LouisvilleLT4

Here are bearing pictures! They could be worse, but they do show some streaks and corrosion. Maybe the worst part is the large super shiny region in the center, where up along either side it's not so shiny and you can see what looks like 2 more layers.





So it looks maybe polished off down the middle, maybe corrosion or an out-of-round bore. I dunno if that's enough to call the engine done, versus driving it a little longer with fresh bearings.

There's more though. I can see a ton of rust on the camshaft, on one of the unused lengths of it where there are no lobes. There's a little discoloration going on up one of the cylinder walls, nothing too bad, except I can also see a ring of rust around the walls at the very, very top of piston travel.

So I don't know what to make of all this. Does this engine still have enough life left it in it to drive a little longer? Right now you probably have some suggestions of what you'd do. I'll say I don't want to wait months for a machine shop to rebuild, this is my only car and it's been down long enough.

Who sells shortblocks (edit: new is OK) ? I'd like to not downgrade to LT1 parts, preferably go the other direction, bigger bore and lighter parts. But where to look?

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antfarmer2

There is a lt4 with trans 74k on ebay five hours from you on ebay

cardo0

Well if u just want to crank it for a compression test wipe those bearings with assembly lube and bolt'm back in.

I just dont know what your trying to do with the motor. Bad oil samples and those brgs show micro scratches but no serious damage. Yes the polishing in the center of the brg is where the crank lays on startup untill the oil press lifts it up. Ok rust on the cam between lobes means the engine sat long long time and u know it had water. What that means is the cam lobes had corrosion also that was wiped clean by some amount of engine running. Dont fool yourself that cam is slowly wearing away as the hardened/treated surface has been penetrated.

Now i have rolled new brgs in (well just the 2 scratched ones) when i found just a couple of deeper scratches than what u have (polished the crank journal also from under the car with 600 grit paper). I think here your problem is more global but not fatal yet - it will be fatal in the near future.

My advice is to bolt it back together as is and drive it to a better location for work. Compression test will not change the fact the engine is going to eat itself sooner than latter. I say less than 10K mi for sure but may well be sooner.

Get it together again to save yourself towing fees. Then find/rent a location to work on it or a shop that will replace the motor.

So lets talk replacements now. The LT1's are still fairly common and most boneyards will sell an used replacement for under $1000 with 30 warrenty. I find part out F-body LT1 cars all over craigs list - many stand alone LT1 engines there also. Next option are the B-body LT1 cars (and station wagons). Most of these where iron head LT1's w/lower compression and smaller cam but will still bolt right in your car. BTW the LT1 iron heads out flow the aluminum LT1 heads (but not the LT4 heads). U may find an old caprice or roadmaster w/LT1 and can buy the entire car for less than $500 to remove the motor. U have to be careful though as there is a "baby" LT1 (L99) that was only 4.3L (265 c.i.) and unless u want an economy corvette its better to pass those up. The baby LT1 has a 4.3 number cast on the side where the 350/5.7 LT1 has 327 cast there. Caution here as u dont know the condition of a used engine unless u can do a compression test and leakdown tests - also watch it run.

Now for rebuilt short blocks/long blocks try ATK. They have a performance shop now and will build a stroker LT1/LT4 short block at reasonable price w/2yr warranty. ATK is a large rebuild company and most of the stock rebuild engines u find at the parts stores - O'Riellys, Auto Zone etc. - are ATK motors. Heck i think ATK sells a stock rebuilt LT1 for around $2000 (w/warranty).

What would i do for a daily driver? I would find a local shop in Louisville to R&R the motor and overhaul it. Most engine shop love the sbc chevy and probably fight to rebuild an LT4. U will get a short warranty also. Most car owners have forgotten engine overhauls rather than replace their car. But fleet operators still need overhauls and there are still engine shops that service the company fleet cars for this. Dealers do this also but quite a bit more $$.
Im serious there are shops that will R&R the motor, rebuild it and get it back to u in a few weeks sometimes a couple of weeks for around i'll say $2,500. Price'm out as this will get u back on the road w/o a garage of your own.

Good luck.

LouisvilleLT4

Thanks for the diagnosis, it's good to hear an explanation for the cam rust.

Since I'm trying to leave the engine better off than stock and have a high budget, maybe I should be looking at brand new engines, with re-built ones only as a backup? Ideally any differences would be race-oriented, so keeping it at a 4-bolt main block, with same weight or lighter internals meant to reach 6.3k rpm. But who sells brand new performance LT1/4 engines? What are the big names? And small ones?

P.S. I walked to Pep Boys asking about buying an LT1/4 and they pulled up something from Probuilt $2800 minus core, but there are no 2nd gen engines listed on http://probuiltengines.com so I couldn't find anything out about it at all.

cardo0

http://www.high-performance-engines....ain-p/sp33.htm

BTW u need an LT1 intake if using LT1 heads: https://www.golenengineservice.com/e...block-383400hp
and: https://www.golenengineservice.com/e...ock-396ci550hp

IMHO u will be just as well off with a overhaul of your original motor with a little bigger cam. Try the LT4 hot cam or even the step up 12370846, 12370847 Hydraulic Roller cams. If u dont really know what u need then u can waste a whole lot of money learning by trial and error. Getting a local shop to overhaul for u with the LT4 hot cam is a safe way to bust 400hp for the least $$$ and effort.

Good luck and hope u dont make it painful. Hot rodding should be fun and it is once u sort it all out.

cardo0

Heres ATK stock remain LT1 at Advance Auto: http://shop.advanceautoparts.com/p/s...1&prefZC=40201

Funny the 4 bolt main LT1 long block is cheaper: http://shop.advanceautoparts.com/p/s...ctp/20705650-P

LouisvilleLT4

Hey I got a question. Let's say I get one of these new Golen or ATK shortblocks. Would I be able to re-use my old LT4 heads on them? What if I don't machine them first, just to save more waiting? All of the Golen blocks are bored out a little too, I don't know if that matters.

cardo0

Those are your decisions to make and its getting confusing when u say u "have a high budget" but look for so many short cuts. IMHO those heads need a rebuild which will clean them up and get rid of the tiny metal particles in them know. The heads need better springs for a larger cam too. And not regrinding/cutting the vlvs with the heads off is unthinkable. When heads are reconditioned they shave them flat, clean, inspect, replace any bad parts, grind the vlvs and pressure test for leak. The short blocks still need cam, lifters, oil pan, dampner, water pump and a lot more tiny parts i cant think of now. I guess what im saying is your putting tired old heads on a fresh block with a lot of good performance parts. U dont change the brakes and put the old fluid back in, u just dont and nobody does.

Well i can tell your not afraid to dig into the engine. But i dont think your gonna get the details like brg clearance and vlv lifter preload adjustment correct and u will be right back in the same situation again with an expensive short block. BTW an original LT4 with your VIN # stamped on it could be valuable in the future if not already.

I suggest u find a good engine shop to overhaul that engine for you and u can find a rebuild-able LT1 core motor to overhaul and learn on. Tell the shop u want to retain the VIN # stamping on the block and u want a larger cam with matching vlv springs. And even if u dont and swap the engine yourself u still need to find a machine shop u can work with (for at least the heads). But if your in a hurry then i say buy and install a reman long block and rebuild your LT4 as u study up do it correctly.

Hey its your car and i think an original LT4 is pretty cool. Just hate to see it go south on you when it could be a lot of fun to own and drive. Part of the problem is there are so many options its difficult to choose.

Good luck.

LouisvilleLT4

Thanks. Not looking for shortcuts money-wise, just time-wise. I literally didn't know whether or not people replace their heads and shortblock together usually - but if it's like re-using brake fluid, or if the norm is for them to not be flat enough for a new block, I wouldn't dream of it.

Another possibility you didn't mention that I'm curious about is getting the brand new shortblock, but sending the heads off to a professional to be overhauled. In my mind the heads are what really make it an LT4 and I'd like to keep it an LT4 by keeping those castings. If that would run me near $3000 in parts + labor I might as well just buy the new ones from Golen instead, getting the longblock, except then I wouldn't get to really keep it an LT4.

Is that option a good idea? Is turnaround any quicker on machining heads?
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cardo0

I think u need to contact Golen as they maybe interested in doing something with your block and/or heads. Maybe golen will take just your heads and build u a woopazz motor for ya just to bolt in.

TPIS is another LT1/LT4 specialist but they dont have motors on the shelf waiting for sale like Golen - though performance engines are their business and they will build to order.

But those 2 LT1/LT4 specialists can give u much better information than i ever can. Even give'm a call on like a friday afternoon when they are probably slow customer wise.

BTW ive had dialog over the internet with Lloyd Elliott of PortWorks and cant stand the guy - i'll leave it at that.

Good luck man and let us know how it works out.

mtwoolford

why was all that water in the engine in the first place? maybe something as simple (and relatively inexpensive) as a blown head gasket?

LouisvilleLT4

It was my first hunch, but the oil testing folks said no. All H20, no glycols or sodium or whatever found. Just ignited gasoline blow-by.

mtwoolford

did someone try to fill your gas tank with a garden hose? HEY it happens; that water had to come from somewhere

LouisvilleLT4

That's what I'm saying, it came from blow-by. When you burn a gallon of gasoline the result is almost a gallon of water I've heard I'll bet it was that or maybe condensation from sitting for over a month although probably not since it was sealed before draining.

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Anyway the other day I decided on a Golen Engine street-strip 383 shortblock for $3000 plus whatever else I get (cam, springs, etc). You weren't kidding, Chad at Golen really knows a lot about these engines and could tell me exactly what HP and torque to expect if I re-used my current LT4 heads. He didn't advise against it even though he sells heads - he said my old heads would fit with no modifications and re-surfacing them flat might be all I need to do for reliability, something easier to get done than real machine work. I guess I'll see, condition-wise once the heads are apart.

Turns out Golen did not actually have the engine on a shelf already made, and needed 3-4 weeks to deal with their current orders. Since that approaching the time it takes a re-builder, I called the rebuilder Brian Cunningham used (qmp racing) and got a quote from them, but they said it'd take twice as much time at least, and prices start at $4500 and go up from there for performance parts. For that money I could have that brand new warrantied shortblock from Golen.

For extra parts, I bought Golen's high capacity oil pump for something cheap like $40, and he tack welds the pickup on so I won't need to use the pickup retainer I bought. Also bought a rear main seal from them. He offered a keyed hub, I might go with that if it's the right LT4 length and fits the stock damper. Might go ATI as well for weight reduction if I can assure myself I won't have to pull the engine to extract it in case my front cover leaks. Putting that decision off for now. Also putting off the choice of cam for a couple weeks. He recommended a Comp Cams XFI 280 after I said I'm looking for a mild build with torque curve heavily biased towards the low end and a fairly quiet car. I need to read more.
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cardo0

Glad to read u have found something u want to use. Ive always liked Golen motors and they made a business out of LT1/LT4 engines. I hope i didnt mislead u but the block is a used block - not new as chevy no longer sells the block itself as far as i know. But every other part is brand new and FWIW most performance builders will only use "seasoned blocks" and a torque plate honed bore will seal better than any stock block.

Just few items u should be aware of:

The block has been decked and u plan to shave the heads flat so your intake maybe a little miss fit. U may need your intake machined a little as it will move higher between the heads as the block/heads are cut. But contact Golen 'bout this when your ready as they will support u when buying their motor.

U still need to check the oil pickup clearance to the pan even though u are buying a welded p/u. Easy with the engine on a stand.
IMHO u can never read and learn enough 'bout cams to make a decision easy let alone in 3-4 weeks - but it doesnt hurt to learn. I would go with the Golen recommendation as they have considerable dyno time to back it up.

U will need a tune for the whole new performance motor it may run horribly on the stock tune. I used PCM4less as they will take your new engine specs and make u a tune that should work for less than $200. BTW my PCM4less tune ran scary bad for the first 15 minutes until it self learned so dont let it spook u at first.

Finally what u need to study and learn is how to adj the vlvs/lifters. This is taken for granted by most new enthusiasts but it can make your motor eat itself in short time if done wrong - yes even a brand new $3000 motor it doesnt matter. U need to study and learn terms like "base circle" and "zero lash" until u can find them w/o question. I cant be too serious here as u can read countless vlv train failures and engine failures here on the forum(s) from improper vlv adj.

Good luck and let us know of any questions if u need help. BTW u gonna have alot of fun w/500hp - good for u. Im getting jealous.