Layer 1 SOLD-OUT

LS7 Hydraulic Roller Lifters

13

17122490-12 $77.99
Regular price $77.99

When engines are equipped with a hydraulic camshaft, high rpm is limited by the improper position of the internal piston as the lifter inevitably "pumps up". This improper location results in open valves and therefore leads to lost power. These lifters are almost required for any 3800 car shifting above 6000rpm because they help with the typical 5600rpm dip. LS7 lifters are preloaded and have to be installed between 3/8 and 3/4 turn (vs. 1/2 to 1.5 turns on stock lifters)


Sold in a set of 12. If you need QTY 16, click here.

 

How to determine proper push rod length by measuring "lifter preload":
All said and done you need to add up the changes in head milling, block decking, head gasket thickness, push rod length, valve tip height, camshaft base circle lobe diameter, and rocker arm type. This will allow you to calculate the length of push rod needed.

To check for lifter preload or lifter squish you need to first get to zero lash. Turn the engine over so that one valve on a cylinder is open. Because one is open, you know the other is closed, meaning the lifter is sitting on the base circle. With that lifter on the base circle loosen the rocker bolt and then re-tighten with one hand while spinning the pushrod with the other. This way you can tell when everything first makes contact (the valve is touching the rocker tip, the pushrod is touching the rocker & and lifter and the lifter is touching the cam). At this point of first contact you are at zero lash. Everything past this point is lifter preload. Continue to tighten the rocker bolt until the bolt hits its snug point. This is how much lifter preload you have. Each 1/2 turn of the rocker bolt is ~.050 of lifter preload. Your goal is to have between 1/2 turn and 1.5 turns if you have stock lifters or 3/8 turn to 1/2 turn if you have Comp lifters. As you can see the stockers have a lot more room for error.
If you have too much preload and you have exhausted the adjustment of the lifter, the valves will stay open and the car will not start due to lack of compression. If you have too little preload, the valve train will be noisy and you risk exploding a lifter and having a very costly repair.
Description

When engines are equipped with a hydraulic camshaft, high rpm is limited by the improper position of the internal piston as the lifter inevitably "pumps up". This improper location results in open valves and therefore leads to lost power. These lifters are almost required for any 3800 car shifting above 6000rpm because they help with the typical 5600rpm dip. LS7 lifters are preloaded and have to be installed between 3/8 and 3/4 turn (vs. 1/2 to 1.5 turns on stock lifters)


Sold in a set of 12. If you need QTY 16, click here.

 

More Info
How to determine proper push rod length by measuring "lifter preload":
All said and done you need to add up the changes in head milling, block decking, head gasket thickness, push rod length, valve tip height, camshaft base circle lobe diameter, and rocker arm type. This will allow you to calculate the length of push rod needed.

To check for lifter preload or lifter squish you need to first get to zero lash. Turn the engine over so that one valve on a cylinder is open. Because one is open, you know the other is closed, meaning the lifter is sitting on the base circle. With that lifter on the base circle loosen the rocker bolt and then re-tighten with one hand while spinning the pushrod with the other. This way you can tell when everything first makes contact (the valve is touching the rocker tip, the pushrod is touching the rocker & and lifter and the lifter is touching the cam). At this point of first contact you are at zero lash. Everything past this point is lifter preload. Continue to tighten the rocker bolt until the bolt hits its snug point. This is how much lifter preload you have. Each 1/2 turn of the rocker bolt is ~.050 of lifter preload. Your goal is to have between 1/2 turn and 1.5 turns if you have stock lifters or 3/8 turn to 1/2 turn if you have Comp lifters. As you can see the stockers have a lot more room for error.
If you have too much preload and you have exhausted the adjustment of the lifter, the valves will stay open and the car will not start due to lack of compression. If you have too little preload, the valve train will be noisy and you risk exploding a lifter and having a very costly repair.

You are viewing a product listed on the following platform:

3800

Customer Reviews

4.9 Based on 13 reviews
5 ★
92% 
12
4 ★
8% 
1
3 ★
0% 
0
2 ★
0% 
0
1 ★
0% 
0
Write a Review
  • Reviews

Thank you for submitting a review!

Your input is very much appreciated. Share it with your friends so they can enjoy it too!

PD
12/06/2018
Parker D.

Great product

I bought these for my 2004 Monte Carlo SS. Package arrived quickly, installation was easy, and I no longer have ticking. Great price as well.

TK
07/10/2018
Tyree K.

Ls7 lifters

Simple install Came pre greased Fast shipping

DD
02/21/2018
Dave D.

Lifters

Have had these installed for over a year, and they have been fantastic!

GG
12/01/2017
Guest G.

Thanks

Thanks

BB
09/03/2017
Bob B.

No bleed down

Handle extreme spring pressures without any bleed down haven't had the valve float shifting at 6300 redline 6500