PerformanceTrucks.net Forums

PerformanceTrucks.net Forums (https://www.performancetrucks.net/forums/)
-   GM Engine & Exhaust Performance (https://www.performancetrucks.net/forums/gm-engine-exhaust-performance-21/)
-   -   Buying 6.0 with a spun main bearing**PICS INCLUDED** (https://www.performancetrucks.net/forums/gm-engine-exhaust-performance-21/buying-6-0-spun-main-bearing%2A%2Apics-included%2A%2A-550548/)

Tradeordye3000 10-09-2017 11:49 AM

Buying 6.0 with a spun main bearing**PICS INCLUDED**
 
I have the opportunity to buy a 6.0 with a spun main for $350. I plan on rebuilding this engine and stroking it to 408. With the spun main, Is there any block damage that can be associated with this? I just want to know If a engine with a spun main could be rebuilt..

The guy also say the heads have a few exhaust bolts thats need to be removed. Is this to much work? I was just trying to avoid paying $1100 for a new 6.0 block

https://cimg7.ibsrv.net/gimg/www.per...516d0fed91.jpg
https://cimg8.ibsrv.net/gimg/www.per...a90419ce0c.jpg

silvy13 10-09-2017 11:58 AM

i purchase an lq4 a while back for $150 with a bad cam bearing, i rebuilt it to a 370ci and its been holding up fine.its been running for 5 months so far...i would go for it if it was me.anyway once you stroke it you will need a new crank

1994Vmax 10-09-2017 12:54 PM

Without measuring it I would not pay 350... maybe 100 and that's pushing it. A new one would be nice... and really with the extra machine work the screwed up one needs you need to sit down and think exactly how much you save.. Leave the new block standard bore and go 402.

Tradeordye3000 10-09-2017 01:14 PM


Originally Posted by 1994Vmax (Post 5421203)
Without measuring it I would not pay 350... maybe 100 and that's pushing it. A new one would be nice... and really with the extra machine work the screwed up one needs you need to sit down and think exactly how much you save.. Leave the new block standard bore and go 402.

That would be the standard bore with a 4" crank?

1994Vmax 10-09-2017 01:47 PM

Correct.. a 408 is just a 30 thou over bore.

Tig 10-09-2017 07:19 PM


Originally Posted by silvy13 (Post 5421196)
i purchase an lq4 a while back for $150 with a bad cam bearing, i rebuilt it to a 370ci and its been holding up fine.its been running for 5 months so far...i would go for it if it was me.anyway once you stroke it you will need a new crank

How bad was the damage from the spun cam bearing? How'd you fix it?

I have a Gen IV 6.0, was told it was a flood motor. After further inspection and disassembly realized it was a spun cam bearing. Center bearing.

Lundy 10-09-2017 10:55 PM

As long as the bearing hasn't cut into the block side of the main, it can be line bored and honed. But it can't cut too much into the main cap either being a cross bolt cap. I have a 6.0 that the cam bearing walked out on, and lost oil pressure and lost a couple rod bearings and and just moved the main bearing a bit. Cam journal housing mic'd on the money so I studded the mains and sent it to be line honed. Cleaned up nicely. It really depends on how bad the bearing ate into surrounding metal.

Dangrebel 10-10-2017 08:12 AM

That looks a lot better than the 6.0 block i built to a 408. I just had craft racing line bore/hone mine and it was fine. The bearing in mine was extremely flat and in pieces. That block will clean up fine. Tell the machine shop to use their best judgement.

1FastBrick 10-10-2017 10:18 AM

I wouldn't go more than $150.

And with out seeing the block side it hard to tell of it will clean up.

Is the cap loose and easy to pull out? If so the cap is no good... the cost to fix will be more than buying a good engine

Tig 10-10-2017 09:02 PM


Originally Posted by Lundy (Post 5421256)
As long as the bearing hasn't cut into the block side of the main, it can be line bored and honed. But it can't cut too much into the main cap either being a cross bolt cap. I have a 6.0 that the cam bearing walked out on, and lost oil pressure and lost a couple rod bearings and and just moved the main bearing a bit. Cam journal housing mic'd on the money so I studded the mains and sent it to be line honed. Cleaned up nicely. It really depends on how bad the bearing ate into surrounding metal.

I'll have to double check to see the extent of the damage.
Honing and line boring. Maybe I was misinformed but, don't LS' have three different size cam journals? After line boring and honing would the appropriate sized bearing then be installed? Sorry, new to this engine machining stuff.


All times are GMT -5. The time now is 05:02 AM.


© 2024 MH Sub I, LLC dba Internet Brands