Rebuild the old 350 tbi or order a crate motor

[30backs]

what is the best and most cost affective way? Do I rebuild my current motor in my 88 r20 350 tbi or go to crate motor? This is my daily driver so not wanting anything to extreme.

 

[Swims350]

rebuild. tons cheaper if YOU do it.

you can get complete kits with new pistons and then of course all the normal things, gaskets, rings, bearings, but the MASTER kits have cams as well I'm pretty sure, point is, $300 for the master kit usually.

I rented a honer for mine that chucks into a drill, like $20 at autozone, and a ring compressor which was like $10. I already have a torque wrench, so that pretty well covered it.

alot of the time I don't replace cam bearings, but a machine shop can do it for you.

machine shop is what costs, anything you have done aint cheap, but if you have them do nothing and do it yourself, you MUST let them mic the crank to see if it's in spec, and if not you can order a crank kit with bearings for like $200.

I got lucky mine used standard bearings no work needed.

I ordered most of my stuff from northern auto parts and some from summit.

I ordered new rings from summit, oil pump, then the gasket set, and cam kit from northern. I got my mains locally, from advance and then bought rods from summit(bearings)

I paid like $15 for the oil pump,
almost $100 for the cam kirt, had new lifters, and a timing chain set with it.
it was like $35 for the mains
$around $20 for rod bearings
freeze plugs are under $20
rings ran me about $30 I think
the gasket kit ran me $40

a new crate motor is gonna set you back at least around 2k.give or take a couple hundred if you can find deals.

 

[gpmorgan]

If I were going to get a crate engine, I would get a GM crate only. For the money, and the fact everything is new with 3 yr and 50k mile warranty, it's a hard deal to beat.
I personally would rebuild it. That way I would know every thing is done correctly. I've found even buying new Dart aluminum heads that the spring heights were not set correct. If the crank, rods, and pistons are still good, I don't see why they can't be reused. That would be depending on what kind of shape the cyl. bores are in. I would definitely put a new cam and cam bearings in it. All specialty tools needed, as mentioned, can be rented at part stores. This would take a little more time than getting a crate engine but to me it is more satisfying to know that I built it myself and saved money in the process. One of the main things, if you decide to do it yourself, is to make sure that all the parts are clean upon assembly. Anyway, thats just my 2 cents worth.

 

[Jims86]

GMPP replacement, and be done with it. There are 2, so watch out. You want the 190hp, 4 bolt main version.

 

[30backs]

What is the other option hp wise?

 

[Swims350]

last I checked was 160

one thing I see some ppl haven't mentioned on crate motors, if you are going to use tbi, then you have a few things to watch out for...

one the cam you use, this applies to rebuild or crate, make sure the duration and lift and what not will all work ok with the tbi computer. This is why I ordered my cam from northern stock replacement. crate motors have one in them already and I couldn't say if they'd work with stock tbi or not.

2nd tbi itself, the intake mostly. You either need an intake to fit the crate motor, because of the heads, alot I seen use the old 2 bolts on either side, and the 4 bolt holes are different angles on tbi intake and heads compred to carb intakes and old style valve cover type heads like pre 87.

Now what this means would be for a crate motor, you can buy an adapter plate to fit pretty much any old 4bbl carb intake and then bolt the throttle body to it.

If said crate motor had tbi heads then you could reuse your intake, but if it has vortec heads you need a new intake for vortec heads(they don't have 4 center bolts) and then use the same plate or buy the expensive vortec tbi intake.

Now some crate motors I see do not have an intake, your old school tbi MIGHT work on them but the 4 bolt holes would need elongated to make the bolts in the center work and perhaps some odd washers. IMO best bet for a crate would be a new carb or old stock carb intake and then the plate. I know most new intakes run $120 and up and the plate I think is around $50 or so?

Another problem you can run into is the egr system if you plan to reuse it. Most carb intakes if you can find an aftermarket one with egr, is completely different then your stock egr valve, not sure how that would work. May just be as simple as buying the correct egr for that manifold. Other things may need to be modified as well like throttle cable brackets and what not that bolt to the intake and may not on the aftermarket ones.

So another optin could be if you can find a crate short block, take your heads to a machine shop, or do it yourself and do a valve job on them. That would help alot with the issues I mentioned.

 

[Jims86]

last I checked was 160

I think thats for the 4.3

 

[Jims86]

last I checked was 160

87 up. 1/2tons wer 210 hp/300tq
3/4 and 1 tons were 190hp/300tq. only difference is the lower Compression and 4 bolt mains on the 8700+ GVW trucks.

 

[Irishman999]

Going off your original question, save up and buy a crate motor.

First off, no one on this forum "builds an engine", putting an engine together is just "assembling an engine". "building an engine" involves making parts fit that dont fit together, "assembling an engine" is ordering goodies on the internet according to your specs.

If you have plenty of downtime, a good steady flow of cash go my route and assemble an engine. Be ready to spend a shitload of money, I thought I was going a cheap route but it turned out to cost 10 times what I thought it would. Things add up so quickly it will make your head spin.

I am in the final stages of my big block and could have just ordered a crate motor for what I have spent. If this engine fires over its a victory for me but if it comes apart its just another story of "should have just got a crate motor".

Judging by your original question, I would say a crate motor is the way to go.

 

[Swims350]

big blocks always cost way more then small blocks do.

As for the 160 hp I wasn't talking stock I meant the crate engines, I remember in a book seeing a 160 and a 190 crate.

 

[gpmorgan]

I've done several standard "rebuilds" on small blocks that were way cheaper than crates. It's like anything else, you can spend what you want to. For a daily driver with no frills it's not that expensive. Time consuming, yes, but if done correctly you can expect a good engine with longevity to boot.

 

[Irishman999]

I've done several standard "rebuilds" on small blocks that were way cheaper than crates. It's like anything else, you can spend what you want to. For a daily driver with no frills it's not that expensive. Time consuming, yes, but if done correctly you can expect a good engine with longevity to boot.

I agree with you on that completely.

You have to consider the temptation to go aftermarket as well. After you secure a clean enclosed work area and buy all the stuff why not just put a little extra into the engine to make it worth your time and effort. Once you open the door to aftermarket stuff you might as well just spend as much as you can afford on every component.

My example is the small block I was working on before my big block, I know the stock rods would have been just fine. I could have got them checked out and worked on by my machine shop but for a little more I got brand new Eagle rods that are stronger and loaded with arp fasteners already. That kind of thinking is what costs money.

As of now, if my big block runs and nothing comes apart it will be a victory. I wanted the challenge and satisfaction of doing it but I could have the same power under warranty for about the same money if I went with a crate motor. Had I done that I could have been driving the truck months ago.

 

[30backs]

I would like the satisfaction of doing it myself and as long a machine shop cooperates with me it shouldn't be that time consuming. My only real concerns is finding something major wrong when I tear it down and having to drop serious money on heads ,rotating assembly or machine shop. I'm not sure of the internal condition of the motor is does puff a small white smoke when you crank it and uses a little oil.

 

[Irishman999]

I would like the satisfaction of doing it myself and as long a machine shop cooperates with me it shouldn't be that time consuming. My only real concerns is finding something major wrong when I tear it down and having to drop serious money on heads ,rotating assembly or machine shop. I'm not sure of the internal condition of the motor is does puff a small white smoke when you crank it and uses a little oil.

If you have options on a machinist shop around, word of mouth is a big thing. I went with my machinist because I saw one of his small blocks in a pulling tractor absolutely getting its ass kicked and it held together. If time is an issue dont try it, turn around time at a machine shop is slow. You cant really expect to set a deadline or get your stuff back quick, my machinist is backed up for the next year doing everything from mud racing engines to tractor pull engines. Thats another thing to consider, how much circle track racing is around you? The more motorsports going on in the area the longer the line. Its not something to rush, you might consider just getting a core to rebuild while your truck still runs.

What you find inside is not the biggest concern, a puff of smoke means you will be boring the cylinders over sized. My small block had a piston come apart and leave huge ugly grooves in the cylinder wall, I thought it was going to be a deal breaker but it machined out no problem, I even gained more displacement by doing that. The worse news you will find during dis assembly is cracking, cracks in the right places means the block is no good.

If its not knocking and still running most likely you are looking at around 500 bucks for your machine work. that should include cleaning the block, boring cylinders and hone matching them to pistons. Add to that the crank work, if the crank needs to be machined you will be looking at a couple hundred more. If the crank specs out you can get away with just a cheap polish, my machinist charges 40 bucks for a polish.

You could run into problems with heads, I dont know what heads you have but I have read that TBI heads are prone to cracking. If the heads check out you could get them rebuilt for a few hundred bucks.

Another thing to consider is if you will do this again, if you plan on doing it again invest in the tools. Main tool is the torque wrench, with this much money invested already get a good one. I found a bad ass snap on torque wrench on craigslist for 120 bucks! All the other small stuff you will need is on ebay for cheap. Micrometers are a good idea so you know what to expect during teardown but in theory you could just take the parts to a machinist and let him do his thing. Once you get it all back your crank clearances can be checked with like 2 bucks worth of plastigauge and piston ring gap clearance can be checked with feeler gauges.

Best thing at this point you could do instead of reading my internet ramblings is go to a book store and find a book by Dave Vizard about rebuilding small block chevy engines. Read it cover to cover, it will tell you just about everything you need to know about this.

 

[30backs]

ok thanks for all the info