NEED HELP!!!! I think hughes engines sent me 1.5 rockers instead of 1.6 ratio...ughhh

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daves66valiant

daves66valiant

68 Dart 340/727:66 Signet Vert 340/5spd: 68 D100
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I have checked, double checked, sextuplet checked the rockerarm geometry on my 340 with 360 j-heads. Pushrod clearance was done, valve stem wipe pattern is perfect, spring retainer clearance is fine, pushrod-rocker adjusting screw geometry is fine..........everything is perfect except I do not get the advertised valve lift. I followed the setup instructions to the "T"

Dave at Hughes Engines said I should be getting the advertised lift numbers or at least very close. He said it was possible that the roller rockers may not be 1.6 ratio like I ordered. They have the correct part # stamped on the arms themselves but I am getting nowhere near full valve lift. Some douchebag (human error) at the supplier (Probe) probably stamped them wrong. :mad:

By the way I am using their adj pushrod tool and solid adj lifter tool.

Here are the cam specs from the card. It's a hydraulic roller cam for use with their retro-fit roller lifters in a 340

Grind number HER2228ALN
Camshaft Technical Details
Intake Valve Lift 1.5 .510"
Exhaust Valve Lift 1.5 .510"

Intake Valve Lift 1.6 .544"
Exhaust Valve Lift 1.6 .544"

Intake Duration at .050" 222°
Exhaust Duration at .050" 228°

Lobe Separation Angle 110°
Installed Centerline 107°

Intake Opening at .050" 4° BTC
Exhaust Opening at .050" 47° BBC

Intake Closing at .050" 38° ABC
Exhaust Closing at .050" 1° ATC

Min. Suggested Cylinder PSI 175

Sweet Spot RPM 2500 - 6400


The best lift numbers that I could get were .508" on intake #1. I checked a number of other exhaust and intake lifters on the same bank. Based on the 1.5 ratio #'s (in bold red) I would assume that I received 1.5 ratio rockers. I'm not engine genius, but it is hard for me to believe that I am +/-0.036" off. There cannot be that much angle deflection if I have everything setup according to Hughes' instructions.

This is my dilemma. I can't get 1.6 rockers from Hughes. Hughes has been good and offered to send a 1.6 rocker to double check mine, but they don't even have any available at this time. Not even to sell. The reason is because they took over the manufacturing of these rockers and are not up to speed on production yet. My current option is to send a rocker to Hughes and they will check it on their bench.

My questions to my fellow FABO members is......DOES ANYONE HAVE A SPARE SMALL BLOCK 1.6 RATIO HUGHES ROLLER ROCKER THAT I CAN BORROW????? :notworth::notworth::notworth:

Thanks in advance. Buttoning up this engine is really holding back my resto at this point.
 
I don't have a Hughes rocker but it shouldn't matter, the ratio is the ratio. I have a MP roller tip rocker that actually hasn't been used so you could use it to check the lift with.
 
Did you measure the actual lobe lift of the cam measured at the lifter itself, if so what was it and what's it supposed to be. If it's correct it should be .340" The cam could be at fault or they gave you the wrong one.

I installed 1.5 Hughes rockers on my BB with a .509 cam and I had exactly .509" at the top face of the valve retainer.
 
demon seed said:
Did you measure the actual lobe lift at the lifter itself, if so what was it and what's it supposed to be. The cam could be at fault.
Click to expand...

Wish it were that easy. :) Checked that early on when following the instructions for the camshaft install. Lobe Lift was dead on. 0.340"

Yeah, Dave from Hughes said I should have gotten 0.544" off the retainer.

I got .510" a couple of times but I averaged about .508-.509" I'm sure there was some slight angle deflection because I'm using a stiff spring instead of a weak checking valve spring. Shouldn't really make that much of a difference though.
 
Dave, it's not uncommon for a production line 59* block to lose .030 or more valve lift through rotten pushrod angles. IIRC all you need is a 4* angle to lose ~7% linear motion.

If it was a 1.5 rocker, you'd be in the .480 lift at retainer.

You still using the solid lifter to check?
 
I forgot what I was gonna say.....damn rob she wrecks meeeeeee :thumblef:
crackedback said:
Dave, it's not uncommon for a production line 59* block to lose .030 or more valve lift through rotten pushrod angles. IIRC all you need is a 4* angle to lose ~7% linear motion.

If it was a 1.5 rocker, you'd be in the .480 lift at retainer.

You still using the solid lifter to check?
Click to expand...
 
Guitar Jones said:
I don't have a Hughes rocker but it shouldn't matter, the ratio is the ratio. I have a MP roller tip rocker that actually hasn't been used so you could use it to check the lift with.
Click to expand...

I don't see any reason why it wouldn't work either. I have plenty of shims and spacers to line it up. If another member doesn't come forward with a hughes rocker by tomorrow I will PM you my address.

Thanks.
 
crackedback said:
Dave, it's not uncommon for a production line 59* block to lose .030 or more valve lift through rotten pushrod angles. IIRC all you need is a 4* angle to lose ~7% linear motion.

If it was a 1.5 rocker, you'd be in the .480 lift at retainer.

You still using the solid lifter to check?
Click to expand...

Yes I'm using the solid adjustable roller lifter tool that Hughes provided me.

That's pretty shitty to loose 7%

I should call hughes back and ask them about it.
 
Quote: I got .510" a couple of times but I averaged about .508-.509" I'm sure there was some slight angle deflection because I'm using a stiff spring instead of a weak checking valve spring. Shouldn't really make that much of a difference though.

Nope, won't make a difference. I was using the installed valve spring and dampener when I checked mine and they were dead on.
 
I spoke with Crackedback tonight and he gave me a good explanation of the rotten pushrod angles in our small block mopars. Made sense. Back to happy motoring and ordering up my pushrods. I will talk with Hughes about this matter and see if they offer a similar explanation.

Thanks again Cracked
 
I have 1.6 Hughes rockers and my roller cam is 360 lobe lift. I'm only getting
.540 lift at the exhaust valve on their 3644 roller cam which is where the cam spec is for a 1.5 ratio rocker. I checked the lobe lift and it's right on the money @ .360 so I know the cam is correct as listed. Did the whole setup with their solid adjustable lifter and pushrod too. Got the geometry perfect and I was dissapointed to see how much lift was lost due to the poor lifter/pushrod angle. I've been told that the roller lifters being so much taller in a LA block makes it even worse as far as loss of lift goes. Having seen where I ended up on lift, I would have to agree!
 
I don't know maybe my 1.6 Crane rockers are more than 1.6 but even on the intakes with the W5 offset my .454 lobe lift cam is still netting .698 at the valve with .020 lash. That is only a loss of .008. The exhausts net out at .700 which is only a loss of .006.

Losing .030 of lift just to the pushrod angle seems like too much to me.
 
I bought some of Hughes 1.5 and 1.6 rockers and they were almost dead on.
 
Don't know how you guys are getting your numbers and I can't. What engine and heads are you running to get the advertised lift in you application? You running aluminum rockers or ductile? Hyd or solid? Just curious.

Robs explaination still seems the most sound. Glad I picked a bigger lift cam and higher ratio to combat crappy Lifter/pushrod geometry.

Hughes still says I should get .544. So I'll send them a rocker and then I'll have piece of mind either way.
 
I have a Ultradyne roller cam. Lift is .556 with 1.5 rockers. When switching to 1.6 rockers,everyone told me it would give me .593 but after measuring everything it actually had .577 lift. So I only gained around .020
 
Well I tried out Guitar Jones' MP 1.6 rocker and my lift improved to .515 After examining things a bit more I shortened the adj pushrod tool as small as it would go and worked from there. My best lift after trying different shim stacks was .520 with the Hughes 1.6 rocker without any shims. So that makes a .024 loss due to crappy pushrod/lifter angle. So that is a 4.41% loss compared to 6.25% before rechecking. The valve stem wipe pattern and geometry at 60% max lift .312 was near perfect.

I'm going to get my pushrods cut and button this sucker up. I'll have to live with the 4.41% lift loss. Doubt I'll ever feel the difference in seat of the pants driving.
 
3-3.5 showing. I didn't pull the rocker off to measure.
 
Can you really can't get a mic around the true base circle, because the ramp actually starts a lil before hand?

too much adjuster below the rocker gives more lift, too lil gives less.

I go with about 1 thread below the rocker
 
demon seed said:
How many threads are you showing on the adjuster screw on the back side of the rocker.
Click to expand...

What engine combo did you have? Block, heads, lifters, cam? Would be interesting to know.

The hydraulic roller lifters are 9/16" longer than flat tappets. Thus making the pushrod/lifter angle even worse.
 
1wild&crazyguy said:
Can you really can't get a mic around the true base circle, because the ramp actually starts a lil before hand?

too much adjuster below the rocker gives more lift, too lil gives less.

I go with about 1 thread below the rocker
Click to expand...

These are not like the other brand rockers. One thread showing was the best for the MP rocker. Not so for Hughes on my engine. Their instructions clearly state to start out with the adjuster 0.450" below the rocker with LA blocks as a starting point. No magic number of threads showing. The detailed instructions are on their website. I've followed them to the best of my mechanical ability. A new set of hands and eyes and experience would be helpful. This is a new experience and user error is probable. In a rare case my heads may be the problem. I have no idea what was done to them prior other than some porting.

This has been frustrating with conflicting information and my inexperience as well. Hughes checked my rocker and it's fine. Today, they still say I should get the .544. **** if I'll get .544. I'll waste another couple hours on it tomorrow. :cwm21::cwm21:
 
You want to get .544 lift, set the indicator to .025 and start there. :)

I have a clearer opinion of Hughes now... I guess they know how to correct trig/physics/angular loss.
 
I know it all depends on the length of the adjuster, but all the aluminum rockers I have used ...you only end up with about 2 or so threads up top and about 1 1/2 on the underside.

But I think i saw somewhere that the hughes rockers use extra long adjusters....I guess thats how they get the number, just by exaggerating the lift via adjuster.

Consider the rocker/valve tip geometry, is the wear mark in the middle of the valve tip?

Where in so cal are you ?
I am in vista
 
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