4 bolt main windsor block
- Thread starter 65mistress
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brianj5600
Active Member
Caps are not the problem, it is the main webs. The older the better. Boss 302 blocks are tough, but rare.
65ShelbyClone
Founding Member
Depending on who you ask, a Boss 302 could be either a 4-bolt Windsor or a 302 Cleveland. Other than that, no factory 4-bolt 351Ws were made. For that you have to consult the likes of Dart or World(to the tune of $2500). I just picked up a D4 351W shorblock and it looks like it actually has extra material cast in for a second set of main bolts(like my 2-bolt 351C block). Maybe Ford had plans that were never realized 
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brianj5600
Active Member
I am not aware of a single part that interchanges between a Boss 302 and a cleveland. Oh wait, some of the valvetrain and valve covers are the same. Still the Boss was available before the cleveland so....65ShelbyClone said:
the boss 302 was the only production windsor block that had 4 bolt mains. you can install 4 bolt mains on the middle three mains on a 351w as there is enough material in the webs to allow for that. milodon has a four bolt main conversion for the 351w blocks.
65ShelbyClone
Founding Member
Then again, its nots really worth converting to 4-bolt when a girdle will not only achieve the same thing, but also hold both halves if the block together if it splits. Theres a better chance of saving the rotating assembly that way.
brianj5600
Active Member
I chose not to run a girdle for the fact that they don't save the motor. The intake manifold holds the two pieces together and that is what saves the rotating assembly. Of all the block failures I've read about, none lost the rotating assembly. Girdles help cap walk, but not block cracking. Why would you put a part on a motor for when it breaks? Why use anything other than stock parts if the block will break first? Forged crank and h-beams in a roller block = waste of money, with or w/o a girdle IMO.
Route666
Active Member
Ahh I thought girdles were originally designed to stop the caps walking and thus burning up the bearings and journals. Surely if your engine is going to produce enough power to split the block it is going to bounce the caps first?
main cap girdles doo add strength to the bottom end, and do allow you to make more power before the block splits apart. they are in fact a better investment than 4 bolt main caps. the reason the girdles work is because they tie the bottom end together and change the path in which stress flows through the block.
65ShelbyClone
Founding Member
brianj5600 said:
Nobody said they did save the engine or kept anything from cracking. I said there was a better chance of saving the rotating assembly with one. The block will still split, but you have alot more than the oil pan and intake to hold it all together. Also, if you overpowered 130lbs of iron, would you rely on a chunk of cast aluminum and a piece of stamped sheetmetal to take over? I'm not saying you're wrong for not using one, just that a girdle is an extra layer of potential protection for a block that is likely inadequate for many intentions.
Take valvetrain failures out of the picture and most failures I know of were related to a connecting rod, it's bolt, or a bearing. The crack in the block is usually from the rod escaping 
DSS built my short block, and based on the materials and tolerances they set they said I am good for 7,000 to 7,750 RPM. I bought a cam that'll peter out at just over 6K.
DSS built my short block, and based on the materials and tolerances they set they said I am good for 7,000 to 7,750 RPM. I bought a cam that'll peter out at just over 6K.
65ShelbyClone
Founding Member
Edbert said:Take valvetrain failures out of the picture and most failures I know of were related to a connecting rod, it's bolt, or a bearing. The crack in the block is usually from the rod escaping
DSS built my short block, and based on the materials and tolerances they set they said I am good for 7,000 to 7,750 RPM. I bought a cam that'll peter out at just over 6K.
Thats funny because in various 5.0 forums you hear more about blown or turbocharged roller motors splitting up the middle before the rods fold.
IMO, its good you arent going to use the full "potential" of your DSS. Even the Sportsman 302 blocks apparently crack at less than the old FMS rating of 600hp. I believe roadracers were pulling out the front main web around 450hp and long periods up around 7000rpm.
brianj5600
Active Member
Block strength is the main reason I went with a 9.5" block. I'm sure people have broke them too, but I've never heard of it. I think cap walk in the 351 is a problem above 700 or 800 hp though.
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