Roller Rockers for Alpine Engines (not V6)

[alpine_64]

I have no idea! I think the guy who built my engine 20 years ago must have selected them and determined the right size.

Is there a reason it's relevant?

I just remember that isky used to do hollow cromoly pushrods but they were different to stock. Iirc jarrid had mentioned they wwre slightly different size and also weaker than stock ( this was around 2003.... So might be best if jarrid chimes in)

 

[Jay Laifman]

Here are pictures of the shorter stock pushrod from Sunbeam Specialties next to the lighter but longer ones I had in my car.

 

[RootesRacer]

I just remember that isky used to do hollow cromoly pushrods but they were different to stock. Iirc jarrid had mentioned they wwre slightly different size and also weaker than stock ( this was around 2003.... So might be best if jarrid chimes in)

I had never had any experience with the Isky parts till Chris Albers engine builder (Taylor engines in Whittier CA IIRC) used them and Chris called me over after his startup that the engine was running weird.

I suspected valve adjustment and when he pulled the valve cover off, it was clear he had a bent pushrod.
Not sure of the "how" on the bend but considering it was just low RPM break in, the strength of the pushrods came into question.

I dont recall if he got a single replacement from Isky or if he got an NOS set.
The engine went on as normal after whatever replacement he came up with.

I will also mention that I bought some sunbeam isky lifters thinking they would somehow be magic and they turned out to have thicker walls and were substantially heavier than stock ones. From what I recall, those that used isky lifters in racing sunbeams would drill lots of holes through the walls to lighten them. I ended up not using them.

 

[DanR]

Here are pictures of the shorter stock pushrod from Sunbeam Specialties next to the lighter but longer ones I had in my car.

Jay, The push rod on the left in 2nd PIC's is like my SV 1725 ones....

DanR

 

[Jay Laifman]

I have measured the ratio.

I got .306" for my cam lift. I have a Holbay H120 cam. I hope that matches some Holbay cam.

For the stock rockers I got .442" of movement measured on the spring retainer.

For the roller rockers, I got .456" of movement.

.442/.306 = 1.444

.456/.306 = 1.490

I had ordered "stock." So I would have expected closer to 1.4:1. If my measurements are correct, I got closer to 1.5:1. The big question now is if I have clearance for that extra .014".

The rockers and shorter pushrods are all in and gaps adjusted. With that, I'm getting .431" movement of the valve at the spring retainer.

.431"/.306" = 1.408

Looks like they are dead on the 1.4 stated factory ratio.

I won't be able to run it until probably late Saturday due to commitments. But all I have to do is put the side plate back on and change the oil.

 

[Jay Laifman]

Installed and running nicely. Sadly, the one thing I was hoping to fix was valve train tapping noise - and the tapping is now louder! Is that a characteristic of roller rockers?

I'm going to run the engine with the valve cover off and see how much oil comes out of the holes on the rockers. I've seen various comments on this board about the oil just weeping out of the stock holes, to some people saying that it sprays around. Is there a "correct" version? I know that mine basically weeped at idle before. I'm wondering if I'm not getting enough oil to the rockers - though they certainly don't look like it, and if I don't have a good valve cover gasket, I definitely get oil leakage!

 

[RootesRacer]

Installed and running nicely. Sadly, the one thing I was hoping to fix was valve train tapping noise - and the tapping is now louder! Is that a characteristic of roller rockers?

I'm going to run the engine with the valve cover off and see how much oil comes out of the holes on the rockers. I've seen various comments on this board about the oil just weeping out of the stock holes, to some people saying that it sprays around. Is there a "correct" version? I know that mine basically weeped at idle before. I'm wondering if I'm not getting enough oil to the rockers - though they certainly don't look like it, and if I don't have a good valve cover gasket, I definitely get oil leakage!

What did you set the lash to?

 

[Jay Laifman]

Good question. I did Alpine stock -.012 intake and .014 exhaust. But, I was just thinking as I set them if the Holbay cam requires different settings or different method. I'm pretty sure the Holbay called for the same gaps. But I don't know if it is the same procedure. The stock procedure, for example says to do 4 when 1 is fully open, etc. Doesn't the Holbay cam position the lobes at different locations, and would that impact the procedure for setting the gaps? I don't think so - since 4 cylinder, 4 stroke is the same with the same firing order. And it is still exhaust to exhaust setting. And the Holbay difference is intake to exhaust lobes, not exhaust to exhaust. But, I was thinking about it before.

 

[Jay Laifman]

Here is what Harland Sharp says about settings:

Follow cam manufacturer guidelines. Each application will vary. Hydraulic cams with stock rocker arms normally require 1 full turn tighter
from zero lash (no clatter). Roller rocker arms should be tightened no more than ½ turn from zero lash.

I actually don't understand how they say to do manufacturer guidelines, and then give details for setting.

 

[Jay Laifman]

I just found a post saying that the stock Holbay setting is .013 intake and exhaust. All my Holbay docs are at work. So I can't check. I might try the .013 setting and see if that changes anything.

 

[Jay Laifman]

Grrrr. Dang forgetfulness. Can't say rookie error. In my eagerness to share the progress, I forgot that the lash has to be reset after warmed up. Much better. We'll see tomorrow morning whether or not the old tapping is also gone.

Please pardon my digression.

 

[RootesRacer]

Grrrr. Dang forgetfulness. Can't say rookie error. In my eagerness to share the progress, I forgot that the lash has to be reset after warmed up. Much better. We'll see tomorrow morning whether or not the old tapping is also gone.

Please pardon my digression.

Yeah, my next question would be if you set them again hot.

Higher lift rate cams usually have lesser lash settings than stock cams.
I set mine to .012 intake and .014 exhaust which is .002 tighter than stock.

If you are up on keeping the lash in check, you can tighten them a bit more yet for more quiet operation but you have a bit more risk to deal with.

 

[Jay Laifman]

All is good! The silence of the rockers and the old clacking being gone is music to my ears!

I think I will go to the first post and updated it so people don't have to read the whole thread!

 

[Alpine 1789]

I think I will go to the first post and updated it so people don't have to read the whole thread!

What a great idea! This would be a best practice for anyone who starts what turns out to be a long, involved discussion. I will try to remember this the next time I find myself in a similar situation.