Thread: piston/valve clearance with hydraulic cam

Tweet

so i've pulled my engine and awaiting my cam in the next couple of days. it is a hydraulic roller cam and i need to check the piston to valve clearance. issue is it is a hydraulic lifter. how do i set lash properly without the plunger bottoming out in the lifter and making my clearances in accurate?

use a very lite set up spring on the in and the ex set the lash at O .on the valves they need to be very lite you can pick up springs at a hard ware store. some test spring take to much lbs .you will want to check mid lift so you know your push rods are right for the lifters and rocker arms and cam all this comes in to play seeing no ones rockers and lifters are not the same

i understand that. thank you for the quick reply. but the issue is i was going to use the clay method. and wheni turn the engine over it will depress the plungers when i try to to make the impressions. sorry i was not clear before. but if i use lite springs the plunger will over come the light check springs and i could check with a dial indicator. what to do

i do not use clay i check on over lap and all the way thru but i use a dial in or feeler gauge but i done so many i know what is 080+ by looking at them

ok. so if i just installed light springs on I and E and at the 20 btdc and 20 atdccheck for the amount of space between the rocker tip and the valve stem tip correct. and what about side clearance of the valves?

Originally Posted by Jason383454

ok. so if i just installed light springs on I and E and at the 20 btdc and 20 atdccheck for the amount of space between the rocker tip and the valve stem tip correct. and what about side clearance of the valves?

well if you have two springs then you just check over lap and check the intake valve gets in the way of the piston as for checking side clearance where ? valve to valve relief room ? yes valve stem center line to rocker tip /roller tip contack point is to center line of valve at mild lift

yes i belive there is clearance there but i was getting little worried about it. they are only 2.19/1.88 valves so they are not extremely big. just to make sure the side of the valve does not contact the valve relief of the piston.

mark the pistons with layout past or art oil past paint .marker pen will work as well put piston @ tdc the with the spring off spin the valve with your hand with head on the block this should make a mark on the pistons .when i need to fly cut i have made up a pick punch out of old valves and just go from center line of mark to tell me if i have room this will work to . but your valves are not big but check it any ways if i have alot over 080+ of PV room i do not check it

if i don't have to pull the heads i won't. i'll try the light springs first. if i had more than enough clearance like that then i should be ok for side clearance. they are not hugely domed. i just don't want to play patty cake with my valves. if i have clearance issues then i will pull heads and try both your paste way and the caly as well. i'm sorry but i'm new at this part of clearancing and have never had to worry about it before
thank you for bearing with me and helping

Originally Posted by Jason383454

if i don't have to pull the heads i won't. i'll try the light springs first. if i had more than enough clearance like that then i should be ok for side clearance. they are not hugely domed. i just don't want to play patty cake with my valves. if i have clearance issues then i will pull heads and try both your paste way and the caly as well. i'm sorry but i'm new at this part of clearancing and have never had to worry about it before
thank you for bearing with me and helping

clay is not going to work your just going to push the plunger down before you get any good reading in it .i have used a solid roller lifter if i use clay but i do not use it any more for pv checking but still used clay for other things

ok. i
ll do the light spring and feeler guage method. now i should be able to find light springs at a hardware store so i'll head there tomorrow. they just have to be close to the outside diameter. about pound 5 lb springs

Originally Posted by Jason383454

ok. i
ll do the light spring and feeler guage method. now i should be able to find light springs at a hardware store so i'll head there tomorrow. they just have to be close to the outside diameter. about pound 5 lb springs

they can be much smaller the ones i have are about 3/4 ID and are very lite less then 5 lb they just need to hold up the valve and the valve seal if a PC type will just about do the job with any test spring it all

cool i will find some springs tomorrow and hope my cam shows up tomorrow as well

To answer your original question:
Pat touched on it when he advised using solid roller lifters. That's fine if you're a builder and have solid rollers laying around that you can use. For the home builder, that's not an option. What I and others have done in the past is to disassemble two lifters and remove the innards, replacing them with shims or spacers of the correct diameter and thickness to shim up the interior of the lifter body to the bottom of the pushrod cup with the snap ring installed. It's difficult to shim to the exact point where you can get the snap ring seated, but you can get close. After your PV checking, you can return the two lifters to their original use as a hydraulic and go ahead with the build. Optionally, if you have old hydraulic rollers to spare, is to disassemble and fill with shims or JB Weld, then replace the pushrod cup and snap ring. Using JB Weld, you can get it dead nuts. These will then become toolbox items to be used in subsequent builds. You could check with some of the local automotive machine shops. They may have a couple of hydraulic rollers they will give you or sell cheaply that you can modify. Make sure they are the same length from roller to pushrod cup as the lifters you will use so that effective pushrod length (lobe to rocker) will be the same as the length you will use in your build.

yep i have some like that as well with a flat lifter cam . but some retro lifters you can not get the valving out of the lifter .with the link bar on it they can not be removed from the lifter as it must be the last step in building the retro roller lifter so if you are going to do it this way .tell me what make they are i may have one you can rework i use more then one roller lifter so i do it another way