replace the timing chain??

[trans665]

im about to have a local speed shop put a new nitrous cam in my car next week, i already ordered a high flow oil pump that pumps 18 percent more then the stocker, should i also do a different timing chain, or just leave it alone?? car will be pushing 600 hp on the hose.

[Stingr69]

The cam chain/tensioner is a controversial decision. Here is my take on it.

If you are modifying the factory valvetrain with stiffer springs and faster cam ramp rates, you are incresing the load on all the rest of the parts. The tensioner was never designed to handle the incresed load and neither was the stock cam chain. Many shops will advise you to remove the tensioner and replace it with the older design black plastic block and a stronger chain/gear setup when adding an aftermarket cam and that makes sense to me.

Stock GM cams (including the ZR-1 Corvette cam) use the stock tensioner, gears and chain but everything bigger than that probably need to upgrade to prevent failure. JMO.

-Mark.

[Russell James]

Contact Katech. They have a C5R timing chain, and can also make suggestions on what style of tensioner to use.

I'd go with the C5R timing chain, and the old style block instead of the LS3 tension, and a blueprinted oil pump. Katech has a blueprinted oil pump as well. Or maybe someone could go through the one you bought. You want to make sure the bypass bore is perfected. Common problem is the bypass valve sticking in the bore, even on the aftermarket high flow ones.

Most also recommend a 3 bolt cam. Loctite everything.

[SUX2BU]

I've installed hundreds of cams. I don't like ported oil pumps and upgraded timing chains. The only problems I have ever had with oil pumps was 100k mile stockers and a few brand new ported oil pumps. If you have a ton of miles I recommend a new stock pump. As for the timing chain, I would only replace if you have a ton of miles. The slight stretch after a bunch of miles will cause your timing to be off a bit.I do recommend everyone changes to a 3 bolt sprocket.

[flyby]

Replace it or wish you had in a deay short time.

[trans665]

thanks for all the input... i just ordered it from comp cams

[mike@newera]

Don't change the tensioner if you are using VVT, it is necessary to retain accurate cam timing to put a load on the chain.

[camarohead]

Originally Posted by SUX2BU

I've installed hundreds of cams. I don't like ported oil pumps and upgraded timing chains. The only problems I have ever had with oil pumps was 100k mile stockers and a few brand new ported oil pumps. If you have a ton of miles I recommend a new stock pump. As for the timing chain, I would only replace if you have a ton of miles. The slight stretch after a bunch of miles will cause your timing to be off a bit.I do recommend everyone changes to a 3 bolt sprocket.

Originally Posted by Russell James

Contact Katech. They have a C5R timing chain, and can also make suggestions on what style of tensioner to use.

I'd go with the C5R timing chain, and the old style block instead of the LS3 tension, and a blueprinted oil pump. Katech has a blueprinted oil pump as well. Or maybe someone could go through the one you bought. You want to make sure the bypass bore is perfected. Common problem is the bypass valve sticking in the bore, even on the aftermarket high flow ones.

Most also recommend a 3 bolt cam. Loctite everything.

Originally Posted by Stingr69

The cam chain/tensioner is a controversial decision. Here is my take on it.

If you are modifying the factory valvetrain with stiffer springs and faster cam ramp rates, you are incresing the load on all the rest of the parts. The tensioner was never designed to handle the incresed load and neither was the stock cam chain. Many shops will advise you to remove the tensioner and replace it with the older design black plastic block and a stronger chain/gear setup when adding an aftermarket cam and that makes sense to me.

Stock GM cams (including the ZR-1 Corvette cam) use the stock tensioner, gears and chain but everything bigger than that probably need to upgrade to prevent failure. JMO.

-Mark.

i am near a cam change for my ls3 and i know all 3 of you guys are very mechanically inclined. thinking whether to do the timing chain and oil pump change when i do my cam change and i guess there's just not a right answer on this. my installer says there is no need, but if i insisted, he would change em. still up in the air on this...

[Stingr69]

Originally Posted by camarohead

i am near a cam change for my ls3 and i know all 3 of you guys are very mechanically inclined. thinking whether to do the timing chain and oil pump change when i do my cam change and i guess there's just not a right answer on this. my installer says there is no need, but if i insisted, he would change em. still up in the air on this...

Keep this in mind - You have to drop the oil pan and remove the oil pump to change the tensioner. That was also a deciding factor for me. If you already have the pan dropped to change the tensioner and cam chain you might want to replace the oil pump while you have it off the car. I went with a stock ZL-1 cam so the stock tensioner was good and the pan and oil pump did not have to come off. I was able to skip a bunch of the steps shown in the DIY Cam Swap thread because of not changing all that other stuff. The ZL-1 cam can run all stock valvetrain but it requires a different cam timing gear but still no pan drop. If you are going to an aftermarket cam swap then you will have a bit more $$$, work and parts to do the install. It was less money and less work for me to leave well enough alone.

The tuner shops seem to believe you need to change to the older style rubbing block and upgrade the chain/gears when doing an aftermarket cam swap because of the bigger springs and bigger cam lobe lift rates. You have to think they know a little something about blowing stuff up and how to prevent it. Those few added parts are actually cheap insurance and you will have it all apart anyway.

-Mark.

[camarohead]

Originally Posted by Stingr69

Keep this in mind - You have to drop the oil pan and remove the oil pump to change the tensioner. That was also a deciding factor for me. If you already have the pan dropped to change the tensioner and cam chain you might want to replace the oil pump while you have it off the car. I went with a stock ZL-1 cam so the stock tensioner was good and the pan and oil pump did not have to come off. I was able to skip a bunch of the steps shown in the DIY Cam Swap thread because of not changing all that other stuff. The ZL-1 cam can run all stock valvetrain but it requires a different cam timing gear but still no pan drop. If you are going to an aftermarket cam swap then you will have a bit more $$$, work and parts to do the install. It was less money and less work for me to leave well enough alone.

The tuner shops seem to believe you need to change to the older style rubbing block and upgrade the chain/gears when doing an aftermarket cam swap because of the bigger springs and bigger cam lobe lift rates. You have to think they know a little something about blowing stuff up and how to prevent it. Those few added parts are actually cheap insurance and you will have it all apart anyway.

-Mark.

thx for the reply mark...i definetly want the car to be as reliable as possible, just gonna go ahead and change everything..