Author Topic: Street engine cam timing  (Read 3838 times)

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allrightmike

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Street engine cam timing
« on: November 10, 2019, 10:35:48 AM »
   Is it still common practice to set cam timing one or two degrees advanced for
a street use engine to allow for a bit of chain stretch or just to pump up low end torque?


Mike.

plovett

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Re: Street engine cam timing
« Reply #1 on: November 10, 2019, 10:57:10 AM »
Most cams have advance ground into them and you don't need to advance further unless that is what your engine and combination like best.   There is no rule, but most cams have about 4 degrees advance already, if you install dot to dot and check to make sure it is accurate by degreeing the cam.

I think chain stretch is a misnomer as the chain doesn't exactly stretch, but rather the links wear and the timing can be affected by that.

So, in my opinion no, you don't need to advance most cams a couple of degrees for chain stretch.   Just make sure it is where you want it, preferably degreed with a degree wheel.

JMO,

paulie

plovett

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Re: Street engine cam timing
« Reply #2 on: November 10, 2019, 11:00:34 AM »
Also, if you degree the cam make sure you have the chain tight when make measurements.  That is, you have turn the engine over in the direction in normally turns until you get to your measuring point.  That keeps the chain taut and makes the measurements more accurate.  If you don't do that the chain will be loose and the measurements will be off. 

paulie

plovett

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Re: Street engine cam timing
« Reply #3 on: November 10, 2019, 11:46:07 AM »
It depends on the combination, too.  If you have a big cam and low compression, you might advance the cam to get some low rpm power back.  If you have a small cam and high compression, you might retard the cam to prevent detonation.  That is just a start.

So no definitive answer, especially without specific information about the combination and cam spec's, but just for chain stretch, I still say no.

JMO,

paulie
« Last Edit: November 10, 2019, 11:57:31 AM by plovett »

blykins

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Re: Street engine cam timing
« Reply #4 on: November 10, 2019, 12:40:09 PM »
Depends on the entire combo.  Sometimes I’m 6-8 degrees advanced, sometimes I’m straight up, sometimes I’m a few degrees retarded.

I would like to point out that there’s a lot of “internet standards” that are wrong...for instance, advanced cam timing does not always cut top end and retarded cam timing doesn’t always make more top end.
Brent Lykins
Lykins Motorsports
Custom FE Street, Drag Race, Road Race, and Pulling Truck Engines
Custom Roller & Flat Tappet Camshafts
www.lykinsmotorsports.com
brent@lykinsmotorsports.com
www.customfordcams.com
502-759-1431
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cjshaker

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Re: Street engine cam timing
« Reply #5 on: November 10, 2019, 02:09:45 PM »
Sometimes I’m 6-8 degrees advanced, sometimes I’m straight up, sometimes I’m a few degrees retarded.

I'm several degrees retarded. That's what my parents told me when they had me tested... ;D
Doug Smith


'69 R-code Mach 1, 427 MR, 2x4, Jerico, 4.30 Locker
'70 F-350 390
'55 Ford Customline 2dr
'37 Ford Coupe

blykins

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Re: Street engine cam timing
« Reply #6 on: November 10, 2019, 02:16:08 PM »
Sometimes I’m 6-8 degrees advanced, sometimes I’m straight up, sometimes I’m a few degrees retarded.

I'm several degrees retarded. That's what my parents told me when they had me tested... ;D

Yeah, I had a double entendre when I wrote that too lol
Brent Lykins
Lykins Motorsports
Custom FE Street, Drag Race, Road Race, and Pulling Truck Engines
Custom Roller & Flat Tappet Camshafts
www.lykinsmotorsports.com
brent@lykinsmotorsports.com
www.customfordcams.com
502-759-1431
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plovett

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Re: Street engine cam timing
« Reply #7 on: November 10, 2019, 05:18:37 PM »

I would like to point out that there’s a lot of “internet standards” that are wrong...for instance, advanced cam timing does not always cut top end and retarded cam timing doesn’t always make more top end.

I said you might advance the cam to gain some low end.   I didn't say it is always that way.   I would bet 90% of the time in 90% of applications it is true, though.  Until you advance it too far.   How far is too far?  LOL!   

JMO,

paulie

plovett

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Re: Street engine cam timing
« Reply #8 on: November 10, 2019, 05:19:54 PM »
My cam has a 108 degree centerline and the intake centerline is right around 105 degrees.   Is that right for every combination?  Of course not.

What about "chain stretch"?

paulie

allrightmike

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Re: Street engine cam timing
« Reply #9 on: November 10, 2019, 05:21:50 PM »
  Once again I really do appreciate your generosity of knowledge. The engine that is going in my Starliner is a 427 10.5 comp. comp. 282S Iron heads single plane EFI 411 gearvenders and converter to be determined. Being a heavy car I was considering setting cam advanced a couple degrees but after reading the response I will go straight up at least as a starting point. This will be for street use.

 Mike.


 

plovett

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Re: Street engine cam timing
« Reply #10 on: November 10, 2019, 05:31:09 PM »
  Once again I really do appreciate your generosity of knowledge. The engine that is going in my Starliner is a 427 10.5 comp. comp. 282S Iron heads single plane EFI 411 gearvenders and converter to be determined. Being a heavy car I was considering setting cam advanced a couple degrees but after reading the response I will go straight up at least as a starting point. This will be for street use.

 Mike.

Yes, that cam already has 4 degrees advance ground into it.  So If you install it straight up and everything is "right" then it would have 4 degrees advance already. 

That is not always the case though.   Minute differences in parts (or poor machining) can add up and alter the cam timing.   I once put together a 351W with a cam that was advertised to have a 110 degree lobe separation angle and a 105 degree intake centerline.   When I put it in dot to dot, the intake centerline was 112 degrees.    I advanced it 8 degrees to get it close. 

Still, in my opinion, dot to dot is the best starting place given your compression ratio.

JMO,

paulie

blykins

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Re: Street engine cam timing
« Reply #11 on: November 10, 2019, 05:54:52 PM »

I would like to point out that there’s a lot of “internet standards” that are wrong...for instance, advanced cam timing does not always cut top end and retarded cam timing doesn’t always make more top end.

I said you might advance the cam to gain some low end.   I didn't say it is always that way.   I would bet 90% of the time in 90% of applications it is true, though.  Until you advance it too far.   How far is too far?  LOL!   

JMO,

paulie

I wasn't replying to you, Paulie, just making a general statement. 

I hate to harp though, but "straight up" and dot to dot is not the same.   Straight up actually means the LSA = ICL.  So, if you have a 112 LSA camshaft and install it straight up, the ICL would be 112 as well.   Sorry, pet peeve of mine. 
Brent Lykins
Lykins Motorsports
Custom FE Street, Drag Race, Road Race, and Pulling Truck Engines
Custom Roller & Flat Tappet Camshafts
www.lykinsmotorsports.com
brent@lykinsmotorsports.com
www.customfordcams.com
502-759-1431
Instagram:  brentlykinsmotorsports
YouTube:  Lykins Motorsports

blykins

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Re: Street engine cam timing
« Reply #12 on: November 10, 2019, 05:58:13 PM »
  Once again I really do appreciate your generosity of knowledge. The engine that is going in my Starliner is a 427 10.5 comp. comp. 282S Iron heads single plane EFI 411 gearvenders and converter to be determined. Being a heavy car I was considering setting cam advanced a couple degrees but after reading the response I will go straight up at least as a starting point. This will be for street use.

 Mike.

Based on your specs, I would put that cam on a 110 ICL. 

That cam should be a 110 LSA with a 106 ICL.  So it's ground with 4 degrees of advance.  I'd degree it to be sure, but theoretically, I'd put that cam 4° retarded.  10.5:1 with a heavy car can put you in a hairy spot and I'd be more comfortable with some lee-way there.
Brent Lykins
Lykins Motorsports
Custom FE Street, Drag Race, Road Race, and Pulling Truck Engines
Custom Roller & Flat Tappet Camshafts
www.lykinsmotorsports.com
brent@lykinsmotorsports.com
www.customfordcams.com
502-759-1431
Instagram:  brentlykinsmotorsports
YouTube:  Lykins Motorsports

Heo

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Re: Street engine cam timing
« Reply #13 on: November 10, 2019, 06:02:07 PM »
I have a 282S in my current 390 Galaxie. It was off, i don't remember how many degrees
changed timing gears it was off the same degrees had to use a Ford Motorsport
timinggears with 8 positions to get it lined up per instructions 4 deg. adv
My 390 10.5 comp ironheads single plane 750 carb  2.70 isch gear 29 inch rear tires
works fine, a Little slow of the line but its more from the highway gear/Converter
as son i get rolling i begin to pull like a steam train, cruises nice at 1500 rpm very
drivable, enough vaccum for Powerbrakes, 11.5 inch/Hg idling
and you have more inches and 4.11
 



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plovett

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Re: Street engine cam timing
« Reply #14 on: November 10, 2019, 06:59:15 PM »

I would like to point out that there’s a lot of “internet standards” that are wrong...for instance, advanced cam timing does not always cut top end and retarded cam timing doesn’t always make more top end.

I said you might advance the cam to gain some low end.   I didn't say it is always that way.   I would bet 90% of the time in 90% of applications it is true, though.  Until you advance it too far.   How far is too far?  LOL!   

JMO,

paulie

I wasn't replying to you, Paulie, just making a general statement. 

I hate to harp though, but "straight up" and dot to dot is not the same.   Straight up actually means the LSA = ICL.  So, if you have a 112 LSA camshaft and install it straight up, the ICL would be 112 as well.   Sorry, pet peeve of mine.

No worries.  I was just clarifying.  And I agree that "straight up" and "dot to dot" are not the same thing.  They could be by coincidence, but still not the same things. Dot to dot is just "dot to dot".....that is however the cam is ground and how the parts go together.   "Straight up" means having the same intake centerline as lobe separation.   I am with you.  :)

paulie
« Last Edit: November 10, 2019, 07:02:12 PM by plovett »