Author Topic: Single row timing chain (Read 5800 times)

for3ver · « **on:** September 28, 2011, 04:09:37 PM »

I am looking to install a single row timing chain does anyone know where I can purchase the parts? I have been trying to contact metric mechanic with no luck. Any leads would be great.

bflan2001 · « **Reply #1 on:** September 28, 2011, 07:17:10 PM »

I've also been trying to get in contact with MM for the same reason, no response for several weeks.

the parts they sell are made by them, I don't think anyone else sells them

wazzu70 · « **Reply #2 on:** September 28, 2011, 07:23:11 PM »

Did you call Metric Mechanic? I never have had a problem getting a hold of them. They don't respond to emails as well.

Take your sprockets to a machine shop and have them machine off the outer row of teeth. Figure out the chain pitch and order a chain. Its pretty simple.

Personally I would only do this modification if I exhausted every other option. Even then its questionable. If you dont have cams, put your money there first for sure!

bflan2001 · « **Reply #3 on:** September 28, 2011, 07:26:03 PM »

I haven't tried calling in, guess I should dust off the old land line huh

DanOKC · « **Reply #4 on:** September 29, 2011, 02:42:02 AM »

Check this post here:
http://www.m42club.com/forums/showthread.php?t=13377&highlight=single+chain

for3ver · « **Reply #5 on:** September 29, 2011, 11:05:26 AM »

Well I am replacing all my timing components and figured I might as well upgrade. I tried calling yesterday but no answer. Does anyone know how much its gonna cost?

bflan2001 · « **Reply #6 on:** September 29, 2011, 07:08:49 PM »

Thanks for the link, Dan! I pm'ed him, I'm almost positive he'll be cheaper than MM, they are never cheap.

for3ver · « **Reply #7 on:** September 29, 2011, 08:13:52 PM »

So I got a call back from MM today and they said 250$ which isn't too bad. You have to send your gears to them and they shave and balance them and then send you them back with the single row chain.

Ryann · « **Reply #8 on:** September 29, 2011, 09:22:10 PM »

Funny, in some circles this mod would be viewed as a downgrade. For example Mercedes has a two row "upgrade" for certain V8 w126's and there are several aftermarket two row "upgrades" for the normally single row Toyota 22R/E.

wazzu70 · « **Reply #9 on:** September 29, 2011, 10:00:19 PM »

Yes, the chains are two row for a reason. Not like BMW was not aware they had the option to use single row.

Timing chains stretch and wear. IMO its not worth the weight savings at the sacrifice of robustness.

bflan2001 · « **Reply #10 on:** September 29, 2011, 11:43:46 PM »

Quote from: NickHertlein;107069

Yes, the chains are two row for a reason. Not like BMW was not aware they had the option to use single row.

Timing chains stretch and wear. IMO its not worth the weight savings at the sacrifice of robustness.

some people say (maybe even MM, i don't remember where i read it) the single row chain lasts longer because of the reduced weight

wazzu70 · « **Reply #11 on:** September 30, 2011, 03:19:06 PM »

People may say that, but it does not make sense. The forces going through the chain are from the tension created by the crank "pulling" the cam gears along. This major force does not change with a lighter chain, only the force required to move the additional weight of the chain which is fairly small.

You now have a similar tension spread over a smaller area of chain link so you are actually accelerating stretching and wear.

Like mentioned, people UPGRADE to a double row chain to avoid the issues of a single row unit.

romkasponka · « **Reply #12 on:** September 30, 2011, 04:44:42 PM »

Quote from: NickHertlein;107078

People may say that, but it does not make sense. The forces going through the chain are from the tension created by the crank "pulling" the cam gears along. This major force does not change with a lighter chain, only the force required to move the additional weight of the chain which is fairly small.

You now have a similar tension spread over a smaller area of chain link so you are actually accelerating stretching and wear.

Like mentioned, people UPGRADE to a double row chain to avoid the issues of a single row unit.

Yes, but for high rotational speed you will get high centrifugal (with heavy chain) forces which limits engine speed. On motorbikes I saw some conversions to gears.

wazzu70 · « **Reply #13 on:** September 30, 2011, 06:32:47 PM »

They sell gear conversions for American V8s too. Mostly due to torque potential on that level motor.

When you turn your engine over by hand, where are the tension forces in the chain coming from? When the engine is spinning faster do you think the chain mass adds more to the tension than twisting the cams and depressing the valves?

If your valvetrain did not exist, then you could focus more on chain mass removal. At that point though, you wouldnt need a chain at all.

romkasponka · « **Reply #14 on:** October 01, 2011, 02:48:20 AM »

Quote from: NickHertlein;107086

When you turn your engine over by hand, where are the tension forces in the chain coming from? When the engine is spinning faster do you think the chain mass adds more to the tension than twisting the cams and depressing the valves?.

Could be, I do not know. And other thing is resonant frequencies.