timing chain question...

[86 got boost]

Now is this true, i have a new dbl. roller timing chain in now, was told by a few national fanatics that im loosin HP, that I should put the original nylon chain in, NEW though of course... my 86 had dbl roller in it when I bought in 2000 rebuilt in 03' w/ new chain... now im skeptic... is someone pullin my chain or is this true, and the best thing about it they say 100 HP loss, just a little exstrordinare hugh?

 

[Jerryl]

Now is this true, i have a new dbl. roller timing chain in now, was told by a few national fanatics that im loosin HP, that I should put the original nylon chain in, NEW though of course... my 86 had dbl roller in it when I bought in 2000 rebuilt in 03' w/ new chain... now im skeptic... is someone pullin my chain or is this true, and the best thing about it they say 100 HP loss, just a little exstrordinare hugh?

If the harmonics of the chain are setting off the kncok sensor (false KR), you will be loosing power. Not sure about 100 HP though. (depending on the level). See, on a 300 HP car, that is 33%, but on a 1500 HP car, that is 6% loss.
If "they" are "not pulling" your chain, tell the "fanatics" to help you "pull and replace the chain", ........ wait :biggrin: , maybe you need to hang around some other more knowledagble fanatics if they really think that. :tongue:

Edit:
I am far from an expert, but many who "Think", "Are not".

 

[86 got boost]

no its not hang around, these guys own shops and/or work for asked me what i was using for a chain... yes that blew my mind but if theres any body that knows more i'd like to know cause I dont see a diff. only like jerryl had said about the KR...

 

[zeus87gn]

They are pullin your chain. The nylon gear is to make the engine quiet. Yes, it does reduce rotational weight, but it's not worth it in my opinion. You can do many other upgrades to make the engine faster with the steel gear and overcome your losses. Destroying your motor isn't worth what little you will gain with the fcty gear.

Go with the double roller if you already have it.

The harmonics of the chain won't mess with the knock sensor.
Frequencies are different.

 

[86 got boost]

thats exactly what i said, but the roller i have, is loose w/out the tensioner, i had matched from the old roller and the tensioner was grooved... replaced chain and tensioner and now reading all the timing chain probs i have to replace the chain and get rid of tensioner... did not know at time... but now the chains i recieve all fit loose, is there a place i can get a fitted chain, i've also noticed idle problems, fluctuates and dies when put in gear, but raise rpm up 200 its great, now it makes sense the chain is loosening when idleing and when givin gas it tightens what a joke, but i have to go in and redo rings anyway so not to frustrated just need info... thanks guys for the info.

 

[zeus87gn]

Can't really answer that one. I've never really messed with a double roller...just stock replacement aftermarket in all metal. Mine didn't need a tensioner as it was snug right out of the box.

Maybe some others will chime in.

 

[BlackBandit]

If the new chains are loose on your engine than it was probably line hone/bored when rebuilt. This changes the center line of the crank. You can buy chains with an over sized crank gear to overcome this. HTH james

 

[86 got boost]

the roller chain is from poston, came w/ huge slack enough that the new tensioner tightened it up, but the old roller that was there grooved the tensioner and before rebuild drove for 30,000 miles w/ no problems, dont know how long before chain was replaced before i owned?... thanks for the fast replies...

 

[ijames]

Any hp loss from friction will show up as heat. 100 hp is 74,600 watts - think what a heater that size would do to the front of your motor . There may be small differences in losses but nowhere near 100 hp. What I've read about the double roller chains is that if the back side is smooth like the stock chain you can use the tensioner, but if it is lumpy it will saw right through the tensioner and you have to leave it out.

 

[87TIGN]

What is the tensioner? What does it look like?
-Andrew

 

[granitestategn]

factory

The stock tensioner can be used with the "silent" type smooth backed, stock replacement chains. If the chain is a roller chain (like a bicycle chain), ie "double roller" high performance timing set, you can't use the tensioner, as Carl said. The tensioner is a spring loaded plastic thing that pushes against the slack side of the chain between the sprockets. It takes up slack as the chain stretches/wears. You can get both parts of the tensioner at any parts store. Supposedly, the roller chains stretch quite a bit causing them to be loose.

 

[BlackBandit]

I don't thing the "tensioner" is all that big of a deal. It's actually a dampner and if you get a good prestretched double roller I wouldn't sweat it. I mean think about it. It's not like that spring is going to suck up the slack in the chain and stop your cam timing from changing. I think it just stops the chain from slapping around on the "loose" side. Take some measurements, call up a buick vender, and order a chain that fits. Of course, if you have a stock cam/valve train you'd probably be money ahead just going to autozone and getting a stock setup. HTH. james