Re: Timing chains,gears and stretching
[Re: shoebox]
#943443
03/05/11 04:13 PM
03/05/11 04:13 PM
|
Joined: Dec 2006
Posts: 2,110
Byron, NY
W.I.N. Racing
top fuel
|
top fuel
Joined: Dec 2006
Posts: 2,110
Byron, NY
|
'01 P1500, Blown/Inj BAE,/Veney ,Bruno/CS2,Dana 60
'01 Dodge 3500 S Cummins Auto, Fresh air kit, 4" Exhaust,
'05 Dodge Magnum R/T - Too Much to list
'60 Willys CJ5
'01 International LPX - Project,DT466, Allison
'64 Plymouth Valiant, Inj 528 Hemi, 2spd
|
|
|
Re: Timing chains,gears and stretching
[Re: W.I.N. Racing]
#943444
03/05/11 07:17 PM
03/05/11 07:17 PM
|
Joined: Jul 2010
Posts: 791
Bama
Randy..
super stock
|
super stock
Joined: Jul 2010
Posts: 791
Bama
|
|
|
|
Re: Timing chains,gears and stretching
[Re: Thumperdart]
#943447
03/06/11 07:01 PM
03/06/11 07:01 PM
|
Joined: Dec 2009
Posts: 1,074
detroit, mi
POS Dakota
super stock
|
super stock
Joined: Dec 2009
Posts: 1,074
detroit, mi
|
Quote:
Quote:
What wears or stretches more on dbl roller timing chains? Top cog? Lower sprocket? I just got a more " economy " timing set and wondering if i should advance the cam a little to compensate for wear ?
Don`t know what these guys are joking about but a few builders I know advance it for that reason to compensate for chain stretch. At Pettis we`d boil the chains to impregnate the hot oil into em and lessen the stretching that takes place on a running engine. 
It's true.
This is why this time around I have a geardrive.
When I took my smallblock apart the last time the chain was hanging so damn bad if I reversed the engine it would have skipped teeth.
No more of that crap...now I'll supposedly destroy my engine with "harmonics" instead. 
We shall see! 
|
|
|
Re: Timing chains,gears and stretching
[Re: shoebox]
#943448
03/06/11 07:06 PM
03/06/11 07:06 PM
|
Joined: Aug 2003
Posts: 43,159
Bend,OR USA
Cab_Burge
I Win
|
I Win
Joined: Aug 2003
Posts: 43,159
Bend,OR USA
|
The cheaper sets chains will stretch so you need to install it straight up or 1 or 2 degrees retarded to start with. As the chains stretch the cam starts advancing, moves the intake lobe closer to TDC, I think   As the chain gets longer between the two gears the cam sprocket moves towards the top of the motor, IE advancing  You might want to rethink using that cheap timing sets,I put a Cloyes True roller timing set in my street low deck stroker motor that has a solid roller cam with 630+ lbs opened pressure, I shift it above 7000 RPM and it is a street/strip motor with over 3000 street miles on it also, same chain and gears for five years now I have had that motor apart several times since the first build, change cam timing, change cams, change the crank to a longer stroke, changed heads then and then to freshen the rings once to get rid of the low tension oil rings  good parts are worth the money  Trust me on that
Last edited by Cab_Burge; 03/06/11 07:24 PM.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
|
|
|
Re: Timing chains,gears and stretching
[Re: POS Dakota]
#943449
03/06/11 07:13 PM
03/06/11 07:13 PM
|
Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY
Master
|
Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
|
It's true. This is why this time around I have a geardrive. When I took my smallblock apart the last time the chain was hanging so damn bad if I reversed the engine it would have skipped teeth. No more of that crap...now I'll supposedly destroy my engine with "harmonics" instead. We shall see!
I've been running a gear drive on my engines for
for years, I love them
|
|
|
Re: Timing chains,gears and stretching
[Re: MR_P_BODY]
#943450
03/06/11 07:25 PM
03/06/11 07:25 PM
|
Joined: Dec 2009
Posts: 1,074
detroit, mi
POS Dakota
super stock
|
super stock
Joined: Dec 2009
Posts: 1,074
detroit, mi
|
Quote:
It's true.
This is why this time around I have a geardrive.
When I took my smallblock apart the last time the chain was hanging so damn bad if I reversed the engine it would have skipped teeth.
No more of that crap...now I'll supposedly destroy my engine with "harmonics" instead.
We shall see!
I've been running a gear drive on my engines for
for years, I love them
I was bashed about it because of what people hear, and what happened to some other guy etc. Just misinformation.
When i demand proof to back the claim, no one produces naturally.
I know you run a stout combo, and you have credibility here. So hearing you tell me this kind of reaffirms my thought. I asked a few builders and they say the timing is super accurate and that they are durable. So I went for it.
The only people I never hear bad about them from are the ones who are using them and enjoying them!
I love the idea of eliminating the timing chain as a possible weak link and the associated changes in timing you get over a longer period as the chain stretches.
I do believe the chain dampens harmonics, but how detrimental can they be is the question if no one is having a problem in the first place?
|
|
|
Re: Timing chains,gears and stretching
[Re: shoebox]
#943453
03/07/11 02:23 AM
03/07/11 02:23 AM
|
Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY
Master
|
Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
|
Quote:
well this timing set is a middle of the road set with a nice heat treated machined lower sprocket and a nice japanese chain but the topcog is "normal". i can go -4 0 or +4deg. i think its "advance to make up for the slack". a well respected pontiac engine builder told me on his UD custom flat tappet poncho cams he like to advance them 3-4 so when it does slack out the intake centerline ends up where he wants it. im going to call him tomorrow thanks
When you degree the cam in you should always be going
in the one direction so there is no slack but chains
do stretch..... he was most likely advancing the
cam to gain more torque... not so much for the
stretch aspect... but it does cover up some of it
|
|
|
|
|
