why bore to 408
12-10-2006, 11:53 PM
#1
why bore to 408 why does everyone bore the 6.0 block why not leave it and keep it a 402 and take the extra money. only ask cause i work at a GM dealership so i get parts at cost. i can buy a 6.0 block and build my own motor cheaper than buyin one. i will be movin within 3mo so i need to get a motor quick i cant afford a LS2 like i want and need a motor and to get my motor out of the shop and my car off the lot before i tell my dick head boss off.
so im keepin my cam and heads for the iron block just need to know the reason for the 30 over all the time
so im keepin my cam and heads for the iron block just need to know the reason for the 30 over all the time
12-11-2006, 12:31 AM
#3
LOL what the hell does that mean a 6L block is a 6L block still 4in bore u 408 guys only bored it 30over doesnt answer the question why.
a 6.0L block is already 4.000 why go 4.030 doesnt make sense to me unless it a used block. but most companies say " new 6L block bored to 4.030" blah blah blah 408
if i buy a new block i can save 80$ on boring it and loose OH NO 6CI wow
P.S. your car sounds sick
a 6.0L block is already 4.000 why go 4.030 doesnt make sense to me unless it a used block. but most companies say " new 6L block bored to 4.030" blah blah blah 408
if i buy a new block i can save 80$ on boring it and loose OH NO 6CI wow
P.S. your car sounds sick
12-11-2006, 12:56 AM
#4
Banned
iTrader: (5)
Join Date: Apr 2003
Location: Chicago
Posts: 1,890
Likes: 0
Received 0 Likes
on
0 Posts
Often people will use a salvaged 6.0 block, iron blocks have a tendency to core shift, its good practice to bore these blocks then hone with torque plate etc.
My motor was built from low milage newer iron block (LS2 head bolt style) salvaged, the bores looked good, so all that was done is, hot tank the block and hone. You end up with 402ci iron block setup.
Wouldn't bore a block unless its needed. Answer your question?
My motor was built from low milage newer iron block (LS2 head bolt style) salvaged, the bores looked good, so all that was done is, hot tank the block and hone. You end up with 402ci iron block setup.
Wouldn't bore a block unless its needed. Answer your question?
12-11-2006, 08:00 AM
#5
Registered User
iTrader: (15)
Join Date: Aug 2005
Location: BTR, La
Posts: 1,363
Likes: 0
Received 0 Likes
on
0 Posts
I probably wouldn't bore unless necessary, but I'd really consider the fact that a 4.030" bore motor would breath better as the cylinder walls would shroud the valves less than a 4.00" bore. It's probably worth more than a few hp. If you buying an aftermarket rotating assembly, the extra cost to get the slightly larger bore is insignificant- basically just the cost of boring THEN honing your block. Considering your block will be at a machine shop anyway before you build it, it's nothing in terms of additional cost.
Ben T.
Ben T.
12-11-2006, 10:06 AM
#6
well the valve unshroud wont really matter useing my 205 AFRs.
but is it needed is manditor do you have to id rather not also since burnt a piston and put a big dent in my cylinder wall and cant bore it enough now in my ls1 so i wanna keep as much wall as i can incase this would happen again so i can rebuild it.
but is it needed is manditor do you have to id rather not also since burnt a piston and put a big dent in my cylinder wall and cant bore it enough now in my ls1 so i wanna keep as much wall as i can incase this would happen again so i can rebuild it.
12-11-2006, 01:08 PM
#7
Launching!
iTrader: (5)
Join Date: Jul 2005
Location: Corona, CA
Posts: 236
Likes: 0
Received 0 Likes
on
0 Posts
Its not mandatory. In your case, since you are buying a brand new block its not really worth it. You can always bore it out later if you have to do another rebuild. If I were in your situation I would just finish hone to the piston manufacturer's specs and leave it at that. The reason most guys including myself bore .030 over is because they have a used block like Fraser said.
Advantages:
-Unshrouding the valves
-6 more cubic inches
Disadvantages:
-$Cost of boring
-the $cost of having to have the cyclinder wall thickness checked in the future in case you need to go .060 over in the future.
Advantages:
-Unshrouding the valves
-6 more cubic inches
Disadvantages:
-$Cost of boring
-the $cost of having to have the cyclinder wall thickness checked in the future in case you need to go .060 over in the future.
Trending Topics
12-11-2006, 09:13 PM
#9
It's not a necessity, just a "why not" sort of thing. If you scar a wall with a stock block, you will need to bore it and use larger pistons/rings. If you scar a wall in a bored .030 block, you will need to bore it and use larger pistons/rings. It's the same strategy either way. Plenty of people run, or have run, .060 over blocks with a sonic test with no problems, including myself. If you are speaking strictly based on technicalities, then yes a .030 over block will have stronger walls than a .060 over block. Will you be pushing enough HP for it to actually matter, though? My 375 iron block was built for a 250 shot by FMS. That should tell you that .060 over isn't really as unsafe on a street motor as it's hyped up to be.
