduce the base circle. The alternative of larger lobes and corresponding base circles may produce a camshaft lobe too big for passing through the bearing shells during installation.
Does that make sense? I kind of typed it up in a hurry! :roll:
Cheers, Adam.
Only way to measure a cam in most situations is to slap it in a block with a NEW solid lifter and make sure your test pushrod and dial gauge are square to the lifter top.
One reason the base circles may be smaller on a performance cam is that lift = (lobe peak-base circle). Remember that the billets from which they're ground, are pretty standard. To achieve this extra lift, it is thus necessary to reduce the base circle. The alternative of larger lobes and corresponding base circles may produce a camshaft lobe too big for passing through the bearing shells during installation.
Does that make sense? I kind of typed it up in a hurry! :roll:
Cheers, Adam.
So basically they are offset? If so, then having them smaller would'nt be needed because the lobe tip is the highest point and so therefore it would always fit. I think I get what your saying but I'm still confused at the reasoning. Anyone have an equation that will use my numbers and give me a actual measurement?
geberally also when a cam is made the tip of the lobe can't extend farther than the bearing surface. So this means to increase the lift the base diameter has to be reduced.
Ronn, Adam is 100% correct on all measurments. The cam i got from Mike @ FSPP degreed in to perfection. Clay Smith products are quality. I would be very confident to just install the cam with one of Mikes adjsutable full roller timing chain & gear set.If you want more low end power advance the cam 2-4 degrees. I f you want more midrange just intall it straight up. Don't even waste your time measuring it, just put the cam in & you will smile when you floor the throttle. William
OK, another question..since the new cams base is 70 thou smaller..this means I could mill the head 75 thou and it would be back to stock tightness at the rockers with 5 thou to take up any slack and at the same time giving me the 9.2 CR I want right? This is a 76 250 block with a 75 head.
I was talking to a guy at Clifford the other day while I ordered the port divider for my head, and he swears that the dual pattern cam is a mistake in the ford sixes. He says that with a dual pattern the engine won't start making power until about 1800rpm. He says that dual pattern cams are Vee Eight appropiate but not for the straight sixes.
I know that clifford sells cams, so that may have a bearing on his claims, but I'm a tad bit concerned as my dual pattern 264/274 112* and dual roller timing set was just put in the mail from FSSP. Now I'm wondering if I should have stayed with a single pattern.
I'm going to be using a 1979 head milled down to bring up the CR, and plan on replacing it with one of the alloy heads when the dust settles latter this year. Is that dual pattern going to give me the low end torque that I need with a big log head?
Thanks,
Kris
I know that clifford sells cams, so that may have a bearing on his claims, but I'm a tad bit concerned as my dual pattern 264/274 112* and dual roller timing set was just put in the mail from FSSP. Now I'm wondering if I should have stayed with a single pattern.
I'm going to be using a 1979 head milled down to bring up the CR, and plan on replacing it with one of the alloy heads when the dust settles latter this year. Is that dual pattern going to give me the low end torque that I need with a big log head?
Thanks,
Kris
I can understand his apprehension, William. You've got years of experience; I've learned the hard way over five or six years and Ronn's just getting a grip on the sixes. Plus we regularly beat on manufacturers and their products!
It would be good to dial the cam, even if treating it as self-instruction. Another diagnosis skill for whenever it may be needed!
Regards, Adam.
It would be good to dial the cam, even if treating it as self-instruction. Another diagnosis skill for whenever it may be needed!
Regards, Adam.
Lift is a function of the difference in the base circle and the lobe. It's entirely possible to have a smaller lobe on a higher lift cam.
LameHoof65
Famous Member
This is where I start questioning my knowledge and understanding. I am getting ready to get into this cam/rocker-&- milling the head deal and I have posted on this a couple of times. Seems there may be some reluctance to give opinions on this and I think I can reason why---This is the place we get too--where all the variables of performance intersect, literally! Tolerances and degrees get pretty specific to the individual and his engine. So, as a novice maybe you all can help me out by letting me detail how to get to making that critical decision and confirm whether I have a handle on it or not:
1) Know your piston to deck clearance
2) Know your compression at that deck clearance
3) Know where you want your power range
4) Know what your induction is and will be in the future
(for me I am doing the dual pattern cam in hopes it will allow me to use a turbo later, my understanding is dual pattern will give a more smooth or regular pulse.....kind of like equipping for better (pulse-timing).
5) Use the double roller timing chain (easier to set because of incremental placement keys on the crank??, billet steel is stronger and less likely to break, and it will not loosen up as readily???
6) Cam and Rocker Arm must match relative to piston deck clearance
Please if I have left anything out here let me know--I don't mind criticism, especially when it means I may seriously mess up my engine. And one more question---what difference does it make regarding dual pattern cams and whether it is a 6 or an 8?? I have heard others mention this
but they can never give me a firm basis for that opinion.
1) Know your piston to deck clearance
2) Know your compression at that deck clearance
3) Know where you want your power range
4) Know what your induction is and will be in the future
(for me I am doing the dual pattern cam in hopes it will allow me to use a turbo later, my understanding is dual pattern will give a more smooth or regular pulse.....kind of like equipping for better (pulse-timing).
5) Use the double roller timing chain (easier to set because of incremental placement keys on the crank??, billet steel is stronger and less likely to break, and it will not loosen up as readily???
6) Cam and Rocker Arm must match relative to piston deck clearance
Please if I have left anything out here let me know--I don't mind criticism, especially when it means I may seriously mess up my engine. And one more question---what difference does it make regarding dual pattern cams and whether it is a 6 or an 8?? I have heard others mention this
but they can never give me a firm basis for that opinion.
Ok, just to let yall know...in no way shape or form did I intend to say I was ripped off by Mike. I guess it sounded that way and well, looked that way too but I'm kinda new to this and was concerned. If I offended anyone , I'm sorry. I just need to understand all this really well. I need to learn and want this to be a beast of an engine when done. And knowing that the cam/head/carb is what really determines the flow you get well..it starts with the cam. The way the 2 measured just threw me. it does'nt look right..maybe it is. I'm none the wiser, thats why I ask. So please don't mis-understand me, I meant no harm. Sorry Mike and those working with him.
I still need help understanding if anyones willing to write a book on it here. I have ordered the falcon six guide from Mike so I can't wait for that.
I still need help understanding if anyones willing to write a book on it here. I have ordered the falcon six guide from Mike so I can't wait for that.
i believe that Crane Cams has a good FAQ section
someone here linked to a cam manufacturer's FAQ and said it did a great job of explaining it, so maybe that'll help
http://cranecams.com/?show=faq&id=2
someone here linked to a cam manufacturer's FAQ and said it did a great job of explaining it, so maybe that'll help
http://cranecams.com/?show=faq&id=2
A
Anonymous
Guest
No wrong intent taken...understand you were just asking questions.
Steve-O
Steve-O
WhitePony":1mvuexjp said:
I think you hit the target...Clifford doesn't sell dual pattern. I've never heard anything from any reputable engine builder that dual pattern is a mistake on 6's. Why would they be good for one and not the other. All engines operate on the same basic principle.
I think Clifford is really fighting hard to regain lost customers on the Ford six market, so they say things about products they don't carry, and promise products that never seem to materialize (Aluminum head anyone?)
Slade
