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Tech Area => General Buick Tech => Topic started by: Steve Wood on March 05 2014, 05:22:48 PM

Title: double roller plus tensioner plus bad luck
Post by: Steve Wood on March 05 2014, 05:22:48 PM

ow......

Title: Re: double roller plus tensioner plus bad luck
Post by: Pyro6 on March 05 2014, 05:41:21 PM

That yours??

Title: Re: double roller plus tensioner plus bad luck
Post by: Steve Wood on March 05 2014, 05:45:25 PM

nope..I don't use a tensioner...gu y sent the pic to me asking about using a tensioner on a roller chain a second time-this one made 3000 miles before it broke, got caught in the crank gear, broke the chain and destroyed the cover and front of the pan

Title: Re: double roller plus tensioner plus bad luck
Post by: Pyro6 on March 05 2014, 05:53:17 PM

Thought so, had to ask.

Title: Re: double roller plus tensioner plus bad luck
Post by: Forzfed on March 05 2014, 06:02:44 PM

What a mess!  Glad I'm not using a tensioner.

Title: Re: double roller plus tensioner plus bad luck
Post by: Scoobum on March 05 2014, 06:10:39 PM

Stock junk works just fine for me.

Title: Re: double roller plus tensioner plus bad luck
Post by: Steve Wood on March 05 2014, 06:34:37 PM

he has a roller cam

Title: Re: double roller plus tensioner plus bad luck
Post by: Scoobum on March 05 2014, 06:40:42 PM

Like I said...my stock junk works just fine.

Title: Re: double roller plus tensioner plus bad luck
Post by: Steve Wood on March 05 2014, 07:33:47 PM

Be that as it may, there is a benefit to using a larger cam when employing a large turbo.  And, it seems that a roller cam produces better longevity when going to that larger cam.

Title: Re: double roller plus tensioner plus bad luck
Post by: Charlief1 on March 05 2014, 08:10:29 PM

That's a TA timing cover I believe. I believe you can use a tensioner, but not the stock one. It's a hard rubber so it would get chewed up easily. Now if you went with one for a later 3800 it's got a very hard plastic block so it wouldn't be subject to the same issues. :icon_smile:

Title: Re: double roller plus tensioner plus bad luck
Post by: Scoobum on March 05 2014, 10:04:26 PM

Quote from: Steve Wood on March 05 2014, 07:33:47 PM

Be that as it may, there is a benefit to using a larger cam when employing a large turbo.  And, it seems that a roller cam produces better longevity when going to that larger cam.

Longevity...ye s. Be that as it may...there's two S2 cars in the Toronto Area and a twin turbo SBC Regal with roller cams running 11's. Maybe they should try flat tappet?

Title: Re: double roller plus tensioner plus bad luck
Post by: earlbrown on March 05 2014, 10:11:55 PM

That looks like a hi-vo chain, that's smooth on the outside, which is OK to use with a tentioner.

 Blow up the pic and look at some of the link pins. It looks like it might have been a chain failure that resulted in the carnage, not a tentioner problem that started it.

Title: Re: double roller plus tensioner plus bad luck
Post by: Steve Wood on March 05 2014, 10:33:23 PM

Don't know, guy had three thousand miles on the engine, tensioner came apart, got caught between the chain and the crank gear and locked up breaking the chain and wrapping a section around the gear ending up in the damage to the cover and pan you see.

If the tensioner is not made to be used specifically with a roller chain so that it meshes correctly, I am not doing it...I don't care if it is hard rubber, or jello, I am not trying it :)

Title: Re: double roller plus tensioner plus bad luck
Post by: Steve Wood on March 05 2014, 10:52:11 PM

Quote from: Scoobum on March 05 2014, 10:04:26 PM

Quote from: Steve Wood on March 05 2014, 07:33:47 PM

Be that as it may, there is a benefit to using a larger cam when employing a large turbo.  And, it seems that a roller cam produces better longevity when going to that larger cam.

Longevity...ye s. Be that as it may...there's two S2 cars in the Toronto Area and a twin turbo SBC Regal with roller cams running 11's. Maybe they should try flat tappet?

I don't know anything about the cars so I have no idea why they don't run better but I know there are lots of possibilities that don't necessarily have anything to do with whether the cam is a roller or a flat tappet :)

My statement was that a roller cam made it easier to use the potential of a large turbo.  Given that a turbo is simply an air pump, if one puts a large turbo on a car that has poor volumetric efficiency such that the output of the turbo cannot be consumed, then the car is not going to perform to its potential--assuming the engine builder had a reason for selecting that turbo...now, we know assumption is dangerous and perhaps the Toronto engine builders were dealing with too much assumption and not enough understanding.

In a 231 " Buick, a major bottleneck is the cam profile when trying to use a big turbo.  A bigger cam that will turn more rpm will allow the turbo to make more use of its capacity because all formulas for VE depend greatly upon total rpm used.  Given that we normally don't like to turn a stock block to 7000 rpm, a roller cam allows us to use a lobe that provides more area "under the curve" and start increasing efficiency of the process at a lower rpm.  It will also allow us to spin it up to around 6000 rpm which, in my opinion only, is about the point where stock junk starts edging upon the total junk point.  So we get better efficiency at a lower rpm and carry it forward to a point about a thousand rpm higher than so called stock junk.

If we use a flat tappet cam, we don't gain as much under the curve and we have to use quite a bit of spring pressure to keep the lifter planted which might be okay on some cars; but given the poor lifter location on some of the lobes of our engines, we shorten the life of the lifter and cam-hence my longevity comment.  And, of course, we are still rpm limited on a stock block.

It's all about the synergy of the parts in the combination if one wants to give the tuner the best chance of squeezing out the potential hp.

Title: Re: double roller plus tensioner plus bad luck
Post by: motorhead on March 06 2014, 10:35:51 AM

Well, now ain't that some shit?

For our LS1 build I am employing an "LS2" chain damper to prevent potential chain wrap.  This damper sits inside the chain/gear assembly in the void between the gears - single row timing chain with a .600"+ lift cam and 400lb/in dual springs.

Tell me again why we saddle ourselves with these dinosaur engines for reasons other than nostalgia?

Title: Re: double roller plus tensioner plus bad luck
Post by: Steve Wood on March 06 2014, 01:14:01 PM

I don't know...maybe because it is fun to blow punks off the road with old, obsolete, archaic cars?

Title: Re: double roller plus tensioner plus bad luck
Post by: motorhead on March 06 2014, 01:21:38 PM

Quote from: Steve Wood on March 06 2014, 01:14:01 PM

I don't know...maybe because it is fun to blow punks off the road with old, obsolete, archaic cars?

I raced an old Amish goat farmer with a horse and buggy once... once.

Title: Re: double roller plus tensioner plus bad luck
Post by: Steve Wood on March 06 2014, 03:06:05 PM

Don't feel bad.  I am sure you are not a virgin when it comes to losing

Title: Re: double roller plus tensioner plus bad luck
Post by: Scoobum on March 06 2014, 03:46:27 PM

I run 135 pound valve springs on my engines. The lighter springs soften up easy at high RPM's and high boost levels. Been there...done that.

Title: Re: double roller plus tensioner plus bad luck
Post by: daveismissing on March 06 2014, 03:56:24 PM

Quote from: Steve Wood on March 06 2014, 03:06:05 PM

Don't feel bad.  I am sure you are not a virgin when it comes to losing

"like"                        "like"                           "like"                      "like"

Title: Re: double roller plus tensioner plus bad luck
Post by: Forzfed on March 06 2014, 10:03:45 PM

Quote from: Scoobum on March 06 2014, 03:46:27 PM

I run 135 pound valve springs on my engines. The lighter springs soften up easy at high RPM's and high boost levels. Been there...done that.

That's a lot of weight on your front end! :icon_lol:

Title: Re: double roller plus tensioner plus bad luck
Post by: motorhead on March 07 2014, 07:35:42 AM

Quote from: Steve Wood on March 06 2014, 03:06:05 PM

Don't feel bad.  I am sure you are not a virgin when it comes to losing

You have to lose a few to really appreciate the victories. 

"Let me tell you something you already know. The world ain't all sunshine and rainbows. It's a very mean and nasty place and I don't care how tough you are it will beat you to your knees and keep you there permanently if you let it. You, me, or nobody is gonna hit as hard as life. But it ain't about how hard you're hit. It's about how hard you can get hit and keep moving forward. How much you can take and keep moving forward. That's how winning is done!"

Title: Re: double roller plus tensioner plus bad luck
Post by: Pyro6 on March 07 2014, 08:38:37 AM

Does Vince Lomardi owna Buick?? Or is the that Newt Rockney??

Title: Re: double roller plus tensioner plus bad luck
Post by: Steve Wood on March 07 2014, 09:51:47 AM

that's Rocky right after he knocked down Adrian because his beer was not cold enuf

Title: Re: double roller plus tensioner plus bad luck
Post by: bcn30141 on March 09 2014, 10:19:44 AM

Are those screws for holding the seal in place really needed or is that how it came?

Title: Re: double roller plus tensioner plus bad luck
Post by: earlbrown on March 09 2014, 04:14:55 PM

It's a patch done by TA for an extra cost.   On the chinese covers they put the seal in from the front for some reason.  The screws are there because if the front seal blows out during WOT, you suddenly have 4 oily tires to contend with.

Title: Re: double roller plus tensioner plus bad luck
Post by: tb3 on March 12 2014, 10:01:27 AM

buddy of mine made the same mistake, but fortuneatly for him the tensioner broke and just fell into the oil pan with no other damage