What main bearings for a high performance engine?

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maca

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Hey guys I'm rebuilding my 360 stroked to 408 turbo magnum. It has around 800hp at the crank. I will be spinning it to around 6500 RPM.
Just wondering what main bearings people are running in the bigger horsepower engines. I have read that half groove bearings are better to take the extra hp loads but full groove bearings seem to be more commonly available.
Anyone had any experience running both.
Clevite 1266hg and
ms1051p clevite
Are the two I've been looking at
 
I've always used 1/2 groove. But I just built my 408 shortblock last weekend and used a scat kit. It came with 3/4 groove clevite bearings!
 
Thanks for the reply mate do you know what the part numbers on those bearings are
 
I don't remember them. I'll have to look when I get over to my friends shop this weekend.
 
1994redram said:
I don't remember them. I'll have to look when I get over to my friends shop this weekend.
Click to expand...
That'll be much appreciated as I'm struggling to find many bearings here in Australia and they have to order from the states. even if you tell me what kit it was I might be able to contact them and find out what bearings it comes with
 
For any Aussies looking for this in Australia I found them at precision international under this part number
Eb2707m5000pf
 
BTW, OP, the trade-off is:
- Full groove mains give better rod bearing oiling which is an area of concern of the SBM oiling design at the highest RPM's
- 1/2 groove mains makes the load on the main bearing oil film lower..... less chance of pushing it out under high pressure

That 3/4 groove set is a compromise of the 2 factors... maybe a great idea!
 
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maca said:
Hey guys I'm rebuilding my 360 stroked to 408 turbo magnum. It has around 800hp at the crank. I will be spinning it to around 6500 RPM.
Just wondering what main bearings people are running in the bigger horsepower engines. I have read that half groove bearings are better to take the extra hp loads but full groove bearings seem to be more commonly available.
Anyone had any experience running both.
Clevite 1266hg and
ms1051p clevite
Are the two I've been looking at
Click to expand...
For that power level you should use the "H" series clevite bearings.
The "H" is for high performance and these series of bearings have features for high performance such as increased bearing clearance,
Increased bearing crush, and they are a harder bearing. Imho
That motor should have a lot of other block oiling mods as well imho.
 
Duane said:
For that power level you should use the "H" series clevite bearings.
The "H" is for high performance and these series of bearings have features for high performance such as increased bearing clearance,
Increased bearing crush, and they are a harder bearing. Imho
That motor should have a lot of other block oiling mods as well imho.
Click to expand...
Hey Duane
What block oiling mods do you suggest
 
The only thing I'll say about 1/2 vs 3/4 and full groove bearings is that I used full grooves on one of my mills and it had a hard time making oil pressure. It made just enough pressure for the requirements 10 per 1,000 RPM and that was with 20/50 oil.
 
maca said:
Hey guys I'm rebuilding my 360 stroked to 408 turbo magnum. It has around 800hp at the crank. I will be spinning it to around 6500 RPM.
Just wondering what main bearings people are running in the bigger horsepower engines. I have read that half groove bearings are better to take the extra hp loads but full groove bearings seem to be more commonly available.
Anyone had any experience running both.
Clevite 1266hg and
ms1051p clevite
Are the two I've been looking at
Click to expand...
I've used kings bearings. They are very good and my cousin who dirt races has been using them for years. 1/2 groove are what is in mine
 
roccodart440 said:
The only thing I'll say about 1/2 vs 3/4 and full groove bearings is that I used full grooves on one of my mills and it had a hard time making oil pressure. It made just enough pressure for the requirements 10 per 1,000 RPM and that was with 20/50 oil.
Click to expand...
In the big block?
High volume oil pump?
Pick up tube size increased?
 
roccodart440 said:
The only thing I'll say about 1/2 vs 3/4 and full groove bearings is that I used full grooves on one of my mills and it had a hard time making oil pressure. It made just enough pressure for the requirements 10 per 1,000 RPM and that was with 20/50 oil.
Click to expand...
Did you tube the block oil galley,did you have a high volume pump?
 
maca said:
Hey Duane
What block oiling mods do you suggest
Click to expand...
You should start with a full read of the sticky thread by Guitar jones.
It is a good start on block and bearing shell mods
The guitar jones oiling thread is lengthy but there is a lot of info there.
Also we have had several other lengthy discussions on this board
And i am hoping another one is about to start in another thread.
Use the search feature.
 
Thanks for all the links guys. I'm still not sure how oilng mods will help my engine though. When I strip it down after it's been running for a period of time I don't have a lot of wear that would suggest insufficient oil. My main issue is oil pressure. For some reason I just can't seem to get decent pressure in this engine. I don't feel that changing the spring in the pump to increase the pressure will help either because as far as I know that's a pressure relief valve and it has to reach a certain pressure before that opens. I don't think mine's even reaching that pressure.
 
Watch those bearings closely! I had one set and I still have them that had no Groove no hole in the number 5! Of course they send a new set when I sent them pictures...
 
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