General Chat
Q:
According to many shops, stores, and mechanics in Las Vegas and on the web. A rebuilt block is this:
Washed, but not machined
New rings
New bearings
New gaskets
And they usually want about 1K plus for these engines.
My idea of a rebuilt engine is:
Washed, magnafluxed, and tolerances checked
If tolerances are out machined back into tolerances
New rings
New pistons if bored over
Connecting rods checked for tolerances and cracks if either exist a new stock set used
New bearings
New oil pump
New Gaskets
Head checked for tolerances and cracks if either exist machine work and replacement of parts
New water pump
Crankshaft and camchsfts checked for tolerances and cracks if either exist replacement or machine
New timing belt
New hoses
Now which do you think sounds like a rebuilt motor? I just went to a dealer to check out a "rebuilt" VH45 for my possible 300ZX. the damn thing looked like he went 4x4 with it then washed it off with a hose. The timing belt had visible cracks, The oil pan had a huge dent in it, and the crankshaft flywheel end was rusted. You've gotta be kidding I asked him when it was rebuilt he said recently, I laughed and said yeah if 1995 is recently. Guy got pissed and I went.
I just do not see how some of these f nuts get over on people. I know some rice head retard is going to buy it for a project he will never be able to do, but 1225 for a beat on VH45 I think not.
Progress:
Z32 Had to sell for DD 06 Sentra :(
S30 one of these days I will get around to putting it all back together.
A:
sounds to me like the first one is rebiult, and the second is remanufactured.
"The Z's disease won't make anything turn black, wither, and fall off, nor turn cancerous." - Tony D
"Take it to a track where BOTH drivers mean business or it's just one sided mechanical masterbation." - Hybrid77z
A:
The first one sounds more like a ring job.
My idea of a rebuilt engine
New Gaskets
New rings
Cylinder/piston tolerances checked honed
Crank/cam tolerances checked
Valves/Seats checked reground
New oil pump
New water pump
New timing chain/belt/gear
Once you get into machining and regrinding cranks and cams I consider it to be remanufactured.
'60 Chevrolet Apache 10 235cid Stovebolt 6
'79 N/A MT (My Dad's but I drive it)
'81 Turbo (Mine)
FSM: $60
Shop Manual: $20
Reading the manual: Priceless
A:
there were two 91 Infinitis with the 45 engine in them last month here in SoCal---206XXX, and 213XXX miles on them...they would have gone for $175 each on the "mid week engine special"...
"Rebuilt" is not a term with a definition.
"Remanufactured" is usually a little more quality built in.
Anybody with a set of wrenches can rebuild like you mentioned, but to rebuild it right you will spend 3X the money so it will last another 300K miles.
Like I have said many times before, most of the engines that "need to be rebuilt" here DON'T need it one bit, they're just following myths, legends, and internet parrots.
Many times, "rebuilds" like you mentioned are worse off that simply finding a high-mileage factory assembled motor and runnint IT in the car!!!
People screw up crap all the time, they are idiots.
People Are Idiots, Just look around here and you will see!
Tony D: "Knowledgeable but Caustic"... rationull
My brother from another mother calls himself "Willie D"
A:
Well if the car has been driven rather calmly, as in not racing it, running it low on oil, etc, and it's had routine maitenane, then a lot of times an owner might just have their mechanic rebuild it. And if the car was driven lightly and not meant to be a balls to the wall performance machine then all a motor with high miles usually needs is washed to get dirt and grease off, then new rings to help seal it and get compression back where it needs to be, new bearings, well new because new doesn't have 100,000 miles on it, and new gaskets. Gaskets get old and leak and break apart. There you go, a rebuilt engine.
Your idea is like the other guy said, remanufactured. You're paying more for the extra work and detail put into it. If you want a motor for your 300ZX, why go through all the hassle of putting a motor in there that's 50% bigger than your current motor? It seems in 300ZXs, the 3.0 v6 barely fits, why put in a 4.5 liter v8? lol
However if you're dead set on a VH45, and you're going to pay for all that money for custom motor mounts, wiring, fuel system, etc...why not pay a little more and have the motor rebuilt by a Nissan mechanic, or at least a guy you trust.
A:
No, you don't wash it off and slap rings in it and call it rebuilt!
That was the point of his post, and mine!
The art of mechanical work is degrading every day, and what people call a 'rebuild' would NEVER have been considered anything more than a 'refreshening" or 'freshened' engine----like in competition.
Running a flexhone down the bore and sticking new rings on 100K mile pistons is a cheap way to do it, and if you don't MEASURE CAREFULLY you WILL get burned!
People Are Idiots, Just look around here and you will see!
Tony D: "Knowledgeable but Caustic"... rationull
My brother from another mother calls himself "Willie D"
A:
I actually had to rebuild mine! When i tore the motor down i found out that one of the rod bearings had disenegrated and the rod was banging up and down on the crankshaft. When i took the rings and pistons out, i found out that some of the rings were broke. IM not sure if that was me or the PO, but im assuming it was me. I had to rebuild mine, but i am glad i did it. It was actually kind of fun and i learned a lot! Plus now i how to do it for the next Z that i get!
-John
Absolute Z Club
L.A./Orange Counties
73 240, PnP E88, webers, coil-overs, 17's, "Bolt-In Power Steering", train horns; you know, the norm... "Yea its green, but the chicks love it"
A:
Why VH45? Because there is no misplacement for displacement. And yes the VH will fit there is already someone on this forum that has done the swap with GREAT results.
Progress:
Z32 Had to sell for DD 06 Sentra :(
S30 one of these days I will get around to putting it all back together.
A:
i'm an amature and "rebuilt" my own L28 a few years ago. as long as you take it slow, clean, think before doing, and can measure, the result will be better than a general shop.
I'm gonna disagree with tony ONLY on his point that most engines do not need it. MOST engines that i now see in yards and project cars have had a hard 25-30 years and NEED to be pulled apart and inspected. his statement was true maybe 10 years ago, but time is taking it's toll on these things. cams, cylinder walls, water passages will rust. most good engines have already been pulled. you never know what the engine condition is by a simple compression test.
79 280ZX -The best selling sports car of all time
A:
Any Z engine with between 180 and 250,000 miles on it requires littel if nothing on the bottom end, almost regardless of upkeep.
As long as a modicum of maintenance is done on these engines, very little wears. I have pulled bottom ends apart for parts, and when piking the journals find the bearings and journals not even worn to the high end of NEW tolerance.
There is, and ALWAYS HAS BEEN, a tendency to overrebuild machinerey in the USA. This usually is due to lack of proper diagnostic training and simple mechanical ignorance. I can't tell you the number of times people put incomplete rebuilds together, only to have problems again within 10, to 20,000 miles.
If you do a PROPER REBUILD, the engine will give you the same life expectancy as the OEM engine did, and the majority of people doing them will NOT go to that length to accomplish it properly, and cut corners, and then wonder why they have problems so soon.
These engines are NOT Small Block Chevy and Fords. They do NOT require major money and major rebuilds every 100K miles.
I would not consider a rebuild on any engine with more than 100 to 125psi compression on all cylinders when hot compression checked, and has verifiably less than at LEAST 300K on it.
Chances are the parts you put in will not be as good as what you took out in the first place, and the engine has miles to go before requiring anything.
Changine a cam is a service item, not a rebuild item. Rust in the water jacket is a SCRAPPAGE concern, not anything that will be solved by a rebuild, as for cylinder walls, if the compression tests good---there's nothing wrong with them, and on any engine other than our Bonneville engine where it had .080" scores in all six cylinders from walked gudgeon pins (albiet VERY EXTREME AND ODD FAILURE) I have never seen an L-Engine that "needed" anything other than a deglaze and rering of standard size. Far too much boring of blocks going on here!
People Are Idiots, Just look around here and you will see!
Tony D: "Knowledgeable but Caustic"... rationull
My brother from another mother calls himself "Willie D"
A:
totally agree with everything.
the only problem then is really knowing if the engine has 150K, 250K or 350K (or 450K) on it and what the previous upkeep was (some people drive with blown head gaskets or never change the oil till the car dies and then the engine is in the yard).
these engines are bulletproof if you take care of them.
A:
Pulling the oil pan or the head and washing everything down is not a rebuild, and in most cases is all that would be "required" in 99.99999+% of the cases.
Most of the time, engines have seals or issues with the head, but underneath nothing goes wrong.
Chances are good, if it's a running engine (even rough) the bottom end will be fine.
Pulling the pan for a flush of sludge and carbon, as well as a reseal of the gasket and sticking a head gasket on is hardly a rebuild---and is kind of the point. The first post asked if that was a rebuild, and it's not. it will end up bing less durable than the stuff that was in there an all mated and run in together.
In many cases, I have seen rings out of a 100K mile L-Engine that still did not have an even band in the chrome around them---they weren't fully seated yet!!!
IMO, from 150-250 is the prime age for the most performance out of an L-Engine that was factory assembled. The parts are FINALLY worn in giving a good seal, all the burrs and caastings rubs are well burnished and not causing problems with extra friction....the engine is in it's optimim run-in configuration. Mine with 225,000 on it has 185psi of compression.
The way it was running in the 81 it was in, the former owner told me "the engine is shot, it needs an overhaul".
Yeah, riiiight! Took it off his hands for $100! POS car, but that engine was GOLDEN! Couple of cans of motor flush to clean out the sludge, couple of cans of Techron to clean out the fuel system, Viola! Clean, Strong Running Engine! Still has the factory oil pan gasket on it. And that was at 186,000 miles. Now, at 225,000 it's running as strong as ever, compression pressures have stabilized and equalized (we are talking less than 5 psi between cylinders!).
Had I listened to the P.O., this engine would have been torn down, all it's carefully honed and mated surfaces disturbed, and NO WAY would I be as well off as I am today.
I can see "going in to look and clean" but that DOES NOT include breaking free any rod or maincap bolts!
The head is a different story, they may need hardened valve seats installed, or a valve job, usually at least seals---and people get freaked by old head gaskets for some reason....but beyond that, you risk ruining a good mated set of components just to go looking around to find nothing in the VAST majority of cases.
People Are Idiots, Just look around here and you will see!
Tony D: "Knowledgeable but Caustic"... rationull
My brother from another mother calls himself "Willie D"