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Big Block Chevy core motor values

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Old Mar 5, 2014 | 03:07 PM
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Default Big Block Chevy core motor values

Hello, have a question on Big Block engine values, hope someone here has some input.

Looking at 2 BBC motors for projects, one for my Corvette (454), one for my El Camino (400 BBC). Have been looking for mostly stock-type motors (or rebuilds) with factory style pistons and internals. Nothing crazy. I am not concerned with numbers or any of that, but of course do wish to get the best parts possible.

All info is per the sellers, so actual initial installation or usage is not known, along with the types of internal parts the motors have. I will be trying to get together with the sellers to get more info. Also, I am not afraid of decent rebuildable motors if these need to be gone thru.
What would be a fair price for each of these?

454 motor, 1971 LS5

1971 LS5 motor, 512 block, 820 heads, stock type (CR) pistons. Running motor removed and replaced with bigger motor when engine had oil pressure issues. Heads are excellent shape, w/2.19-1.88 valves, EVERYTHING has been replaced and are set up for a max cam lift of .550. Heads have no more than 2000 miles.

Probs: The oil pressure changed, was always about 68 to 70 when first start and stay there till warmed up. After that it usually goes to 40 (idle) till step on gas and back up to high 60's. Now it would hold about 68 for about 10 seconds and then drop down to 50 sometimes 40 and 30. Pick up RPM’s and it goes to only 50, sometimes won't even go that high, just stays in the 30's. Bad pump maybe or excessive bearing clearances?

Also has a piston slap starting around 2200 rpm on light load, however no issues when taken to 5500 (don’t know how often it went there). Seller recommends new pistons, which I had hoped to avoid changing as I cannot do that at home.

Maybe if oil pump replaced it has more miles to go. All the numbers are on the block to verify an LS5 engine. Will double check that.
Seller will let the engine go for $1500 to rebuild.

400 BBC motor

400 engine with the 290 heads, stock type (CR) pistons, described as from 1970 Chevelle. Running motor removed and replaced with bigger motor when cam lost a lobe.

Probs: Needs new cam and lifters. Has replacement pushrods, needs one rocker assembly (don’t know why). Per owner, maybe disassemble and clean, new cam/lifters, rod/main bearings, gaskets, and should be good to go. Seller doesn't think there is extensive damage beyond one cam lobe and its lifter. Motor is a long block with tin.

Per seller, four months ago it dyno'd in car at 336 hp and 392 torque at the rear wheels, with a 5 speed manual trans, so that equates to about 395 hp and 461 ft/lb torque at the crankshaft.

Per seller, engine had been rebuilt prior to owner buying the car (about six years ago and six or seven thousand miles ago), keeping original bore/pistons. The prior owner spent about $5,000 on the rebuild.

Price unknown, was told 290 heads worth about $300/pair.

Anyone have any input on these as far as valuation?

Last edited by chevygod; Mar 5, 2014 at 03:07 PM. Reason: spelling...
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Old Mar 5, 2014 | 03:47 PM
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Originally Posted by chevygod
Hello, have a question on Big Block engine values, hope someone here has some input.

Looking at 2 BBC motors for projects, one for my Corvette (454), one for my El Camino (400 BBC). Have been looking for mostly stock-type motors (or rebuilds) with factory style pistons and internals. Nothing crazy. I am not concerned with numbers or any of that, but of course do wish to get the best parts possible.

All info is per the sellers, so actual initial installation or usage is not known, along with the types of internal parts the motors have. I will be trying to get together with the sellers to get more info. Also, I am not afraid of decent rebuildable motors if these need to be gone thru.
What would be a fair price for each of these?

454 motor, 1971 LS5

1971 LS5 motor, 512 block, 820 heads, stock type (CR) pistons. Running motor removed and replaced with bigger motor when engine had oil pressure issues. Heads are excellent shape, w/2.19-1.88 valves, EVERYTHING has been replaced and are set up for a max cam lift of .550. Heads have no more than 2000 miles.

Probs: The oil pressure changed, was always about 68 to 70 when first start and stay there till warmed up. After that it usually goes to 40 (idle) till step on gas and back up to high 60's. Now it would hold about 68 for about 10 seconds and then drop down to 50 sometimes 40 and 30. Pick up RPM’s and it goes to only 50, sometimes won't even go that high, just stays in the 30's. Bad pump maybe or excessive bearing clearances?

Also has a piston slap starting around 2200 rpm on light load, however no issues when taken to 5500 (don’t know how often it went there). Seller recommends new pistons, which I had hoped to avoid changing as I cannot do that at home.

Maybe if oil pump replaced it has more miles to go. All the numbers are on the block to verify an LS5 engine. Will double check that.
Seller will let the engine go for $1500 to rebuild.

I would pay maybe, a big maybe $1000 - you don't know what else is wrong, is the crank indeed good, will that need to be turned etc? might not only be piston wrist pin slap, could now be metal that went throughout motor. I would feel a lot better at $750 - if not I would move on, there are tons of running big blocks on craigs etc for $1000, $1200 in trucks etc that you can hear run before being pulled. There was just a 512 short block locally, spun bearing all else looked great, it sold for $500. I know the guy and he told me what he got. he also was going to stand behind it that the block could be used in current bore, pistons were good etc and that it just needed a crank turned and bearings

400 BBC motor (402 you mean?)

400 engine with the 290 heads, stock type (CR) pistons, described as from 1970 Chevelle. Running motor removed and replaced with bigger motor when cam lost a lobe.

Probs: Needs new cam and lifters. Has replacement pushrods, needs one rocker assembly (don’t know why). Per owner, maybe disassemble and clean, new cam/lifters, rod/main bearings, gaskets, and should be good to go. Seller doesn't think there is extensive damage beyond one cam lobe and its lifter. Motor is a long block with tin.

Per seller, four months ago it dyno'd in car at 336 hp and 392 torque at the rear wheels, with a 5 speed manual trans, so that equates to about 395 hp and 461 ft/lb torque at the crankshaft.

Per seller, engine had been rebuilt prior to owner buying the car (about six years ago and six or seven thousand miles ago), keeping original bore/pistons. The prior owner spent about $5,000 on the rebuild.

Price unknown, was told 290 heads worth about $300/pair. You can buy brand new alum Pro Comps for $1000 for the pair. So what is the best way to go? $300 for used heads that you need to spend $300 to $400 on to make sure they are ready to go..or just buy a new pair of alum Pro Comps which will work great on most peoples street strip set ups without a problem.

Anyone have any input on these as far as valuation?
....
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Old Mar 5, 2014 | 03:50 PM
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I would probably get something like this and build myself, or if you couldn't work with local machine shop to build it for you
http://palmsprings.craigslist.org/pts/4359544930.html

flexible on price, maybe pay 200 or 250, then put 2 - 3 grand into it - ask that they just guarantee that block is not physically cracked

new eagle rods, crank, pistons etc
http://www.ebay.com/itm/Eagle-Bbc-454-Balanced-Rotating-Assembly-2pc-030-Big-Block-Chevy-Dome-/310873457144?pt=Motors_Car_Truck_Parts_Accessories&hash=item48618081f8&vxp=mtr
or this...
http://ventura.craigslist.org/pts/4357209979.html

Last edited by BOSTONCAMARO; Mar 5, 2014 at 03:52 PM.
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Old Mar 5, 2014 | 03:53 PM
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Then buy these this is for a PAIR, NEW, 2 cylinder heads
http://www.ebay.com/itm/Big-Block-Chevy-396-454-Aluminum-Cylinder-Heads-Complete-Assembled-300cc-Bolt-On-/390731791684?pt=Motors_Car_Truck_Parts_Accessories&hash=item5af96dfd44&vxp=mtr
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Old Mar 5, 2014 | 03:56 PM
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I bet with that rotating assembly, the used 454 all trued up, bored or honed as needed, the alum oval heads, decent cam, intake, the motor would make a solid, dependable 425 HP all day long, maybe more HP even...
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Old Mar 5, 2014 | 04:25 PM
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Damn, I didn't need to see that.
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