This thread will document my teardown and rebuild of a Chevy 350 small block engine.

This may be old hat to many of you, but I have never done it before and figured some of you may be interested as well, especially if you are considering putting one of these into your 914.

The engine that I am starting with is a 4 bolt main block truck engine out of a 1985 Chevy K20 3/4 ton pickup. I am not yet sure what the engine will be when I am done with it. I want to build a 383 stroker engine. But, the parts for this engine are so nice that I may stick with stock displacement and just go with better heads and intake. The heads and intake have all the smog stuff on them, so they are not going to be used.

Enough with words. Time for pictures.

First, lay out your tools on the rear trunk of your old Porsche. Only the finest work jacket will do to keep the paint scratches to a minimum.

For tear down you need 4 wrench sizes (all inch sizes). 3/8, 7/16, 9/16, and 5/8th. You will want to have these sizes in deep sockets and wrenches. You will want to have at least one breaker bar to break torque on most of the 9/16 and 5/8 bolts. Also a rubber hammer, pry bar, and scraper will be needed.

The beast:

This is the engine that I am going to be tearing down. It was pulled out of the donor truck Dec 10th and mounted on the engine stand the next day. Don't even think of trying to do this without an engine stand. This 1000 pound stand only cost $50, and it is money well spent. Fair bet my 914 has a little bit of engine envy right now....

Valve covers first.

Valve covers need to come off first, as they impinge removing the intake. One off in the picture above. You need a 7/16 deep socket to take off the nuts that hold the valve covers on. Lots of sealant was used here.

Valve covers, carb and intake are off.


Pretty easy so far. Time to go for the heads. The rods going into the block are all the push rods. They come up from the cam and operate the valves. The orange ball of fire is my heater. 70K BTU of warmth to stave off the cold, even with the garage door open. I even had to take off my warm overalls, as I started sweating with the heater and the overalls both. The intake was attached with 9/16th bolts. There was considerable sealant used, and getting the intake off was difficult. I ended up using a pry bar to get it started, and hold it up enough to get my fingers in there to pull the rest off.

First head is off.

This is the point where I had to do some soul searching. It was pristine! The cylinder walls look like they were just done. There was no carbon ring at the top of the cylinders, which is common for an engine with miles on it. The PO of the donor truck said the engine had been rebuilt 4000 miles ago. But given the condition of the truck and the electrical system (the spark plugs were rusted and fell apart on removal) I had my doubts. Now, though... it took a fair deal of will power to not just button the engine back up again and put new heads and intakes on it. But, I am a stubborn man at times... I am going to rebuild this engine, darn it! This is how I learn. The heads bolts were 5/8s and were heavily torqued. I needed a breaker bar to get them started.

With the heads off I took off the pulley and damper. The damper was a PAIN to get off. Lots of prying with the pry bar all over to keep it from cocking. One of those things where I probably should have used a puller, but I did not have one the right size or the desire to go and get one.

to be continued....

Heads are off, and it’s time to remove the oil pan. Remember to drain the oil BEFORE turning the block upside down!


When the block is turned over, all the coolant still in the block will drain out. This took me by surprise...

By the time I got a catch pan under the block, it was a bit late.... Live and learn. Lesson, just because the block is on your stand and you think it’s fully drained - it isn't.
The oil pan was held on by 3/8 nuts (I think it may have been 7/16...) with 9/16 bolts at the ends. Once the bolts are free, and the keepers removed, it still took a few good whacks with the rubber mallet to get the pan to come loose.


Oil pan is off. Now you can see the oil pump, crank assembly, and the tip of the timing chain.

Time to start removing pistons.

In this picture you can see what makes a "4 bolt main" block. On most Chevy small blocks the crank is held in place with 2 bolts on the keepers. As you can see, these keepers have 4 bolts each. Looking down into the bore you can see the honing in the cylinder. Rods were fixed with 9/16 nuts, and I needed a breaker bar to get them loose.


8 pistons and rods ready to be moved upstairs for cleaning and possible re-use.


Crank is now out. They call these engines "mouse motors." There is very little small about them. My size tens for reference. The crank may get reused, or it may not. One of the bearings was very worn, which was troubling. Only one of the bearings was worn, the rest looked great. But one of them was through all the babbit material and almost looked like it had not been changed when the engine was rebuilt. Or it could mean that the crank is bent slightly - which can happen.

more coming!

The cam is still in the block. I have not yet figured out how to remove it. Pretty sure I need to pull the freeze plug at the back of the engine and slide out the cam. But aside from that and a few bits and bobs, the engine is now totally torn down, and I am ready to start cleaning the block.



So, what’s next?
Well, obviously, the cam needs to come out. However that works.
Then I am going to pull all the freeze plugs and start cleaning out the galleries. Oil and sludge build up in the galleries and that can hurt the engine over time. CLEAN CLEAN CLEAN.

Also, I am going to do some dressing on the block. Open up some oil drain holes, take off rough edges, and do other things to improve the qualities of the block. Then the block will go to my local machinist. I need to find out what size everything is, and let him run it through the hot tank. I am pretty sure the cylinders were cut to 30 over, and I do not think that they will need to be recut. I do want to see if the crank needs to be standard or over. That will affect bearings and what parts I get. I'll do the hone job when it gets back. Then clean it some more, and paint it.

So thats all I have for today. I'll update the thread as more gets done.
I have to say, it is very tempting to put this into the 914.... Especially if I build the 383.

Zach

350's are junk. Get a 440 for that p.o.s. A 440 keeps it in the family too istead of some Chevy bastard. Kinda like when your hot cousin marries that goofball computer geek down the street instead of you. 350's are easy enough any redneck can GET ER DUUNNNNN

Cam comes out easy enough, straight through the front of the block. Just make certain you don't nick the bores when removing/installing. Take it easy, and support it as best as you can. Bolt the gear back on to hold on to and support it as it passes through

I sure hope you had the factory spec Folgers coffee can to put all of your nuts and bolts in. Let me know when you get ready to install your cam bearings, I will tell you the secret to awesome oil pressure. Also, if the heads you have are in good shape, might wat to shave off a few thousandths. Besure to have them magnafluxedto make sure there are no cracks. I also recommend double tension springs with a shim to make that valve pop quicker. Gee, I used to build about ten of these a day back about 30 years ago. A small block 400 would be a nice motor to build also. Good luck with everything.


Shoe

I can't wait to see that engine installed. Keep the pics coming.

A stock 350 bottom end rebuild with a decent cam and some heads that flow would be a nice motor.

What are you going to put it in when it's done?

get a long bolt to thread into the cam and pull it out the front. the long bolt gives you good leverage to handle the cam as it comes out.

did you see the small plug on both sides of the block at the bottom of the block.... that drains the coolant out.

find or buy a set of votec heads. they make great power! brand new from gm or other suppliers cost less than a refub on old heads! check it out form jegs or summit!

if the crank needs turning you could prolly get a stroker kit for about the same cost as turning the crank and buying all the bearings. [a 383 stroker would be great for that truck]

pick a good combo cam and intake kit from edlebrock, you'd be happy you did.

use brass for the freeze plugs and oil galley plugs.

get the premium gaskets that have the inserts for the oil pan and valve covers and such, it limits how much "crush" you can tighten down on the gaskets and makes leaks less prone.

oh !!! and those "keepers" are called "main caps" DO NOT MIX THOSE UP! keep them in order by number and how they came off [front to back in the saddle they came out of]. if you mixed them up you'll be paying for a line bore.

same with the rod caps keep them together and exact as they came off!

pm me with any questions if you need to. i think i had a sbc rod for a rattle in the crib as a baby!

ah, so thats what those are. Yeah, they are still capped.


Something need turning somewhere. The main bearing was trashed. Someone in 715 land said it could be a bad rod, but all the rod bearings looked good.



DERP! Guess I will be line boring. I think I know how the main caps came off, but I don't know I know how they came off. An expensive lesson.

The rod caps are ont he correct cylinders, but I did not not them end for end, so they are probably wrong too.

If I go to a 383, the rods will be replaced anyhow. And that is looking more and more likely.




That restoration thread is in the sandbox. But this thread could have 914 application so I am putting it here.
Zach

Before you go assuming you ned a line bore, clean and check the caps, if the engine was rebuilt, the rebuilder may have stamped them with the correct placement

Lets talk intake and cam.
I would like this engine to make power lower in the rev range. It will probably never see 6000 rpm, and hopefully won't see 5000.

goal is to be able to spend most of its time under 3K.

Any hints on what I want to be looking at?
Zach

The Summit Racing catalog section for RV's and towing.

The 5,6 in my Titan spends most of its time under 2000 rpm - and most of that between 1000 and 1500. But it revs freely to its 6500 rpm redline and yes, I've had it there a few times (stupid PA "onramps" involving highway-speed merging from a stopsign...)

It is, however, a 4-valve engine...

I have an RV cam in my engine, but its one of the higher rpm RV cams. With the right fuel management they have bucket loads of tq...

After some experience with the GEN III Chevy motors I'm pretty well convinced that going back to GEN I SBC's is well, going backwards. Unless there's a personal attachment to the old school SBC or perhaps a period correct reason to build one up, the GEN III or later (LSx) motors are a considerable step forward. For the money you're going to spend on that 350 build, you could buy a low mileage LQ9 truck motor pull-out for around $1500. 6.0L 345 HP, 380 ft-lb, 10:1 aluminum heads, all the accessories, with modern EFI and they'd probably throw in the electronic throttle pedal and module. Driveability will be way better, as will your MPG. And if it's horsepower you want, these motors really respond to cam swaps and PCM re-programming.

Of course if you're doing the 350 build for your own sake, then so be it. I'll monitor your progress with interest.

Andys

the 383 build reuses the rods.

a 383 kit has the 3.75 crank and pistons that have the correct wrist pin hight for the 3.75 crank.

i doubt the p/o line bored that block, most low preformance rebuilds don't line bore.

the vortec heads will make excelent torque with an rv cam.
dollar-dollar these heads will be the best investment for power over the old heads. [read up on them] also these heads take a different intake mounting design [bolt holes are different] so make your mind up on these early before buying a intake.

shorter advertized duration with some good lift [450-475] will do good.


the ls motors are awesome but you loose the k.i.s.s for a truck like that. and there is no way you could be concerned with fuel economy with that truck!

a mild 383 built right will have big block type torque and great power, expect about 400-450 ft lbs from 2500 -3500rpm.

...but too much can be as bad as too little.
More torque than the driveline is built for leads to the path of more expensive upgrades. Bigger transmission - bigger cooling to reject the additional heat of more power and driveline. Bigger driveshaft. Bigger 3rd member.

The weakest link is always - something. I prefer it be the engine making less power than the driveline can handle. This doesn't leave you parked on the shoulder of the big hill during a tow wondering how you're going to replace the rear axle or driveshaft... (Which can itself go to hell in a handbasket, because if the driveline breaks, you better have loads of confidence in your E-Brake/Parking Brake, because 'Park' in the transmission ain't gonna do diddly...)

If you're just whittling into the safety margin, that's one thing, but going over the line foreshadows nasty consequences. Yeah, I know lots of guys still run 901/914 gearboxes behind SBC's in 914's - but they are for playing, and trucks are for working... (E.g. - I'm pretty sure that cubic yard of topsoil I hauled home in the half-ton Titan was more than the 1000-lb payload it's rated for...)

well coming from some one that bought a ..... foriegn "full size pick up" .....

the engine and tranny he got came out of a real 'merican 1 ton pick up!!!!

and true the only weak link here would be the stock unrebuilt tranny, but those are very inexpensive as exchange rebuilds [around here less than $1,000 for a 700r4]

the rest of the drive train... have you looked at the truck? it's a military truck!!! he could beat the living crap out of that and not hurt the drive train!

and i wouldn't get to hung up on making low rpm power wioth the stock axles 'cause those are most like around 4.88 or bigger gears.
freeway running even with tall tires will be around 2500 rpm or so.

Yes, from the distant shores of Kentucky...

I saw that. But as this is a 'general-interest 914' thread, it was a general-interest comment.

And yes, I have built an engine so well it broke the transmission...

I think my real point here is that the cost of these LSx motors (even with the 4l80e) out of the trucks, is how cheap and plentiful they are and make them a particularly attractive replacement. I'd bet you would damned near double your fuel mileage even in "that truck." It's just crying for a late model drivetrain.

BTW, there's an LS1 conversion forum that has tons of valuable swap information to guide you through just about anything that's liable to come up, BTDT.

Andys

Hi Zach,

I hate to be the Buzz-Kill here, but I would like to suggest taking a look at your whole power & drive train as a unit.

From what I've tracked about conversion cars, if you plan to run the STOCK 901 trans, you have to look at about a 350 HP limit (and what ever torque the engine develops as this power level) or things will BREAK!! Next, take a look at the puny CV joints with only 4 bolts! Also, at this power level, you can keep your stock crank and rods.

When I looked at building my conversion, I wanted to go BIG so I built a 500 HP 383, but I also had to cough up $2300 for a 930 trans and lucked into used 911 SC/Turbo half shafts for $80 (they fit the 914 hub bearings) and finished off with 911 wheel flanges.

I've posted a lot of stuff on the Paddock forum on chassis, handling, engine cooling, etc. as it will take some work to get things to operating as an intregal package.

Unless you plan on chasing down a 930 4-spd, or better, a G-50 5-spd (the Pantera 5spd also can be made to work), my recommendation is to build a nice 350, not bother with a 383 and use a low-end cam as a member suggested.

Summit has small-port aluminum heads for something under $900, if that's in your budget. Small ports work great for low-end through mid-range operation along with the mild cam. Not only do aluminum heads look great, but you save 50 lbs off the top of the tall V8. Since the whole design of the chassis was based on a pancake motor, the heavy V8 really messes up the CG, causing much more roll than originally planned. The less tall weight the better.

I hope I haven't spoiled your day, but a mild engine will give you a great running, reliable daily driver that gets decent mileage. My 383 gets only 13 MPG!!!!

Best,
Terry

ya kinda missed that he's not putting it into a 914!

the picture of the old army truck is where the mouse will live.

I have to say I am not to worried about breaking parts from too much power with this.

Its a 5/4 ton truck. D60 front axles, d70 rears. HD transmission. all gear transfer case. Where I have to watch out is revs. The transfer case wants to cruise at around 2800 rpm, and can overheat if driven at high revs for long periods. Was designed for a max speed of 45mph, after all. I can swap out Tcases, though, to an NP205 that is just as strong and can handle the revs easier. I just don't want to unless I need to. Or I can find a Warn overdrive for a t18/t98, and fix the issue that way.

I have been reading Vizards book on 350 budget performance, and he seems to like the Scat 9000 series cranks. So I started looking at things like this:
http://www.summitracing.com/parts/SCA-1-90455/

It includes the crank, rods, pistons, rings, bearings, etc. for a 383.

There is a problem either with my current crank or one of my rods. Or the shop that did ,y engine reused a bearing. but the wear pattern for the journal is weird. the engine may need line boring anyhow.

My goal for tomorrow is to get the block clean and prepped for a trip to the machineist.

Does anyone know how much a stripped block weighs? I am guessing it weighs about as much as a dressed 914 motor.

Ya kinda missed that he did say he was tempted ...

But knowing Zach's Jedi like powers when it comes to resisting temptation, it's probably safe to say you are right ....

If it's going in a truck, I say go with the 383. Hauling needs torque.

If it's going in a 914, I say de-stroke it. Higher revs!!!

Andrew won't even drive his because it's too torqey. A 302 would be best in a 914. High hp and not too high torque.

Completely stripped it is easily movable by one person.

you don't need forged pistons thier noisey compaired to hypers so you can shave a few bucks there.

if you stand the block on end you can put your arms thru the second holes down and lift like that [well thats what i did when i was younger haven't tried as of late].

have you looked up the vortec heads?

About 30 minutes after I made my post last night I was snoring. They are on my research list, to be sure.

Definitely worth looking for a set. The thing to not is they do use a different intake and exhaust manifold than the non-vtec heads. No problem since you need to buy all that anyway Plenty iof them around. IIRC all 350's after 1990 have them. Different valves on some but best bet would be a truck or van in a junk yard

1996 was the first year of the vortec heads. i wouldnt buy used, brand new they are cheap!

knock off copies are good look here http://www.jegs.com/p/RHS/RHS-Pro-Torker-S...426753/10002/-1

Cams.

I have been reading on cam selection.
My block is an 85 - so it means I am going to be using flat tappet cams unless I spend $$$ to retro fit in a roller cam. Given the nature of the work I am going to be asking the engine to do, I do not think the performance is worth it.

However, I am reading lots of folks say that most flat tappet cams won't survive breakin with modern oils, and rollers must be used. is this the case, or is there a brad penn oil that flat tappet dudes in the cast iron kingdom are using?

Zach

with proper break in oil and the cam gets a moly greese put on the lobes when you install it. you run the engine for 20 min to break in the cam on first start up. then if you find some oil with moly in it you should be ok for the first 1,000 miles.

After breakin use diesel motor oil it still has all the good stuff as diesels don't use o2 sensors. I hate to say it but you really should start with the ls motor. You are sorta like starting with 914 type technology on you chevy. Old style gaskets and seals and such. You can by a very expensive intake and oil pan gasket that will help. I have several "built" sbcs and the price is the same but the old stuff as in 85 will always leak more oil and be less efficient. I have a ramjet in my 86 blazer. It uses the vortec heads and 1.6 roller rockers and a roller cam. It makes 350hp 400ft lbs stock and has good low end torque. A normal truck newer ls does just about that good for way less money. When I built my 63 j200 gladiator with a 350 sbc in 1980 I used a 4bolt main sbc. I used a high torque cam with a 600 holley and a offenhauser dual port intake. The intake has the ports seperated all the way to the head ports from the carb. This makes great velocity for chamber filling at slow speeds. It would pull in 3rd gear with the stock 4:09 gears at about 1k rpms. With 31.5 12:50 tires, big back then. It has headers and good exhaust. One mistake I made was 10:1 compression though, lots of water injection and slower timing on crummy gas. Newer style heads will help this though.

The biggest problem with vortec heads is the accessories. I had to build all the brackets for the stuff on the front of the motor in the blazer with the ramjet. Or just use a 96 up truck serpentine belt setup. Vortec heads are great though for street performance and the price can't be beat.

I also used a adapter to put the sbc on a t90 tranny in the jeep. That was junk. The input shaft kept ruining the pilot shaft bushing and before I would take it apart to put a new one in (it's a bigger od than the stock chevy one) seems like it's 9/16 od and the chevy is 1/2 so you gotta make a new one. It would always ruin third gear syncro from the shaft moving from the poor front end support, so that meant also repairing the tranny. So then I went to a chevy saginaw passengercar 4 speed to a adapter to the t18 transfer case. Then even with two sealed bearings in the back of the tranny in that adapter the 90w kept migrating and over filling the transfer case. I would have to open the fill plug on the transfer and drain the excess out and put more in the tranny. I even made a inner fender breather for both the tranny and the transfer trying to fix it. When I finally blew the bottom out of the saginaw on the deer lease from low grease, I drug the truck 130 miles home and put a 400 auto and 205 transfer in it and the problems were solved. Now this wasn't just a hunting wagon it saw 80 plus highway speeds and it ran good. With the saginaw tranny it would get rubber in three gears if I tried. I did destroy the rear end carrier once but the original axles are still in it. Also in the j200 it comes with the 258 ohc motor so the radiator is not up to snuff for a high compression 350. My 79 j10 has a 360 in it and jeep used a saberr saw on the radiator support to make room for a bigger radiator and to move it forward. My 63 has had several radiators in it trying to get it to run cool on a 100 degree day with ac on. It now has two 16 inch fans on a 396 camaro radiator and is still marginal. Either use the short water pump or a electric pump and for sure a fan shroud. Keeping the hot air from recirculating through the radiator at slow speeds is a real challenge. Oh yeah I even have the hood lovered to try and get the heat out. On the earlier hoods the inner support unbolts so the hood can be louvered. Then you gotta build a inner shield under the louvers over the motor, to keep water from puddling in the intake when it rains.

If you just want to chug around get a good stock motor and tranny and transfer and leave it alone. You will still need money for the radiator and stuff. If it uses the old slave cylinder type power steering (like the ones on old mustangs and corvettes) you might want to switch over to chevy truck style power steering, it will need a different pitman arm though.

I am nearly done stripping the block for the machinist. I know, slow right? Well I took a few days off for the holidays, and then took a few days off due to a stomach flu, so this is only really day two.

How do you remove the cam bearings? I am reluctant to tap them with anything as I don't want to scratch the case under the bearings. Is there a special tool or something for this? Or do you just grab a drift and tap them out.

All the freeze plugs are out. That was a sucky job as I knocked the first big one into the water jacket before I got the technique down. Got it out, but there was cursing involved - mostly covered by the music coming out of my garage.

I also ported the oil return at the end of the top of the case. The casting was ugly, so I cleaned them up. I am going to stay flat tappet, not going to go roller for the cam. I don't mind using high zinc oil - its not like this truck will have ANY emissions equipment for the zinc to burn out. If Brad Penn has a break in oil suitable for a 350 (and I bet that they do), I'll use that when I run in the cam.

The engine is off the stand, and ready to be taken to the machinist tomorrow.

Zach

the machinist will remove the cam bearings.

it takes a special tool to install/remove them. have him install new cam bearings for you while he's doing the rest of the milling.

My 383 dreams have been killed.

A sizable stipend that I was promised at work has been rescinded due to "budget cuts." So, now I am going to be pretty much forced to reuse the pistons, crank and rods that I tore down.

I figure that I have gone from around $3K that I could put into this engine to about $1000. I am going to need to go back to the drawing board and see what can be cobbled.

Zach

no big deal!

you can still build a good engine from that stuff.

clean the engine your self, get some bore brushes and brake clean and wire brushes and do the cleaning your self.

borrow some micrometers and check the taper of the cylinder bores. a few .001's won't hurt. get a bearing and ring kit, and if the bores are good just use a "bottle brush" hone [actually a glaze breaker] and put a cross hatch in the cylinders for the rings to seat to.
rent a cam bearing tool to install those.
spend your money on:
-heads, if you can come up with the 850 for the after market vortech heads that is where you will see the best bang for buck. the after market heads can come with both intake and valve cover bolt pattterns.
-cam, call the cam co. and tell them the heads intake and compression and what the engine is going into and they can give you the best cam pick.
-intake, you can find on craigs list and e-bay cheap.
-headers. a set of shorty or mid length can be found e-bay or craigs list.
shop and wait for the deals.

For what this is going in you really don't need a ton of H.P. you'll never use most of it. That trans and rear are so damn low, and you want tit for puuling anyway. Look up the specs on H1's, Unimog's, Pinzgauer's etc. they are the ultimate 4WD's and they have very little h.p. For what you have and want a 350 with a cam and some flow work will be perfect. Cam intake, headers, exhaust, and a 650 holley will be plenty. Toss in the V-tec's and you'll have all you can ever use. Too much h.p. and you get tire spin, LAST thing you need in a 4wd.


don't go big, go smart