Hot Rod Forum banner

Testing an engine before purchase?

3K views 22 replies 8 participants last post by  russ69coupe 
#1 ·
Hey guys I need some advice...I've posted regarding this engine before..so I found out this 454 engine has the 781 heads...is a 2 bolt...the guy at the performance shop by my house wants $950 for the complete block..has.new edelbrock intake, harmonic balancer and water pump..I was excited when I found out the engine had the large oval port heads..I have the money to buy this engine..but I want to make sure the engine is in good shape...it is completely stock...what do u guys recommend? Compression test? FYI the engine is not inside a car...it is on a stand...Thx for the advice I appreciate it
 
#2 · (Edited)
The only engine i have bought without hearing it running came in the Mustang i bought. I lived 12000miles away. As i could not hear it running i had a third party listen to it who said it was ok. Total B---S---. The "new" stroker needed stripping to solve the knocking. Loose cam gear caused cam and lifter failure and a sump laced with cast iron shavings from cam and lifter failure.
If you cant see the internals for a visual inspection by taking a rod and main bearing cap off then IMO i would fire it up as a condition of your purchase.
IMO i would fire the engine and have an oil pressure gauge inserted in it. If it blows blue smoke and rattles.:mad:....... if coolant leaks..:mad:......head gaskets, the list goes on.
If it cant be fired because its on a stand, find a cradle on wheels to sit the engine in, radiator , two hoses, battery and a switch and starter. Running without an exhaust could prevent you from hearing any knocks or rattles.
Al.
 

Attachments

#4 ·
Compression test will only tell you if the valves and rings are good. It wont reveal any cracked blocks, heads, head gasket leaks, or bad bearings. If the seller will give you a warranty that's wirth the paper it's written on, then I'd say go ahead, but if there's no warranty, and you can't hear it run I would pass.
And if he can set it up to run be sure it's running with coolant so it can run long enough to be sure it's OK. Had a friend who bought a 350 from a car and the hoses and water were drained. Seller said he was getting ready to pull it, so could only run it long enough to hear it and see oil pressure. After we installed it we found it had bad head gasket and had to pull the heads and put new on.
Cheap fix, and a lesson learned.
 
#5 ·
Well I spoke wig the guy this morning..he said I can do anything I want with the engine...can fire it up, leakdown and compression test, remove valve covers, intake etc..so it seems he has nothing to hide..so you guys recommend to fire this thing up? I will ask him about the warranty later on I forgot to ask..lol.. he tells me he GUARANTEES its good...and I can do any kind of test I want to it before purchase
 
#6 ·
Just comoression test all the cylinders and run it for a while. At least til it gets up to temperatue, then for a few minutes after.
When buying an engine that you are just going to install as is you always need to test it first. But since most guys will rebuild it first its not necessary to hear it start.
 
#7 ·
Im not going to install it right away..I'm going to throw in some new pistons and all that good stuff before installation..and port the heads and bore .030...guy says the engine has under 10k miles...but who knows and he will be showing me the receipt of the rebuild when I c the engine this week
 
#8 ·
If you're planning all that work to the engine, then why buy a rebuilt engine? Makes no sense at all. You could buy a core for less than half that, and then do the rebuild yourself.
I'd either leave it alone, or get a builder engine, not buy a rebuilt and rebuild it again.
 
#10 ·
Hmmm ... $900 probably isn't so bad a price, even if you consider it to be a "running core" ... (as it sounds like you considering it to be).

'781 heads, carb and intake alone are probably worth at least 3 or 4 hundred.

"Warranty" from a private sale isn't usually worth the paper it is written on, IMO, and certainly will never cover any costs to repair or replace n excess of the purchase price.

You can be sure that he'll be deducting the full retail value of that new intake, etc, as "salvage" from any claim ... and will likely have the receipts to back it up. It just never ends well. :(

Perhaps if you tell the seller that this engine will be going to the machine shop for teardown and evaluation, (which is your intention anyway) and that you'd be willing to give the machine shop a deposit large enough to pay for gaskets and re-assembly ... it might put you both in a position of mutual trust. Until the inspection has been performed and you have paid the negotiated price, the engine remains the property of the seller.

If and when you are happy with the results of the inspection, and completed the purchase, it then becomes your sole property ... and he signs off on the work-order. This also allows the seller to offer the sale of the engine to you
"as is" letting him off the hook for any further offer of "warranty" ... because you won't need it. You'll know what you have.:thumbup:

If the engine DOES check out OK, I'd add:
  • a balance job. My machinist assures me that my 2-bolt 454 is guaranteed to be good to 7,000 RPM
  • a set of new (ie ARP) fastners all around on the rods and mains.
  • New oil pump, intermediate shaft, and pickup screen. Don't let anyone talk you into cleaning and re-using an old screen. Tack-weld the new screen to the pump.
  • All new frost plugs, a block heater (if winter driven) etc.

It's all more cheap insurance, and SO much easier to do at this stage in the build.:thumbup:
 
#11 ·
Ok so u r suggesting I would be better off and save more money if I just got my hands on a core and rebuild myself? Because I do have a 454 gen v..i put it on sale on Craigslist ..I still have it...reason why I am selling is to put money into this other engine I found if it checks out OK...and because bolts are stuck in harmonic balancer and heads..another reason why is because I found out i need a special gasket to throw mark iv heads on it and I'm also risking a coolant leak..I have four 454 manuals arriving to my house this week so I can do my read and do my research to try to learn how to do a few things myself..now you guys have me thinking if this other engine is actually worth it? I know at the end of the day its up to me...what do you guys think? Sorry if these are some ridiculously dumb questions..Ive barely entered the hotrodding world :)
 
#13 ·
In a nutshell; if you're buying a $950 454; and then you're going to yank out the rotating assembly; you're left with a $200 block. Now; what if this guy already has it punched oversize and you have an issue disassembling it, lets say you scratch a bore, do you have enough 'meat' left to still use the block?

If you're interested in buying a motor to change the heads, cam etc...thats fine; however, when you change the rotating assembly and factor in things like balancing; the only thing you're saving money on is the block and head castings.
If the heads have quality parts and their cost, plus the cost of a bare block is approx 900 bucks; it MAY be a good deal.

If he used rebuilder pistons, bulk springs etc, etc....it'll probably be a wash money wise so just build what you want. Talk to a reputable machine shop in your area; you have a BBC to either rebuild or trade in for a new shortblock. Hell the machine shop probably has a 454 shortblock in a bag on a stand, just add heads, intake, distributor, carb, pan and accessories.
 
#16 ·
Okay I came to a conclusion guys...I'm going to stay with the engine I have..found a pair of 049 heads for $150..going to take them to a shop for a valve job and some minor porting..new pistons, victor reinz gaskets as the block I have is a gen v..thanks a lot guys at least now I won't be stressing so much about these decisions..one more question..my goal is to reach between 450- 500hp mark..would I have to rebuild the bottom end or no?
 
#17 ·
You'll hit 450 easy. Just get all new bearings, that will be fine. Maybe get the crank checked just in case.
I'd shoot for 9.5:1 compression. Port and polished heads, performer rpm manifold, and a cam with an rpm range starting somewhere between 1200 and 1600 rpm. Will be a nice torquey motor.
 
#18 ·
Rebuild, or build up?
If you're going to do any machine work you'll always want to rebuild the bottom end, but at 450-500 hp you don't need anything extra beyond a good rebuild. I always have my cranks checked, and turned if needed. I also have all block mains align bored; it's cheap insurance. After that it's just new bearings of good quality. Any good machine shop should check bores and either bore or hone them to whatever piston you'll be using.
 
#19 ·
I'm going to take the engine to a reputable shop so that they can check it out for me that way I know what I have to do..btw...what exactly does a rebuild consist of? I know the kit comes with pistons, bearings, rings, gaskets..and a few other things...but other than the rebuild kit...what machine work is actually done to the engine? Perhaps porting and polishing the heads? Or??...
 
#20 ·
Porting and polishing will be extra. Usually any machining is extra. The rebuild price is basically r&r'ing the parts.
Let the shop do it's stuff before you buy any kit. Until they measure and check everything there is no telling what you will need in what size.
Plus, the shop may be able to get you a better deal on parts than a kit would. Sometimes.
I know there is a lot of info on what a "good" rebuild entails here and other places. Maybe in the books you are getting.
Good luck,
Russ
 
#21 ·
Got it...so one thing is for sure..I'm going to take the heads to a shop to get them ported..if they can give me a fair price on the rebuild I might just take it..if not..then I may just have to take this on myself after I've read a few books and watched some dvds..my friend is rebuilding a 350 so I might go help him out so I can get some idea of what it consists of..thanks u guys have been a great help
 
#23 ·
The assembly isn't hard as long as you have patience. But if the machine shop work is garbage your engine will be garbage, so make sure to get lots of opinions on the shops in your area before choosing one. Price shouldn't be the number one factor in choosing a place.

Russ
 
#22 ·
Here's what I have done when I get machine work done on a std. rebuild.
Hot tank and magnaflux the block for cracks. That's always first, so you know you're starting with a good block.
Bore or hone the cylinders, depending on what they need.
Align bore the mains to ensure it's all true and to size.
Size and inspect all the rods. I also have the shop press the new pistons on at that time.
Check the crank and turn as needed.
Clean and check the heads. New valves or refinish the valves. I always use SS valves if they don't have them in the heads, and new hardened seats if they don't have those. Check all the springs, and do a valve job on the heads. New guides and seals.
Once that's done I have them flush the block and install new brass soft plugs, and all the threaded plugs too.
I also have the shop press in all new cam bearings.

When I get it home I fit all the rings to the cylinders they will go in, then install them on the piston/rod for that cylinder. I plastigauge all the bearings, just to double check the shop's work and then install all the new main and rod bearings.
Then just reassemble the rest the pieces, cam, oil pump, lifters, heads, etc, etc.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top