1.6 Rocker Arms for /6

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bill find out what they do to deheat treat also what temp and how long they heat treat we have a heat treat at work I also have a good sized oven that I could use
I also have a awesome tig welder and a couple spare sets of rockers

on a different note bill I installed a rev manual valve body and a deep trans pan on that 904 I had yesterday and I'm getting all the parts and pieces to start my Turbo header I just ordered 400 bucks in butt weld Eli and a merge collector
aaron
 
twofosho said:
To change (increase) the ratio you need to either move the pushrod pocket closer to pivot point (center of the rocker shaft in this case) or lengthen the distance from the pivot to center of the valve. A longer arm on the valve side of the rocker would also require you to move the rocker shaft farther from the valve stem to keep the tip of the rocker centered on the valve stem). Pushrod length would change only if a change was needed to keep the new configuation rocker arm (different ratio in this case) sweeping accross the center of the valve stem as it moves up and down following the cam lobe. Hope that makes it a little clearer.
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Back in the dark ages (my youth,) I used to try to make my '51 Olds 88 "fast" (on a severely-limited budget.)

One thing I discovered was that the original 1.5:1 ratio rockers that Oldsmobile used from '49 to '51, were superceded by some 1.8:1 units, in 1952 (but with a cam that had less lobe lift.) Then, in 1955, the '49 cam went back into the (new) models, WITH the 1.8:1 arms... cheap hop-up for Oldsmobile (and ol' Bill!!!):colors:

This rocker ratio juggling has (obviously) been around for a long time...

The 1.8:1 arms picked my car up three tenths (three car lengths!)

I was a convert... :)
 
I've discussed this with Bill and have actually modified the factory arms. I made the cut closer to the adjuster bolt. Nothing fancy, .070" cutoff wheel and mig welded back together. I think the ratio is in the area of 1.58:1. I never checked each arm individually to see their difference but I immagine they are no different than the variences experienced in the factory arms. I never ran them in a race environment as I hurt the old engine before I could get them on. I did have them ready to go since I put them on the car & lashed & numbered them so I could make a quick change at the track.
 
twofosho said:
Unless you're a good enough machinist to take some chunks of heat treated 6061 and whittle out new pieces from scratch, it seems like it would be a whole lot easier, cheaper, and more reliable to just have a cam ground to the specs you want end up with using the stock rockers, and not screw around with modifying them.
I have wondered how practical an idea it would be to redo the rocker shaft stands to accommodate some sort of high ratio V8 rockers and shafts, or if there's even room in the slant head for those kind of shenanigans, although I bet Madmax or Mr. Dutra have or would have gone down that road if it was viable.
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well i have been doing alot of looking and its hard to find a cam what has a lobe lift of say .400 with a duration that makes the 6 still usable... for us guys with stock bottom ends i dont want to push over 6200... so im running at 6K right now with 246 @ .050... in order to get a cam with that much lobe lift i would have to be in the 265 @ .050 range... usless...
 
Aftermarket cast iron rocker arms are mentioned in a lot of the early-'60s Slant-6 buildup articles. About a decade ago I found a set, new old stock in a mouldering box. Snagged 'em, cleaned 'em up, and stashed 'em.

The box says "1960-62 Valiant Lancer Plymouth Dodge 170 225 6cyl 1.6 ratio Intakes Only". I'm not sure why the admonition not to use them on the exhausts. Perhaps the thinking was that rockers like these would only be used with a camshaft much biggger and compression much higher than stock, and using these 1.6:1 rockers might cause the exhaust valves to smack the pistons...? Seems odd to me. The old buildup articles show them being used on intakes and exhausts.

The casting quality is really nice and I might've installed them on one of my engines the last time I had the top end open, but I noticed that these rockers have only one oil passage, from the shaft bearing rearward to the adjustor/pushrod area. There's no oil feed to the front of the rocker. That's no good for valve tip/rocker tip lubrication. I also thought to add the missing passage, but that seems like very delicate work, and I'm not familiar enough with casting intricacies to assess the risk of breaking or otherwise ruining a rocker in the attempt to drill the forward passage.

So, here're the pics:

gotha1.jpg
gotha2.jpg
gotha3.jpg
gotha4.jpg
gotha5.jpg
gotha6.jpg
 
srixon4406 said:
bill find out what they do to deheat treat also what temp and how long they heat treat we have a heat treat at work I also have a good sized oven that I could use
I also have a awesome tig welder and a couple spare sets of rockers

on a different note bill I installed a rev manual valve body and a deep trans pan on that 904 I had yesterday and I'm getting all the parts and pieces to start my Turbo header I just ordered 400 bucks in butt weld Eli and a merge collector
aaron
Click to expand...

Aaron,

I have an appointment on Friday to show the heat treatment guy the rocker arms and he will determine the temperature for the annealing process, then, and set up a Rockwell hardness test to determine the Rockwell number.

The re-heat-treating, after the cutting and welding, can restore the original Rockwell hardness to the arms. I will attempt to get the numbers of the hardness and the oven temperatures, so you can duplicate the process at your work.

That would be so COOL, if you could duplicate the entire process at your work!

I'll get back to you on Friday and tell you what I learned.

On a different tack, I am relieved that you decided to go with the 904 instead of a manual 4-speed. I have NOTHING against 4-speeds... they are a lot of fun, and generally a bit quicker than an automatic, but I think, in this application, given the situaton (slant-six TURBO,) a 904 is the best choice. My hat is off to YOU, for having the flexibility in your thinking, to make this decision, having been so far down the road to a 4-speed setup.

Not many of us would have the maturity and lack of "ego" to do that. I really admire that.

I will be very interested to see your tubing header, when it's finished. I think we might have made a mistake in designing our header with long pipes, because of the possibility of heat loss through the (considerable) length of tubing walls on the way from the head to the turbo; I hope you're able to get around that glitch... make it as short as you can, would be my advice. Remember; heat + horepower, when it comes to turbo exhaust impellers!

Having just spent $400.00 on pipe, I'm sure you can imagine how we got $1,000.00 in the one we built, with having driven 400 miles (round trips) to get it T.I.G.'ed, and another 400 miles to get it coated. Plus the cost of the welding and coating...

Good luck, and don't forget the wastegate... LOL!!!:eek:ops:
 
slantsixdan said:
Aftermarket cast iron rocker arms are mentioned in a lot of the early-'60s Slant-6 buildup articles. About a decade ago I found a set, new old stock in a mouldering box. Snagged 'em, cleaned 'em up, and stashed 'em.

The box says "1960-62 Valiant Lancer Plymouth Dodge 170 225 6cyl 1.6 ratio Intakes Only". I'm not sure why the admonition not to use them on the exhausts. Perhaps the thinking was that rockers like these would only be used with a camshaft much biggger and compression much higher than stock, and using these 1.6:1 rockers might cause the exhaust valves to smack the pistons...? Seems odd to me. The old buildup articles show them being used on intakes and exhausts.

The casting quality is really nice and I might've installed them on one of my engines the last time I had the top end open, but I noticed that these rockers have only one oil passage, from the shaft bearing rearward to the adjustor/pushrod area. There's no oil feed to the front of the rocker. That's no good for valve tip/rocker tip lubrication. I also thought to add the missing passage, but that seems like very delicate work, and I'm not familiar enough with casting intricacies to assess the risk of breaking or otherwise ruining a rocker in the attempt to drill the forward passage.

So, here're the pics:

gotha1.jpg
gotha2.jpg
gotha3.jpg
gotha4.jpg
gotha5.jpg
gotha6.jpg
Click to expand...

Dan, thanks a lot for sending those pix, along with the explanation!

That was really interesting!

I had heard that cast rockers were made, but had never seen any.

You always have valuable information to share. Thanks a lot for frequenting this BB.... we all appreciate it.
 
Shaker223 said:
I've discussed this with Bill and have actually modified the factory arms. I made the cut closer to the adjuster bolt. Nothing fancy, .070" cutoff wheel and mig welded back together. I think the ratio is in the area of 1.58:1. I never checked each arm individually to see their difference but I immagine they are no different than the variences experienced in the factory arms. I never ran them in a race environment as I hurt the old engine before I could get them on. I did have them ready to go since I put them on the car & lashed & numbered them so I could make a quick change at the track.
Click to expand...

Tom, I appreciate your input... especially, since you've already done this.
Could you possibly take a picture of one of those modified arms, so we can see how it was cut?

Curious minds want to know... :)

Thanks for the info!!!
 
I ran these for about 30 minutes on a stock head. Not the greatest welding but had no issues. Oil made it to the push rod ball/cup with no issues.
 

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Shaker223 said:
I ran these for about 30 minutes on a stock head. Not the greatest welding but had no issues. Oil made it to the push rod ball/cup with no issues.
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Tom,
Thanks a LOT for the pictures! Was it dificult to weld that heat-treated metal?
 
The welding did seem a little more difficult than mild steel. The nice part is you can weld 360 degrees around the cut and maintain its strength. TIG welding would work nice here. As you can see, not much heat is put into the arm. I used a standard cut off wheel. .070" I believe. It moved the ratio to around 1.58:1. Stock push rods would work but only marginally. I had to run the adjuster in quite a ways for the distance change. To do it right, new push rods would be in order.
 
It's a little off topic....but these rockers are 2:1, OHC, and have rollers that contact the cam, and have hydraulic lash adjusters at the tips.
 

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I talked to the owner today of
http://www.harlandsharp.com/products.htm
and had a long talk about him make up some sets of 1.6 billet roll rockers he told me he was way to busy right now but maybe in March he would be willing to start the process of making a couple sets they look to be a very nice product does anybody no of this company there out of Ohio and honestly he sounded very willing to tackle the project
Aaron

One more thing there rocker arms are warranty FOR LIFE!!
 
srixon4406 said:
I talked to the owner today of
http://www.harlandsharp.com/products.htm
and had a long talk about him make up some sets of 1.6 billet roll rockers he told me he was way to busy right now but maybe in March he would be willing to start the process of making a couple sets they look to be a very nice product does anybody no of this company there out of Ohio and honestly he sounded very willing to tackle the project
Aaron

One more thing there rocker arms are warranty FOR LIFE!!
Click to expand...

lol ever heard of harland sharp??? lol
 
I have talked to Harland sharp before to and they said no how no way. So I guess the ones "ordered" from RAS didn't pan out?
 
Haven't heard back from them and been a tad bit busy,but I guess it's time to rattle a cage and see where we are on these !!
 
6pakattack said:
Haven't heard back from them and been a tad bit busy,but I guess it's time to rattle a cage and see where we are on these !!
Click to expand...

Rattle rattle i have a set ready to start cutting apart I got my tig welder over the weekend but I still have to get a bottle of gas and some tungsten but maybe this week I'll post a couple pics
Aaron
 
srixon4406 said:
Rattle rattle i have a set ready to start cutting apart I got my tig welder over the weekend but I still have to get a bottle of gas and some tungsten but maybe this week I'll post a couple pics
Aaron
Click to expand...


I am working on an identical project, trying to make a fixture to hold the arms for precise cutting, and another, slightly modified version of the same fixture to hold the two pieces together for welding.

A lofty goal for a guy who has trouble making an edible omlette...:violent1:
 
Let me know how these projects go,I'll have two sets of rocker arms sitting here if anyone decides they want to make more 1.6's !!!:prayer:
 
slantsixdan said:
Aftermarket cast iron rocker arms are mentioned in a lot of the early-'60s Slant-6 buildup articles. About a decade ago I found a set, new old stock in a mouldering box. Snagged 'em, cleaned 'em up, and stashed 'em.

The box says "1960-62 Valiant Lancer Plymouth Dodge 170 225 6cyl 1.6 ratio Intakes Only". I'm not sure why the admonition not to use them on the exhausts. Perhaps the thinking was that rockers like these would only be used with a camshaft much biggger and compression much higher than stock, and using these 1.6:1 rockers might cause the exhaust valves to smack the pistons...? Seems odd to me. The old buildup articles show them being used on intakes and exhausts.

The casting quality is really nice and I might've installed them on one of my engines the last time I had the top end open, but I noticed that these rockers have only one oil passage, from the shaft bearing rearward to the adjustor/pushrod area. There's no oil feed to the front of the rocker. That's no good for valve tip/rocker tip lubrication. I also thought to add the missing passage, but that seems like very delicate work, and I'm not familiar enough with casting intricacies to assess the risk of breaking or otherwise ruining a rocker in the attempt to drill the forward passage.
Click to expand...

If these are the same as "Gotha", don't bother finding them. I can ship you a half dozen broken ones and you can put those on display. These rockers can not take high spring pressures or high rpm's. Still cool but not raceworthy.
 
Here some pics I was bored working new years eve last night so I had some time to work on the 1.6 rocker arm idea that me and Bill were discussing
imagejpeg_3.jpg
imagejpeg_4.jpg
imagejpeg_6.jpg
 
So is it the Kerf from the cutting blade that changes the fulcrum point to 1.6 ?? And,would you be offering your services as I don't have the smarts or tools to do this !!:prayer:
 
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