Looking for early Oldsmobile Rocket knowledge. I am dissecting a J2 motor that was out if a 49 drag car. It had the lumpy valve covers and Isky adjustable rocker arms underneath. Valves springs have gold metal retainers.
Upon pulling the valley cover I found lots of rust and roller lifters.



Heartsick at first I started wiping a cam lobe and it looks encouraging. The cam and lifters almost appear to be coated in assembly lube. There is standing oil in a corner of the valley and in the bottom of the intake. Looks like old school "pickling".
My question is about the lifters. I have not seen one like them. Do any of you have experience with them? Who, might have made them? Does this indicate possible roller cam? Who might know how to clean and refurbish them.
Much appreciate any insight.
Grant

 

Isky roller lifters and the springs above them are their rev kit.

 

That "Rev kit" is definitely a step back in time.

 

Thanks, so far it looks like they went all Isky. Would they possibly run these with a solid cam or only with a roller cam?

 

The "rev-kit" was only used with roller cams. In those days valve springs were not developed enough to control adequately the rest of the roller cam valve train; thus the assist of the "rev-kit"!

 

The dimpled valve covers add bunches to the cool factor, probably repops, originals are impossible to find, repops are getting almost that scarce.
If mine I would take the whole set up to a good machine shop and see what could be saved and what is too pitted, its piece of history. A motor could be made better from new parts(Ross Racing if you have the money and time), but somewhere nostalgia would be lost... Just me... Tedd

 

I fully intend to go for a refresh of this motor and saving as much as possible. I think the valve covers came out of iskendarian stock with all the valve train stuff. Really looking forward to seeing the specs on the cam. I suspect it may have Jahns pistons in it so need to get the heads off.

 

Consider trying an electrolysis bath for some of the rust removal.

 

Couldn't stand it so went to the shop and removed a head. Rockers look excellent so they are a keeper. Heads will need to be done so will try to find stainless valves and have hardened seats installed. Exhaust valves were eaten up.
Cylinders have no ridge, can't even catch a fingernail.
Best can see crosshatch. Second is the worst, don't know if hone would clean it up.



Any one got a guess on compression ratio with this piston? Couldn't find any indication of manufacturer. Bore measuring 4.120 so will need to sonic check it.
Currently assuming pistons and cam will be to much for the street even if salvagable

 

Isky sold the valve covers and supplied them to Oldsmobile.......so the story goes. There were never any "Repops", its the original run of 200 pairs that were manufactured. I think only 200 pairs sounds lower than I would have expected to hear.
Jahns pistons were very popular for Olds pistons, back in the day. I never saw a Jahns piston catalog to know what compression ratio's were available. I do know they offered "forged" 12 1/2 to 1. The stock pistons were pretty much flat, so I am guessing you have forged 12 1/2 to 1 pistons.
Look for numbers on the cam to help figure out what cam you might have.

Compression ratio, see above.
Check the heads closely for cracks.

Since the bore is 4.120", it has been "punched" to 394 cubic inches. I think you should sonic check the wall thickness. You might be able to use an O.S. or custom 394 piston.
Disclaimer: I "think" the 371 and later 371 & 394 pistons have the same piston pin to crown height (now called the "compression height") My 1958 CSM shows 1.895" to 1.898". You need to check the 1959 to 1964 CSM to verify that its the same.
Connecting rod center to center is 6.625" according to the 1958 CSM. I have a 1964 CSM, but I can't find it right now. Charlie Jones will be able to help with his 1963 CSM.

 

Great info, thank you. I am bracing myself to have to have custom pistons. When I have a little bettter knowledge of what I am looking for I will reach out to Tony.
What would max bore be with a 371? I will absolutely sonic check the block. Did the heads have a common place they cracked?
Grant

 

Wow, what a find. Those pics ae really something. Really shows that a person should take a engine that has sat years apart and not just roll it over and try to start it if it is free turning. Can you imagine all those rust grit particles running around it that engine in the oil!? I am following- really cool!

 

The 394 (and '59 & '60 371) rods are longer due to the increased deck height over the "57 & '58 371.
But the good news is that the pin to crown height remained the same.
That is why 394 pistons will work in a '57 or '58 371.
The '57 & '58 heads had smaller chambers than 394's did so a flat top 394 piston that had 10 & 1/2 compression with a 394 head had even more with the smaller chamber'.
Perhaps as much as 11 to 1. Not a problem with 100 octane gas back in the day, but too much now.
That rust pitting will probably require an additional .030 bore, but these beasts had thick cylinder walls.
I think you will be OK, but sonic check them anyway.

The story I got on the dimpled rocker covers was they were made by Olds and sold through the parts dept as part of a package of adjustable rockers and solid lifters.
Later on. the leftover covers were bought by Isky, who had them chromed. And sold them as part of their adjustable rocker arm package.

 

Max bore for a 1957-58 "371" would be based on material thickness in your cylinder walls. Thats where the ultrasonic check for thickness will guide you.
1. "My thought" is to find a machine shop that can precision hone the bores with a honing plate. I can't help but wonder if a 455 honing plate would work, since they are the same bore size (4.125") and cylinder head bolt pattern could be close enough, to see where they clean up.
2. If honing won't clean up the cylinders, then you have to bore them, and cylinder wall thickness will be important. I would try to hold boring to .020" but you may have to go .030".
3. At this point, You need to talk to Race-Tech Pistons or Egge about custom pistons. My question would be, what "slug" are they using for your pistons. Do they use a different slug for 371 (4.00" bore) than the 394 (4.125" bore) ? My reasoning process here is........is it easier to get a .145" O.S. piston for a 371 or a .020" O.S. piston for a 394 ? Since you are getting "custom" made pistons, you should be able to specify the size. When I talked to Race-Tech, custom pistons for my 371 were about $750 a set.
4. I would have the block "decked" for a square and flat deck surface.
5. You should clean the top of about four pistons and mark them #1, 2, 7, and 8). Then measure how far down in the hole they are. When you remove the pistons, you can check "compression height" (piston pin center to top of piston edge (crown). I haven't found a deck height listed anywhere yet, but it does enter into compression ratio calculations.
Head cracks I believe they crack between the intake and exhaust centerline in the combustion chamber. This in generally in the center combustion chambers on #14 heads, but I have heard the same for a few #16's. Note: #14 (1957), #16 (1958) heads.
6. CC the heads for curiosity. I "think" I might have NHRA minimum limits saved someplace, I just can't find them right now.

Thank you Charlie. I thought I remembered what you stated about deck height and connecting rods, but wasn't sure, without checking.
Charlie, you may be partially right about the dimpled valve covers. I do know I have seen five pairs in my life and four sets were in my own hands. The chrome W-1 valve covers I saw were chrome plated locally in Waterloo, Iowa when I was a "boy". The other four sets in my hands have been in the last five years and were not plated. The ones I know about were the leftover stock from Isky.
Now for some nostalgia.......1969 catalog

 

These valve covers have definitely never been chromed. Great information and thank you for sharing the catalog picture. Sounds like custom pistons are in the future no matter what. I could probably get away with 30 over dished 394 with these heads or stock flat tops and a set of Tony's heads maybe. If it is just a couple of cylinders that are bad I would consider sleeves. If the compression height is the same why did flat top 371 pistons yield 9.5 and 394 flat tops 10?
I may not fully understand compression height.

 

" Compression height " is actually a misnomer. But it is common.
The proper term is pin to crown distance.
It is the distance from the centerline of the piston pin to the top of the piston. (Discounting any pop-up or dish. )

Compression ratio depends on a number of factors.
1. The volume of the cylinder.
2. The amount that the piston crown comes short of reaching the deck at TDC.
3. The volume of the pop-up or dish in the piston top.
4. The volume of the combustion chamber,
5. The compressed head gasket thickness.

 

Lets just go step by step and not get to many things going to cause confusion. Charlie is very knowledgeable and has a wealth of experience. Charlie got 394 pistons from Egge, I believe. I am not sure what oversizes they make for 394. In the "old days", piston manufacturers made +.020", +.040". and +.060" pistons. I think they have decided to only offer +.030" and +.060" to reduce inventory. Race Tec can make them any size you end up with and it would all be the same "custom price".
You really need to two things.
1. Hone or bore and hone the cylinder in the worst shape. This would give you and idea what to do. I wouldn't sleeve a cylinder unless you need to.
2. Ultrasound the cylinders because you are already .120" O.S. to determine cylinder wall thickness.

The compression ratio has to be computed with your machine shop's measurements. They used different thickness head gaskets in 1958. The NHRA head CC's in 1958 were different than 1957. I don't know what the 394 had.
Head gasket 1957 is .025" 1958 is .040"
NHRA Head CC's 1957 is 72.0 1958 is 75.0

http://racetecpistons.com/wp-content...structions.pdf
Scroll down to Fig. 2. Dimension "CD" is compression height (piston pin centerline to crown).

 

Great advice that I will follow. I do have a set of victor 57 j2 only head gaskets which may not be the smart choice. Ordered a small valve spring compressor to try and get the Rev kit out. Thank you all for your patience and involvement, it is a big help and I don't take it lightly..

 

Charlie is really knowledgeable and meticulous.
Until you measure the thickness of those head gaskets, you won't know. You need to get your heads CC'd. Because of the "lumpy", 1/8" O.S. pistons and roller cam, I suspect that the heads may have been milled. I hope you are also making the measurements I suggested in step #5 of an earlier post. Write them down, they could be important later.

 

ncboat,
There is a two digit number cast on the top of one of the exhaust ports.
Should be like 17 or 18.
That number will tell us what year engine we are dealing with,

 

Charlie, these are early 57 "14" heads, which match the J2 which is an early 57 setup.

 

Got the engine up on the engine stand finally. Removed the rev kit which was a learning experience. I believe all the roller lifters will clean up and be able to be used. Talked to Isky but they have nothing. Pulled the cam and this is very interesting.
The cam is iskenderian and marked RR3 9207. In a buick or pontiac I can find a rr3
and it is listed as superstreet. Gotta find Isky catalog for oldsmobile.

 

On the internet I found a reference to a Ford Isky RR3 cam as having .440 lift and 286 deg duration, 0.018" lash. I'd make up a fixture with a dial indicator and degree wheel to profile the lobes.

 

That would have been a radical cam "back in the day".

 

I have found rr3's for a 392 hemi and early Cadillac and Buick and all match what you found. Duration of 268 and 440 lift. Valve opening and closing differed a few degrees but duration remained 268.
I am wondering when duration started at .050 or .006.
iskenderian called it superstreet and what I could find may have been engines running constantly at high Rpm. There is a note it would be good in a light vehicle with a stick. What part of the cam specs would gave been considered radical Ralph? Would they be considered radical today?

 

I was referring to the 286 degrees. Stock cams may have only been 240250 degrees and .400? lift or less.

The "measured" duration started at whatever lift the manufacturer decided. Harvey Crane came up with the .050" lift of the valve lifter to rate duration for his cams, when most cam makers where using .004", .006" etc. whatever the car makers used. Harvey's big advertising campaign was how Crane Cams made made more power with less duration than other cams. Now, this sounded like Harvey Crane made a discovery that made his cams provide more power than any other manufacturer. WOW. if you were reading a hot rod magazine, you wanted a Crane cam, right ?
Harvey Crane saw on a flow bench that "appreciable air flow" through the valve throat didn't begin til the valve was .050" off the seat. Over the years all cam manufacturers started rating their cam duration at .050" lift.

 

Talked to Ron Iskenderian last night. Very nice conversation and he was very helpful.
cam specs as I have them:
Intake 34-72 Exhaust 72-34 duration 268 (248 @ 50) lift 440 w 1.5 rockers
lash .18
Ron commented this was a mild cam. I will have to get new springs and replace the aluminum keepers.

Camcraft is here in the state and I am going to try and see them in May. They were very positive about working with this roller cam.

I am going to do my best to include it in my build along with roller lifters and rev kit.

 

A good choice would be the '58 thru 64 " beehive " valve springs and retainers
They should drop right in. At one time they were spec'd to replace failed '57 springs.
You will need to use the later style valve stem seals too.

 

Do some checking because I thought Olds rocker arm ratio was 1.8. The 1958 CSM doesn't tell, but NHRA Tech specs show them as 1.8 for 1957 and 1958.
Back in the 50's, 268 degrees was pretty hot. Do you mean replace the aluminum retainers ? I think you'll want 10 degree retainers and "split locks".
Camcraft is my choice for a 1957-58 cam. .

Thats nice to know.

 

The Isky adjustable rockers that I have are 1.5. I assume when you bought "the" kit you had to make the switch. I suspect this car was running a modified class, certainly not stock.
When talking to camcraft I said maybe I should drop the roller and just go with one of yours. He said heck no you've got the roller let's try and save it. My kind of shop.

 

I am curious what they did to change the rocker arm ratio that much. The distance between the valve stem and rocker arm shaft centerline would have to be the same distance on both the 1.5 and 1.8 rocker arms. The only thing to change the rocker arm ratio would have to be the push rod end distance to be increased, which might require elongating the push rod holes in the head.

Where (AMA, NASCAR, NHRA, etc.) the engine was used would answer a few questions. A roller cammed engine wasn't widely used because of the cost.

I have been impressed from my talks with Hunter at Camcraft.

 

Started cleaning using WD40 and a brush. It actually works pretty good on this. I wanted it to drain into the pan so I could drain it before turning it over. I will have the block hot tanked but I am encouraged by how it cleans up. I accept it will need new pistons because the compression would be to high with these. The question Is what size.

 

I never found online a copy of the Isky roller cam page for the 371. I splurged and bought a copy if the 1961 Iskenderian catalog. I thought I would post it here in case someone else needed it. Part of the fun is look at the prices. Also of note is the listing for the dimpled valve covers for $15.00.

 

I never found online a copy of the Isky roller cam page for the 371. I splurged and bought a copy if the 1961 Iskenderian catalog. I thought I would post it here in case someone else needed it. Part of the fun is look at the prices. Also of note is the listing for the dimpled valve covers for $15.00.

 

Definitely an Isky set of Roller lifters and springs. Either 505 Magnum or 550 Leguerra Roller cam. Both made for revving higher than a 57-58 Olds was meant to go. I know from experience. Plus the spring tension from the spring on lifter will cause premature lifter/cam surface failure. If all else good, remove those springs and run with just the dual springs atop the valves. Should have a really wild idle. Ran similar set-up in a 50 Olds Coupe. Engine bored 394, dual quads, Vitar Hydro-stick. Spun a rod bearing at least 4 times from going up to 7,000 rpm in 2 & 3 gear. Ran 4.30/4,56/4.88 & 5.38 gears. 4.30 best. I've got valve gap settings somewhere for this setup

 

Cam is an iskenderian RR3 which is currently at camcraft. They will determine what they are able to do with it. Looks like I will use Lunati rollers and sleeve the lifter bores.

 

Were you using stock 371 connecting rods ?

 

The engine was bored to 394 ci with Jahns pistons, full floating pins on stock rods.

 

Yes. Learned too late that they stretched under high rev loads. Had Jahn's 10.5 pistons, P,P, & CC'd heads to 11:1 comp. Should have gotten Aluminum rods and Nitrided the crank. Long ago in a distant Galaxy.

 

Dang.