[sdbob]

I have been noticing same on my SD timing bouncing. I have the Cloyes Tru roller.Guess I'll pull it and replace it as I have a new set I bought form Paul spots I think it is 3 under. I have been reading and watching the responses on how to check stretch.The coast side through the fuel pump hole is sloppy. The car has been slowing down.DAA

[grivera]

Originally Posted by Cliff R

http://www.ebay.com/itm/Pontiac-V-8-...e9eb04&vxp=mtr

This is the set I use here. There are several different types of the stock sets, Dyna Gear has the iron top sprocket, which is OK. I like the set in the picture with the stronger top sprocket.

The Mopar offset key set has been discontinued for some time. The Mr Gasket offset keys are the only ones currently available that I know of....Cliff

Cliff- any idea why this description in the ebay ad?:

"Can be used for any Pontiac camshaft applications - but not recommended for Performance applications - see my other auction for those"

[Cliff R]

Maybe Paul doesn't trust them for "high performance" use?

I have to chuckle when I read that because I have 4 trophies from Norwalk, a couple from some pretty big "street car" events, and quite a few nights I've won at our local track......and one of those chains was turning the camshaft in my engine for most of those races, aside from the short time period I ran the Rollmaster till it stretched out and nearly walked off the sprockets........Maybe I need to step up the performance level of my vehicle a little bit so I can qualify for something better?

Seriously, I've been using them here in Chevy, Olds and Pontiac applications for over 30 years and have had zero issues with any of them, at any power level.

This "true roller" deal with the billet sprockets has became increasingly popular in recent years, and there are decent parts, but they still stretch out in long term service. The ONLY advantage I see with them is deadly accurate cam movements without using or needing offset keys, or drilling the sprockets for bushings, etc.

The only thing that's not going to stretch out is a gear drive, but I don't like or trust them......Cliff

[madokie]

Smokey Yunick prefered gear drive over chains, and only used chains if the rules mandated it. he also put the new chains in a tub of hot oil for 3 days before instalation.He once said they made a timing chain cover with a plexiglass window and ran a sbc at 5000 rpm and the chain was jumping and snapping around like a snake on a red hot steel plate. after reading this thread i will be saving my money and using a stock link chain set.. but what about people that run competition and need all the power they can make? Something wrong with our Pontiac gear drives cliff ?? their are 2 types as far as i know.and what about belt drive?

[HWYSTR455]

Edelbrock and Milodon are the 2 gear drives I know of, then the belt drive. I heard someone mention that Proform makes one too, but I personally wouldn't even consider one from them.

The Edelbrock 'floating' dual idler setups require much care/attention in setup, especially with line bored blocks and/or larger than usual bearing clearances. My understanding is the dual idlers can cause excessive chatter/harmonics, and actually eat power. And if it gets sloppy for some reason, it is possible for the gears to bind. Not sure, but I believe Comp Cams bought Pete Jackson.

The Milodon is the only one I would consider using, which is a single idler design. My understanding is the single type causes less chatter/harmonics, and is much more stable, because it uses a plate that is fixed. (and can be adjusted). Machine work I think is required, but the Milodon unit has individual parts that are serviceable, so you don't have to buy a new setup when servicing. I looked into using one a while ago, and decided it wasn't worth the cost or risk, especially since the amount of power gain is almost un-measurable. And that's when they are working at 100% optimum.

Belt drives cure most of the harmonics issues, but belts stretch too. Ever watch a car with A/C running and look at the A/C v-belt? Hold the RPM at like 3k, and look at the belt. That thing is flopping around, waving back and forth. Same thing on a timing belt, but not as much because it's shorter. Newer engines actually use tensioners, to help control belt harmonics and timing fluctuations, as an example.

Personally, why mess with something that isn't broke? What's wrong with timing chains, be it link or roller? So, you run a roller, if it gets sloppy, change it. If it doesn't last to 80k -120k miles, then you need a different brand/design. Around that number of miles, you should be doing a top end freshen-up anyway, valve job, etc., so doing a chain is part of it.

I remember back when, all the guys who ran gear drives thought they were cool. Not. Amazing how many failed, and in a number of cases would take out an engine. It was like a fad that everyone had to do gear drives. I did the homework before jumping on that band wagon, glad I did.

If there's inaccurate info I may have stated, and someone has the knowledge to correct, I'd be curious to hear, and update my mental files.


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[gtofreek]

I personally do not like gear drives. They cause a lot of valve train harmonics. Especially the noisy ones. I would never run a stock link belt setup either. I have yet to see one that was tight after 10,000 miles. They are always loose as a goose whenever I see one in service. To each his own I guess.

Back in the 90's, I rebuilt the 2.8 V-6 in my S-10. Back then, the only chain available was the stock link belt setup. That's what I used. A Sealed Power kit. After 100,000 miles, it was so loose it was jumping teeth. Jumped a total of 3 before it wouldn't run anymore. When I changed it, it was so loose I could just lift the chain up and over the teeth. The cam gear was also totally eaten away, and the ends of the teeth were razor sharp. No thanks to link belts. I never had a roller chain get that loose and jump teeth.

[Cliff R]

A wide link belt set is EASILY good for 100,000 miles, I've seen the narrow sets go 250,000 miles in late model GM 350 engines.

NONE of these roller chain alternatives are going to go any further than that, and every single one I see with a lot of time on it is just as loose as any link belt set would be, if not more so.

Folks should not get the impression here that a true roller chain with billet sprockets is going to run any further than stock replacement stuff. They may not last as long, as I found out in my last engine.

In the big scheme of things it really doesn't matter as most folks are not going to put 100,000 miles on any of these cars in the next 30 years.

As mentioned earlier, the best direction is to go to the higher end stuff, and NEVER get the 3 keyway sets, they seldom if ever come out where you need them to be. Go 9 keyway with the good imported chains, billet sprockets and enjoy a set that will last quite a while and let you put the cam right where it's supposed to be......IMHO....Cliff

[Schurkey]

Originally Posted by rexs73gto

I have a question? If the block has been line bored does it need to have the longer timing chain every time?? Also how do you know how much longer do you need??? Is it nessasery to use a longer chain each time when the block has been line bored?

If the block has been line-bored, you MIGHT need the "shorter" set; which contrary to what most folks seem to think, does not have a shorter chain--it has a microscopically-larger gear to take up the slack.