400 sbc 60 over too much?
#21
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iTrader: (1)
I would consider using MLS head gaskets such as the FelPro 17030 . I believe you would have to drill the steam holes.
I have not ever ran one that was more than .040" over, a sonic check is a must.
I have built 5 different (3 511 casting and 2 509 casting) stock block 400 Marine engines and have had sealing issues with the center cyls.
The last engine that I built for my 20 CIG has additional #6 cooling lines tapped into the heads to cool the center cyl. this is popular with circle track engine builders.
I had no sealing issues the last time I tore it down for freshening after 5 seasons .
I have not ever ran one that was more than .040" over, a sonic check is a must.
I have built 5 different (3 511 casting and 2 509 casting) stock block 400 Marine engines and have had sealing issues with the center cyls.
The last engine that I built for my 20 CIG has additional #6 cooling lines tapped into the heads to cool the center cyl. this is popular with circle track engine builders.
I had no sealing issues the last time I tore it down for freshening after 5 seasons .
#24
No i screwed up... he said this is a 4.155 bore which equals a .030 bore over on the block. SO... it will be 406. I have no idea how I got .060 out of this. My builder was laughing at me saying he would never use a 400 with 60 over on it, and he was surprised i didnt say anything to him when i was under the impression he was using a 60 over block. I look like a dumbSh*t i guess.
Last edited by chrisf695; 03-16-2012 at 05:41 PM.
#25
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I've always heard the 509's were the blocks to use. Although they are two bolt, many splay the center three. Heard the four bolt crack in the web. Heard the higher nickel content rumor also about them.
#26
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the four bolt is the same in the webbing as the two bolt block. BUT the extra main bolt holes WEAKEN the webbing. the splayed bolts go into a diff part of the web and don't weaken it. when it comes to refresh time, just do the rings. boats rarely wear the bores much. they either break, or they get water in them and break. they don't very often live long enough to wear out. not even in the sportfish forums. especially not here.
#27
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the four bolt is the same in the webbing as the two bolt block. BUT the extra main bolt holes WEAKEN the webbing. the splayed bolts go into a diff part of the web and don't weaken it. when it comes to refresh time, just do the rings. boats rarely wear the bores much. they either break, or they get water in them and break. they don't very often live long enough to wear out. not even in the sportfish forums. especially not here.
#28
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boats rarely wear the bores much,please tell me whear you get this kind of false information,the fact is a marine engine is much harder on bore ware,espically high perf ones making good hp,this is due to the rpm,s being higher.espically engines with long stroke cranks.
Ive had many boat engines that needed bore jobs at 400 hours from the constant high RPM running and pounding doled out. (that was 3 seasons of use in that particular mill) BBC's are worse than SBC's in this regard.
I think a boat engine is subjected to about the hardest possible load you can put on anything- its like towing a trailer uphill with the brakes on every time you turn the key plus ad a batch of bad fuel every now and then from a marina.
I do agree with the statement on the block which is why I had my 406 splay capped where the tap goes into the thick part of the block at an angle.
Lots of great info being laid out here regarding casting#s
UD
#29
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chrisf695:
Don't be so quick to call yourself a dumbass. People with too much pride and ego to ask questions are the dumbasses!
Just remember that "Dumb Questions are easier than Dumb Mistakes!"
Good of you to ask the question, not to assume, and learn!
Best Regards,
Ray @ Raylar
Don't be so quick to call yourself a dumbass. People with too much pride and ego to ask questions are the dumbasses!
Just remember that "Dumb Questions are easier than Dumb Mistakes!"
Good of you to ask the question, not to assume, and learn!
Best Regards,
Ray @ Raylar