Swap or Rebuild??

[ivorton74]

So I started my truck today and realized its really beginning to smoke more and more. At first it would smoke on start up but now it smokes sometimes while driving but the engine does still run great and strong. So Im tryin to decide..should I have my motor rebuilt or should I swap in a newer motor? Which would be cheaper? I really woulld like a vortec motor out of a 95 suburban or something but they might be pricey. What would u guys do? Gimme ur humble opinions

[JPalmer81]

Is it a 305 or 350? What are you wanting to do with the truck? Are you looking for a daily driver or a purpose built truck? If you rebuild it yourself that is cheap if u just do a bearing a ring replacement. It will be much more if you have a shop do it for you.

[ivorton74]

its a daily driver.has a 350 in it. im tryin to make into a nice lil cruiser...fixin it up piece by piece. would like to swap my t350 for a 700r4 for the highway.

[JPalmer81]

yeah, the TH350 is junk, and 700r is much better... if ur just gonna cruise with it, just do the basic overhaul, put some headers, edelbrock performer intake with the edelbrock 600cfm carb(1406), throw some glass packs on it and drive the snot out of it.

[wilkin250r]

Some people like the idea of the original engine in their truck, it could be a selling point down the road.

Aside from that, my experience with those around me is that if you have the knowledge and time, rebuilding it yourself is cheaper (and possibly more rewarding). But if you're going to have a shop do it, and engine swap is most often cheaper and easier. The places that pump out engines do so like an assembly line, in massive volume. Their labor is often cheaper, and they're processes are often better than your local garage doing a rebuild on your engine. When you're cranking out 50 engines a week you can often do the whole process cheaper and better than a local shop trying to fit an engine rebuild in between oil changes and brake jobs.

[old Rusty C10]

my problem is time is always of theessence so i went ahead and bought a jegs motor and just swapped it out.. while not the cheapest it was certainly the quickest and hopefully the most reliable

[Firebirdjones]

Depends on the individual and what you have available to you.

Good machine shops are always a question, and how much you want to spend could determine the outcome there. Waiting is always fun too

I usually save the machine shop building for numbers matching muscle cars where crate engines simply aren't an option.

If there is a crate engine out there however that fits your needs and originality isn't a concern, it's certainly a nice way to go.

If all you want is a vortec style gen 1 engine, instead of swapping in a 90's vintage 350 (that may need rebuilt anyway) I'd rebuild the one you have and install a set of vortec heads.

Only other difference with the newer block would be a 1 piece rear main and the ability to add GM style roller cam with the spyder setup rather than a retro fit kit for an older block. Neither of those additions are enough to persuade me to look for a newer block.

[ivorton74]

I know my way around vehicles but when it come to tearing into a motor I just dont trust myself. I dont want to ruin anything. I would rather a professional do it. My mechanic is very reliable and knows his chevys. Unfortunately he doesnt rebuild motors anymore. He said it'll be better just to swap in a newer motor. But thats another story. I've been lookin around online and found some but I just keep think..what if I buy a faulty motor?...I just want to make sure I buy a good motor. A motor and trans combo would be a big plus as Im lookin for the overdrive gear for the freeway.
I also like the idea of havin the original motor in my truck. Thats why Im torn. Im tryin to figure out what's best. Thats why Im askin u guys.

[Firebirdjones]

Some of those ideas are personal preference. You'll have to decide what makes you happy.

If you aren't comfortable rebuilding one, and a used engine makes you nervous (it does me too) then it sounds like a crate engine is the way to go.

[misternash2]

with the uncertainty of gas prices, i'd look into a 5.3 swap. the junkyards are full of em. they are cheaper than ever. i did mine two years ago, and haven't looked back. it really isn't too much harder than a basic engine swap. the harnesses are simple. battery hot, coil wire goes to 12v "key" power, starter wires are the same ones you use now. (purple start wire and the others for truck power. it is intimidating, but it's really not bad. i get right at 20 on the highway.

[JPalmer81]

So many people are intimidated on tearing into there motor, don't be, go buy some books or even some DVDs and do it yourself. A 350 overhaul is so easy and doesn't take too many specialty tools, it is fun and would be an excellent learning experience for you. And if you some how mess something up, parts are very cheap and their are tons of resources to help you. I say go for it, but that is my humble opinion.

[ctandc]

This is just my opinion.

If you are uncomfortable with tearing into the guts of an engine, you might be better off with purchasing a ready to run replacement engine.

Buying a used engine is literally a crap shoot. Unless you can hear / see it run before buying, and run a leakdown and compression test on it, you truly don’t know what you’re getting.

Rebuilding a small block Chevy is not hard. The biggest stumbling blocks for people new to the process is usually cleanliness, taking accurate measurements and following the steps. The inside of an engine has to be SPOTLESS when putting it back together. There are several VERY good books aimed a

Another option is looking for a rebuilder in your area, and purchasing a rebuilt 350 short block and adding Vortec heads and intake. With a decent cam that would make a reliable, fun to drive engine.

Yet another option is to call around to call your local machine shops. Many times they have engines for sale. Ready-to-run engines, many times it’s the case where the owner got all the work done and couldn’t foot the bill. Depending on the shop, you can sometimes get a good deal, because they are simply trying to get their labor and parts back out of the engine.

[Slonaker]

I went with a 350 Chevy crate engine, part number 10067353. It is $1500, and has free shipping right now at Jegs. Otherwise I would do an LS swap, but then you are back to taking a chance with a used engine...

Slonaker

[76k10]

You just wasted $1500. I am sure your valve guide seals just needed to be replaced. This is a $75 repair, and an afternoon's work. Definitly quicker than swapping an engine.

[Slonaker]

Originally Posted by 76k10

You just wasted $1500. I am sure your valve guide seals just needed to be replaced. This is a $75 repair, and an afternoon's work. Definitly quicker than swapping an engine.

I think you have me confused with the original poster. Valve seals were definitely not going to fix the knock my old 305 had...

Slonaker

[esbstuff]

Originally Posted by 76k10

You just wasted $1500. I am sure your valve guide seals just needed to be replaced. This is a $75 repair, and an afternoon's work. Definitly quicker than swapping an engine.

If your engine just smokes at startup and quits within 5 minutes this is the problem and this is a do-it-your-self, saturday morning project...

[76k10]

Originally Posted by Slonaker

I think you have me confused with the original poster. Valve seals were definitely not going to fix the knock my old 305 had...

Slonaker

My mistake. You are right on that one.

[Firebirdjones]

Originally Posted by 76k10

You just wasted $1500. I am sure your valve guide seals just needed to be replaced. This is a $75 repair, and an afternoon's work. Definitly quicker than swapping an engine.

Originally Posted by esbstuff

If your engine just smokes at startup and quits within 5 minutes this is the problem and this is a do-it-your-self, saturday morning project...

It's hard to say. I've found that most engines once they reach 70k miles or more, it's generally more than valve seals. With higher mileage in most cases they have worn valve guides, in which case a seal won't completely fix the issue.

Stock gen 1's either use umbrellas (which aren't much good at oil control) or they use the 0-ring on the stem (even worse for oil control). With a worn guide either of these version will still suck oil down the guide.

There are positive seals made for stock guides that snap down and have much better oil control. It may stop some or most of the smoking, but if you have worn guides, oil usage is still going to happen to some extent.

Anything with high mileage and a start up smoking issue, to fix it right, requires pulling the heads and heading to the machine shop for guides, valve job, and seals, at which point you can machine the guide for the positive seal of choice.

[76k10]

Originally Posted by Firebirdjones

It's hard to say. I've found that most engines once they reach 70k miles or more, it's generally more than valve seals. With higher mileage in most cases they have worn valve guides, in which case a seal won't completely fix the issue.

Stock gen 1's either use umbrellas (which aren't much good at oil control) or they use the 0-ring on the stem (even worse for oil control). With a worn guide either of these version will still suck oil down the guide.

There are positive seals made for stock guides that snap down and have much better oil control. It may stop some or most of the smoking, but if you have worn guides, oil usage is still going to happen to some extent.

Anything with high mileage and a start up smoking issue, to fix it right, requires pulling the heads and heading to the machine shop for guides, valve job, and seals, at which point you can machine the guide for the positive seal of choice.

70k miles is not that many nowadays. Any old GM V8 that has not had its valve seals replaced, will exhibit the symptoms mentioned in the OP. Most recently I had a Buick 350 that smoked heavily on startup and take-off from idle. I replaced the valve seals, and no more smoke. None.

Also, the OP states the engine runs great. I don't know about you, but I don't pull heads or do valve jobs on engines that run great, unless I am swapping for something better.

[Firebirdjones]

Originally Posted by 76k10

70k miles is not that many nowadays. Any old GM V8 that has not had its valve seals replaced, will exhibit the symptoms mentioned in the OP. Most recently I had a Buick 350 that smoked heavily on startup and take-off from idle. I replaced the valve seals, and no more smoke. None.

Also, the OP states the engine runs great. I don't know about you, but I don't pull heads or do valve jobs on engines that run great, unless I am swapping for something better.

Nowadays engines are different, completely different ball game when speaking of LS engines. We are talking gen 1's that used the same tech since 1955, or any other engine throughout the 60's-80's. Worn guides are very common.

I didn't mean pull heads just to do valve jobs,,,,when you do valve guides, a valve job is a must do procedure after that, whether it needed one or not. An engine with worn guides may run fine, but it's not a fine running engine in my opinion,,,if you get what I'm saying...Any engine that requires frequent checking of the dipstick needs attention as far as I'm concerned.

Now I'm not saying putting a simple set of valve seals on is a bad idea, just that it's not usually the "fix all" cure for sucking oil on a higher mileage engine. Not that you would waste alot of money either. Only $20 for seals and a set of valve cover gaskets, and a bit of your time. So if it doesn't completely cure the oil sucking problem it's not like you're out alot of money or time.

Just laying it all out here so the original poster isn't dissappointed and knows exactly what he might get into.

[76k10]

Originally Posted by Firebirdjones

Nowadays engines are different, completely different ball game when speaking of LS engines. We are talking gen 1's that used the same tech since 1955, or any other engine throughout the 60's-80's. Worn guides are very common.

I didn't mean pull heads just to do valve jobs,,,,when you do valve guides, a valve job is a must do procedure after that, whether it needed one or not. An engine with worn guides may run fine, but it's not a fine running engine in my opinion,,,if you get what I'm saying...Any engine that requires frequent checking of the dipstick needs attention as far as I'm concerned.

Now I'm not saying putting a simple set of valve seals on is a bad idea, just that it's not usually the "fix all" cure for sucking oil on a higher mileage engine. Not that you would waste alot of money either. Only $20 for seals and a set of valve cover gaskets, and a bit of your time. So if it doesn't completely cure the oil sucking problem it's not like you're out alot of money or time.

Just laying it all out here so the original poster isn't dissappointed and knows exactly what he might get into.

I agree. Well said.

[Firebirdjones]

It's all good bud, I know everyone means well. Didn't mean to come accross in a negative manor if that's how it sounded. I'm all for the easy fixes if it works

[notyo_cheez]

Cheap (not the best) fix: get some Bardahl (sp) Motor Honey and put that in the crankcase. It won't smoke any more after that, you're only out a few bucks and since the engine's got lots of miles on it, so what if it craps out. You'll be due for a new one anyway, and have the justification for it when it does.

Intermediate (not really THE best) get a remanufactured long block from O'Reilly, Pep Boys, etc and swap it out. Compared to the Goodwrench plant you are only saving a few bucks but you can take the core in and not hassle with disposing of your junk. They have assemblies with new tinware too.

Best fix, get the Goodwrench crate from jegs.com for $1500 and free shipping, swap out the long block and be done. You get 3 years/100K miles so if the stem seals crap out at 70K claim it and get another one.

[ivorton74]

Thanks for all ur input guys. I have been lookin at those goodwrench motors in the jegs and summit catalogues. If I had the money I would get one of those. This small town that I live in here in south dakota has nothing. Everything good is at least an hour away. Finding a machine shop or a good speed shop or something is not easy to find here. I wish my mechanic would rebuild engines but oh well. My minds just racin with thought and ideas.
BTW this is my 350. original motor with almost 89000 miles on it. completely stock. ill try to post a vid of it running

[ctandc]

If the miles are legit, it shouldn't need replacing.

Do a compression and leakdown test and go from there.