Low Mileage SBC Minor Rebuild: What to do?

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Re: Low Mileage SBC Minor Rebuild: What to do?

Post by NewbVetteGuy »

Schurkey wrote: Thu Oct 11, 2018 1:14 am Put the original engine in a bigass plastic bag. Oil the cylinders and the original stampings on the deck surface. Vacuum the air out of the bag just after tossing in a few desiccant packs, and tie the bag SECURELY shut. Stuff it under the workbench in your garage for "later".

Build or buy the 383 you actually want.
It's not a valuable block and never will be. The only reason I want to keep the #'s is sentimentality, honestly. It's a single family car with 14.6k miles and I just like having the original #'s matching block in the car.

An engine isn't an engine if it isn't igniting fuel and creating kinetic motion, IMHO; it's a really heavy paperweight.

If it was some super valuable engine from a collectible car, maybe I could see putting the block in a bag and getting another block, but it's a 1979 plastic bumper Corvette. It's never going to be worth significantly more with or without the original engine.


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Re: Low Mileage SBC Minor Rebuild: What to do?

Post by NewbVetteGuy »

rebelrouser wrote: Thu Oct 11, 2018 8:50 am Adam, I teach engine rebuilding, this is what I tell my students, locate the specifications for the engine, measure and inspect each component, after you compare your measurements with the specifications for each piece of the engine, you decide to use the component as it is, have it repaired or rebuilt, or you replace it with a new one. All the things you mentioned in your post can be measured and compared to specifications. Many shops replace things like rings and bearing, oil pumps, with every rebuild. Some states have laws about what a shop to replace to sell the job as a rebuild. If you are doing the work yourself it is your decision.
I appreciate the feedback; it seems like good, generic advice for a generic rebuild, but does everything on a such a low mileage motor actually need replaced?

What does NOT need to be replaced on a very low mileage, 40 year old engine? -That's the crux fo the question.


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Re: Low Mileage SBC Minor Rebuild: What to do?

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CGT wrote: Thu Oct 11, 2018 12:52 pm Whats a L82 350 really worth anyway?...or what it came out of? Not exactly prime muscle car material. I would use it.
So incredibly little if turned into cash; as a functioning engine moving my car down the road a lot more. -I agree; totally using it. An engine that sits in the corner ISN'T an engine in my book but that's some sort of metaphysical statement, I think.

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Re: Low Mileage SBC Minor Rebuild: What to do?

Post by NewbVetteGuy »

Krooser wrote: Fri Oct 12, 2018 9:34 am Save that engine and build another... I've seen a couple guys do what you are suggesting only to have themselves scared to death of blowing up that numbers matching block.

Buy a core block and go from there. It's likely a good machine shop will have one in stock...
I don't care if it blows up. If it blows up, it was the weak parts that died and the whole engine gets better. If the block dies, then I get a newer and better block. -Natural Selection in the Engine Jungle. :D


I'm just looking for advice on what parts I can AVOID buying new (and can safely reuse) and what the minimum set of machine shop procedures is that I should do, taking into account that the engine really has so few miles.


I realize I must've epically failed at asking the question because the answers I got were, from my perspective way out in left field, so I'm trying again to ask more clearly.


-I want to reuse the stock pistons and crank. (So it's still a stock 1979 L82 bottom end and because why waste the $$ when the bores are beautiful and I've got a fully forged bottom end that can handle my HP and RPM.)
-I do not want to and see no need to go to a +30 bore.

-The coolant passages are totally crusted up with dexcool sludge and I had quite a bit of carbon deposits scattered all over everywhere so I'm thinking I should get it hot tanked.

-I have to pull the pistons and crank (all that's left in the block currently) to get it hot tanked- does this mean I need to buy new rings? If not should I anyway?

-My mains bolts are SUPER long to accommodate the stock L82 windage tray; my new Champ CP60LT oil pan has the windage tray integrated into the oil pan and I'm almost certain I'm going to have to switch to stock-style bolts -I might as well go with ARP bolts for added strength -is the clamping pressure increase significant enough between stock mains bolts and arp bolts (not studs) that I will have to have the mains align honed?(or can I just PlastiGauge them and if they're in spec, run em?)

-If I buy new rings are there any obvious and reasonably priced upgrades to make? (Napier 2nd?)

-If I buy new rings that means mandatory honing and recommended torque plate honing, right?

-I have to remove the big-side rod bolts to get them off of the crank to get the rods and pistons out; I'm pretty sure you're not supposed to reuse them- If I upgrade to ARP rod BOLTS (not studs) does the difference in clamping pressure require me to have them rehoned? (or can I just PlastiGauge them and if they're in spec run em?)


I've bolded the top 4 questions that seem to me to be the combination of the most important and most unknown to me right now.


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Re: Low Mileage SBC Minor Rebuild: What to do?

Post by FC-Pilot »

OK, I am a low buck guy and can apreciate wanting a running engine instead of a car sitting. If I were in your shoes I would do this. Pull it apart slowly and mark every piece as to where it was, including bearings. Tank the block. Soak and scrub and clean the pistons and rods and make sure the pin bores are lubed (as to plan on reusing the rods and pistons just as they are). I would personaly toss the rings as rings are so much better today, and there could be light rust or something on those rings. If the bearings look gorgious then reuse them (making sure you had them marked for specific locations). I would still double check clearances though as better safe than sorry if the factory might have been "off" on the inicial build. I would consider a quick hone on the cylenders (just a kiss, nothing more) for the rings to seat. Maybe even a dingle ball brush (as we are talking low buck). I would put fresh cam bearings in as if give you the chance to clean all the oil passages out very well before putting them in and then assemble the short block as you would a real hot build. Now the heads I would take a little more time on as maybe some home port work and having them decked could be a real added bonus to performance as well as making sure the guides are right with a fresh seat job. I would see money well spent there. Ring seal and valve seal would be your biggest disapointments as long as power expectations are realistic. Throw as thin of a head gasket as piston to head clearance will allow, while making sure your piston to valve clearance is also good and then break it in well and enjoy. I dont remember if you had specific power expectations, but with those parts and not being able to control much of your clearances I personally would not shoot for more than an honest 350 to 375 HP.

Many of these guys have much more esperiance than I and could probably advise you better on what you have, but that is just what I would do. Good luck and let us know how it goes.

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Re: Low Mileage SBC Minor Rebuild: What to do?

Post by Schurkey »

NewbVetteGuy wrote: Tue Oct 16, 2018 2:52 pm I'm just looking for advice on what parts I can AVOID buying new (and can safely reuse) and what the minimum set of machine shop procedures is that I should do, taking into account that the engine really has so few miles.
-I want to reuse the stock pistons and crank. (So it's still a stock 1979 L82 bottom end and because why waste the $$ when the bores are beautiful and I've got a fully forged bottom end that can handle my HP and RPM.)
"I" would scrap the pistons in favor of something "better", "better" meaning modern thin rings, full compression height, flat tops if yours are dished. I don't know what you have currently for piston crown.

HOWEVER, you would not have to replace the pistons as long as they're in good condition--no scores, no cracks, skirts not distorted, etc.
NewbVetteGuy wrote: Tue Oct 16, 2018 2:52 pm-I do not want to and see no need to go to a +30 bore.
I don't see that as a problem IF the bores are not tapered or otherwise worn/cracked/distorted.
NewbVetteGuy wrote: Tue Oct 16, 2018 2:52 pm-The coolant passages are totally crusted up with dexcool sludge and I had quite a bit of carbon deposits scattered all over everywhere so I'm thinking I should get it hot tanked.
I agree that it should be cleaned. Hot-tanks are kind of an endangered species due to EPA regs. More likely shot-blasting followed by jet-wash. Don't forget about cam bearings and all the core- and oil-gallery plugs
NewbVetteGuy wrote: Tue Oct 16, 2018 2:52 pm-I have to pull the pistons and crank (all that's left in the block currently) to get it hot tanked- does this mean I need to buy new rings? If not should I anyway?
I would buy new rings.
NewbVetteGuy wrote: Tue Oct 16, 2018 2:52 pm-My mains bolts are SUPER long to accommodate the stock L82 windage tray; my new Champ CP60LT oil pan has the windage tray integrated into the oil pan and I'm almost certain I'm going to have to switch to stock-style bolts -I might as well go with ARP bolts for added strength -is the clamping pressure increase significant enough between stock mains bolts and arp bolts (not studs) that I will have to have the mains align honed?(or can I just PlastiGauge them and if they're in spec, run em?)
When the block is at the machine shop getting hot-tanked or jet-washed or shot-blasted or however they clean blocks, hand them the new bolts, ask them to measure the main bores for distortion. Then ask them to verify that the bore alignment is acceptable.
NewbVetteGuy wrote: Tue Oct 16, 2018 2:52 pm-If I buy new rings are there any obvious and reasonably priced upgrades to make? (Napier 2nd?)
The obvious "upgrade" is to thinner rings, but that means new pistons. Other than that...quality moly-top-ring ringset.
NewbVetteGuy wrote: Tue Oct 16, 2018 2:52 pm-If I buy new rings that means mandatory honing and recommended torque plate honing, right?
I would dingle-berry brush the bores and let it go...if the bores are sound to begin with.
NewbVetteGuy wrote: Tue Oct 16, 2018 2:52 pm-I have to remove the big-side rod bolts to get them off of the crank to get the rods and pistons out;
No. You'll remove the nuts, not the bolts. Don't knock the rod-bolts against the crank journal when you pull the pistons/rods out.
NewbVetteGuy wrote: Tue Oct 16, 2018 2:52 pmI'm pretty sure you're not supposed to reuse them- If I upgrade to ARP rod BOLTS (not studs) does the difference in clamping pressure require me to have them rehoned? (or can I just PlastiGauge them and if they're in spec run em?)
You remove the rod bolts, you WILL need to have the rods resized/honed.

Plastigauge will not verify rod bore distortion. It verifies clearance across the diameter that it's lined-up with.





I'm doing a similar rebuild to a '96 Vortec 350. New cam bearings, new rod bearings, new rings, new seals 'n' gaskets and block plugs, new flexplate because the original was broken around the flywheel bolts. I had the decks cut, and one cylinder bored due to rust pitting from storage. One new piston, of the regular "Vortec" design, although I'd have preferred to use TBI Caprice pistons as they're flat-tops and also have a thin-ring package different from the Vortec thin-ring package. The rest of the bores have .0015 of wear, which I fully intend to ignore. Dingle-berry crosshatch. I pulled all the lifters apart and cleaned them one at a time. I'll re-use the Vortec cam. I'm even re-using the main bearings, oil pump and maybe the timing chain/sprockets because I can't find anything wrong with them.

Still undecided about heads and intake. Vortec heads need a $500 intake manifold and expensive EGR plumbing. Stock swirl-port heads suck for power. I have some aluminum heads that'll work for EGR, but the middle two bolt holes won't line up with the original TBI intake manifold.
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Re: Low Mileage SBC Minor Rebuild: What to do?

Post by Newold1 »

Holy engine dilemas Mr. Bill:

"Advise, a wise man don't need it and a fool won't heed it" :roll:
The Older I Get, The Dumber I Get :wink:
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Re: Low Mileage SBC Minor Rebuild: What to do?

Post by NewbVetteGuy »

FC-Pilot wrote: Tue Oct 16, 2018 4:52 pm OK, I am a low buck guy and can apreciate wanting a running engine instead of a car sitting. If I were in your shoes I would do this. Pull it apart slowly and mark every piece as to where it was, including bearings. Tank the block. Soak and scrub and clean the pistons and rods and make sure the pin bores are lubed (as to plan on reusing the rods and pistons just as they are). I would personaly toss the rings as rings are so much better today, and there could be light rust or something on those rings. If the bearings look gorgious then reuse them (making sure you had them marked for specific locations). I would still double check clearances though as better safe than sorry if the factory might have been "off" on the inicial build. I would consider a quick hone on the cylenders (just a kiss, nothing more) for the rings to seat. Maybe even a dingle ball brush (as we are talking low buck). I would put fresh cam bearings in as if give you the chance to clean all the oil passages out very well before putting them in and then assemble the short block as you would a real hot build. Now the heads I would take a little more time on as maybe some home port work and having them decked could be a real added bonus to performance as well as making sure the guides are right with a fresh seat job. I would see money well spent there. Ring seal and valve seal would be your biggest disapointments as long as power expectations are realistic. Throw as thin of a head gasket as piston to head clearance will allow, while making sure your piston to valve clearance is also good and then break it in well and enjoy. I dont remember if you had specific power expectations, but with those parts and not being able to control much of your clearances I personally would not shoot for more than an honest 350 to 375 HP.

Many of these guys have much more esperiance than I and could probably advise you better on what you have, but that is just what I would do. Good luck and let us know how it goes.

Paul
Thanks, I appreciate you taking the time to actually give me advice. I have already bought new cam bearings. (Durabond CHP-8) I also have brand new Profiler 195cc intake / 64cc combustion chamber heads and the felpro 1094 0.015" shim gasket.

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Re: Low Mileage SBC Minor Rebuild: What to do?

Post by NewbVetteGuy »

Newold1 wrote: Tue Oct 16, 2018 5:45 pm Holy engine dilemas Mr. Bill:

"Advise, a wise man don't need it and a fool won't heed it" :roll:
Seriously?!?

I'm literally here asking for advice.


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Re: Low Mileage SBC Minor Rebuild: What to do?

Post by NewbVetteGuy »

Again, thanks for the reply. I've worked really hard and have gone really slowly to try and make good decisions that are in alignment for what I want for the top-end of the engine, but I really don't know what to do regarding the bottom-end and I haven't such much advice focused on taking a good, low mileage forged bottom-end and making it as good as it can be for what it is.

I've asked a lot of theoretical questions on here over the past couple years to try and better understand theory, but this one gets very practical and real in a hurry for me, so getting some advice that takes the specifics of what I have into account is definitely appreciated. -The other context is I'm just looking for this "refresh" to last just a couple of years so I can get the car all reassembled and get the car done for its 40 year anniversary. Then when I tell my wife that it "needs a rebuild" in 2-3 years I can put a stroker kit in it and give some machine shop a gold brick to do it up right.

I obviously don't know what SHOULD be done and I'm looking for the "SpeedTalk Opinion" to balance what my machine shop's opinion is. (Feels like a better idea to have an opinion from a 3rd party that doesn't stand to personally profit either way from my decisions.)

I added follow-up comments / questions inline below in Italics followed by "[Newbvetteguy]".
Schurkey wrote: Tue Oct 16, 2018 5:35 pm
NewbVetteGuy wrote: Tue Oct 16, 2018 2:52 pm I'm just looking for advice on what parts I can AVOID buying new (and can safely reuse) and what the minimum set of machine shop procedures is that I should do, taking into account that the engine really has so few miles.
-I want to reuse the stock pistons and crank. (So it's still a stock 1979 L82 bottom end and because why waste the $$ when the bores are beautiful and I've got a fully forged bottom end that can handle my HP and RPM.)
"I" would scrap the pistons in favor of something "better", "better" meaning modern thin rings, full compression height, flat tops if yours are dished. I don't know what you have currently for piston crown.
[NewbVetteguy] They're flat top, forged L82 pistons with one big valve relief that looks like a "unibrow"; about 0.025" down the hole, +0.015" FelPro 1094 shim gasket, I think 5 cc valve relief, I calculated a 10.2:1 static CR as is.

What's wrong with the pistons other than the old-school ring pack?
(I called TotalSeal last Friday and asked about their shims that let you run thin metric LS-style rings on these old 5/64", 5/64", 3/16" pistons and they priced out a package that used 1.2mm, 1.2, 3/16" oil ring, gap less steel PVD coated, napier 2nd -they went crazy and priced out a $490.11 ring pack so I got scared away. I know I should put new rings on them, I just need to call them back and ask from something much closer to stock that's still an improvement...)


HOWEVER, you would not have to replace the pistons as long as they're in good condition--no scores, no cracks, skirts not distorted, etc.
NewbVetteGuy wrote: Tue Oct 16, 2018 2:52 pm-I do not want to and see no need to go to a +30 bore.
I don't see that as a problem IF the bores are not tapered or otherwise worn/cracked/distorted.
NewbVetteGuy wrote: Tue Oct 16, 2018 2:52 pm-The coolant passages are totally crusted up with dexcool sludge and I had quite a bit of carbon deposits scattered all over everywhere so I'm thinking I should get it hot tanked.

I agree that it should be cleaned. Hot-tanks are kind of an endangered species due to EPA regs. More likely shot-blasting followed by jet-wash. Don't forget about cam bearings and all the core- and oil-gallery plugs
[Newbvetteguy] Also appreciated. I'm with you on the cam bearings. I've removed all the coolant plugs except for the one where 1/2 of it broke off and stayed behind in the block last weekend... The oil gallery plugs I didn't know to worry about. -Just remove them before taking the block to be cleaned? (Can I reuse them later or better to buy new replacement ones?)


NewbVetteGuy wrote: Tue Oct 16, 2018 2:52 pm-I have to pull the pistons and crank (all that's left in the block currently) to get it hot tanked- does this mean I need to buy new rings? If not should I anyway?
I would buy new rings.
[Newbvetteguy] Thanks, I figured but it makes me feel better to hear someone else say it.
NewbVetteGuy wrote: Tue Oct 16, 2018 2:52 pm-My mains bolts are SUPER long to accommodate the stock L82 windage tray; my new Champ CP60LT oil pan has the windage tray integrated into the oil pan and I'm almost certain I'm going to have to switch to stock-style bolts -I might as well go with ARP bolts for added strength -is the clamping pressure increase significant enough between stock mains bolts and arp bolts (not studs) that I will have to have the mains align honed?(or can I just PlastiGauge them and if they're in spec, run em?)
When the block is at the machine shop getting hot-tanked or jet-washed or shot-blasted or however they clean blocks, hand them the new bolts, ask them to measure the main bores for distortion. Then ask them to verify that the bore alignment is acceptable.
[Newbvetteguy]Simple enough.
NewbVetteGuy wrote: Tue Oct 16, 2018 2:52 pm-If I buy new rings are there any obvious and reasonably priced upgrades to make? (Napier 2nd?)
The obvious "upgrade" is to thinner rings, but that means new pistons. Other than that...quality moly-top-ring ringset.
NewbVetteGuy wrote: Tue Oct 16, 2018 2:52 pm-If I buy new rings that means mandatory honing and recommended torque plate honing, right?
I would dingle-berry brush the bores and let it go...if the bores are sound to begin with.
[Newbvetteguy]You're the 2nd person to say that; it must be true. I've used a flex hone before; I can definitely manage that one.
NewbVetteGuy wrote: Tue Oct 16, 2018 2:52 pm-I have to remove the big-side rod bolts to get them off of the crank to get the rods and pistons out;
No. You'll remove the nuts, not the bolts. Don't knock the rod-bolts against the crank journal when you pull the pistons/rods out.
[Newbvetteguy] *Forehead Smack* Yea, I didn't think that one fully through... I've got some vacuum hose to put over the rod-bolts. -Just to confirm, I can reassemble it with stock rod bolts?
NewbVetteGuy wrote: Tue Oct 16, 2018 2:52 pmI'm pretty sure you're not supposed to reuse them- If I upgrade to ARP rod BOLTS (not studs) does the difference in clamping pressure require me to have them rehoned? (or can I just PlastiGauge them and if they're in spec run em?)
You remove the rod bolts, you WILL need to have the rods resized/honed.

Plastigauge will not verify rod bore distortion. It verifies clearance across the diameter that it's lined-up with.

[Newbvetteguy] Damn. I was hoping I could just put two pieces on it 90 degrees apart and it kinda WOULD verify rod bore distortion...



I'm doing a similar rebuild to a '96 Vortec 350. New cam bearings, new rod bearings, new rings, new seals 'n' gaskets and block plugs, new flexplate because the original was broken around the flywheel bolts. I had the decks cut, and one cylinder bored due to rust pitting from storage. One new piston, of the regular "Vortec" design, although I'd have preferred to use TBI Caprice pistons as they're flat-tops and also have a thin-ring package different from the Vortec thin-ring package. The rest of the bores have .0015 of wear, which I fully intend to ignore. Dingle-berry crosshatch. I pulled all the lifters apart and cleaned them one at a time. I'll re-use the Vortec cam. I'm even re-using the main bearings, oil pump and maybe the timing chain/sprockets because I can't find anything wrong with them.

Still undecided about heads and intake. Vortec heads need a $500 intake manifold and expensive EGR plumbing. Stock swirl-port heads suck for power. I have some aluminum heads that'll work for EGR, but the middle two bolt holes won't line up with the original TBI intake manifold.

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Re: Low Mileage SBC Minor Rebuild: What to do?

Post by NewbVetteGuy »

Frankshaft wrote: Thu Oct 11, 2018 11:28 am I can tell you one thing. It will never peak at 6000 with that intake. 5000 is more in line where it will peak.
I was told 5,800 or 5,850 RPM but by someone with far less experience than you, though. I'd love to see a couple hundred RPM more than 5,000 but as long as it's got gobs of torque (for a 350) to go with it, I'll be happy.

Out of curiosity, are you basing that just on runner length, runner length & cam, or runner length, cam & runner ID; or something else entirely?


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Re: Low Mileage SBC Minor Rebuild: What to do?

Post by Schurkey »

NewbVetteGuy wrote: Tue Oct 16, 2018 8:22 pm [NewbVetteguy] They're flat top, forged L82 pistons with one big valve relief that looks like a "unibrow"; about 0.025" down the hole, +0.015" FelPro 1094 shim gasket, I think 5 cc valve relief,

Could be worse.

NewbVetteGuy wrote: Tue Oct 16, 2018 8:22 pm[Newbvetteguy] I've removed all the coolant plugs except for the one where 1/2 of it broke off and stayed behind in the block last weekend... The oil gallery plugs I didn't know to worry about. -Just remove them before taking the block to be cleaned? (Can I reuse them later or better to buy new replacement ones?)
Core plugs, oil gallery plugs come together in a kit. About $6--$8.
NewbVetteGuy wrote: Tue Oct 16, 2018 8:22 pm[Newbvetteguy] I can reassemble it with stock rod bolts?
I am.
NewbVetteGuy wrote: Tue Oct 16, 2018 8:22 pm[Newbvetteguy] Damn. I was hoping I could just put two pieces on it 90 degrees apart and it kinda WOULD verify rod bore distortion...
Not my first choice. Have the machinist handle this for you.
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Re: Low Mileage SBC Minor Rebuild: What to do?

Post by tresi »

I think you're wanting our blessing more than our advice. I can not tell you how many times bores that people told me looked great had .005, .006 taper or more. Seeing the cross hatch after you 1 1/2 down the bore means little, what's the wear at TDC? Stock forged cranks and pistons aren't that great. Yes rods and mains need resized when new bolts or studs are installed. Pistons can measure great at the skirt but the ring grooves can be worn out. If you want to clean and reseal a stock motor that's fine if you want to use it for basic transportation. I really don't mean to harsh but that's the way I see it.
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Re: Low Mileage SBC Minor Rebuild: What to do?

Post by NewbVetteGuy »

tresi wrote: Wed Oct 17, 2018 12:59 am I think you're wanting our blessing more than our advice. I can not tell you how many times bores that people told me looked great had .005, .006 taper or more. Seeing the cross hatch after you 1 1/2 down the bore means little, what's the wear at TDC? Stock forged cranks and pistons aren't that great. Yes rods and mains need resized when new bolts or studs are installed. Pistons can measure great at the skirt but the ring grooves can be worn out. If you want to clean and reseal a stock motor that's fine if you want to use it for basic transportation. I really don't mean to harsh but that's the way I see it.
Thanks for being willing to say that. That's the OPPOSITE of what I want. I want the advice, but advice that considers the situation and stays somewhat near the universe of on topic.

I started a thread to ask for advice on rebuilding the bottom-end and provided context on what's on the top-end and right away I got feedback that was either completely irrelevant to what to do about the bottom-end or just boilerplate high mileage SBC rebuild advice like "terrible intake; I wouldn't go with that." "Just get a stroker kit" "Start putting money in your retirement account as early as you can".
Some super random, full-on Asbergers stuff early on (*Sigh* "Yes, I understand that Jeopardy is on at 4:00, but I fail to see what that has to do with the question...")


This is one of the (many, many) things I don't understand; this is sort of the framework my thoughts are coming from: What's the typical range a from-the-factory SBC usually goes before it needs a rebuild? 40k miles, 50k miles, 60k miles?!? Whatever that number is, why can't my engine run to somewhere near that range with a stock bottom end before it needs bored and new pistons and a major rebuild?

My understanding is that most OEM SBC blocks will get one, maybe 2 rebuilds and then they're toast and you need a new block. -Why would I dramatically shorten the life of my block with 14k miles and bore it and get new pistons and have it jump straight to "mid-life"? (poor block never got to be a teenager and go to college!)

I hear things like the stock bottom ends are fine until well beyond 450 hp and RPM matters more; I'm building a 6,000 and under (or 5,000 and under by a number of estimates) with some pretty strong agreement of below 450 hp to WAY below 450 hp...



If there's something about the stock bottom ends that are just a ticking time bomb and I'd be stupid to put all these expensive top-end components on a stock block, then PLEASE SAY SO, but some basic insight into "why" would be great. I'm a "why" person; can't live without the "why".


What are the things that should really be examined by the machine shop to determine if the bottom end is good-to-go as a very close to from-the-factory stock bottom-end for a couple of years and miles?
-There have been some great replies on that front and I appreciate it. Obviously, they need to check over the bores super closely including taper; if there's anything wrong with the bores and too far out of spec, then my hopes to use it for a while as a stock bottom-end are over and I'm moving the 383 stroker kit and all the machining goodies route.


There are some "political sensitivities" with my build and my wife at the moment and honestly if I've got a "good enough" bottom end and can get the engine reassembled and back in the car, and get all the old parts outta my house and have a running and working car for a while, it buys me a lot and makes pulling the engine again for a full 383 bottom-end rebuild in late 2020 a MUCH more feasible option. -The "Eye of Sauron" is turning it's gaze on me right now and I'd really like it to turn somewhere else for a while... lol!




Adam
novadude
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Re: Low Mileage SBC Minor Rebuild: What to do?

Post by novadude »

With that kind of low mileage, I wouldn't touch the bottom end at all. Swap heads/cam/intake and call it good. I can's see replacing good rings, bearings and rod bolts for no good reason. I've done ghetto top end swaps on short blocks with more mileage that ran well, and continued to run well for a long time. Knock out the freeze plugs and flush the water jackets with a high pressure hose and leave the bottom end in one piece.

The comments about factory cranks, rods, and pistons not being that good is kinda funny. L82s had "the good stuff", and those parts would have been coveted up until the 1990s when all the cheap aftermarket stuff started coming on the scene. Even the garden variety cast stuff in L48s will last forever in a 350-400 hp engine at < 6000 rpm. Not every street engine needs fancy parts to keep from exploding in the first 100 miles.

Just my opinion.
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