6.0 lq4 going to shop need advice on what I need
07-29-2017, 03:40 PM
#1
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6.0 lq4 going to shop need advice on what I need Hey guys, so I have a 2000 lq4 block out of a Silverado I picked up cheap to replace my 5.7, I plan on reusing everything from my 5.7 that I can( possible spun main or rod bearing im still taking it apart) my question for you guys is I'm having the lq4 block cleaned up and bored .30 for a 370 I am not going to be running any sort of power adder and the cam Im reusing is a tsp v3 cam I'm curious with the lq4 being bored .30 over will that affect what main, cam and rod bearings that I will need? I just wasn't sure if I should get all the bearings I need now or let he shop clean the block and take measurements and let me know what sizes but if I can be proactive and figure all that now that would be great, any and all advice is appreciated
07-29-2017, 05:31 PM
#2
I would wait and see what the old engine looks like after you tear it apart. If you want to try to reuse the crank from the old engine and a main or rod bearing has spun, it might need .010" under bearings. If that's the case, I like to measure the ID with the bearings in place and bolts torqued and use that to determine the OD for the crank to be ground to in order to get the right clearance.
07-30-2017, 02:13 AM
#3
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I've bought a couple of "2000" lq4's that had the long crankshafts in them...
Your probably way ahead of this, but if not, don't let the long crank/short crank early 6.0L difference bite you...
07-31-2017, 02:52 PM
#4
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I would wait and see what the old engine looks like after you tear it apart. If you want to try to reuse the crank from the old engine and a main or rod bearing has spun, it might need .010" under bearings. If that's the case, I like to measure the ID with the bearings in place and bolts torqued and use that to determine the OD for the crank to be ground to in order to get the right clearance.
08-01-2017, 10:47 AM
#5
I would wait and see what the old engine looks like after you tear it apart. If you want to try to reuse the crank from the old engine and a main or rod bearing has spun, it might need .010" under bearings. If that's the case, I like to measure the ID with the bearings in place and bolts torqued and use that to determine the OD for the crank to be ground to in order to get the right clearance.
08-01-2017, 01:03 PM
#6
TECH Resident
Good rule of thumb for clearance is.0125 inches per inch of shaft diameter. Of course some will not agree but I have used that for along time with no issues.Let the shop buy and fit the bearings to what ever shaft you choose then if there are issues they have some skin in the game. They will need to fit the pistons and rings also. My.02 worth. Edit, should have been .00125 per inch of shaft diameter Sorry if I muddied up the waters.
Last edited by cookseyb; 08-17-2017 at 06:51 AM. Reason: incorrect decimal point placement
08-01-2017, 01:20 PM
#7
We have complete kits with literally every part youd need to complete a bare block. Normally cheaper even than the machine shop will charge and more complete. We can actually get you flat tops instead of dished pistons to add some cr and promote better power. That complete kit with literally everything (minus cam and lifters) runs $620. Normally its $650+
Id recommend a 4.030 bore. It will clean up any issues the orig bore had and promot more power. The oversize pistons are same price as reg size.
Id also recommend letting the machine shop check, magnaflux, and polish and chamfer the crank. They can then let you know what you need for bearings.
If youd like to know more, please let us know!!
Id recommend a 4.030 bore. It will clean up any issues the orig bore had and promot more power. The oversize pistons are same price as reg size.
Id also recommend letting the machine shop check, magnaflux, and polish and chamfer the crank. They can then let you know what you need for bearings.
If youd like to know more, please let us know!!
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08-01-2017, 01:31 PM
#8
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We have complete kits with literally every part youd need to complete a bare block. Normally cheaper even than the machine shop will charge and more complete. We can actually get you flat tops instead of dished pistons to add some cr and promote better power. That complete kit with literally everything (minus cam and lifters) runs $620. Normally its $650+
Id recommend a 4.030 bore. It will clean up any issues the orig bore had and promot more power. The oversize pistons are same price as reg size.
Id also recommend letting the machine shop check, magnaflux, and polish and chamfer the crank. They can then let you know what you need for bearings.
If youd like to know more, please let us know!!
Id recommend a 4.030 bore. It will clean up any issues the orig bore had and promot more power. The oversize pistons are same price as reg size.
Id also recommend letting the machine shop check, magnaflux, and polish and chamfer the crank. They can then let you know what you need for bearings.
If youd like to know more, please let us know!!
yea I planned on having the block bored .30 over and using a set of 4.030 dss racing pistons with -5cc of valve clearance because when I spoke to Texas speed about my v3 cam they said with my prc 2.5 ls6 heads being milled .20 over for that cam that I really couldn't go any bigger with a cam, so I chose the dss racing so if I find that my cam was damaged at least I could go bigger if need be
08-01-2017, 02:57 PM
#10
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08-02-2017, 10:03 AM
#14
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So I'm sorry to sound like a noob but with the block being bored .30 over that won't affect what cam bearings I get correct? Is there situations where you would need different sized cam bearings?
08-02-2017, 10:05 AM
#15
I like .001" per 1" of journal diameter as a starting point, but it depends on what the engine will be used for and what material the rods and block are made of. For a mild NA (<550whp) iron block build, I'd shoot for .0022" on the mains and .002" on the rods. You could even go a little looser or tighter, say +/- .0002", and it would be fine too.
08-02-2017, 10:17 AM
#16
There are some variations in the year split so sometimes measuring the OD of the bearing is better or id of cam bore.
The difference is in the front/rear cam bores. Early design is 2.32 in the later design is 2.34 it seems like a VERY small amount but youll run into issues if you do not know.
08-16-2017, 05:17 PM
#17
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I figured I would ask this here before starting a new thread, so I spoke with Texas speed to get exact specs on the prc 2.5 ls6 heads I bought from them and they said I had 61cc chambers 2.02 intake and 1.575 exhaust valves and that the heads were milled .20 over for my tsp v3 cam, so here's my question what head gasket should I be running if this is a 370 build and also what kind of compression ratio am I looking at? I plan on running ls2 rods stock crank and flat top 4.030 oversized pistons with no valve relief and this will be strictly on 93 pump gas. Also is the v3 cam a good cam to use still if the compression is higher or is there something that would still fit that would really maximize this setup? I want to try to get as close to 500whp as possible, this same setup on my 5.7 made 440whp
08-16-2017, 05:30 PM
#19
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