Correct shape upper radiator hose for 67 BB w/K19

[Mike S]

 After doing a lot of searching for the correct shape hose and not finding one, I'll post the question here.
For the 67 (68?) 396 owners that have the K19 smog pump and dual belt drive alternator, what type of upper radiator hose are you using?
  Below is a picture of the upper radiator hose that has been on my car since I bought it in 1980. Looking at the factory clamps (dated 1/67) I believe this hose is original. Notice the shape which easily clears the double alternator belts. I also attached a picture of the restored 67 396 w/o K19 and the hose is shaped differently and appears to be what is available today.
Though the hose shape available today clears the single alternator belt, it looks like it will be dangerously close to the double belt drive of the K19 Camaro. 

Mike

[bertfam]

The 1967 L35 (and L78) engines used pulley P/N 3844100, which is a single groove pulley (AIM, UPC K19, Sheet A13, item 15). You're running a dual groove pulley so that's why it's too close.

Ed

[Mike S]

It appears the AIM is not accurate with regards to a 396 w/K19. Check out Leon's 67 with the same MZ motor and belt configuration:
http://www.camaros.org/forum/index.php?topic=11931.msg97183#msg97183
  I wonder how many 396 w/K19 's were produced for the 67 model run.
Mike

[bertfam]

Sorry, can't help you there. The AIM shows 3844100, BUT it also shows the 3874422 was used before that (see note 8 on 2-17-67). I can't find ANY info on the 3874422, so maybe it was a 2 groove pulley? I say that because note 9 deleted a second belt. It doesn't say WHERE that belt was used, but maybe they went to the single groove pulley BECAUSE of the closeness of the radiator hose?

I'll see if Martin has any additional information on this.

Ed

[Mike S]

I just noticed the revision section too and agree with your explanation.
But, I'd be very curious what Martin has to say too.
I suspect Chevy used what pulley's it had on hand to make things work for the 67 BB Camaro. I mean, for the L35 it is using a cast iron P/S pump pulley and the crank pulley is the same 3-groove cast iron as used on the L78.
  Is there any way to tell if the hose is original if no markings are visible? I see some stamping in the rubber with letters/numbers.

Thanks!

Mike

[bertfam]

It's also interesting to note that in the 67 AIM, UPC 6, Sheet A7, all the drawing show just one belt for the alternator (generator), a single groove pulley, but no notes at all. And, in addition, to help confuse the issue, none of my 67 AIM's have pages UPC 6 Sheets B1 or B2 in them. (The pages that show the radiator hoses.) Typical!! There may have been a note showing a different hose for the early cars with the 3874422 pulley.

Ed

[bertfam]

After banging my head against the wall, I finally remembered a semi-related issue with the 68-69 Corvette w/427. In the December, 1968 Chevrolet Service News, they state that the upper hose "can come in contact" with the alternator pulley (see attached). In my case (I have a 1969 L36), you can see how close that upper hose comes to the pulley (bottom picture)!! As a matter of fact, you can see that I've had to "twist" the hose a bit so it doesn't rub (see the wrinkles at the elbow)! Hose and belt aren't original, but alternator and pulley are.

Ed

[KurtS]

I've seen several original 67 L78's with the double alternator pulley. It's been discussed here before.

[cook_dw]

Unfortunately the hose has already been replaced.

https://www.msn.com/en-us/Autos/classic-cars/1967-chevrolet-camaro-ss396-spends-43-years-stuck-in-a-pole-barn/ar-BBTxXYo?li=BBnbfcL

Link courtesy of Jon Mello:

[Mike S]

Thanks, Darrell!
I see two things in this photo. One is the use of the double groove pulley on a late 67 bb. And the second is the radiator rail with the 4 holes like mine has as mentioned in a previous discussion. One thing in common my car has with this car is they both were made at LOS. The radiator especially being it has holes and some of the observations here is there were no holes.

[Marty]

I don't have anything to add. I had a hose on my 68 BB that was hit by the belt. The new one isn't factory but clears the belts easily.
67 smog info is not very well documented. It used some Corvette parts from what I remember. I think it was Mike's car a long time ago.
We need lots of photos and part numbers and should put together an article on them.
Martin

[john302]

Have located three 1967 L78s with the dual pulley on alternator .All three cars were original . Also all three are La built cars. The dual belts have nothing to do with the smog.

[Mike S]

 I tend to agree, John. IMO, it is what LOS had on hand for the alternators. Interesting how so far only LOS BB's show that pulley usage.

Mike

[bertfam]

Well, let's look at it from a supply standpoint. Van Nuys also built full size cars and the same alternators were used on these as on the Camaro. I haven't done much research on this, but a quick look in the P&A shows that there WAS an application where the full size car used a dual groove pulley (P/N 3947155 - see bottom attachment), so perhaps that's the explanation? (Also note that it shows a Camaro application for this pulley as well)

I also found this in the P&A (see top attachment), stating that "NOTE: In some cases double groove pulleys may be used in place of single groove pulleys." This is a service application note, but it may hint of something that could also have been done in production.

Ed

[Mike S]

Outstanding detective work, Ed! 
Now...if I only can find the upper hose P/N. I'm researching upper hoses for that time period on other model cars. So far nothing came up yet.

Mike

[bertfam]

There's nothing that shows a different part number between "with K19" and "without K19", so the 396 hoses were P/N 3909866 and 3909868 (see attached)

Ed

[KurtS]

And I've seen the double pulley on NOR L78's too.

[cook_dw]

[bertfam]

And I've seen the double pulley on NOR L78's too.

Well, that blows my theory. I'm back to thinking the pulley in the notes (P/N 3874422) wasn't discontinued after all, but we still don't know how many grooves that one had. The only thing I can find is that it was removed from service in March of 1972, but that doesn't help us any.

Ed