The Ford Barn

aussie merc · 02-26-2017, 02:15 AM

wondering if any one has tried advancing the cam 1 tooth and whether the result was worth the effort talking to some old timers they recon it made them go better but had to be carefull what fuel you ran YOUR THOUGHTS

41LjH · 02-26-2017, 06:51 AM

I have also heard this, but from the flathead racing crowd. ON the 8BA the timing marks line up at 2 degrees advance to begin with so moving the alignment advances/retards even more.
The cam grind is also a factor. At best it is hit or miss and unless you have an adjustable timing light it will be very difficult to determine final timing.
I am finishing a 265 build with a H&M regrind Isky400 Jr.
I considered what you are asking but decided to go straight up.
Remember the racers aren't concerned with longevity on their engines

GOSFAST · 02-26-2017, 08:04 AM

Quote:

Originally Posted by aussie merc

wondering if any one has tried advancing the cam 1 tooth and whether the result was worth the effort talking to some old timers they recon it made them go better but had to be carefull what fuel you ran YOUR THOUGHTS

Wouldn't really recommend moving any cam one complete tooth but "degreeing" them in should always be checked.

We recently devised our own method for "moving" the Flathead cams a few degrees if necessary, uses the same setup including the "pills" as the SB & BB Chevy's.

Thanks, Gary in N.Y.

P.S. Takes a bit of machining but fairly simple. Here's a couple shots showing the finished pieces (I had placed these up here somewhere in a previous post)!

JWL · 02-26-2017, 08:24 AM

That would be a MAJOR change in cam timing. More than I have ever experimented with. Engine performance with a stock cam would be terrible. Probably ANY cam would reject such a change.

To see pictures of the cam gear drilling fixture and see the specific impact of a smaller cam timing change refer to my book "Flathead Facts" beginning at around page 75. I do not remember the numbers as I type this but even a smaller change was very noticeable.

rick r · 02-26-2017, 09:53 AM

In the 60's Hoerst Charlie sold a cam gear with several sets of mounting holes. This enabled you to advance the cam timing. We ran one on a flarhead powered Altered. Don't know if it helped, but was a good talking point.

Bored&Stroked · 02-26-2017, 10:05 AM

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That would result in over 16 degrees of advance at the crank - so 'No', that would make no sense.

360 / 44 = 8.18 x 2 = 16.36 crankshaft degrees of timing change per tooth

Also, cam grinders will tinker with how much 'advance' they put into various grinds - it is common in modern OHV times from many 'performance street cams' to have about 4 degrees of advance built into them (this makes up for timing chain slack).

Advancing a cam usually brings more lower RPM power, retarding usually moves the power band higher. Usually you're not moving a cam more than 2 - 4 degrees one direction or another. (I have specially drilled flathead cam gears that allow me to choose which set of bolts to use and how much to move it - either direction). Another way is to use offset cam gear 'bolt bushings' (which is not the way I like to do it).

With all that said, what is most important is to degree in the cam to figure out if it was ground correctly - and is even close to the timing tag. I've seen some cams from some big names - that were way off on timing (at the .050 number - which is where you usually measure). There are multiple ways to check/validate cam 'advance/retard' timing - the two most popular are the .050 method and the intake centerline method. In order to do this accurately you need a solidly mounted degree wheel (larger the better), a dial indicator and a good magnetic base:

2015-05-11 22.32.30 copy.jpg

Many of today's cam grinders will supply a timing tag that will tell you how they want the cam installed -- lots of times they will tell you what number they want on the 'intake centerline' - like 107 degrees. Just so you know the 'intake centerline' is not the same as 'lobe separation angle' - so don't get confused between the two. In order to know the LSA, you have to know the intake and exhaust centerline numbers - than divide by two.

Here is a simple document on some of this - one of the easier ones to understand:

CraneCams-Degreeing.pdf

Here is a timing tag for an Olds 455 roller cam I just had ground - notice the 107 degree number:

Bullet-RollerCam-TimingTag copy.jpg

Ol' Ron · 02-26-2017, 11:07 AM

During my early years running the stock car, I spent a great deal of time changing cams and advancing cams. Nothing worked as planned and the truth is: This only works when everything else it working right. There are to many variables affecting the operation of a car. I doubt that any change you make, won't be that notifiable, especially at part throttle. Where street engines spend 90% of their time. The only place I could see an improvement is at Bville, might gain a mile or two.

02-26-2017, 02:15 AM	#1
aussie merc Senior Member Join Date: Sep 2016 Location: sydney australia Posts: 1,030	changing cam timing wondering if any one has tried advancing the cam 1 tooth and whether the result was worth the effort talking to some old timers they recon it made them go better but had to be carefull what fuel you ran YOUR THOUGHTS

02-26-2017, 06:51 AM	#2
41LjH Senior Member Join Date: Dec 2011 Location: NW North Carolina Posts: 461	Re: changing cam timing I have also heard this, but from the flathead racing crowd. ON the 8BA the timing marks line up at 2 degrees advance to begin with so moving the alignment advances/retards even more. The cam grind is also a factor. At best it is hit or miss and unless you have an adjustable timing light it will be very difficult to determine final timing. I am finishing a 265 build with a H&M regrind Isky400 Jr. I considered what you are asking but decided to go straight up. Remember the racers aren't concerned with longevity on their engines __________________ 3 pedals, 3 gears, no valve-covers.. *Now THAT* is a hot rod** !! https://www.youtube.com/watch?v=ZmwwB34vxJE

02-26-2017, 08:24 AM	#4
JWL Member Emeritus Join Date: May 2010 Location: Fitzgerald, Georgia Posts: 2,204	Re: changing cam timing That would be a MAJOR change in cam timing. More than I have ever experimented with. Engine performance with a stock cam would be terrible. Probably ANY cam would reject such a change. To see pictures of the cam gear drilling fixture and see the specific impact of a smaller cam timing change refer to my book "Flathead Facts" beginning at around page 75. I do not remember the numbers as I type this but even a smaller change was very noticeable.

02-26-2017, 09:53 AM	#5
rick r Senior Member Join Date: May 2010 Location: Woodville Ontario Posts: 227	Re: changing cam timing In the 60's Hoerst Charlie sold a cam gear with several sets of mounting holes. This enabled you to advance the cam timing. We ran one on a flarhead powered Altered. Don't know if it helped, but was a good talking point.

02-26-2017, 10:05 AM	#6
Bored&Stroked Senior Member Join Date: Jan 2011 Location: Central Ohio Posts: 5,062	Re: changing cam timing Sponsored Links (Register now to hide all advertisements) That would result in over 16 degrees of advance at the crank - so 'No', that would make no sense. 360 / 44 = 8.18 x 2 = 16.36 crankshaft degrees of timing change per tooth Also, cam grinders will tinker with how much 'advance' they put into various grinds - it is common in modern OHV times from many 'performance street cams' to have about 4 degrees of advance built into them (this makes up for timing chain slack). Advancing a cam usually brings more lower RPM power, retarding usually moves the power band higher. Usually you're not moving a cam more than 2 - 4 degrees one direction or another. (I have specially drilled flathead cam gears that allow me to choose which set of bolts to use and how much to move it - either direction). Another way is to use offset cam gear 'bolt bushings' (which is not the way I like to do it). With all that said, what is most important is to degree in the cam to figure out if it was ground correctly - and is even close to the timing tag. I've seen some cams from some big names - that were way off on timing (at the .050 number - which is where you usually measure). There are multiple ways to check/validate cam 'advance/retard' timing - the two most popular are the .050 method and the intake centerline method. In order to do this accurately you need a solidly mounted degree wheel (larger the better), a dial indicator and a good magnetic base: 2015-05-11 22.32.30 copy.jpg Many of today's cam grinders will supply a timing tag that will tell you how they want the cam installed -- lots of times they will tell you what number they want on the 'intake centerline' - like 107 degrees. Just so you know the 'intake centerline' is not the same as 'lobe separation angle' - so don't get confused between the two. In order to know the LSA, you have to know the intake and exhaust centerline numbers - than divide by two. Here is a simple document on some of this - one of the easier ones to understand: CraneCams-Degreeing.pdf Here is a timing tag for an Olds 455 roller cam I just had ground - notice the 107 degree number: Bullet-RollerCam-TimingTag copy.jpg Last edited by Bored&Stroked; 02-26-2017 at 10:16 AM.

02-26-2017, 11:07 AM	#7
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,857	Re: changing cam timing During my early years running the stock car, I spent a great deal of time changing cams and advancing cams. Nothing worked as planned and the truth is: This only works when everything else it working right. There are to many variables affecting the operation of a car. I doubt that any change you make, won't be that notifiable, especially at part throttle. Where street engines spend 90% of their time. The only place I could see an improvement is at Bville, might gain a mile or two.