Dieselfever
New member
What is the piston protrusion suppose to be on a 7.3 . I have all the AERA specs, but it doesn't have a spec listed for this.
-Michael
-Michael
Piston Protrusion
- Thread starter Dieselfever
- Start date
Dieselfever
New member
Thanks Dave, I was going to call/e-mail but weren't sure how busy you guys were.
Mine are .023"-.027", it's a street engine so I'll just keep them at that. What method do you use to measure piston to valve clearance. It's getting the heads I just got back from you all last month, so they've been decked
-Michael
Mine are .023"-.027", it's a street engine so I'll just keep them at that. What method do you use to measure piston to valve clearance. It's getting the heads I just got back from you all last month, so they've been decked
-Michael
As long as the valve recess in the heads are stock depth and you're reusing a stock cam....then you will be fine.
To measure PTV clearance...you'd need to install one rod/piston (no rings required) assy on the crank...a pair of lifters,
then put some clay/play-dough on the top of the piston where it will be crushed by the opening valves..we spray some oil on the valve faces and piston tops to
(temporarily) bolt on a head (with a used HG) and one set of valves...we use light weight test springs @ the valves..and then you'll need to get/use 2 adjustable length pushrods that you can 'unscrew' (make longer) to take up the slack in the lifter.
(we actually disassembled 2 lifters and rebuilt them w/ no internal hydr/spring travel so we don't have to guess on loss of lift @ the valve with factory lifters without oil pressure, just to use for checking PTV clearance)
rotate the engine a few revolutions, and then carefully remove the cyl head..and take a caliper to the clay/play-dough...
a stock engine usually only has @ 020-030 PTV clearance...so it's a tight tolerance, and unfortunately...not many people check this, LOL...
To measure PTV clearance...you'd need to install one rod/piston (no rings required) assy on the crank...a pair of lifters,
then put some clay/play-dough on the top of the piston where it will be crushed by the opening valves..we spray some oil on the valve faces and piston tops to
(temporarily) bolt on a head (with a used HG) and one set of valves...we use light weight test springs @ the valves..and then you'll need to get/use 2 adjustable length pushrods that you can 'unscrew' (make longer) to take up the slack in the lifter.
(we actually disassembled 2 lifters and rebuilt them w/ no internal hydr/spring travel so we don't have to guess on loss of lift @ the valve with factory lifters without oil pressure, just to use for checking PTV clearance)
rotate the engine a few revolutions, and then carefully remove the cyl head..and take a caliper to the clay/play-dough...
a stock engine usually only has @ 020-030 PTV clearance...so it's a tight tolerance, and unfortunately...not many people check this, LOL...
