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Go to HUGHES ENGINES .COM they have a tech sheet you can click on

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I should have been more clear in my original post. I am going by their instructions titled "Rocker arm gemoetry and pushrod length for custom pushrods". It is quite a long process, although it is accounting for rocker geometry as well. I have already checked for that and I am good to go However, in the article they are using a checking spring, and they don't mention anything different in the procedure if using hydraulic lifters and no checking spring

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What the hell are ya doin' ?!?!

Checker springs don't even come in to play here.

1) get a lifter on the base circle
2) install a head with gasket and cinch down
3) install one rocker on a shaft and cinch down
4) if rocker is adjustable, set adjuster so 2 threads are showing
5) install checker pushrod and adjust until only the slack is taken up between the lifter and adjuster - do this by "feel", don't tighten so much as to compress the lifter.

You're done.

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LOL im just doing what the Hughes tech sheet says since im using their 1.6 rockers and I have never done this before

I am using their 1.6 adjustable rockers, and in their tech sheet it says nothing about adjuster thread length, just to set the adjusting screw so that the ball is protruding .450" from the rocker body (smallblock LA spec)

My lifter was only compressing and bottoming out as I was turning the motor over so as to check rocker geometry and pushrod length like the article says...The method you posted seems to be pretty easy compared to what they are saying though. In the method you posted, how do I account for lash? please go easy on me, im just learning this stuff as I go

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With a hydraulic lifter, my rule of thumb is to set it up for the lifter to be compressed between 0.010-0.030". This requires a lot of care to make sure that distance is from just touching zero lash.

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I used a solid lifter. And I set my lash at zero.

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Like my original post says, I don't have access to a solid lifter, which is why I was thinking about shimming up an empty hydraulic lifter..plus my hydraulic lifter is a roller which is taller than a standard solid lifter, although your method would make my life alot easier lol

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I like to use a preload of 1/4 turn ( sorry I can't remember exactly what tha is in thousands of an inch - probably around .015" )

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From what I remember their method is kinda long and drawn out - they tried to make it rocket science . The 2 threads showing thing is probably about the same as their .450". You can't use a hydraulic lifter ( even if it's filled with oil and/or you are using a light spring. I use a "checking lifter" that has the push rod plunger replaced with one that can be screwed up and down. You can do the same thing with a junk Hydraulic lifter as you said. Fill it with washers until you get the height you want - which will be the same as the lifters you will be using less what ever preload you want to use. I run a large ( over .6" ) hyd flat tappet cam. I took my adjustable lifter and set it beside the lifter I will be using. Put pushrods in both lifters. Adjusted my checker lifter so that both pushrods were the same height. I like to use a preload of 1/4 turn ( sorry I can't remember exactly what tha is in thousands of an inch - probably around .015" ) . That way if I accidentally pump them up ( over rev ), I don't bend stuff. You will have to use what ever your cam MFG recommends or what ever and fill your checking lifter with junk until you get to the stock height, less what ever preload you want to run. Hope this helps.

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thanks for the info! I kinda figured the Hughes method was a bit of overengineering, but it didnt hurt to use their method to atleast get my rocker geometry correct. I don't think my cam card had a spec for preload/lash on it but i will double check.

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My lifter was only compressing and bottoming out as I was turning the motor over so as to check rocker geometry and pushrod length like

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My lifter was only compressing and bottoming out as I was turning the motor over so as to check rocker geometry and pushrod length like

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A-HA ! Now I understand ... I didn't realize you were checking the geometry too!

As for the "adjuster protruding .450", that's pretty much what I was getting at with the "two threads showing" statement.

Anyhow,, you don't need to use the lifter/pushrod to check geometry - with the checker springs installed you can just move the rocker through its approximate amount of travel by hand and watch the geometry.

Here's a tip that I just discovered while checking my own about a half hour ago ... check BOTH intake and exhaust (in case they have different base circles like mine has!!)

I wouldn't worry about lash or preload - that's a minimal amount that can be taken up by the adjuster, .010" is not an amount to be worried about.

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My lifter was only compressing and bottoming out as I was turning the motor over so as to check rocker geometry and pushrod length like

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A-HA ! Now I understand ... I didn't realize you were checking the geometry too!

As for the "adjuster protruding .450", that's pretty much what I was getting at with the "two threads showing" statement.

Anyhow,, you don't need to use the lifter/pushrod to check geometry - with the checker springs installed you can just move the rocker through its approximate amount of travel by hand and watch the geometry.

Here's a tip that I just discovered while checking my own about a half hour ago ... check BOTH intake and exhaust (in case they have different base circles like mine has!!)

I wouldn't worry about lash or preload - that's a minimal amount that can be taken up by the adjuster, .010" is not an amount to be worried about.

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Unfortunately I don't have a checking spring available, so I would technically have to shim up my lifter...But my geometry is good

thanks for all the help everybody! Gonna tackle this tommorow so i can get those pushrods ordered and finally button up the rest of this motor

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The engine is an LA with a bone stock bottom end...

I got the pushrods all measured up today, but ran into bigger issues...the intake valve on the heads is deep into the piston, so it looks like im going to be making a piston fly cut tool with the old heads and putting notches into the stock pistons...kinda worried though as to how thick these pistons are

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First... what is the cam installed at and what is the
LSA.... as to the geometry of the rockers... the
push rod dosent change that... you need to raise
or lower the rocker shaft to do that

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The engine is an LA with a bone stock bottom end...

I got the pushrods all measured up today, but ran into bigger issues...the intake valve on the heads is deep into the piston, so it looks like im going to be making a piston fly cut tool with the old heads and putting notches into the stock pistons...kinda worried though as to how thick these pistons are

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First... what is the cam installed at and what is the
LSA.... as to the geometry of the rockers... the
push rod dosent change that... you need to raise
or lower the rocker shaft to do that

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1) You said you checked the geometry and its ok, right?

2) You said you don't have checker springs and you're using hydraulic lifters. So, how have you determined the intake valve "is deep" in the piston? Are you checking this with the cam installed where you want it and turning the motor over by hand with clay in the piston?

"deep" means squat ... its the actual piston to valve clearance through a normal cycle that matters.

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the cam is a 106 LSA installed straight up on a 101 intake centerline

I wasnt referring to the geometry of the rockers. My intake valves are hitting the piston big time when I turn the motor over to check piston to valve. So much so that the valve is cutting into the piston and vice versa. I checked the exhaust valve the same way and its fine...im thinking the combination of the larger intake valve than stock (2.02 vs. 1.88) and the high lift on the cam with small 62cc chambers in the heads and the lack of valve reliefs in factory pistons is what culminated in this.

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Your cam is not straight up... you have it installed
5* advanced... still shouldnt be hitting.... have
you measured yet how much its crashing... why dont
you give use all the specs on the cam and the pistons...
also did you check the balancer when you installed
the cam

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the cam has 5 degrees advance ground into it which is why 101 is straight up (This is what I was told before having the cam ground). The balancer is not on the engine yet, I degreed the cam with the heads off and the balancer off using the intake centerline method and the intake/exhaust open/close method as well.

As far as piston specs go, I really don't have any on them. They are stock 91 LA pistons that came with the motor, factory dished, with no valve releifs. I would say the dish is anywhere from 5-7cc as its not very deep. The chambers on the heads are 62cc

The cam specs are for installed at 101 intake centerline
Duration at .50"- 230/230
Lobe lift (at the valve with 1.6 rockers)- 577/569
Lobe seperation- 106
valve timing at .050 open close
Int: 14 BTDC 36 ABDC
Exh: 46 BBDC 4 ATDC

what do you think?

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the cam has 5 degrees advance ground into it which is why 101 is straight up (This is what I was told before having the cam ground). The balancer is not on the engine yet, I degreed the cam with the heads off and the balancer off using the intake centerline method and the intake/exhaust open/close method as well.

As far as piston specs go, I really don't have any on them. They are stock 91 LA pistons that came with the motor, factory dished, with no valve releifs. I would say the dish is anywhere from 5-7cc as its not very deep. The chambers on the heads are 62cc

The cam specs are for installed at 101 intake centerline
Duration at .50"- 230/230
Lobe lift (at the valve with 1.6 rockers)- 577/569
Lobe seperation- 106
valve timing at .050 open close
Int: 14 BTDC 36 ABDC
Exh: 46 BBDC 4 ATDC

what do you think?

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Its still 5* advanced... maybe you are referring
to what they wanted it installed at(101)... without
the balancer on the engine how did you reference the
crank... I think you have the cam in wrong... that
cam and those pistons shouldnt hit

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so if i retard the cam then I would gain piston to valve clearance? how does that work? What effects on performance would retarding the cam have, and would retarding it 5 degrees help me gain the clearance i need?

I lined up the timing gear marks for straight up on the timing set and found top dead center with a dial indicator on #1 piston as outlined in all the instructions i have ever found i.e. hughes engines, comp cams, my mopar hotrodding book. According to all my calculations and where this cam is supposed to be installed (Straight up at 101) the timing gear and my install are correct.

Please don't take this as me being sure...I am doing all of this for my first time and am still learning. I would really rather not flycut the pistons, but im not sure what else to do...I don't want to compromise performance in an already low compression motor by retarding the cam

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so if i retard the cam then I would gain piston to valve clearance? how does that work? What effects on performance would retarding the cam have, and would retarding it 5 degrees help me gain the clearance i need?

I lined up the timing gear marks for straight up on the timing set and found top dead center with a dial indicator on #1 piston as outlined in all the instructions i have ever found i.e. hughes engines, comp cams, my mopar hotrodding book. According to all my calculations and where this cam is supposed to be installed (Straight up at 101) the timing gear and my install are correct.

Please don't take this as me being sure...I am doing all of this for my first time and am still learning. I would really rather not flycut the pistons, but im not sure what else to do...I don't want to compromise performance in an already low compression motor by retarding the cam

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First off you really dont know where its installed at...
get a degree wheel on it... forget about the dots
they can be way off... just because you lined up
the dots doesnt mean its straight up... you are at
5* advanced from something... when the intake is at
full lift the crank (degree wheel) will say 106*,
thats straight up..... yes when you advance/retart
the cam it changes the valve to piston clearance...
you should get a buddy over to help you install it
and show you how.... I wonder if you used the exhaust
valve instead of the intake
EDIT
did you clay the piston just to make sure it isnt
hitting the lip of the piston... just checking

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I used a degree wheel man...i have followed the instructions to a T...and no, I measured the intake, not the exhaust valve. I know the difference between the two...I said im still learning, not that im stupid lol

Im gonna talk to Brian about this since he did my cam and heads and see what he thinks about retarding these cam specs on my motor...id much rather do that then flycut the pistons

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Hey Mr. P., sorry if i came across like an ass last night, was just a bit flustered with the whole situation and some other stuff that has just put me in a not so good mood lately...everything you asked and stated was valid, and I appreciate you trying to help me out. I think I have this figured out now and I will post up my results as soon as I get them Going to retard the cam so that its installed straight up on and see what happens

thank you

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Rocker shafts are loose or flexing causing the variance in lift. Possibly even the indiator arms are moving slightly (not uncommon).

Also, .080 is too much preload on the lifter, it should only be something like .010 to .025 (I believe). Personally, if it were me, I'd be setting things up with ZERO preload and allowing that as a safety buffer when things finally go together.

You have a head gasket in there, right?
What's your calculated compression right now? What will it be if you increase the head gasket thickness to gain PV clearance? If that's even an option!!

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Use your thin head gasket but just snug it to about
40-50 LBS that way you can still use them... try not
to retard the cam, with your low comp and late valve
closing it would make it a MUTT

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But Mr. P, I was getting insane valve to piston smack before. Still think I should try with the gasket and installing the cam back at 101 (where the 5 degrees advance were ground in). If i try it here again and im still getting PTV contact, what is the issue and what is the fix?

I was worried about retarding the cam so much as well in terms of the effects on performance like you mentioned, but figured it was my only option

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Im also doing all these checks with zero lash

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Im also doing all these checks with zero lash

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I should hope so! Tell me how you would preload a lifter .080 and then put in lash ?!?!?!

I gotta believe that anything you read regarding checking PV clearance told you to mock things up as you would run it ... INCLUDING HEAD GASKETS. Get 'em in there, you've been wasting your time without them.

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