400 sbc horse power

[TX260Z]

Just wanted to know if anyone has an idea of how much hp my engine has based on my combo. I am going to pull it from my 57 belair to put in the z if the combination is right. It is a 400 4 bolt punched 20 over with dish pistons, double hump 1.9 valve heads, cam is somewhere around 27? by 47?, edelbrock dual plane intake, q jet carb, point ign, block hugger headers, 2 1/2 inch single exh. backed by a 5 speed. If anyone has a simular combo or knows how to determine the hp by the combo i would appreciate it.

Thanks

Greg

[jt1]

Why not take it to a chassis dyno before you pull it? Then you'll know if you want to make any changes while it's out. It sounds like about 300 hp to me, the heads are probably a restriction.

 

John

[TX260Z]

Why not take it to a chassis dyno before you pull it? Then you'll know if you want to make any changes while it's out. It sounds like about 300 hp to me, the heads are probably a restriction.

 

John

The belair is not driveable right now, i figured why buy a crate motor for about 3k when i could use this one then drop a bbc in the belair. But if the hp and tq were not at least 300 each then i might as well buy a crate motor since i dont think i would be happy with a stock hp and tq sbc in the z.

[BRAAP]

Greg,

Welcome to HybridZ. JT1 offered sound advice.

 

I say if the engine is sound, install it and enjoy it. The Z should be lighter than your ‘57 so the performance should be more aggressive, (power to weight ratio).

 

Here is THE most accurate answer you will receive with the information you provided regarding your 400 SBC power output.

 

If it runs, it should produce between 200 ft lbs of torque and 100 HP and could make up to 480 ft lbs and 450 HP, all depends on the exact precise details of the parts used, how well those parts compliment each other on a SBC 400, and just as importantly, how well the engine was tuned, i.e. carb jetting and ignition curve. If it doesn’t run, chances are it produces 0 Ft lbs of torque and 0 HP.

 

Unless you give us a LOT more information, this thread is on its way to the shed as this question really has no definitive answer. With such vague specs such as cam specs being between 270-279 duration, (is that seat to seat, or at .050”? what about LSA?), 470-479 lift? Manifold is “an” Edelbrock dual plane, (which one? They make a couple types of dual plane and different variations of those types), we can’t offer forth but mere arbitrary guesses and/or broad vague power ranges.

 

Regardless of the “HP numbers”, (100 HP or 450 HP), what really matters is does that acceleration force you feel when you mash the loud pedal in the ’57 bring a smile to your face? If so, then that same engine in the Z should bring an even bigger smile due to the Z cars lighter weight.

 

Oh, and don’t forget. With some mild to moderate parts upgrades to the suspension of the SBC powered Z car, it will carve corners with ferocious authority.

 

If you like aggressive acceleration and you like sports cars, just do it. You wont regret it.

[grumpyvette]

"Unless you give us a LOT more information, this thread is on its way to the shed as this question really has no definitive answer. With such vague specs such as cam specs being between 270-279 duration, (is that seat to seat, or at .050”? what about LSA?), 470-479 lift? Manifold is “an” Edelbrock dual plane, (which one? They make a couple types of dual plane and different variations of those types), we can’t offer forth but mere arbitrary guesses and/or broad vague power ranges"

 

DITTO!

 

 

Id bet the rear wheel chassis dyno results are not too far from the 270-290 hp range, with the very limited info you posted, BUT THATS ASSUMING A GOOD DEAL, like a basically stock short block, I DON,T KNOW TO BE TRUE , and only ASSUME (having seen lots of vaugely similar mild builds over the years)

[660Z]

It sound like my combo for my 400ci give or take.

 

My combo is 400 std bore w/ flattops, aftermarket heads 202/160 valves same volume as the old 461 double humps -10.0 comp.

.460 cam w/1.6 rockers.

I`m running a Victor jr intake and 830 db holley.

Turbo 350 trans with 11" converter.

 

Before I took it off the road the best time was 12.02 @115 in the 1/4.

The online calulators stated I made 290 hp at the wheel and about 330 at the crank.

 

The Z weight advantage is amazing and can produce results very easy.

 

I took this motor out of my 68 Nova for my 396 bb /stick install. The 400 in the Nova with 882 heads,1.5 rockers ,750dp carb, same convert and trans. I ran it once to see what it would do and turned a 13.8.

 

That same motor, nothing changed except carb started at 12.8 off the trailer and the times would drop dramticly every time I ran it.

 

I say install it as is and have fun. The tourqe of the 400 in a Z is nuts.

[jt1]

posted by TX260Z[/i]

 

The belair is not driveable right now, i figured why buy a crate motor for about 3k when i could use this one then drop a bbc in the belair. But if the hp and tq were not at least 300 each then i might as well buy a crate motor since i dont think i would be happy with a stock hp and tq sbc in the z.

 

I wouldn't buy a crate motor. If the 400 is in reasonably good shape, I'd take the 400 and the $3K and put the 400 in the Z. It will take 1 -1.5K to make/buy the mounts, get it wired and plumbed, fab a driveshaft, and install headers and exhaust. Upgrading the ignition to a HEI or MSD would be a good idea, and you will probably need to upgrade the radiator. Then I would take it to a chassis dyno with a wideband O2 sensor, and get the ignition and carb dialed in. You will likely pick up some power, and you will also find that a 300 hp Z car is pretty much of a terror. Even though that's a mild 400, it's twice the stock hp of your car and will be a ball to drive. Then you can think about what else you want to upgrade, suspension, brakes, interior, or motor, as time and budget permit. It's a slippery slope but a heck of a lot of fun.

 

Edit: Do some research before you make/buy your mounts. I'm pretty sure the stock 400 damper won't clear the rack with JTR mounts. You might want to go MSA, or change to a smaller damper, which might mean rebalancing if you can't find a small diameter 400 damper.

 

John

[dv82xl]

Dude, I have the same engine. My 240 weighs 2520 lbs. That is next to nothing. The car just flys. Unless you're really retentaive about the whole thing, you'll have plenty of HP. I've never had it on the track cause "it's overpowered". I suppose the best advice is get it on a chassis dyno once it's insatalled. But again - it's a hugh difference between a 2.4Lx 6 to a 6.6liter v8! Personally, I do not care how much hp I put out. I see peoples reactions on the street! That's enough for me. Maybe I'm just easily impressed. Drop in the 400 and ENJOY!

[jnjdragracing]

Hey tx260z,

 

My brother Jerry just built his nos motor a 400 sbc. He brought it to the track in the z and ran pretty good times. He going to take it to the dyno next week to do a good tune on it. He is running a solid roller nitrous cam, and dart iron eagle heads. He is getting it tuned on the chassis dyno (HP) and times on the engine to sell it to fund his turbo engine build.

 

If you have not bought the other 400 yet I would wait and talk to him. He will be selling the engine complete carb to oil pan. Probably a good deal too, and it will already be tuned.

 

John

[TX260Z]

Greg,

Welcome to HybridZ. JT1 offered sound advice.

 

I say if the engine is sound, install it and enjoy it. The Z should be lighter than your ‘57 so the performance should be more aggressive, (power to weight ratio).

 

Here is THE most accurate answer you will receive with the information you provided regarding your 400 SBC power output.

 

If it runs, it should produce between 200 ft lbs of torque and 100 HP and could make up to 480 ft lbs and 450 HP, all depends on the exact precise details of the parts used, how well those parts compliment each other on a SBC 400, and just as importantly, how well the engine was tuned, i.e. carb jetting and ignition curve. If it doesn’t run, chances are it produces 0 Ft lbs of torque and 0 HP.

 

Unless you give us a LOT more information, this thread is on its way to the shed as this question really has no definitive answer. With such vague specs such as cam specs being between 270-279 duration, (is that seat to seat, or at .050� what about LSA?), 470-479 lift? Manifold is “an†Edelbrock dual plane, (which one? They make a couple types of dual plane and different variations of those types), we can’t offer forth but mere arbitrary guesses and/or broad vague power ranges.

 

Regardless of the “HP numbersâ€, (100 HP or 450 HP), what really matters is does that acceleration force you feel when you mash the loud pedal in the ’57 bring a smile to your face? If so, then that same engine in the Z should bring an even bigger smile due to the Z cars lighter weight.

 

Oh, and don’t forget. With some mild to moderate parts upgrades to the suspension of the SBC powered Z car, it will carve corners with ferocious authority.

 

If you like aggressive acceleration and you like sports cars, just do it. You wont regret it.

 

Sorry about the vagueness, i bought the engine from a machine shop for $300 as a assembled shortblock, he did not know or remember the cam specs and the pj gear drive and t chain cover was already installed. I got the measurements from a degree wheel and dial indicator. The intake is just a performer. The performance when i drove the belair was great, it had a bunch of torque and when the secondaries opened up it actually broke the tires loose on a 40 roll. The motor only has about 5-7k miles on it. Thanks for the replies, i think i will do it just need to go to summit for the 6.7 inch balancer.

Greg

[TX260Z]

I wouldn't buy a crate motor. If the 400 is in reasonably good shape, I'd take the 400 and the $3K and put the 400 in the Z. It will take 1 -1.5K to make/buy the mounts, get it wired and plumbed, fab a driveshaft, and install headers and exhaust. Upgrading the ignition to a HEI or MSD would be a good idea, and you will probably need to upgrade the radiator. Then I would take it to a chassis dyno with a wideband O2 sensor, and get the ignition and carb dialed in. You will likely pick up some power, and you will also find that a 300 hp Z car is pretty much of a terror. Even though that's a mild 400, it's twice the stock hp of your car and will be a ball to drive. Then you can think about what else you want to upgrade, suspension, brakes, interior, or motor, as time and budget permit. It's a slippery slope but a heck of a lot of fun.

 

Edit: Do some research before you make/buy your mounts. I'm pretty sure the stock 400 damper won't clear the rack with JTR mounts. You might want to go MSA, or change to a smaller damper, which might mean rebalancing if you can't find a small diameter 400 damper.

 

John

It actually wont cost me much to install it, i have a v8 z parts car with everything but the motor.

[TX260Z]

Dude, I have the same engine. My 240 weighs 2520 lbs. That is next to nothing. The car just flys. Unless you're really retentaive about the whole thing, you'll have plenty of HP. I've never had it on the track cause "it's overpowered". I suppose the best advice is get it on a chassis dyno once it's insatalled. But again - it's a hugh difference between a 2.4Lx 6 to a 6.6liter v8! Personally, I do not care how much hp I put out. I see peoples reactions on the street! That's enough for me. Maybe I'm just easily impressed. Drop in the 400 and ENJOY!

Thanks for the reply, i just did not want a z car that would be just as fast as a v8 mustang f body

[TX260Z]

Hey tx260z,

 

My brother Jerry just built his nos motor a 400 sbc. He brought it to the track in the z and ran pretty good times. He going to take it to the dyno next week to do a good tune on it. He is running a solid roller nitrous cam, and dart iron eagle heads. He is getting it tuned on the chassis dyno (HP) and times on the engine to sell it to fund his turbo engine build.

 

If you have not bought the other 400 yet I would wait and talk to him. He will be selling the engine complete carb to oil pan. Probably a good deal too, and it will already be tuned.

 

John

Thanks for the offer, but i already have the motor it is in my belair. I am just kind of short on funds right now but itching for a v8 in the z car. Sounds like the 400 will satisfy me (FOR NOW).