Billet main alignment honing question

[BEATAV8]

May be somewhat off-topic, but I cannot express how much I dis-like double roller chains.

Just removed this Pro gear from my car after 44 runs, most of them around 9.90.

The other 2 chains I have broken over the years were Rollmaster double roller chains.

Next set will be a stock-type link chain with steel gears and a tensioner.

Doh!
I had heard about problems with the rollmaster sets. I wonder why it broke on ya. Could be fatigue or could be overload. A stock style chain has a lot more steel links in it and might hold up better.

 

[Chuck Leeper]

Chain failures were seen @ Reynolds, a couple yrs ago...I think that 3-4 racers [Faaaasst guys!], were relegated to being spectators, for that reason.
Some mentioned very hi spring pressures were the culprit. There was mention of gear drives being the next stop.....[Danny Bee comes to mind??]

Align bores... Many yrs ago, Jim Ruggles and I had a discussion about this topic. His testing had shown that a "special process" was created by the Sunnen rep, to prevent the hone bar from running oversize bores on the end brgs... He said the short OAL of the block was creating the problem.

 

[LOT]

Ruggles book

Chain failures were seen @ Reynolds, a couple yrs ago...I think that 3-4 racers [Faaaasst guys!], were relegated to being spectators, for that reason.
Some mentioned very hi spring pressures were the culprit. There was mention of gear drives being the next stop.....[Danny Bee comes to mind??]

Align bores... Many yrs ago, Jim Ruggles and I had a discussion about this topic. His testing had shown that a "special process" was created by the Sunnen rep, to prevent the hone bar from running oversize bores on the end brgs... He said the short OAL of the block was creating the problem.

Mentions the shortness of the block being a problem. He also says if you don't torque heads on (with gasket) line boring is a waste. Keep in mind this was written in the 80's. As far as chain breakage--many factors come into play. 1 being do you shift to OD or Neutral @ the end of a run or do you let the engine do braking. It's hard on a chain having it loaded in 1 direction and then suddenly loading it in opposite direction.

 

[Nick Micale]

We have been looking into this chain problem for a couple years, and yes, sudden loading in the opposite direction seems to be the problem as it causes the chain to "whip" violently.

It appears the damage is being done at the burnout, not the top end. Doing a burnout at 5-6000 RPM, then come out of the box, and suddenly the tires lock up, or just closing the throttle will whip the chain.

The Rollmaster chain I broke last November was in the burnout box when I lifted the throttle. Also, a local Stage II car broke his chain in a burnout last year.

A loose chain will "whip" very dramatically when this happens. A stock link chain is MUCH stronger than any double roller according to the experts in the field. It is also possible to use a tensioner and a guide to minimize "whip" during engine sudden deceleration.

TA Performance has "killer" link chains for the 455 V-8 as well as nailhead V-8's, and we will soon have one for the V-6, it is now in production.

 

[Nick Micale]

Do you have any idea why those chains broke? I thought the reason for a double roller was the extra strength needed for a roller cam with high tention springs?

That is partly true, the problem is that stock-type link timing sets uses a cast cam gear, this will wear very fast, and in many cases will break the cast gear.

The comparable link chain is twice as strong as a roller chain.

I tried this twice and trashed the cast cam gears, which is why I badgered TA into making a billet gear set.

These sets will be available for both billet roller cams and stock type V-6 cams.

I have 10 sets of these reserved just for my customers who will install them immediately.

 

[Pronto]

So then you are recommending the new TA stock style timing chain set with billet gears. I assume if it's stock style that have the tensioner as well.

Back to the billet caps. What have you found the stock crank/rods with ARP bolts and 2 center billet caps strength range? 10.8-11.00 or can that combo go lower?

 

[Nick Micale]

So then you are recommending the new TA stock style timing chain set with billet gears. I assume if it's stock style that have the tensioner as well.

Back to the billet caps. What have you found the stock crank/rods with ARP bolts and 2 center billet caps strength range? 10.8-11.00 or can that combo go lower?

For mainly street driving, either stock type or double roller should not be a problem. If the build sees a good deal of track time, high RPM's and lots of valve spring pressures, the best set available should be used. Since these new sets should be no more expensive than a Rollmaster, it would be good insurance in any build.

Our experience with with a stock crank in the high 10's has been good for the most part. There is definitely more bearing wear than with a forged crank even when used with steel caps.

Using a 23 year old cast crank at that level is a crap shoot as metal fatigue becomes a factor in how much longer it will last?

 

[gnxtc2]

Nick

I also heard that the fire order also comes into play breaking timing chains, especially with high pressure springs.

Billy T.
gnxtc2@aol.com

 

[bison]

That is partly true, the problem is that stock-type link timing sets uses a cast cam gear, this will wear very fast, and in many cases will break the cast gear.

The comparable link chain is twice as strong as a roller chain.

I tried this twice and trashed the cast cam gears, which is why I badgered TA into making a billet gear set.

These sets will be available for both billet roller cams and stock type V-6 cams.

I have 10 sets of these reserved just for my customers who will install them immediately.

This is good news. Ive talked to a couple top machinists/builders about chain failures. Its very obvious whats stronger when you look at the stock type chain and the double roller styles.

 

[Sweetwater GN]

.

 

[turboc87gn]

Hmm are these new sets available from TA yet?

 

[Pronto]

I don't see anythink new on the website. Give them a call...

 

[jdpolzin]

How much slack is on a double roller normally? I know we cant really measure it but the last two I've installed have seemed pretty loose. I have talked to a few people about it and most people say it's normal. I've also heard of people that try to arrange the chain so that the drivers side has more tension. I could get that to happen at 0deg. Maybe at + or - but i didnt try that because I want to run the motors at 0deg.



I aslso took apart two motors this year with double rollers on them and tensioners. It was actually two in a row. I couldnt believe it. Anybody else ever see tensioners installed in a motor using a double roller? The tensioners didnt look chewed up either.