C1 Road Draft Tube 57-58

[Al C.]

In reinstalling my tube after starter refurbishment, I realized that the tube bracket had been mounted to the rear of the starter, on the long upper bolt (along with the battery ground). The AIM shows the tube bracket mounted on the front of the starter flange, on the lowest bolt.
As my car is early 58, it probably should be like the 57. I've noted in a couple of the catalogs that the crankcase ventilation tube differed between 57 (+early 58) and 58 & later. Could someone email me the applicable 57 AIM page, or explain how these part are mounted in 57-58E??
... AL '58 #378 245hp NCRS SACC

[Robert L.]

Re: C1 Road Draft Tube 57-58

Al,

I think the illustration in the AIM is wrong. I remember having an impossible time installing the ground strap based upon this illustration. It shows the strap at the rear position on the starter. This makes the ground strap too short to reach the battery. A picture on pg 126 of Nolan Adam's technical guide clearly shows the ground strap at the front of the starter. In this position every thing fits just fine.

Hope this helps.

Bob Lemke

MCMLVII

[John H.]

Re: C1 Road Draft Tube 57-58

On my late '57, the arrangement is exactly as shown in the A.I.M. (draft tube bracket behind the bellhousing, then the ground strap, then the washer and bolt head), and everything fit fine when it went together.

[Al C.]

Re: C1 Road Draft Tube 57-58

Bob- Thanks for the reference to p.126, I can see where the battery ground is mounted, I just wish the picture was clearer overall!

As to the road draft tube, some catalogs ignore differences, but Paragon shows two distinct designs of crankcase vent tube AND bracket. My bracket has the ~45 degree bend, which they show as "late 59-62"; they show a 90-degree bend bracket as "56-E59". Corvette Central splits between "56-58E" and "58L-62" but only shows one clamp, with about 45-degree bend.
I'm not sure if my car has the correct parts, and concerned about interference in the mounting. This might be a "Restorer article aopportunity" for someone knowledgeable?
... Al '58 #378 245hp NCRS SACC

[Al C.]

Re: C1 Road Draft Tube 57-58

John H.-
could you email me a scan of that AIM page?
It sounds like yours is set up like mine was, vs. the way the '58 AIM shows (which is repeated in Noland's book p234.
Is your bracket/clamp a 45 or a 90 degree bend?
...Al '58 #378 245hp NCRS #32673 SACC #1704

[John H.]

Re: C1 Road Draft Tube 57-58

Al -

Will shoot you a scan later today

[Robert L.]

Re: C1 Road Draft Tube 57-58

Al,

My car had two different road draft tubes in it since I have had it. The first tube came from a dealership. I had a 61 motor in the car at the time. That tube was too long, so I cut off two inches to get ground clearance (which was the only clearence I was worried about at the time). As I recall, I got the clamp, based upon Richard's recommendation at Paragon.

On the '57 block, a switch was made to the older draft tube. The same bracket was used.

I never had any other clearence problems with this clamp on either tube.

Hope this is helpful.

Bob Lemke

MCMLVII

[Steve Junkersfeld]

Re: C1 Road Draft Tube 57-58

John,

I'm going through the draft tube installation "goat rope" on my 56. After looking at all the documents and photos I can find, I believe that your installation is the correct one - but I have one question that you may be able to answer. How is the top of the starter motor retained to the bellhousing on your car? Does the bolt that holds the draft tube and ground cable come all the way through the bellbousing and starter and have a nut on the end? The AIM and other sources don't really show that.

[James F.]

Re: C1 Road Draft Tube 57-58 -Steve

Steve,
The '56/'57 AIM is not correct as drawn for the '56 Corvette owners. Up to at least all April cast 922 bellhousings, the top bolt of the starter is inserted from the starter nose side. This bellhousnig will be threaded to receive this bolt AND will not have a land on the backside to accomodate a bolt head. Later 922 bellhousings may have a bolt head land and no threads, I would have to check any notes I may have. The '56 ground strap goes against the starter nose. The road tube strap is attached to the lowest starter bolt in '56. '56 restorers trying to follow the AIM will go nuts! Regards,

[Dale Pearman]

Re: C1 Road Draft Tube 57-58

Paragon's information is correct. The brazed turn on the top of the tube is a junction of two 45 degree cuts for late 59-62. Your tube should come out of a "large can appearing" top at a right angle. (early style)

Dale.

[Al C.]

Re: C1 Road Draft Tube 57-58

Bob-
I find another photo in Noland's book, page 182, also having the ground strap on the front. This is a 4-speed; p. 126 is an automatic. BUT, neither engine seems to have a road draft tube!!
I received a scan of the 57 AIM from John H., and I'm going to go with that arrangement (Noland p.124) for the tube and the ground.
...Al '58 #378 245hp NCRS SACC