New 408 build finally started

-
Bobzilla said:
I just had a thought. Remove the exhaust rocker and pushrod to get them out of the way. Use feeler gauges between the shaft hold down and intake rocker arm, on the intake port side. Keep adding feeler gauges until the pushrod goes in and you have ample clearance. My guess is the .350" you already have built in plus whatever the feeler gauge reads should be the correct amount of offset. Does not cost anything to try, and should show if a reasonable offset will work.
Click to expand...

Good idea.
 
9228879E-3BB8-49F1-B602-2A1B0412B6E9.jpeg
1F8AE565-976A-40AC-B5CC-4731BF5580D0.jpeg
04F2C22D-D292-4B98-A597-96B35A0E0096.jpeg
My rocker. Hugh’s big mouth rocker .350
 
With the side loading on small block heads like W-2 and Indy has anyone ever ran a torrington bearing spacer set up on the rockers?
 
justinp61 said:
With the side loading on small block heads like W-2 and Indy has anyone ever ran a torrington bearing spacer set up on the rockers?
Click to expand...


Always. If you are under 260ish on the seat it’s probably ok if you are using iron rockers with a hardened shim in there. With aluminum it’s gets worse. Once you go over that you need a Torrington bearing in there or it will just keep eating the rockers and making a mess.

I narrow the exhaust rockers and put a bearing on each side of it. I’ve been over 340 on the seat and it’s a must at that level. If not, it eats power like the hamburgerler on a Micky D’s nasty burger. And junks the rockers.
 
I’ve gotten about 500.00 in bills from my skin cancer issues so that hit me hard too. I’m sure more will be coming.
 
justin
I've had customers use needle bearings
they claim even "BIG" hp gains
I'd do it
i do not like al to al anyway
PRH
the adjusters should be at different angles, not that they are
and different arm lengths
not that something might work with different length valves
have you tried them?
cheers
 
@yellow rose with 340 on the seat, what were you at rolling over the nose? 700? Why such big spring pressure? Was big rpm the goal? Any part numbers on the Torrington bearings or maybe a link?
 
TT5.9mag said:
@yellow rose with 340 on the seat, what were you at rolling over the nose? 700? Why such big spring pressure? Was big rpm the goal? Any part numbers on the Torrington bearings or maybe a link?[/QUOTE

IIRC when I was at .750 lift it was 800 or a bit more over the nose depending on which spring I was using.

That’s what it takes to make power and shift at 8500-8800.
Click to expand...
 
I was looking at this a little more in the last picture of post 252. Your rockers are mounted on the shafts in their approximate positions. You are holding the pushrod against the intake port to left, I assume. The adjuster appears to be just to the left side edge of where that pushrod diameter is, and it kind of looks like a 5/16" pushrod. So half of the assumed pushrod diameter is around .156" or so. Add that to your .350 offset so far and you would be about .506" and still making contact with the port.
A couple guys mentioned W2 rockers. Harland Sharp's website lists W2/W5 intake rocker offset as .775" according their applications. So stick .425" worth of feeler gauges between the intake rocker and mounting pedestal, just to measure the movement of the pushrod adjuster and pushrod, not worrying about the roller tip at all, and see if the pushrod clears the port. You can practically hold a set of calipers up to that picture and see how much it will take to get the adjuster into that pushrod cup. But then there is no guess work.
 
Bobzilla said:
I was looking at this a little more in the last picture of post 252. Your rockers are mounted on the shafts in their approximate positions. You are holding the pushrod against the intake port to left, I assume. The adjuster appears to be just to the left side edge of where that pushrod diameter is, and it kind of looks like a 5/16" pushrod. So half of the assumed pushrod diameter is around .156" or so. Add that to your .350 offset so far and you would be about .506" and still making contact with the port.
A couple guys mentioned W2 rockers. Harland Sharp's website lists W2/W5 intake rocker offset as .775" according their applications. So stick .425" worth of feeler gauges between the intake rocker and mounting pedestal, just to measure the movement of the pushrod adjuster and pushrod, not worrying about the roller tip at all, and see if the pushrod clears the port. You can practically hold a set of calipers up to that picture and see how much it will take to get the adjuster into that pushrod cup. But then there is no guess work.
Click to expand...



I really really liked your feeler gauge idea so today after my walk since I had to run to town anyway to mail some bills and pay my mortgage I stopped at my local hardware store. And bought a 7/8 lock ring collar. That way I can check with feeler gauges then after I find the needed distance space it over with rocker shims I have and then lock the rocker in place and be able to cycle it. Heck I could even check valve to piston clearance and true valve lift off the rocker to see true lift. Thanks for the suggestion.
 
Last edited:
I’m going to assume the problem is....... if you try and relieve the head more to allow the pushrod to work with the .350 offset rocker...... you’ll break through into the intake runner?

I always assumed the Hughes Bigmouth porting retained the std port opening size(or close to it).
You’ve clearly moved the pushrod side wall,at the port opening, over beyond how the BM heads are.

You’ve moved the wall over farther, so you’re going to need more offset.
Hughes BM
895D43DD-0A5E-469A-81C1-423DDD709763.png


PBR “Bigger Mouth”

7FFA557A-D520-41DD-A61F-DF45DFF79293.png
 
DC2E3091-5287-43D0-AE80-8133C0C35FBE.jpeg
DB965FA3-3A98-4588-A413-03EFF0566C79.jpeg
Ya I’m at 1.300. Would I have had to go that far? No but it sure let me do nice things to the curved wall. Checking with some shims and the lockring I moved the rocker over .283. Minus the .050 shim I usually have in there for adjusting app .230 needed. That’s where I started and now I will back it down to see how tight I can go before rubbing. There is still room to grind more out especially on the bottom because it’s out of the port window. I gotta see if I can get my sonic checker to repeat so I can trust it. It’s not like I couldn’t repair a hole, I just don’t want to have to. I want to check actual valve lift now to see where I’m at.
 
pittsburghracer said:
View attachment 1715499159 View attachment 1715499160 Ya I’m at 1.300. Would I have had to go that far? No but it sure let me do nice things to the curved wall. Checking with some shims and the lockring I moved the rocker over .283. Minus the .050 shim I usually have in there for adjusting app .230 needed. That’s where I started and now I will back it down to see how tight I can go before rubbing. There is still room to grind more out especially on the bottom because it’s out of the port window. I gotta see if I can get my sonic checker to repeat so I can trust it. It’s not like I couldn’t repair a hole, I just don’t want to have to. I want to check actual valve lift now to see where I’m at.
Click to expand...

So .230 plus what you have ready in the rocker (was it .350?????) makes you .580 and that’s less than W2 offset. So you could either have 8 custom offset rockers done up, or you could just order 8 W2 offset rockers.

Either way, it’s not cheap.
 
Not cheap, but at least we know he'll able to make it work.
Now, who can throw guesses as to how much pushrod clearance he'll need at that angle? I assume same kind of clearance as a W2/W5 setup, so how tight does everyone run WITH those heads, and what pushrod wall thickness and diameter would that be with?
I have zero experience with highly offset rockers.
 
Bobzilla said:
Not cheap, but at least we know he'll able to make it work.
Now, who can throw guesses as to how much pushrod clearance he'll need at that angle? I assume same kind of clearance as a W2/W5 setup, so how tight does everyone run WITH those heads, and what pushrod wall thickness and diameter would that be with?
I have zero experience with highly offset rockers.
Click to expand...

I’ve run (and still have some of them) 3/8-5/16 single taper, 3/8-5/16 double taper, 7/16 straight, 3/8-7/16 single taper and and 3/8-7/16 double taper.

I will always run at least a single taper pushrod with offset rockers. Even with just solid lifters.

With the wacky geometry t the lifter and the offset rocker you can’t get the pushrod stiff enough.
 
I’ll be interested to see how the lift works out.
Since it’s a single pattern cam, you can compare the lift at the valve between the offset intake and the straight exhaust.
 
PRH said:
I’ll be interested to see how the lift works out.
Since it’s a single pattern cam, you can compare the lift at the valve between the offset intake and the straight exhaust.
Click to expand...


Honestly I’ve never checked lift this way. I assume you set for zero lash and set you dial indicator on zero on the heal of the cam. If so my .665 lift cam with a 1.6 rocker (off cam card) comes in at app .640 lift. That was with rocker spacing as per pictures above.
 
I set my lash then measured the lift at the retainer.
 
You must log in or register to reply here.
-

Back
Top