Engine set-up advise

[JohnEd]

JC,

I have read tech discussions on "torque specs" and the gist was that lube on the threads will change your torque force a bunch.  The lube on the threads makes it easier to turn the bolt/nut.  Torque "without" grease seems to assume a perfect world of "clean and dry" bolt and hole threads".  Prelim lube will give you the most accurate and repeatable setting but there was a GIANT flaw/warning.  You grease a blind hole and part of your torque setting will be compressed air.  I think that would be especially true for Permatex or locker.  See if the instruction has a caution to "lightly" grease the bolt.  Even if the hole is open, the use of thread locker will cause you to UNDER torque the bolt as the locker presents resistance long before high torque is reached so that resistance must be subtracted from the set torque to achieve the required torque within the parts.

Please share the compression ratio spec for the "high compression pistons" you are using.  What was the "stock" CR?  Are you still planning to use a turbo and if so what is your boost pressure. 

I envy you your shop and project.  Looks and sounds like fun.

John

[lostagain]

Da Book states: "Apply International Compound No. 2, or equivalent, to the threads and to the bolt head contact area (underside) of the bolts. The bolt threads must be completely filled with I. C. no 2 and any excess wiped off." It then goes into the torque specs. (50 lb-ft, then turn the bolts an additional 90 to 120 deg.). The bolts and holes are very clean after removing, so the last re builder apparently did not use any goop. Should I use anti-seeze compound? Or nothing at all? I don't want the flywheel to "fly" off...

The new pistons are 18.7 to 1 comp. I used advice from several competent and very experienced DD mechanics, most of which recommended high compression for my application.

The turbo is going back on. It will be improved by a dry air filter. (From oil bath filter that I have been running). I also got an air to air intercooler at a wrecker's in Calgary, that I have to install as well.

Lots to do yet!

JC

[Old4103]

JC,

I may have missed it, but you ARE using new flywheel attaching bolts aren't you?


Just a thought.

Dallas

[Ed Hackenbruch]

Hey Gary i tried calling you a few days ago and left a message, are you and Gail coming to Yuma? the space is available if you are.   Ed

[lostagain]

Dallas, no I wasn't going to. Should I?

JC

[Old4103]

JC,

Yup,

Every time you remove the flywheel you need to reinstall it with new bolts.

The old bolts have been torqued and the threads stretched and are only good for one use. DD recommends replacing them every time.

This is the same reason you replace the head bolts on a Ford escort... first the bolts are torqued to a certain value and then the bolt is turned 90° to stretch the treads and lock them into place. Once they are removed, they will never retorque correctly and stay that way.

Good Luck, I'd hate to see you have the flywheel come bouncing out from under the bus at 60 mph, especially after all the work you've put into it.

Dallas

[luvrbus]

JC, when you buy the 6 or 8 bolts it will blow your mine to see the thread locker on the new bolts figure that one after reading the book.    good luck

[Old4103]

You'll also probably becrap yourself when you see what they want for those 6 or 8 bolts!

They aren't even plated in gold or platinum!

DF

[BG6]

Dallas, no I wasn't going to. Should I?

Not if you really enjoyed all the work you're doing and you want to do it again soon.

There is way too much energy depending on your flywheel bolts to risk reusing them.

[lostagain]

Thanks for the heads up guys. I'll be making a call Monday morning to order new bolts. Da Book does not mention new bolts, so I wasn't concerned untill Dallas brought it up. Now how about head bolts? Crank bearing cap bolts? Connecting rod bearing bolts?

JC

[luvrbus]

When DD went to the twist and torque they did call for new head bolts but if you have a manual with the torque in lbs I would reuse the head bolts those babies are 11 buck each and rebuilders use the same head bolt.FWIW in section 1.4 page 1 in my book it says use new flywheel bolts.If you need the torque on the head bolts Dallas can help he is my go to guy when I need the torque on head bolts for the DD   good luck

[lostagain]

Thanks Luvrbus,
I had to go to the shop and look at my book. It is the Inline 71 Service Manual, 1978 edition. It does not mention using new bolts, but I beleive you and Dallas, and will get some new ones for the peace of mind. As I posted 10 replies above, it specifies 50ft/lbs, then turn an extra 90 to 120 degrees.

Boy, I am greatfull to have you guys!

[luvrbus]

JC, my manual is 1988       good luck

[84bluebird]

I grew up in Jasper Alberta and road those busses alot. Before the road was built into Marmot Basin Brewster had those in service to bring the skiers to the old upper chalet. Another note is some of those Brewster Couriers were purchased from the Jasper Park Lodge, at that time they had a brown and yellow paint scheme. Do you Jerry at Gainford  50 miles west of Edmonton with his Flxible and Courier collection?

[lostagain]

84bluebird, no I hadn't heard of Jerry with the Courier and Flx collection. Tell us more. Maybe I could drop in if I'm in the area one day. There is a guy, Russ Young, in Lumby, BC, near Vernon, that has about 6 Courier 95s and 96s, plus one on tracks that was a snowcoach at the Columbia Icefield in the seventies. I have gotten parts from him for mine. I drove out of Jasper in winter of 75-76.

Take care,

JC