Tension By Bruce Lee Say: "Don't think..feel"

[TheStig]

I managed to finally complete my engine rebuild with the exception of tensioning my timing belts. It's unfortunate that I don't own the tension tool, but yet 33 beers in the fridge and a brief 30 minutes gor me to think it over on how to tension it.....am I scaring you yet? This will. I've decided to go by feel.

Digging up a workshop manual on the 928, I realized that the factory had tensioned timing belts by the good old 90-degree test prior to the 9201 tension tool's debut. In this case, I tried 90 degrees....felt way too risky to me. I decided to tension to about a 75-80 degree angle. Pictures below show the results. The tension is stiffer.

Anyways, has anyone else ever timed a 944 by hand out there without selling their soul to by the damned P9201 tool? Or am I just a little crazy? I am hoping that the cam belt doesn't have too much tension on it. The balance shaft belt, however, can be twisted 90 degrees.

Hope to see all of you guys at the autocrosses soon when I get this sucker running!

[Dan Chambers]

Andy:

Very, very pretty engine. You've done a fine job of getting your engine back together. Good job! I look forward to seeing you out at the A-X's real soon.

Regarding your tension-by-feel method, I'd have to say I wouldn't risk all that hard work and patience with a "gut feel" method. Too much tension on the cam-waterpump belt ... you overload the bearings on the rollers/tensioners, new water pump (you did put on a new water pump, didn't you?), and risk early fatigue of the belt. Too little tension ... belt stretches, jumps on the cam-wheel .... brand new valves go "bendie-bendie" and you're back to square one .

That's just me, but with such a great looking engine, and obviously all that hard work and time you've put in, I'd bight the bullet, find, beg for, borrow.... the tension tool. For me personally, I'd call AAA, (free) tow it to a shop (Dieter's, Black Forest, Mirage) and have them do the final tension, overall engine check, and first turn-key to start it up. Okay ..... so maybe a few hundred bucks for all that. However, the cost of peace-of-mind after all that hard work...... priceless .

My Dos Pesos.........

Dan

[Jad]

Dans answer is correct, but there really is a decent amount of error that won't cause problems. You PROBABLY would be safe finishing it up and driving it over to a shop to have it retentioned. Then do it again after 1-2K miles as the belts do stretch a bit.

Timing isn't really an issue as far a I am aware, just make sure all the TDC marks on the cam, balance shafts, etc are all lined up when the belts are on.

GOOD LUCK and again, Dan's is the best advice, though some of us may have been in similar situations and not followed the proper method. To be honest, the tool is a piece of garbage in my opinion. You need to be an expert to use the dang tool and get the same ready twice, let alone knowing exactly where and how to get a reading. If you are good enough to really use the tool, you don't need it

[TheStig]

I know how to use the tool....it's just that I have to give a limb up to buy one brand new

I'll see if I can find someone that will let me borrow it just for a couple of hours.

When the head was rebuilt, we did the belt tension by feel also. However, it was a little tight for the belt. After consulting the workshop manuals, I learned to tension it less aggressively by feel. Nevertheless, I don't think I want to take anymore chances on such a fresh motor. BTW, the belts on here are only 1,200 miles old....so I would have to tension the belts on a "3" using the P9201 tool.

[harnishclan]

If you want to use a method other than the 9201, follow this link:

http://www.arnnworx.com/tensioningbelts.htm

I have used (and own) the krikit tool, and haven't had problems with doing so. But Bruce Arnn of the arnnworx website listed above actually describes how to tension by feel. All that said, I would get it close, drive it easy and have a professional check it at the 1K mark before stressing the engine too much.

[Greg Phillips]

Another option??

http://jenniskens.internet-land.nl/Tech ... onTool.htm

Greg

[TheStig]

Interesting idea on that website Greg. Hell both of those links are interesting. I have a buddy that showed me the Kempf tool that is used to tension the belts on the 928 and demonstrated it. Too bad it can't work on my 944.

The motor is ready to go in now! Can't wait to get this baby running. More pics to come

[cone killer]

Hey MONGO,

If you still need the tool then give me a call. You (or anyone local) is welcome to borrow mine as long as I get it back in the same condition as lent Just drop an email and we'll work out the exchange.

See you at the track....

Best Doug

[Dante]

"It's like a finger, pointing away to the moon.

Focus on the finger and you'll miss all that heavenly glory...."


Sorry, couldn't help it!

Engine looks good enough to eat off of. Great job!