Hi,

I dont have a LS1, or even a V8 but Im hoping someone here can shed some light on a problem Im having with my 2.2L OHV chevy turbo motor.

First, a little background.

Motor Hightlights:
Ross 8:1 c/r custom pistons
Eagle Rods
Comp Cams reground cam (hydraulic roller)
ARP head and main studs
SCE copper headgasket wtih o-rings
1.6:1 Crane gold race rockers
R.E.V. Custom oversized SS valves with hardened tips
Isky Dual LS1 valvesprings 175#
Comp Ti Retainers
Modified stock hyd roller lifters (modified to be mechanical rollers)
Custom turbo setup, last dyno @ 13psi boost 247whp/267wftlbs

On my first build up I was running some Comp 125# dual valve springs (stock rate is 75#). After about 6 mo of driving I was tuning my way up to 18psi or so when I began having some serious knocking. It turned out to be the intake valve lifter rollers. (At the time the lifters were completely stock still). Here is a pic of the damage. The exhaust lifters were fine. Also most of the hardened tips on my REV valves were loose.



At the time my builder thought that maybee I didnt have enough spring pressure and the intake valves were opening from boost causing the lifter to "float" and slam into the cam.

For build 2 we changed to the LS1 springs and Ti retainers and did the mods to the stock lifters to make them a mechanical roller. Basicaly he machined some inserts to replace the spring etc in the lifter. I have pics here somewhere. Since I was running the mech lifters on they hydro cam I was running only like 0.006" of lash hot. Cold was zero or negative (made starting intersting sometimes).

After about 1k miles on the new build I had the same knock. That was last fall. Fast forward to yesterday. I pulled the head off, pulled the first intake lifter and it looks similar to the damage the first time around. Again none of the exhaust lifters appear damaged.



and my poor valve




My builder thinks now that the stock lifter rollers and axles just cant hold up to the added spring pressure etc and that they quickly become worn, thus exposing the soft inner metal whcih doesnt last.

We are looking for a race lifter with a tie bar that may fit but there isnt much room for a tie bar due to the way the lifter sits down in the block. (currently we are still using the factory plastic lifter guide plates - see first pic).

I dont think the lifters are twisting any as there is no damage to the stock lifter guides.

Im hoping someone here has seen something similar and can add shed some light on the subject for me.

Any advise would be greatly appreciated

Thanks in advance,

Dan

 

Was this engine originally built for flat tappets? If not, how do the roller lifters
not spin in the bore? Are the lifters oval in shape?

It does seem from the close up photo that the wheel was having trouble
spinning (several flat spots). I'm surprised to see most of the damage on the
edge of the wheels. Makes me think the cam walked quite a bit? What do
the lobes look like?

 

You can not run (read as should not, you already are) a hydraulic lifter camshaft with solid lifters. A hydraulic camshaft does not have clearance ramps designed in to the lobe. The acceleration rate coming off the base is way too much for the components that you are using and in general is just a bad idea. I would call Comp or another reputable Camshaft manufacturer and tell them what you are trying to do. If nescesary you can bush the lifter bores to account for a different lifter bore diameter, but you will need to come up with something with the proper spacing between the two. If you have deep pockets, call Jesel, they can make you solid rollers that do not use tiebars, but it will require some machine work to the block to hold the alignment bar.

 

Motor is originally hyd roller. The lifters are kept from spinning by a guide plate.

more pics

how the lifter sits in the stock guide plate (yep some sort of plastic)


where the lifters are


how the guide plate sits


lobe damage


closer


Dan

 

Interesting wear pattern on the lobes; nothing appears to be damaged on the
base of the lobe?

Same spring pressure, and rocker ratio on intake and exhaust valves?

Just trying to understand why the exhaust lobes/lifters aren't shredded.

 

yes, same exact spring and rocker on both intake and exhaust.


If I recall the base was not worn, at least not like the part shown in the pics.


Dan

 

do we know what the factory rocker ratio for the motor is?....looking at that wear you'd have to think coming off of the base circle of the cam a tremendous amount of force is being exerted on the lifter causing it to slam the camshaft.

 

stock ratio is 1.5:1.

Its strage its only the intake lifters. I wonder if there is something subtle in the cam profiles that just eat the intake lifters. They are the only stock part, well that and the reground cam.

My new plan includes a billet cam with mech profiles and some crower mech roller lifters with tiebars.

 

I managed to find a V6 set of Crower mech roller lifters at a cam place in CA. $325 for the set and it gives me two extra pair. Ill probably do that if Crower cant come thru with some replacements.

I still have yet to find someone that can explain why only the intake lifters are shot

Dan

 

I disagree with your engine builder. That looks like acase of excessive heat to me, except usually you see different colors on the metal. Not sure if cast does that, but a forged steel rod, stainless etc definately do. I'm not metal master though. If you've ever seen a rod that has been run for a bit with a spun bearing, it looks very similar to the damage on your lifter.

 

Is it the closing ramp that is damaged more in the photo's? Might be lofting the lifters at the higher RPM's. How stout are the pushrods?

 

Why not just run solid roller Morels?

 

Not sure. I hadnt looked into them. I need something skirted since my motor doesnt use the SBC oiling like every other motor.

Ill have to look now.

Dan

 

I have some questions for you.

What is the valve lift, intake and exhaust with that cam and 1.6 ratio rockers you are running?

Are you using the Isky 6105SP springs? These are usually installed at 1.800" giving 145 lbs. on the seat - you stated 175 pounds. I'm wondering if there is any chance of coil bind.

My best guess is that you don't have enough valve spring for that now solid roller valve train. The intake valve weighs more that the exhaust which is why you are getting damage there first.

Why did you convert to solid rollers? Are you spinning the engine past 8,000 rpm? An hydraulic roller valve train is much more reliable than a solid roller on the street.

You can indeed run solid rollers on a hydraulic roller camshaft. Most solid roller race grinds have no "lash" ramps.

I would recommend you convert back to hydraulic roller unless you are spinning to 8,000 rpm plus. If the lifters are identical to the LS lifter, you can use the Morel, Isky, Crower etc. replacement race quality hydraulic lifter.

Steve

 

To add to this your valve lash is really tight. I run .020 and most tight lash solid cams are .016...You might try a little bigger lash setting...

 

Ok. Let me start from way back. When I first built the motor I was using completely stock hydraulic roller lifters on a reground cam with Comp 125lb (seat pressure) springs. The car ran fine at 13psi for months. Then while I was doing some tuning at 19psi I started to hear "something". Turned out to be the intake lifters, similar damage to that in the pictures. At the time we thought that either the spring pressure was not adequate and/or the the stock lifters couldnt keep up, and were collapsing causing the lifters to slam into the cam etc. Here is a pic of one of the lifters from the first time, notice the one that is near flat.


And this is the cam card from my regrind (they were able to save the cam which we reused on the second build).



After that we went to the Isky 6205 springs ( listing on Iskys site for them is 175lb at 1.812" and 350lb at 1.260", my installed height is approx 1.875"). Also the lifters were made solid by pressing a small machined/EDMd insert into them and removing the spring. This time I ran the car for maybee 2k miles and only at 13psi before basically the same thing happened again.

Which brings me to today. Trying to figure out wtf to do.

Im not against a hyd lifter and/or cam I just need something that will fit and perform. Im near 100% positive that the V6 lifters will just drop in and work which I think is why I want to stay with solid roller lifters. Plus if I can rev to 7-7500 instead of 6500 Id be happy (IF I can make power up there).

Dan

 

Since it happend as a hyd. lifter and now as a solid lifter, maybe an oiling issue?? Maybe there just not getting enough oil...

 

oiling... could be, my oil pressure was never super great at idle, 10psi hot. It pretty quickly shot up to 45ish from what I recall with any change in RPM (its been over a year).

It also never ran that hot. I think my oil temp in the pan never got above 220-230.

I wonder also if the stock lifters roller and axles just cant take the added spring pressure and crap out fast. Adding extra pressure and the solid lifters just made things worse.

I also question the cam re-grind since it is a common variable.

Dan

 

I am getting an installed seat pressure based on your information of 155# and an open pressure of 240#. Spring rate is 317#/inch. I think you have a spring issue. For example, my open pressure is about 350# and I am N/A.

 

I come up with 155# seat pressure and 330#open.

I have a total lift of 0.306 x 1.60 = 0.4896"

So thats another 0.4896 x 317 = 155# on top of the seat pressure of 155# = 310#.

Right?

EDIT:
What is the intake valve diameter in your motor? Mine are 1.8", which at 30psi accounts for about 75# of "lost" spring pressure. Im just trying to make some comparison as to what spring pressure makes sense.



Dan