351w power limit

[cwh19]

How much power can a factory 351w hold?

[Balaska347]

Not sure but I think I remember 650hp, but dont quote me.

[94svtcobra]

I was thinkin around 600 aswell, u swapping to a 351 now?

[Rodeheavers]

600ish, if you mean the block, the stock internals will not hold that much.

[cwh19]

600ish, if you mean the block, the stock internals will not hold that much.

How much would a junkyard f250 shortblock hold? I was hoping for around the 550 area.

[TheBreeze72]

early blocks are clearly the best 69-74 with the proper block prep. and a main girdle 750 hp is the max ! and with the stock 3" main bearing 7200 rpm max and thats with huge bearing clearance ! the stock early cranks are factory knife edge and are decent ,but still there cast !550 hp max @ 7000 rpm and the stock rods out of early stuff are just that even with arp wave loc bolts 500hp @ 6500 rpm now the truck rods are a tad better design with the football headed / broached bolts ! The big secret to 351w engines is restricting the oil system and bearing clearance per application!I'VE had a bunch of these from the age of 16 and currant and the best bang for your buck is a 71-74 block with main studs and a 69-74 crank with truck rods w/ arp bolts ,flat top pistons even kb's are decent with like 10:5.1 comp and at least 200cc head you could even go a little higher on compression with aluminum heads ,restrict the main to cam galley's run a solid flat tappet cam (under .600 lift) 750 cfm carb & prob. a victor jr. intake ! 1"5/8 or 1"3/4 header depending on the head and tranny combo,and you've got a 500hp street killer around 6500 rpm ,or less on 93 octane i know i ran them for years! on roundy-round very inexspensive (less than sbc) btw i have all of it! (724) 425-1911 dave

[TheBreeze72]

if you've ever heard the saying money talks and B/S walks ! then spend some on 2.75 cleveland main bearing spacers and a 4 bolt billet cap conversion! and run a stroker 4340 ,or profiled billet crank ,4340 rods 6.2 or 6.250 and forged l/w pistons w/ l/w pins and low drag rings ,aluminum 225cc-240cc heads ,950-1050 carb ,solid roller & valve train (specific grind ) drag headers ! and you are pushing the envelope on the stock block indeed ! 625hp 358" @ 7500,650hp 393@7400, 675 hp 408" @ 7250 ,700 hp 420"@7000,725hp 438@6850 and so on ,but thats it for a stock block windsor !horsepower & cubic inch!the svo and dart,world blocks open a whole new realm for power but that goes back to line #1

[Rodeheavers]

if you've ever heard the saying money talks and B/S walks ! then spend some on 2.75 cleveland main bearing spacers and a 4 bolt billet cap conversion! and run a stroker 4340 ,or profiled billet crank ,4340 rods 6.2 or 6.250 and forged l/w pistons w/ l/w pins and low drag rings ,aluminum 225cc-240cc heads ,950-1050 carb ,solid roller & valve train (specific grind ) drag headers ! and you are pushing the envelope on the stock block indeed ! 625hp 358" @ 7500,650hp 393@7400, 675 hp 408" @ 7250 ,700 hp 420"@7000,725hp 438@6850 and so on ,but thats it for a stock block windsor !horsepower & cubic inch!the svo and dart,world blocks open a whole new realm for power but that goes back to line #1


thankd for this GREAT info Dave!!

[TheBreeze72]

really a junk yard f-250 shortblock ? what year ? hope a newer roller block w/ the hardware as well (94-96) well i can tell you this there has never been a 351w with factory forged pistons!69-96 no not even the lightning and even more depressing the only factory flat top was the 69 4V 290HP ENGINE! but like most of us on this forum i like a challange as much as the next person ! so my advice if you really want to max out that combo on pump gas is simular to a pure stock engine i ran some 20 years ago ! use the rod to stroke ratio to your advantage & the tall compression height on the stock cast piston as well as the large dish in the piston too! run a really tight combustion chamber aluminum cylinder head if you can afford it ,but steel will work as well "58cc or smaller the better" plenty of valve lift and most important lots of overlap to lower the cylinder pressure a bit for the pump gas factor ! and curve your timing as well ! believe it or not the engine i'm talking about was not a windsor but an all cast 1970 351c 4v 11:3.1 compression ,custom hydraulic flat tappet crane cam & springs , pure stock (cast iron intake,heads,block,crank,rods,exhaust manifolds,t-chain,balancer,water pump,etc.) and yes factory cast flat top pistons & rings!that being said all the stuff now out there for 351w's that wasn't 20 years ago i'm pretty sure you can top my 380hp 351c 4v that is still running today in a 70 maverick in north carolina!yes never touched !

[scott5]

dave is da man!