guess my rwhp!
05-13-2009, 07:21 AM
#41
holy crap
what all did you do to the block to strengthen it up?
the crazy thing is that i priced out a bunch of stuff for my 400 block, and everything was almost the exact same except that i went a little milder with the cam, at 254/258 @.050 and .630" lift
may i ask how much you put into this engine? i was up to $6500 minus the little stuff and getting the block machined
05-15-2009, 08:35 AM
#42
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773 hp from a stock gm 400 block?
holy crap
what all did you do to the block to strengthen it up?
the crazy thing is that i priced out a bunch of stuff for my 400 block, and everything was almost the exact same except that i went a little milder with the cam, at 254/258 @.050 and .630" lift
may i ask how much you put into this engine? i was up to $6500 minus the little stuff and getting the block machined
holy crap
what all did you do to the block to strengthen it up?
the crazy thing is that i priced out a bunch of stuff for my 400 block, and everything was almost the exact same except that i went a little milder with the cam, at 254/258 @.050 and .630" lift
may i ask how much you put into this engine? i was up to $6500 minus the little stuff and getting the block machined
05-20-2009, 09:53 AM
#44
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most of the stuff i bought was at vendor pricing and the machine work was done as mostly a return favor. so figuring in port work and the actual price you would pay for everything in reality theres about 12k in this motor. but like i said i only have 7k out of my pocket!
05-20-2009, 10:08 AM
#45
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Nice build, great numbers! My friend (daycare provider's hubby) runs a similar setup in his Vega minus the port work and with a Holley on top. Through a 'glide he runs 9.30's all day and is good for high 8's on the bottle. Not sure what he sprays though.
Great job, should make for one nasty ride!
Great job, should make for one nasty ride!
05-21-2009, 11:49 AM
#46
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ah 12k sounds more like it. Probably have about 13k in the 388ci I have at home. Hoping for ~675hp at 7,000-7,200 rpms and 925hp on the bottle.
Serious question for you then. I'm using a 4 bolt 350 block punched out .060 over. Would that stock block handle a VERY occassional 300hp shot (I need nitrous pistons/rings anyway) like...maybe 5-10 hits a year at most or should I get a dart block because you say you're spraying 250hp on a stock 2 bolt 400.
Serious question for you then. I'm using a 4 bolt 350 block punched out .060 over. Would that stock block handle a VERY occassional 300hp shot (I need nitrous pistons/rings anyway) like...maybe 5-10 hits a year at most or should I get a dart block because you say you're spraying 250hp on a stock 2 bolt 400.
05-22-2009, 04:51 PM
#47
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ah 12k sounds more like it. Probably have about 13k in the 388ci I have at home. Hoping for ~675hp at 7,000-7,200 rpms and 925hp on the bottle.
Serious question for you then. I'm using a 4 bolt 350 block punched out .060 over. Would that stock block handle a VERY occassional 300hp shot (I need nitrous pistons/rings anyway) like...maybe 5-10 hits a year at most or should I get a dart block because you say you're spraying 250hp on a stock 2 bolt 400.
Serious question for you then. I'm using a 4 bolt 350 block punched out .060 over. Would that stock block handle a VERY occassional 300hp shot (I need nitrous pistons/rings anyway) like...maybe 5-10 hits a year at most or should I get a dart block because you say you're spraying 250hp on a stock 2 bolt 400.
Last edited by ex-SS-ve; 05-23-2009 at 09:17 AM.
05-22-2009, 04:53 PM
#48
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Nice build, great numbers! My friend (daycare provider's hubby) runs a similar setup in his Vega minus the port work and with a Holley on top. Through a 'glide he runs 9.30's all day and is good for high 8's on the bottle. Not sure what he sprays though.
Great job, should make for one nasty ride!
Great job, should make for one nasty ride!
cannot wait to see what see car traps with the m6 in it. i still gotta overcome the traction part when i get there. ill tune on the 4 link till its just right and hope it all holds together
05-27-2009, 12:51 PM
#50
didnt think that much hp was out of the ordinary for these block. not like they are made from porcelain. just good machine work and the right builder to make it live and be reliable. i have right at 7k$ invested in this. the heads were the area i spent the most money on. 2200$ port job and shaft mount rockers 932$. adds up really fast. cannot wait to see how this thing pulls. and scare a few passengers while im at it!
did you fill the block at all?
05-28-2009, 03:58 PM
#51
A 2-bolt main 400 with the 2-freeze plugs is the strongest factory block.
A 4-bolt main 400 is the next strongest.
A 2-bolt main 400 with the 3-freeze plugs is the weakest.
(unfortunately I spotted my 4-bolt main block, and got it just for the sake of 4-bolt mains, before I learned all this
)
Splayed caps with arp studs in a 2-freeze plug block that's been filled might handle 750whp but personally, I would have gone aftermarket block if I had you top end. Keep her cool and be gentle with the spray!
A 4-bolt main 400 is the next strongest.
A 2-bolt main 400 with the 3-freeze plugs is the weakest.
(unfortunately I spotted my 4-bolt main block, and got it just for the sake of 4-bolt mains, before I learned all this
) Splayed caps with arp studs in a 2-freeze plug block that's been filled might handle 750whp but personally, I would have gone aftermarket block if I had you top end. Keep her cool and be gentle with the spray!
05-29-2009, 07:22 AM
#52
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too much speculation . i would just go into it ***** to the wall. i did it and dont regret it. too many people that are full of **** about these motors too quick to make em look bad. i made 773 all motor on mine and itll be making a hell of a lot more on the bottle. ive gone thru every aspect of this build from taking into account block strength and torsional flex. none seem to have been a problem for me. theyve built wilder motors based on the same block i have. and have equipment to measure the stress on every angle of this block while its being run on the dyno. and when you actually invest into splayed caps and good hardware, quality machine work there should never be issues with reliability.
05-29-2009, 07:43 AM
#53
too much speculation . i would just go into it ***** to the wall. i did it and dont regret it. too many people that are full of **** about these motors too quick to make em look bad. i made 773 all motor on mine and itll be making a hell of a lot more on the bottle. ive gone thru every aspect of this build from taking into account block strength and torsional flex. none seem to have been a problem for me. theyve built wilder motors based on the same block i have. and have equipment to measure the stress on every angle of this block while its being run on the dyno. and when you actually invest into splayed caps and good hardware, quality machine work there should never be issues with reliability.
im assuming it is due to core shift, which seem to be somewhat of a problem with the 400 blocks
06-01-2009, 08:44 PM
#54
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finally got to make a nitrous pull on it. my builder didnt have time to plumb up the direct port fogger. so we installed a plate kit on the 150 pills. backed timing down to 27 degrees. ran the motor up to 7k rpm. it made 905fwhp & 865 fwtq. not one hint of trouble, actually just one.
not enough crankcase venting. after that pull it built up enough pressure to push up a breather!
, actually just one. not enough crankcase venting. after that pull it built up enough pressure to push up a breather! 
06-15-2009, 07:32 AM
#57
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thanks! however i didnt build the motor, just gave the builder my personal tolerances, and what i wanted to run and spec'd out the right cam and heads for it and let him go to town on it!
we will see how it delivers once the motor is bolted between the fenders. my 2700 lb car with this setup will have some very nasty street manners but ill still drive the wheels off of it! probably more than my new car! lol
we will see how it delivers once the motor is bolted between the fenders. my 2700 lb car with this setup will have some very nasty street manners but ill still drive the wheels off of it! probably more than my new car! lol
