First LS7 build. need bearing advice
10-28-2015, 02:53 PM
#1
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First LS7 build. need bearing advice Hi All.
Decided to bite the bullet and move on from my sleeper bolt on ls6 and picked up a LS7 for the car for next spring. Plans are to a. drive it,so reliability is a must, b. I am gonna be hard on it, it wont be a dedicated track car but i intend to race it. It is a otherwise stock engine other than wet sump conversion, katech rod bolts, and had the heads worked (problems addressed) and milled to increase compression to 12:1
Ive always used clevite main and rod bearings. Im now debating on trying to change it up. Ive been reading on the king bearings, and also about the gm coated bearings. I plan to power tour the car next spring and am wanting to keep the car as reliable as possible while trying to get the max out of bolt ons/tune/ and the small work i have done. The crank is a stock gm unit that has been polished.
What is the best option here? I dont necessarily think i need super duper expensive bearings, but i want people who have built these engines to chime in. Is there a bearing that offers better clearance for a polished crank than others? better oiling holes? Im building this as im not looking to change again other than a refresh if needed.
Are all the bearings for ls engines the same also? i know a lot of vendors here advertise the king xp rod bearing set for all ls engines, is this correct?
Thanks in advance for your expertise, and part numbers are greatly appreciated as well. it is a 2009 year LS7 if that matters which i dont think it does.
Decided to bite the bullet and move on from my sleeper bolt on ls6 and picked up a LS7 for the car for next spring. Plans are to a. drive it,so reliability is a must, b. I am gonna be hard on it, it wont be a dedicated track car but i intend to race it. It is a otherwise stock engine other than wet sump conversion, katech rod bolts, and had the heads worked (problems addressed) and milled to increase compression to 12:1
Ive always used clevite main and rod bearings. Im now debating on trying to change it up. Ive been reading on the king bearings, and also about the gm coated bearings. I plan to power tour the car next spring and am wanting to keep the car as reliable as possible while trying to get the max out of bolt ons/tune/ and the small work i have done. The crank is a stock gm unit that has been polished.
What is the best option here? I dont necessarily think i need super duper expensive bearings, but i want people who have built these engines to chime in. Is there a bearing that offers better clearance for a polished crank than others? better oiling holes? Im building this as im not looking to change again other than a refresh if needed.
Are all the bearings for ls engines the same also? i know a lot of vendors here advertise the king xp rod bearing set for all ls engines, is this correct?
Thanks in advance for your expertise, and part numbers are greatly appreciated as well. it is a 2009 year LS7 if that matters which i dont think it does.
10-30-2015, 06:37 AM
#2
It's been a while since I've used Clevite, but I remember them being a little tight. Especially on the thrust. I've been using ACL and Federal Mogul and they seem to work pretty well. For what you're doing, I don't think there's really going to be a noticeable difference between bearing manufacturers from a performance standpoint.
10-30-2015, 09:56 AM
#3
One factor, the LS7 crankshaft I don't believe has a radius on the journals, and while you could use a narrowed bearing for a radius journal, I would rather use a factory style GM rod bearing. Some people have mentioned the 663 type rod bearing doesn't fit the LS7 rod cap nicely. No issues with the main bearings.
Depends on how the main journal is prepped, when I worked at AES they would shave the caps and "dust" the main journal which provided .0025" typically with a standard Clevite 2199H bearing set. Some DIY guys who don't prep the mains find they need a 2199HX bearing that give an extra +.001 over a standard bearing to get the clearance they're looking for. King Alecular bearings are softer than clevite H bearings which gives them more embeddability, which I like.
I always like MOS coating for the bearings, you can purchase coated bearings from most companies or send yours to Calico for coating.
Depends on how the main journal is prepped, when I worked at AES they would shave the caps and "dust" the main journal which provided .0025" typically with a standard Clevite 2199H bearing set. Some DIY guys who don't prep the mains find they need a 2199HX bearing that give an extra +.001 over a standard bearing to get the clearance they're looking for. King Alecular bearings are softer than clevite H bearings which gives them more embeddability, which I like.
I always like MOS coating for the bearings, you can purchase coated bearings from most companies or send yours to Calico for coating.
10-30-2015, 07:24 PM
#4
I put an LS7 rotator in my L92 block, used the factory rods and crank with custom Wiseco pistons. Bearings used were 171-MS-2199P mains and 171-CB-663P rods. Both sets were tight, I had 0.0019" on the mains, 0.0021" on the rods, and 0.007" thrust. Not overly concerned about the clearances, this is a strictly street build, I plan on running Rotella 5w-40 too...
If you haven't yet, DL the Indmar build manual.
If you haven't yet, DL the Indmar build manual.