[MJVAUGHANS]

Originally Posted by Pontirag

-- but if you go with the 1.65 rockers you will cant to make sure ther is no interfearance with any other part, the main concern seems to be the cylinder head wher the push rod go through.

In your opinion, should I use 1.5 or 1.65 ratio rockers? I was thinking 1.5 because that is what I thought the stock ones are. Would the 1.65 benefit me? This is a restoration and in no way a performance project. Upgrades are great along the way, but I am most concerned about reliability.

[Pontirag]

Too many variable to consider to give you an absolute yes or no answer. Personnally I would not hesitate to go with 1.65's. cheap easy way to gain HP. But I would have to evaluate the condition of the engine first. you cant polish a turd

HP pontiac magazine's Rocky Rotella did an article on 1.65's just a few months ago and some comments were made here on it, including some by me. do a search and look up the back issues of HP Pontiac.

if its a low milage engine then it would not strain the engine too much to go with 1.65's

but if its only a 2 bbl engine them I would go with a 4bbl and duals first. just check valve train geometry afterwards to make sure your still good.

[tom s]

dont mess with them for your build,juice aint worth the squeeze.Tom

[MJVAUGHANS]

Yes it has very few miles on the build but I am uneasy about the condition of the cam lobes because I am not sure I broke it in correctly after the rebuild. It has the 2 barrel Bendix-stromberg WW and I had some trouble with setting the timing and carb adjustment initially. It has been bored .060 over, has a complete oem replica exhaust system(small diameter single) and has most of the original parts in it overall. I just want a reliable smooth running engine. To be honest I was a little surprised that finding replacement upgraded rockers would be soo difficult and all of this talk about having to verify the geometry, pushrod length may need to be different, changing the studs to larger screw-in type, elongating the pushrod holes, pushrod oiling may drop the oil pressure. This just sounds like a total PITA! I still have not found anyone local that I feel understands the details of this engine and does not want a blank check to help me. The only reason I don't just replace the rockers with the stock ones off ebay is because I don't know if the studs are oiling.

[Jack Gifford]

Originally Posted by MJVAUGHANS

... The only reason I don't just replace the rockers with the stock ones off ebay is because I don't know if the studs are oiling.

There's a very old thread titled "Help! 389 advice needed!" in '62-66 Big Pontiac TECH' forum, which I just bumped to the top for you. Please read my posts to that thread regarding stud oiling. I hope it will help you determine the status of oil to your studs. Also, one of my posts there has a list of items that could prevent oil from reaching the studs.

For whatever it's worth: the question of 1.5 versus 1.65 ratio rocker arms is moot. I'm not aware that anybody ever made an early ('55-58) 1.65 rocker arm, even back then.

[Pontirag]

best bet then is to stick with stock but read hendricksons and osterstocks Pontiac High Performance publication. it was written back in the day when ther was vertually no HP equipment for the early pontiacs. read it and study it so you are not at the mercy of the nay sayers and fear mongers. Remember... Pontiac raced these engines. the earliest ones were theoreticaly the purest of the racing breed. its only later that they got lazy and simply bored and stroked every year to overcome epa castration.

Since GM no longer supports the early pontiacs, the Rotella article on the 1.65's is all the more interesting and informative. that along with hendricksons and osterstocks book should get you closer to the mark.

the whole geometry issue is because many rockers that claim to be 1.65 dont even come close, I recall some builders would order up and buy like 100 rockers at a time and measure each one to get several sets that were at least 1.65 or more. thats where geometry issues come in. Consistancy is much better today but its important to at least know what you got because Off shore(chicom) brands can still be out there.

dont be afraid of your engine, its a Pontiac, It will eat chit and spit the bones out

[Safari Larry]

Originally Posted by Pontirag

... all speculation aside, the 55 lifters are unique. Lots of piffle banter and blather on what the difference is but no hard facts.

See attachment for some hard facts from October 1955 "Pontiac Service Craftsman News". Four types of lifters were used in 1955, three of them are explained in the Shop Manual, the fourth is explained in a Service Craftsman News.

[MJVAUGHANS]

I like that it is a Pontiac motor and I defend them all the time against chebbie sheep. I especially like to point out that Pontiac/GMC was the first with the 288 OHV V8 in a truck and not the 265 because I am a diehard truck guy. It is just the idiosyncrasies that are bogging me down.

[Pontirag]

yes very much worth it

I would get a copy of Jim hands book, he goes into great detail about the benifits of 1.65 rockers. and what may be required to install them. and thirty years earlier(?) Hendricson and Osterstock also went into some detail , in thier book about the 1.65's and valve train geometry. In fact in a second book they wrote more specifically about HP Parts that were available back then, they go into additional detail about 1.65 installation requirments.

hands Book,Rocky's book and both books written by Hendrickson and Osterstock,
I would also get Angles and McCarthy's book as well. they should be on every Pontiac fans book shelf

I would seek out a copy of Rocky's magazine article on the 1.65 rockers sold by Melling

I did a bit of research on Mellings rockers and was able to get a part number and a source of vendors who sell Mellings products as Melling does not sell the 1.65 directly to the public. I dont recall the specifics but a search will bring the thread back up and again Rocky's article gives alot more specifics.

Both Hand and Hendrickson and osterstock deal with installing 1.65 rockers and valve train geometry related to the installation of 1.65 rockers and also in more general terms.

another interesting point brought up by hendrickson and Osterstock was the use of an offset woodruff key for the cam gear.that too is in thier book. but you'll have to get a copy and read it for yourself.

And dont worry about your engine, they were tough enough to use in GMC trucks rated up to like 2 tonnes under warrenty no less.

[tom s]

Guys,1.65 rockers like RA IV and RA Vs wont work on the early heads!Maybe chevy,for sure 62-63 421 SDs would and with some care a roller tip will.Be very careful on the road you take.You will fo rsure need screwin or pinned studs.Tom

[Pontirag]

why wont they work?

[Jack Gifford]

Originally Posted by Jack Gifford

There's a very old thread titled "Help! 389 advice needed!" in '62-66 Big Pontiac TECH' forum...

MJV- posts #6 & #7 of that thread tell how to check stud oiling. Have you done that yet?

[Safari Larry]

Originally Posted by Jack Gifford

MJV- posts #6 & #7 of that thread tell how to check stud oiling. Have you done that yet?

That's a great discussion on top end oiling! Go directly to it at this link.

[MJVAUGHANS]

Jack-yesterday I was able to finally rotate the crank while spinning the oil pump and I got oil to squirt out of every one of the studs on the drivers side! I did not try the passenger side yet but i was surprised and happy that it does oil. I want to check the otherside to be sure. So if they both check out, that means it oils crappy. Maybe that is normal though?? I just think it should have more than that circulating. I have 2 rockers that are different color because of the heat on them.

But, it appears that no one makes or has ever made roller tip rockers for the 287 and it is not the same as any of the later models so i am only left with the stock stamped steel. Even if i installed 7/16 studs the rockers I bought would still have the wrong spacing.

[Pontirag]

the rockers you bought were described as fitting a 287? like a NOS or NORS rocker?

[MJVAUGHANS]

This is what I bought:
PRW 0845501 1.52 x 7/16" Sportsman Steel Roller Tip Rocker Arm for Pontiac 287-455 and 4.3L V8 1958-81.

It said 287 pontiac, I figured the 7/16 stud size was just a recommended upgrade so that did not alarm me too much, and it was 1.5 ratio which is stock. Bottom line is I was sucked in by the listing and it is WRONG.

I am going to return them and decide what I want to do. I may do some experimenting.

[Bill Hanlon]

Originally Posted by MJVAUGHANS

I have 2 rockers that are different color because of the heat on them.

I had a rocker start squeeking on my '57 GMC (Pontiac) every day driver about 10 years ago. I pulled the rocker and turned a real small drill bit into the hole on the side of the stud by hand. I shot some brake cleaner into the hole 3 or 4 times, letting it sit for 5 minutes or so between applications. I put some moly assembly lube on the ball and rocker and re-installed. Left the valve cover off and started the engine. Within a minute oil was flowing (slowly, like the others) in the rocker. Bolted the valve cover back on. 50,000+ miles later the rocker is still on my truck and apparently working OK.

These stud oiled rockers don't move near as much oil as the pushrod oiled rockers we are used to seeing.

By the way, since that squeeking I have gathered 16 of part number 522974, Kit - Valve Rocker Arm for 56 (not 55) through 59 (and maybe later) Pontiacs. Kit consists of rocker arm, ball and pushrod. Bought them a few at a time on eBay.

[MJVAUGHANS]

Bill-Well what you say makes me feel a little better about mine because they don"t look like they are getting very much oil at all and everyone that has ever looked at it makes a comment about how little oil is flowing in the heads. Still playing around though.

[MJVAUGHANS]

Originally Posted by Jack Gifford

[I need to search old notes to remember which rocker arms worked for me].

Jack-Do recall which ones you used?

[Jack Gifford]

I only remember that they were from a junkyard SBC engine, I think from the seventies. I still need to look through old boxes of parts and old notes; be patient...