Roller Rockers 1.5 vs 1.6

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Assemble everything and clay your piston tops, turn the engine over by hand, disassemble and check clay thickness.
Yeah, it's a lot of work. This way you know what you've got.

I can't remember the stuff we use at work. It's some sort of machining clay for checking tolerances like below.

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And then I suppose you can leave the head gasket out and just add the compressed thickness of the gasket to the measurement.
 
What do you mean if the stands are corrected?
The radius for the shaft is not machined properly. Check out some recent Speedmaster threads to see discussions about this issue.
 
And then I suppose you can leave the head gasket out and just add the compressed thickness of the gasket to the measurement.

If you're up for some trig, otherwise, include the head gasket and torque it down properly.
 
If you're up for some trig, otherwise, include the head gasket and torque it down properly.

Is that gasket reusable then? Probably depends. I have felpro 1008 for my build.
sorry for the hijack Doc.
 
don't overthink it. Measuring without the gasket is fine. If the piston has a valve relief in it, that 268 camshaft usually has no issues with clearance with either rocker. If the ICL is way off, then you can have an issue, but it would have to be WAY off.
 
The radius for the shaft is not machined properly. Check out some recent Speedmaster threads to see discussions about this issue.

@DentalDart Here's a post showing the issue.

The whole thread is a good read. Lots of answers.

Here's an image posted of the issue:
b70cf2e8-b180-42cc-a4c4-293b98989757-jpeg.jpg
 
Dental,
Bouncing suspension is caused by failed/failing shock absorbers. Springs could also be sagged, but replacing springs without the shocks will shorten the life of the springs.
 
Dental,
Bouncing suspension is caused by failed/failing shock absorbers. Springs could also be sagged, but replacing springs without the shocks will shorten the life of the springs.

Shocks are new, 2 years old, springs I didnt replace.
 
Shocks are new, 2 years old, springs I didnt replace.

What did you use? One of the 'cheapest' made parts in the aftermarket are shocks. Most box store shocks are junk when new and wear rapidly. Sadly, good replacements are not cheap.
I went with Viking double adjustables. At around $800 for all 4, they're one of the most affordable options for decent quality adjustable shocks. Hotchkiss also makes some decent ones, but I wanted double adjustable.
I can also say that the adjustments on the Vikings actually make a difference. Turned to full stiff, my car will ride like a dumptruck. Set to full soft, it rides like 'stock'. In the middle, it really helps control the wheels the way I expect and has major impact on traction, wheel hop, etc.
Then I added assassin bars - now there's no tendency for the rear to walk around when I lose traction and the wheel hop is completely gone. It also firmed up the rear suspension a bit and will let me soften the ride on the street. Since I'm on street tires, it actually makes it even easier to bust them loose. Kinda spooky having it haze the tires and loosen up in 3rd gear :eek:
 
What did you use? One of the 'cheapest' made parts in the aftermarket are shocks. Most box store shocks are junk when new and wear rapidly. Sadly, good replacements are not cheap.
I went with Viking double adjustables. At around $800 for all 4, they're one of the most affordable options for decent quality adjustable shocks. Hotchkiss also makes some decent ones, but I wanted double adjustable.
I can also say that the adjustments on the Vikings actually make a difference. Turned to full stiff, my car will ride like a dumptruck. Set to full soft, it rides like 'stock'. In the middle, it really helps control the wheels the way I expect and has major impact on traction, wheel hop, etc.
Then I added assassin bars - now there's no tendency for the rear to walk around when I lose traction and the wheel hop is completely gone. It also firmed up the rear suspension a bit and will let me soften the ride on the street. Since I'm on street tires, it actually makes it even easier to bust them loose. Kinda spooky having it haze the tires and loosen up in 3rd gear :eek:

I used KYB shocks... when I did most od the car I was still in Dental School and even more poor than I am now :D

Ill probably buy better ones at some point.... I'm a dentist now and still "poor" lol. My wife really just calls me a cheap ***... :bs_flag:
 
I used KYB shocks... when I did most od the car I was still in Dental School and even more poor than I am now :D

Ill probably buy better ones at some point.... I'm a dentist now and still "poor" lol. My wife really just calls me a cheap ***... :bs_flag:

I know the feeling..
It took me 4 years to get around to buying the Viking shocks. They were $525 when I first found them.. Food for thought ;)
 
Bouncy is caused by shocks, so they are/have failed. There is a reason that Bilstein, Koni etc cost more.....
 
What did you use? One of the 'cheapest' made parts in the aftermarket are shocks. Most box store shocks are junk when new and wear rapidly. Sadly, good replacements are not cheap.
I went with Viking double adjustables. At around $800 for all 4, they're one of the most affordable options for decent quality adjustable shocks. Hotchkiss also makes some decent ones, but I wanted double adjustable.
I can also say that the adjustments on the Vikings actually make a difference. Turned to full stiff, my car will ride like a dumptruck. Set to full soft, it rides like 'stock'. In the middle, it really helps control the wheels the way I expect and has major impact on traction, wheel hop, etc.
Then I added assassin bars - now there's no tendency for the rear to walk around when I lose traction and the wheel hop is completely gone. It also firmed up the rear suspension a bit and will let me soften the ride on the street. Since I'm on street tires, it actually makes it even easier to bust them loose. Kinda spooky having it haze the tires and loosen up in 3rd gear :eek:
Sounds like good shocks but questionable tires. You might try a 10.5 drag radial
 
Sounds like good shocks but questionable tires. You might try a 10.5 drag radial

I have an 8 3/4 with 3.55 sg sitting in the corner. It's an ebody housing, but I have a b-body housing next to it. One of these days it'll get swapped and installed and then it'll be time for new wheels/tires ;)
 
I know the feeling..
It took me 4 years to get around to buying the Viking shocks. They were $525 when I first found them.. Food for thought ;)

I put QA1 single adjust on all 4 corners of both my older heaps... what a difference. I keepem set pretty low.. anything over 6 of 13 settings and it you feel every nook and cranny in the road.
 
:eek:
I ‘m just about at the point where I almost wouldn’t even run stock stamped rockers in a stock motor. I would go with what you’re considering, it wouldn’t surprise me if you don’t notice an improvement just by installing decent (even factory ductile with the ratios matched) 1.5 ratio rockers with the geometry corrected with the aforementioned B3 kit.
In the old days, we would put some modeling clay on one piston, assemble one head, one set of pushrods and rockers, slowly turn the engine over by hand, remove the head, and do a look see. If you are going to just change rockers, and want a Mopar site internet friend to approve the change, if something goes wrong, send them a bill.
 
How do you decide on which ratio to get?

I didnt get any when I purchased my aluminum heads but now SM has all the SS rockers in stock ( well kinda...) so since they haven't had any in 7 months I think I may pick up a set... I kinda want 1.6 for a little "extra" lift from my cam but worry about valves hitting pistons?

Build...
30 over 340, pistons all around .012 out of the block
Xe268h camshaft
SM CNC fully assembled heads (pictured)

I know I know buy the expensive ones that are "better..."

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I recommend watching the David Vizard youtube video on LCA selection. Part of his Powertec 10 series. Ep 17 and Ep18 cover rocker arms and discusses when a higher ratio rocker is likely to improve torque and in which situation it will likely reduce torque. Torque is the value we can measure, while power is a value calculated from torque and RPM. LCA is critical to maximise output and needs to be determined using DV's 128 formula;
128 - (cylinder displacement for one cylinder/ intake valve diameter × 0.91).
 
Duration is what causes valve to piston contact not lift. Max lift is not a concern. Guys listen to @PRH here. And @DentalDart you measure for P to V at split overlap around 10-15 degrees + or - not at TDC compression.
Partly so. Both can cause interference issues, which must be checked every time components of the valvetrain or piton are changed. A high lift rocker may benefit from retarding the cam 2° to 3°. This would increase valve to piston clearance, but the only way to know what the engine wants is to test on a dyno. On a solid lifter combination, tightening or loosening valve lash by 0.002" may be required.
Watch the videos as he has a lot of useful information. Granted most seems to apply to Ford or Chevy engines, the one thing you need to remember is that ports, valves and pistons do not know or respond to what name is on the hood. They respond to airflow and compression ratio. The general rules apply to all, like short turn radius. Once you introduce power adders, some of that changes. Larger, better flowing exhaust becomes important. Turbos respond to low restriction exhaust, from the valve out.
 
Ummm.... In the Motor... :poke: :lol:

You my friend are talking chinese to me right now. I would love to know the real answer to that but really I have no idea what the answer is and I have no idea how to check it. Hell I have no idea what the tools are to check it either...
Minimum valve to piston clearance occurs at about 10° BTDC or ATDC as the intake valve is opening and before the piston moves away from TDC. Modeling clay is put on the valve reliefs about 3/16 thick. Install light checking springs available at a hardware store. Install the head with the piston down 1/2" to 3/4". Gasket is not required as a gasket will increase your clearance. Carefully turn the engine through 2 revolutions. Then remove the head and cut the modeling clay from center of the engine to the outside, and pry half off. The remainder can be measured with a caliper to determine the clearance. The outside edge of the valve head to the valve pocket can be measured at the same time.
Another tip from DV involes cutting back the deep side of the intake pocket (relieve) toward the cylinder center. This improves low lift flow and promotes swirl. It does not need to be ground right to the bottom of the valve pocket. 1/8" is good and at 30° from the cylinder center line. Check piston crown volume to equalise before balancing.
 
How do you decide on which ratio to get?

I didnt get any when I purchased my aluminum heads but now SM has all the SS rockers in stock ( well kinda...) so since they haven't had any in 7 months I think I may pick up a set... I kinda want 1.6 for a little "extra" lift from my cam but worry about valves hitting pistons?

Build...
30 over 340, pistons all around .012 out of the block
Xe268h camshaft
SM CNC fully assembled heads (pictured)

I know I know buy the expensive ones that are "better..."

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With 0.012 out of the bore you want to watch quench clearance. Probably looking at a compressed head gasket of 0.050" thickness.
For a 0.030 over 340 with 2.02 intake valves, cam LCA for best performance should be 104.6°. A 106° LCA and 1.6 rockers should work well. What is important is the overlap triangle. The high lift rockers snap the valve open quicker, increasing low lift flow during the critical overlap "cycle". This could require retarding the cam 1° or 2°. That aids V-P clearance.
 
I want the 1.6s with the steel hold downs, but they are not in stock right now... maybe they will be in the next week or 2. I'm in no rush, just need something to tinker with on the car. Everything else I want to do costs to much money.

I have seen that these rockers are essentially the same exact ones as the PRW which is why I will buy these instead of PRW, at 1/2 the price. Plus I have a friend who has the SM on multiple motors and they have been good to him.
Watch the DV video on high lift rockers, Ep 17 and Ep 18. The effective ratio changes as lift progresses. One rocker could have 1.4:1 off the seat and 1.7:1 over the nose. Another could be the other way around. Quick off the seat aids low lift flow with the high ratio coming off the seat. Then if the ratio reduces as max lift is approached, this slows the valve preventing float.
There is a lot more to rockers than meets the eye. Miller made rockers and wrote about mid-lift. Research is required.
 
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