Valves

[Granny]

Can you please advise me on which chev valves you guys use as replacement valves my engine is a 1951 C1BA
Thanks in advance
Granny

[Ol' Ron]

The 1.5 and 1.6 SBC valves Have the same stem diameter, but are about .060" longer. Which makes them ideal to use with hi lift cams like the L-100. The 1.72 valve can be used in the untake, but I don't see the benefit of using it in a street engine.
Gramps

[Granny]

Thanks Gramps for that
Granny

[40 Deluxe]

An advantage of the 1.6" valve is it gets the valve up higher in a seat that has been ground too deep. In effect that unshrouds the valve and gives a little more effective lift.

[Tim Ayers]

Another advantage is you can get top quality hi flow valves for Chevy much cheaper than the flathead version.

[russcc]

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Here is an example of a Manley Performance Chevy valve with a 1.600 head OD, .240 stem OD, 4.84 OAL.
Photos

[Offy 220]

Originally Posted by 40 Deluxe

An advantage of the 1.6" valve is it gets the valve up higher in a seat that has been ground too deep. In effect that unshrouds the valve and gives a little more effective lift.

I had this problem with my 59a block with deep intake valve seats with the stock size 1.5". I contacted Old Ron for advice and he suggested I regrind the seats for the larger 1.6" Manley valves. I used my Neway hand valve seat grinding setup and the results worked out great! As Old Ron suggested the longer valve stems work out perfectly with the high lift cams - I have an original Bill Jenks 3/8's Potvin [.375 lift] in my 59a. Great advice from 40 Deluxe and Old Ron!

[Ol' Ron]

Back in my yut I did allot of valve jobs. Put one or more 1.5 valves in theseol flat motors just to fix a bad seat.
G

[russcc]

I have a set of those Manley Chevy valves for sale on the EV8 swap meet site, also at Hershey, C4S-35 Mon.-Thurs.

[Granny]

Hi russcc, Thanks for your info but I live down under so will not be at Hershey and the shipping cost to here would near double the Cost
Granny

[supereal]

In our shop we use the Chevy valves in rebuilds to match the hardened seats we install.

[Craig CT]

Originally Posted by Ol' Ron

The 1.5 and 1.6 SBC valves Have the same stem diameter, but are about .060" longer. Which makes them ideal to use with hi lift cams like the L-100. The 1.72 valve can be used in the untake, but I don't see the benefit of using it in a street engine.
Gramps

Hi Ron; I hope you're well. Are all SBC valves good or is there a year range? Thanks, Craig.

[Ol' Ron]

Originally Posted by Craig CT

Hi Ron; I hope you're well. Are all SBC valves good or is there a year range? Thanks, Craig.

Craig
ot sure when the 1.6 valve was introduced , the 1.5 cost $2.95 and the 1.6 was 5.95. So 16 valves was quite expensive when running a hi lift cam. I didn't see the reason to run them in the exhaust unless the deats were bad. Replacing the seats wasalso very expensive to do it right.
You have to understand, money was in short supply raising 4 kids, and the price of adj lifters went up to over 20 bucks a set. so I build allot of engines for other people. My favorit engine back then was the Olds 370ci engine, another reason you couldn't use the stock trans and rear end. The La Sall trans got scarce, but the Caddy boxes were only 20/30 bucks, but you had to buy a Hurst shifter anothe 50 bucks shot. So you can see why racing was expensive.
Then waz the good ol days
Gramps

[Tim Ayers]

There is quite a range of Chevy valves. From budget replacement to Serve Duty. The price goes up accordingly. I'd try to find ones with undercut stems under the head to give you maximum flow.

If you really want to get slick, have someone taper and install bronze inserts into the valve guides to also improve flow into the port. Inserts just improve wear and help to prevent sticking valves.

[Ol' Ron]

Yes Bronz incert are best, but expensive. Just knurl the cast iron guides, much cheaper, and will last as long as the rings do. There must be a reaon for every modification, and not for spending money.
Gramps
PS thats why I don't use 1.6 valves in a street engine.

[Ol' Ron]

Ntt

[Granny]

Can some one please give me part number for the 1.5 chevy values they use it their rebuilds
Thanks in advance
Granny

[Bored&Stroked]

Just so everybody thinks it all the way through. When you lengthen the stem, you also lengthen the installed length/height of the valve spring. So, make sure you have your valve springs tested and know at what installed height they need to be to deliver the correct LBs on the seat.

I frequently use Isky 185G springs on my high-performance builds and I take a steel Chevy valve retainer and cut it back for the 185G springs. The retainer is much thicker than the stock 49-53 ones, so it helps take up the longer spring distance of the 1.6 valves.

Also, when buying new 49-53 style valve guides, it is best to have the exhaust guides that do NOT have the intake seal groove cut into them. Why? Well, the more surface area on the valve guide OD, the better heat transfer from the exhaust valve into the block - this is important for valve cooling (exhaust side). You'll see a 'solid' type exhaust guide below.

I also make aluminum 'spacers' to put against the guide to set the final installed height. I don't like stacking up 3 or 4 .060 spring shims (I'm a bit picky):

Retainer2 copy.jpg

Retainer1 copy.jpg

ExhaustValveComponents copy.jpg

ExhaustValveSetup copy.jpg

[Ol' Ron]

This is all very good information, Pay attention here!
Gramps