Modified Buick 320ci Straight 8 Engine

BuickSedanette

New Member
Hello
I own a 1950 Buick with 320ci Engine. I was always believing that it was equiped with hydraulic lifters.
Now I have found out that my 320ci Straight 8 engine does not have the standard hydraulic lifters. It is running with solid lifters, please see attached pictures.
As I need to change several push rods I do not exactly know if I can follow to the valve lash adjustment regarding the specs of a solid lifter engine like the Buick 40 or 50 series.
Also I have already contacted oldbuickparts.com to ask for pushrods that measures 13.38 to 13.46 inches, but unfortunately they dont have them and even dont know a source to buy such.
What would be a good reason to have the hydraulic lifters changed to solids?
Many thanks for any help!!!
 

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I can't imagine any advantage. Are you certain it is actually a 1950 engine in your 1950 Buick? Engine serial numbers (located by dipstick) start with 5635021-7 for 1950.
 

BuickSedanette

New Member
My engine number is 67415347 located by dipstick. I think the camshaft has been modified and that was the reason to change the lifters to mechanic. However I need these pusrods and dont know where I can buy such...
 
These fellow will build push rods to whatever length you require: https://www.pushrods.net/

The ends of the I8 push rods which I have dealt with simply push on and can be easily removed with a with a slide hammer with a end built similar to the image below. You must be careful pushing the ends back on to not push then too far and bend a rod. I would recommend experimenting with a few old rods first.

The valve train is adjustable, so the length just has to be approximate to allow the oil passage in the adjuster to be open to both the push rod and the rocker arm.

Solid lifter push rods are much longer because the rods seat near the bottom of the lifter.
Here is a video removing a push rod end:
https://youtu.be/-vUzw9f_W5Y

The 320 from '48-52 all ran the same push rod part number.
The reason someone would change to solid is they are after performance. It would be quite likely that the builder would have had the camshaft reground to take the best advantage of the solid lifter. If so, it is possible the ramps may be ground a little steep for hydraulic lifters.

I am reading your number as a 320 too. Double check with 263 rocker cover is about 30 3/4" long and the 320 rocker cover is about 33 3/4" long as found here: https://www.teambuick.com/reference/ident_engine_til_52.php
 

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Buick started using hydraulic lifters on the 320 part way into the 1948 model year. See attached dealer service bulletin from '48 that details changes made to accomodate the hydraulic lifters.

The 320 mechanical lifters used a no 1319209 pushrod on '41 to early '48 cars. It was part of a pushrod kit no 1393664 which included the pushrod, stud, and nut. Www.buickfarm.com shows to have these in stock. Examples show up on eBay as well and indicate an overall length of 13-11/16" with the tips in place. Maybe this is the part used in the rebuild of your 1952 engine. If the rebuilder used parts for a 320 before '41, the part nos are different.

The lash adjusting procedures (road test or shop method) are the same for the 248 and the 320 by looking at a couple of shop manuals from '42 and '48.
 

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BuickSedanette

New Member
Hi there
These are all very helpful information. Many thanks for that!
I have contacted buickfarm.com and asked for the correct pushrods. Second option will be the Smith Brothers for custom pusrods.
Many thanks again for getting me a plan to get the correct pushrods for my modified 320ci staight 8 engine!
 
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