ISKY cams
Le Mans Master
Joined: Oct 2010
Posts: 6,937
Likes: 848
From: melbourne florida
2023 C3 of the Year Finalist - Modified
flat tappet cams are ground with a taper to keep the cam in position making a button unnecessary . anything is possible, if its not needed leave it out.
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
Good morning
My quench is .060 because the pistons installed are sp 345 which has a height of 1.567
That puts my deck at .045, with a shim gasket, I end up with .060. they are flat tops with 4 reliefs. If you recall any of my previous posts, I have multiple issues. The cam going flat, the high cranking pres., oil drawn into the intake via pcv, the list goes on and on. My plan is to remove the engine, (1) check the cam with a degree wheel, could be installed wrong, (2) do a leak down test with the rockers removed so I can compare tdc and bdc leakage If that checks out, (3) look at the bearings for damage from crap floating around (4) new cam install and valve train. I did talk to strub, I got some delfi lifters from him, he suggested Isky. I'm beginning to ramble on an on so, One more question, the builder installed a cam button during assembly, is it needed for a flat tappet? If the cam can't float a little, could it cause the lifters not to rotate? Thanks guys (I'm getting a head ache)
My quench is .060 because the pistons installed are sp 345 which has a height of 1.567
That puts my deck at .045, with a shim gasket, I end up with .060. they are flat tops with 4 reliefs. If you recall any of my previous posts, I have multiple issues. The cam going flat, the high cranking pres., oil drawn into the intake via pcv, the list goes on and on. My plan is to remove the engine, (1) check the cam with a degree wheel, could be installed wrong, (2) do a leak down test with the rockers removed so I can compare tdc and bdc leakage If that checks out, (3) look at the bearings for damage from crap floating around (4) new cam install and valve train. I did talk to strub, I got some delfi lifters from him, he suggested Isky. I'm beginning to ramble on an on so, One more question, the builder installed a cam button during assembly, is it needed for a flat tappet? If the cam can't float a little, could it cause the lifters not to rotate? Thanks guys (I'm getting a head ache)
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
Anyone feel free to correct me if I'm wrong.
In the pic of that lifter the wear pattern appears to be dead center on the lifter.
Shouldn't the cam lobe ride slightly off center to aid in rotation of the lifter. The cam lobe also has a slight angle ground into it to do this as well IIRC.
hamck, it could be that you are correct, and the cam button prevented the cam from moving into the proper position to aid in rotating the lifter.
In the pic of that lifter the wear pattern appears to be dead center on the lifter.
Shouldn't the cam lobe ride slightly off center to aid in rotation of the lifter. The cam lobe also has a slight angle ground into it to do this as well IIRC.
hamck, it could be that you are correct, and the cam button prevented the cam from moving into the proper position to aid in rotating the lifter.
Thread Starter
Instructor
Joined: Jun 2014
Posts: 185
Likes: 10
From: S W pa. pa
I stopped in the shop when he was assembling it, I noticed the cam button. He told me that it would keep the timing steady, when the cam drifts , the timing fluctuates.
Only 4 lifters were like that, the rest were ok. I asked strub about just replacing the lifters, but he felt it would be a waste of time.
Only 4 lifters were like that, the rest were ok. I asked strub about just replacing the lifters, but he felt it would be a waste of time.
Thread Starter
Instructor
Joined: Jun 2014
Posts: 185
Likes: 10
From: S W pa. pa
Anyone feel free to correct me if I'm wrong.
In the pic of that lifter the wear pattern appears to be dead center on the lifter.
Shouldn't the cam lobe ride slightly off center to aid in rotation of the lifter. The cam lobe also has a slight angle ground into it to do this as well IIRC.
hamck, it could be that you are correct, and the cam button prevented the cam from moving into the proper position to aid in rotating the lifter.
In the pic of that lifter the wear pattern appears to be dead center on the lifter.
Shouldn't the cam lobe ride slightly off center to aid in rotation of the lifter. The cam lobe also has a slight angle ground into it to do this as well IIRC.
hamck, it could be that you are correct, and the cam button prevented the cam from moving into the proper position to aid in rotating the lifter.
Wouldn't the cam gear prevent the cam from going too far? Is the gear suppose to ride on the block surface? If not, then possibly the cam was in too far, lobe wasn't off center and the lifter didn't turn.
Le Mans Master
Joined: Apr 2006
Posts: 5,403
Likes: 95
So millions upon millions of engines built by GM, Ford, Chrysler, AMC, Studebaker there timing was fluctuating with no cam button they did it wrong for around 50 yrs. This man should have called them let them in on the secret. The cam is constantly sucked backwards on a flat tappet cam with the gear up against the block. Yes you can not make the cam go to far back. Roller cam lobes are flat nothing tugging on them backwards so they have a cam plate or cam button to keep the cam from moving forward.
Last edited by Little Mouse; Dec 15, 2014 at 08:19 PM.
Le Mans Master
Joined: Apr 2006
Posts: 5,403
Likes: 95
Hamck, You have already made two wise decisions you picked a cam with sort of middle of the road rate not real high intensity and you called straub and he sold you a good quality lifter. Stack the deck further in your favor buy using a spring that can work with less pressure. PAC american made behive. Its not like your running high RPM or a race cam where you may be forced into using a dual or triple spring.
Last edited by Little Mouse; Dec 16, 2014 at 11:15 AM.
Thread Starter
Instructor
Joined: Jun 2014
Posts: 185
Likes: 10
From: S W pa. pa
Hamck, You have already made two wise decisions you picked a cam with sort of middle of the road rate not real high intensity and you called straub and he sold you a good quality lifter. Stack the deck further in your favor buy using a spring that can work with less pressure. PAC american made behive. Its not like your running high RPM or a race cam where you may be forced into using a dual or triple spring.
The head spec. is 1.250 s 120 @ 1.700 / .510 max Are these Springs compatable with that cam??
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Le Mans Master
Joined: Apr 2006
Posts: 5,403
Likes: 95
Guess i have looked at more aggressive cams and the springs they need to long. Nice that you have a cam needs no more spring then that. The 1.250 size Dia. 120 seat are pretty good indicators those springs are for use with a flat tappet. What is the rate and the open pressure. Looks like more room then you need for your lift.
Last edited by Little Mouse; Dec 16, 2014 at 06:05 PM.
Thread Starter
Instructor
Joined: Jun 2014
Posts: 185
Likes: 10
From: S W pa. pa
Thanks for replying Little mouse
That's all the info. that came with the heads,1.25 dia. single/120#@ 1.7 installed /.510 max. There's a gadget to measure that right? maybe I could borrow one when the time comes. I got to get off my butt and get the motor out to start this adventure!!!
That's all the info. that came with the heads,1.25 dia. single/120#@ 1.7 installed /.510 max. There's a gadget to measure that right? maybe I could borrow one when the time comes. I got to get off my butt and get the motor out to start this adventure!!!
Le Mans Master
Joined: Dec 2003
Posts: 5,727
Likes: 38
From: Fremont CA
Give Harold Brookshire a call. 662-562-4933
Harold used to own UltaDyne Cams. He also designed cam profiles for just about every major cam company out there. This man knows camshafts!
Mr. Brookshire is a heck of a nice guy and will tell you exactly what you need for what you are trying to do. He is about 75 years old and likes to talk, so have an hour or so to spend if you call. You will be well educated when you hang up the phone!!
Harold used to own UltaDyne Cams. He also designed cam profiles for just about every major cam company out there. This man knows camshafts!
Mr. Brookshire is a heck of a nice guy and will tell you exactly what you need for what you are trying to do. He is about 75 years old and likes to talk, so have an hour or so to spend if you call. You will be well educated when you hang up the phone!!
Thread Starter
Instructor
Joined: Jun 2014
Posts: 185
Likes: 10
From: S W pa. pa
Guess i have looked at more aggressive cams and the springs they need to long. Nice that you have a cam needs no more spring then that. The 1.250 size Dia. 120 seat are pretty good indicators those springs are for use with a flat tappet. What is the rate and the open pressure. Looks like more room then you need for your lift.
open 285# Installed ht.1.700 Max lift .510 bind 1.17
The cam specs are 1.26 dia seat 115 (5 over) open 268 (17 over)
ht. the same 1.7 coil bind 1.160 Am i safe or do I need to change spring also?
Thanks
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
Cam Speced spring rate is #310, 115 seat, 268 open.
The Dart spring calculates to a spring rate of #324, #120 on seat.
285 open-120 closed =165
324 rate x .510 max lift=165.24
Springs will lose 10% many times by the time the cam is broke in anyway. You can take your heads in and have the open, seat, rate, max lift and coil bind checked but I bet they are <5% different across the board from the spec required for the cam.
Last edited by 63mako; Dec 22, 2014 at 09:36 PM.
Race Director
Joined: Nov 2002
Posts: 12,142
Likes: 54
From: Taylor Michigan
Has anyone checked the guide to retainer clearance.?....
It looks like, because the condition of the lifters there never checked as the cam grinders have never given me a bad cam, Appears just to be negligence by the installer.....
A lot of readers on the forum are worried about duration, lift, and springs and rollers..... ect and ect........
but whatever
It looks like, because the condition of the lifters there never checked as the cam grinders have never given me a bad cam, Appears just to be negligence by the installer.....
A lot of readers on the forum are worried about duration, lift, and springs and rollers..... ect and ect........
but whatever
Race Director
Joined: Dec 1999
Posts: 11,096
Likes: 990
From: Sierra Foothills CA
Give Harold Brookshire a call. 662-562-4933
Harold used to own UltaDyne Cams. He also designed cam profiles for just about every major cam company out there. This man knows camshafts!
Mr. Brookshire is a heck of a nice guy and will tell you exactly what you need for what you are trying to do. He is about 75 years old and likes to talk, so have an hour or so to spend if you call. You will be well educated when you hang up the phone!!
Harold used to own UltaDyne Cams. He also designed cam profiles for just about every major cam company out there. This man knows camshafts!
Mr. Brookshire is a heck of a nice guy and will tell you exactly what you need for what you are trying to do. He is about 75 years old and likes to talk, so have an hour or so to spend if you call. You will be well educated when you hang up the phone!!
with both posts. When I bought the solid flat tappet cam for my '69 427 (still running it and love it) Harold asked all the right questions about my situation and then proceeded to educate me for a good while. I only wish I could have understood and retained everything he said. What a nice guy and he gave me exactly what I was hoping for. It was one of the last cams made under the Ultradyne name. He was shut down within a week or two after I bought my cam.I sincerely hope he is OK.
Thread Starter
Instructor
Joined: Jun 2014
Posts: 185
Likes: 10
From: S W pa. pa
The Dart springs are going to be fine if they are in good condition. Checked Dart posted pressures vs speced pressures of the exact spring part # for cam.
Cam Speced spring rate is #310, 115 seat, 268 open.
The Dart spring calculates to a spring rate of #324, #120 on seat.
285 open-120 closed =165
324 rate x .510 max lift=165.24
Springs will lose 10% many times by the time the cam is broke in anyway. You can take your heads in and have the open, seat, rate, max lift and coil bind checked but I bet they are <5% different across the board from the spec required for the cam.
Cam Speced spring rate is #310, 115 seat, 268 open.
The Dart spring calculates to a spring rate of #324, #120 on seat.
285 open-120 closed =165
324 rate x .510 max lift=165.24
Springs will lose 10% many times by the time the cam is broke in anyway. You can take your heads in and have the open, seat, rate, max lift and coil bind checked but I bet they are <5% different across the board from the spec required for the cam.
Thank you all for your responces Merry Christmas !!!
Racer
Joined: Feb 2002
Posts: 378
Likes: 19
I've learned from working in a machine shop that when cam lobes go flat what happens is that the cam metal gets impregnated on to the piston skirts. It gets removed by glass beading the skirts.
So, IMHO, advise that one of the pistons be removed, mask off the ring lands and get it glass beaded, if bits of cam metal comes out of the skirts, then ask your machine shop about whether it's necessary to hone all the cylinders as well as, glass bead the rest of the pistons.
So, IMHO, advise that one of the pistons be removed, mask off the ring lands and get it glass beaded, if bits of cam metal comes out of the skirts, then ask your machine shop about whether it's necessary to hone all the cylinders as well as, glass bead the rest of the pistons.
Thread Starter
Instructor
Joined: Jun 2014
Posts: 185
Likes: 10
From: S W pa. pa
I've learned from working in a machine shop that when cam lobes go flat what happens is that the cam metal gets impregnated on to the piston skirts. It gets removed by glass beading the skirts.
So, IMHO, advise that one of the pistons be removed, mask off the ring lands and get it glass beaded, if bits of cam metal comes out of the skirts, then ask your machine shop about whether it's necessary to hone all the cylinders as well as, glass bead the rest of the pistons.
So, IMHO, advise that one of the pistons be removed, mask off the ring lands and get it glass beaded, if bits of cam metal comes out of the skirts, then ask your machine shop about whether it's necessary to hone all the cylinders as well as, glass bead the rest of the pistons.
Instructor
Joined: Jun 2014
Posts: 178
Likes: 3
From: Pensacola FL
I have found them in several hot rod engines I have rebuilt running flat tappet cams. I have never seen any indication that the button ever contacted the timing cover.
my theory is they were always hanging on the wall at the speed shops that sold the cam and were recommended. Not needed, but sold to the average weekend warrior that didn't know any better.
The same folks were told a big duration cam with a stock 8 to 1 compression 350 in a 81 Camaro would make big horsepower. It actually slowed the car down, but it dang sure sounded good. Go figure..