c2 66 NOS 327 engine-correct damper?

[Chuck Swenson]

I have a NOS...yes NOS :-)66 327 engine casting number is 3858174
with NOS 461 heads. It has the 350hp cam. I curently have a stock 327 damper on engine, 3/4" width, total height 2 3/8", 6 3/4" diameter. Is it OK to use this on the engine or do I need the finned 350 hp 8" version? I want to make sure before I fire it up for the first time. NOS Block and heads were sitting in garage since 66! Also, do the blue and white paint marks that were on the block from factory go back on the engine after being painted orange?

Thanks again for everyone's help!

[Joe L.]

Re: c2 66 NOS 327 engine-correct damper?

Chuck-----

You could use the balancer that you have without really causing any problems as far as engine operation goes. However, this balancer is not really going to be the best if you operate the engine at the higher RPM levels which the L-79 cam is designed to work at. On the other hand, we don't really know if the other internal parts of the engine are L-79 parts, or not, and, consequently, we don't know if they'll support high RPM engine operation, anyway.

In the long run your best bet is going to be to install an L-79 balancer so that you can run an L-79 pulley system. If you use the balancer you have, then you will need to use the base engine pulley system. You absolutely DON'T need to use the "finned" balancer, though, unless you are concerned about "originality". The L-79 balancer is still available from GM under the original part number of 3817173, but it's no longer of the "finned" inner hub configuration. It works the same, though.

If you paint the engine as was done originally for all PRODUCTION engines, the blue and white inspection marks will be painted over. They were never re-applied after engine painting.

[Mike M.]

Re: c2 66 NOS 327 engine-correct damper?

Check the timing chain cover"s timing tab that is spot welded to the cover. It will tell you whether you need the small(Hyd.lifter) harm balancer or the larger finned balancer that the solid lifter engines used. mike

[Chuck Swenson]

Re: c2 66 NOS 327 engine-correct damper?

Thanks Joe for the great info! I started with a NOS bare block, oil pump, oil pan and heads. Everything else I bought this month new. Here's some more specs on the engine: Harden valve seats to run unleaded, three angle valve job w/ new Sealed Power valves, hydraulic, L-79 cam, Sealed Power H660CP hypereutectic skirt coated pistons-STD size, Cloyes double roller timing chain, STD GM forged steel crank with GM rods, ARP bolts and engine balanced. I also have a stock cast iron 327 intake manifold and 67 4bbl Quadrajet for now. Did that come on the 300 hp ver or did they all have aluminum intakes? With this new info, you think I definitely should go with the L-79 balancer?

I bought the timing chain cover, in response to post below, and it is the one for a 6 3/4" balancer. Unfortunately my crank pulleys are off by 3/8". If the balancer I have comes out 3/8" closer to radiator, all the pulleys will line up. Is there an offset crank pully? I'm currently using GM part 3755820BC

Does anyone know the total height of the L-79, GM part 3817173, balancer? Is it 2 3/8" like the one I have now.

I really didn't want to pull water pump, change timing cover and balancer unless it's necessary.

Thanks, Chuck

[John H.]

Re: c2 66 NOS 327 engine-correct damper?

Chuck -

Q-Jets weren't used on Corvettes until 1968; the '66 300hp used a cast iron intake (3872783) and a Holley R3367, P/N 3884505.

[Chuck Swenson]

Re: c2 66 NOS 327 engine-correct damper?

John, thanks, I put "for now" on the above post until I find a correct carb :-) Alt least my intake manifold is correct.

Thanks, Chuck

[Mike M.]

Re: c2 66 NOS 327 engine-correct damper?

just out of curiosity, what if anything is stamped of the engine pad of the nos block and what's the casting date? thanks, mike

[Chuck Swenson]

Re: c2 66 NOS 327 engine-correct damper?

B246, and the engine pad is blank.
Chuck

[Mike M.]

Re: c2 66 NOS 327 engine-correct damper?

You have a winner there if the pad retains its original factory horizontal broach marks, not the radially directed broach marks the local machine shop leaves behind when they deck a block.Pretty valuable block to a 66 owner wanting orig broach marks. mike

[Joe L.]

Re: c2 66 NOS 327 engine-correct damper?

Chuck----

Given the internal parts you're using, your engine should be capable of achieving L-79 performance and RPM levels. However, unless you intend on using the engine at the maximum end of these performance levels, I don't think that the balancer that you have will cause any problems, at all. The 300 hp and 350 hp cranks were, essentially, the same. I would limit engine operation to about 5,200 RPM with the balancer that you're using.

I don't know the exact difference in "length" between the balancer that you have and the GM #3817173. I would expect the difference to be the same as the difference in balancer ring thicknesses (3/4" versus 1-11/16"= 15/16" difference), but this may not be the actual case due to other design differences. The 3817173 is definitely not the same length as the balancer that you have.

The GM #3755820 pulley that you have should work with the balancer that you have, though. So, perhaps your other pullies are the "incorrect" ones for your application, as constituted. In any event, trying to get all the pullies right in a situation like yours can be frustrating. If all you need is a 3/8" outward spacing of the crank pulley to "make things right", you can achieve this with spacers between the balancer and the pulley. Such spacers are available from high performance-type auto supply stores/catalogs.

[Chuck Swenson]

Re: c2 66 NOS 327 engine-correct damper?

Whew! you had me nervous there Mike! I just called machine shop and LUCKILY they did not deck the block when assembling short block. I was worried when I double checked invoice and saw "resurface iron .006", but they said that was for the heads to remove surface rust. They said they absoulutely didn't touch top of block, just honed cylinders. I double checked my before and after pictures and video tape I made before painting and I confimed nothing was done. I briefly mention to shop when I dropped off engine not to touch pad and I'm glad they didn't.

It only has a coat of chevy orange paint on the pad. It was ashame to paint over all the factory marks. It really has alot of blue paint stripes and marks on it! I think I have the last virgin NOS 66 327 block and heads around :-)

Thanks for the info! Chuck

[Chuck Swenson]

Re: c2 66 NOS 327 engine-correct damper?

Excellent, thanks. I need to someone who has a GM #3817173 balancer to find the length. If the length corrects my pully problem, I'll switch. I plan on going to the track once and a while, so I'll have to watch the tach. I've seen different ring thickness GM balancers that have the same length. If the length of the GM #3817173 doesn't help, I'll go with the spacers. Thanks!

[Chuck Swenson]

Re: c2 66 NOS 327 engine-correct damper?

Is the balancer orange too? If I don't pull off, should I tape over the seal in the timing cover so I don't get orange paint on it, or was the engine painted with the balancer on already? I didn't paint my bolts (timing, valve cover, oil pan, etc...) and gaskets either during assembly. I figured if it was incorrect, I could alway paint over them. I like the look of the bolts and gaskets, but if I lose points, I guess I better paint them :-)

Thanks, Chuck

[Joe L.]

Re: c2 66 NOS 327 engine-correct damper?

Chuck-----

The balancer was painted orange with the engine. I wouldn't worry about masking off the seal; the factory didn't do this. However, they usually didn't apply a lot of paint behind the balancer, anyway, and, for originality considerations, you probably shouldn't, either.

The bolts which attach the balancer pulley to the balancer were unpainted as they and the pulley were installed at St. Louis. The oil pan, timing cover, and valve cover (for steel valve covers) bolts were painted with the engine. Timing cover bolts (and timing cover, itself) behind the water pump and balancer may have received partial or no coverage.

[Mike M.]

Re: c2 66 NOS 327 engine-correct damper?

i've seen a number of virgin pad, over-the-counter small block chevy cases. seems like there is an abundance of the in the Columbia River gourge area. mike