lifters?

[ericjon262]

well, they're done!

The LSX springs are beyond a shadow of a doubt have a higher rate than the 60* springs, My only concern is that the bind height is also taller, I haven't measured it, but it is taller (more coils)

[ericjon262]

When GM is making a few hundred thousand of something if they can make the lifter shorter or move a hole to save cost they will even if that means several thousand dollars (or more) in engineering.

Anyone have a set of LSX lifters I could try?

I bought a set of LS7 lifters, and there's nothing special about the insides of them compared to a set of 60* lifters aside from the springs, nothing appearing to be ceramic at least.

[NateD4]

Hey NateD4, I posted a while ago under general discussion but since you got the 3900, you should see if the LSX lifters will fit your block. I know that the 3900 has DOD just like the LSX engines do, so what are the chances that GM would spend all that money to design 2 different DOD lifters for 2 different engines. I was thinking the same thing bout the vvt 3500 since it has a smaller stroke, those lifters and 8000 rpm's isn't far away.

When GM is making a few hundred thousand of something if they can make the lifter shorter or move a hole to save cost they will even if that means several thousand dollars (or more) in engineering.

Anyone have a set of LSX lifters I could try?

[ericjon262]

I put the lifters I had in a cleaning solution, and for got to take them out, now they are gobs of rust... time for another set...

[Keoki1978]

How much interest is there in a higher performance lifter for these engines?

I'm working on my 3.9L build and am trying to get to 8500 RPM with roller hydraulics. I was going to buy a CTS-V lifter with the ceramic ball checks etc.. and see if I can design some guts for the stock lifters that'll work...

With that said, how much interest is there in a higher RPM lifter?

One of my machinists could make me whatever parts I need for an internal swap.

From what I've determined so far matching leak down rates is the harder part especially on used lifters. Anyone have a leak down rig already?

Hey NateD4, I posted a while ago under general discussion but since you got the 3900, you should see if the LSX lifters will fit your block. I know that the 3900 has DOD just like the LSX engines do, so what are the chances that GM would spend all that money to design 2 different DOD lifters for 2 different engines. I was thinking the same thing bout the vvt 3500 since it has a smaller stroke, those lifters and 8000 rpm's isn't far away.

[ericjon262]

a little later than tomorrow, but here you go





Left to right, Comp cams "magnum" "LS7" and stock 60*

[ericjon262]

I took 3 lifters apart today,

1 3400 lifter

1 "LS7" lifter

and

1 Comp Magnum SBC Lifter.

The comp and the LS7 were nearly identical. I also found that if you machined the piston on the V8 lifters down a little bit, you could install them in the 60* and turn them into solid lifters.

Pics tomorrow

[ericjon262]

and FYI, 3800's use "V8" size lifters.

[ericjon262]

got a set of stock lifters, and I've got a set of "LS7" lifters on order with USA Performance here in Pensacola.

The stock lifters were $10 with a free S-10 glovebox!, and the "LS7" lifters are about $150.

[ericjon262]

alright guys, I'm heading to the Junkyard tomorrow for a set of lifters. I'm going to try to make this happen with the LS7 guts in the 3X00 body.

[ericjon262]

Thanks for posting that!

[Superdave]

I found one of the LT1 lifters that I took the springs out of for mine. Hopefully the pictures stay working, my ISP is having issues lately..

Here is the height difference..




Here is a LT1 lifter in a 3500 block with a stock cam at max lift. You can see the oiling hole is up past the lifter bore. You'd have little to no oil pressure using these.. lol





Here is a stock lifter at max lift;

[ericjon262]

anyone have a set of lifters they would like to "donate" to R&D? I'm going to pick up a set of "LS7" Lifters and see if the newer ceramic check balls interchange.

[ericjon262]

Really the issue isn't just with valve springs as much as the collapse rate of the lifters and the internal forces of the ball check valves closing.

The CTS-V lifters have ceramic ball checks in them and are also shimmed to only allow @0.030" hydralic movement (or so I'm told).

I have heard that they are rated to 8500 RPM though and are not the same part number as those used in the LS7.

A rev kit spring system would work fairly well to reduce the valve spring requirements, however from the numbers I've run so far it only buys you a few Hz of natural frequency.

Just my opinion.

everything I've seen is that they are the same. got part numbers?

[NateD4]

Really the issue isn't just with valve springs as much as the collapse rate of the lifters and the internal forces of the ball check valves closing.

The CTS-V lifters have ceramic ball checks in them and are also shimmed to only allow @0.030" hydralic movement (or so I'm told).

I have heard that they are rated to 8500 RPM though and are not the same part number as those used in the LS7.

A rev kit spring system would work fairly well to reduce the valve spring requirements, however from the numbers I've run so far it only buys you a few Hz of natural frequency.

Just my opinion.