[captain pickle]

I've been going in circles trying to find correct data on the valvetrain geometry and if I can get away with 1959 valves in 1960 heads.

I have a 1959 engine that was rebuilt and then the car sat for a long time and debris must have gotten in and wiped out the crank and bearings. I'm doing a clean and freshen on it.

Apparently it got 1960 heads along the way and the valve stems and guides that appear to have been knurned in the past are all out of spec. I was planning to ream the guides up and then install some 0.003" OS valves that I can get and touch up the existing seats. This is nothing crazy and a driver that will get 350 miles a year. And that's when I noticed that the head casting numbers were the same as 2 other 1960 engines I have. The 59 and 60 heads are all dual barrel (not the 3/2 or 425a). Some things I'm finding are saying that the valve length difference is about 0.023" with one longer and one shorter attributed to the different combustion chamber dimensions.

I've also tapped out the rocker studs and lowered the pedistals for screw in studs since one already pulled up. I was planning on using the SBC stamped rockers.

So - question is can I get away with the 59 valves in the 60 heads? I can grind the longer valve stem down but I'm having trouble even finding installed valve spring height to do some checking of where I am. I want to use all the same length pushrods so I don't make that much of a mismatched mess.

So - anybody done this or have advice? My gut tells me it may be possible to adjust into an acceptable geometry is one thing is a little off, but not if everything is a little off. thanks

edit: also I'm missing the water distribution tubes so wondering if I should try to make them of convert the engine to 1960 standard cooling

[peters23]

Looking at the parts catalog, here: https://pontiacsafari.com/
Intakes are the same 58-60 for non-exotic engines.
Exhausts are the same for 58 and 60, but part number differs on 59 for some reason (not sure why).
The 57-60 heads use the same valve head diameters (not sure on length), earlier ones were somewhat smaller.
There is a pretty good chance you can interchange among them.

Finding valves for these early engines is tough.
I ended up re-machining some Ferrea F5146 Stainless BBC valves to fit both intake and exhaust to fit my 1960 389.

You might want to consider going with longer valve stems if you want to run a performance cam and longer springs.

Original 1960 389 valve dimensions:
Intake: 1.882 x 5.320 x 11/32 stem, 30* angle
Exhaust: 1.600 x 5.310 x 11/32 stem, 45* angle

[Safari Larry]

Regarding converting 59 engine block to 1960 engine "conventional" cooling style block, see https://pontiacsafari.com/EngineCooling/index.htm and scroll down to the heading "Engine Differences in Reverse Flow and Conventional Flow"

The 59 engine with reverse cooling first distributes cooling water evenly front to back in each head through the water distributing tubes. Water then flows from heads into the block evenly from front to back through holes in the deck.

The 60 block first sends cooling water directly into the engine block and then up into the heads with more water directed to the back of block and heads. Water flows through the heads towards the front then into the intake manifold and from there into the top of radiator.

To accommodate the difference in water flow and cause most cooling water to flow to back of block, the 60 block has fewer and smaller water holes in the front of deck than the 59 deck. So to convert a 59 reverse flow block to a 60 conventional flow block, you would need to close water passages in the deck towards the front, and I maybe reduce size of some passages.

You would also need to use a 60 front cover and add a water hose from intake manifold water to the front cover.

Does that cover everything? I'm not certain but I think so. I once considered converting a 60 block to 59 reverse flow style but decided against it. Thus the article I wrote to attempt explaining the differences in reverse vs conventional flow blocks.

[captain pickle]

Thank you guys. I guess I'll keep it reverse flow.

I also found all the strange valve uses that Pontiac did, making 58 and 60 the same but not 59, plus all the SD stuff.

I find it odd that overall length of valves is used when a grind on the margin will change the spring height. That is why I was after that dimension so I could check where I was. My question for using 59 valves was that I located some in oversize, but not the 60. I'm trying to avoid replacing the guides so that I do not disrupt the existing alignment of the guides and seats.

I may be looking for "blueprint" level data when backyard close enough is fine for a stock driver.

[peters23]

On these early heads (through 60 anyway) the valve guides are orthogonal (90*) to the valve gasket surface, so placing the head valve gasket surface down on the mill table generally gets them at the right angle.
If placing head gasket surface down you will need a set of 20* angle blocks to get things level.
You can indicate off of the original guide holes and ream for liners.
For completeness the rocker studs are about 11* from orthogonal to the head gasket surface.
For a decent engine machinist with a valve machine this is a walk in the park.

You still need to find valves (and springs) that are close to fitting.
Early engines (through 64) had an open spring height of around 1.530", 65 and later increased to 1.586" to better handle higher lift cams, along with significant head and valve changes.
Many newer performance oriented springs want an installed height around 1.600", so even higher.
Taller springs and valves will give you more flexibility but may need valve cover spacers or taller covers, also will need an adjustable rocker system.

[peters23]

Correction on prior post: "open spring height" in prior post should really be "installed spring height".

You can also get offset valve keepers/locks which can be used to modify the installed height; see:
https://alexsparts.com/valve-locks-keepers/

Many replacement valves will not have the second groove for the O-Ring that Pontiac used for oil control.
While you are in there you can also have the guide bosses machined for Viton style oil seals and skip the O-Rings.
You will need to reduce the height of the boss to prevent the retainers from smacking into the seals.

Converting to an adjustable valve train is also a good idea, especially while heads are off and getting worked on.

[694.1]

I may have some NOS valves around here but the stems would be stock dimension
Might have some gusher tubes as well.
.

[captain pickle]

PM send to 694.1

Thanks again Peters23. Especially for confirming the 11 degree rocker stud angle. That is what I measured when I threaded the bosses for helicoils.

I'm doing the work myself right now, Its a low budget build and I also want to try my had at it. I've reground the valves on another set of 1960 heads and have been working on touching up the seats that have some light rust pits from sitting for 20+years and lapping them in. Then I'll check installed spring height and see what I do from there.

There are some guides already in the heads in question that I was trying to avoid replacing because I know they are concentric with the seats. I'm probably going to have to bite the bullet and replace them and do a carefull job regrinding the seats.

[peters23]

Nice setup work on the Bridgeport!
I have a smaller Rockwell mill which does not have the "nod" so had to get creative and make some angle blocks.
One of my heads differed a bit from the other, had to shim up a bit. Evidently things were not perfect at the factory back in the day.

I am also going to play around with machining the combustion chambers some, to increase volume and reduce the CR.