Hey guys, this is my first real thread on this forum other than a quick question here or there. This thread is documenting a complete and total overhaul on the 4.3l motor of a 1999 Blazer LS. This truck is my dad's ( I have a black 1998 2 door myself) and due to a combination of neglect, several over-heating occurrences, mixture of Dexcool with regular coolant and water causing a nice thick gummy substance to fill the cooling system, and finally a blown intake gasket around the coolant passage in the head allowing fluid to sneak into the combustion chamber and stall it out.....the motor came due for a rebuild. At the very beginning while we were weighing out our options of whether or not to go with a crate motor or to go ahead with the rebuild, we figured that for maybe $200-300 more I could do the rebuild and have more control over the quality of the work and be assured it's not some slapped together 'Hecho en Mexico' deals. Well now I am toward the end of the build and I figured why not chronicle this process and perhaps help someone else make their decision and learn from my mistakes (....you'll see). So without more yapping on I will give you guys some pics of the carnage to feast on, enjoy...

Here it is the day after it was towed to my house...I got to work quickly tearing it down.

http://i27.photobucket.com/albums/c189/timbevis/DSCN9841.jpg

Removed the upper intake, wasn't too surprised by the amount of carbon build up

http://i27.photobucket.com/albums/c189/timbevis/DSCN9842.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN9845.jpg

Then I moved onto the lower intake manifold

http://i27.photobucket.com/albums/c189/timbevis/DSCN9848.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN9849.jpg

And thats when I found the issue...

http://i27.photobucket.com/albums/c189/timbevis/DSCN9855.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN9853.jpg

The heads and block were gummed up pretty bad with this stuff

http://i27.photobucket.com/albums/c189/timbevis/DSCN9852.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN9856.jpg

The gasket was broken up around the coolant passage adjacent to cylinder #6 so I'm guessing this is what cause the stalling issue. I was worried about a possible hydro-locking issue as you can't compress a liquid in a cylinder, but I think there was enough blow-by or there just wasn't enough fluid because the rod did not bend thankfully

Here's a nice chunk of the stuff

http://i27.photobucket.com/albums/c189/timbevis/DSCN9851.jpg

Well I think 10 is the picture limit per post so I'll end here and pick it up in another post.

Those rear coolant passages look yummy! LOL

I am working on getting the picture posting limits changed. It is a bother... You could display the automatic thumbnails from Photobucket and link to the full resolution shots if you'd like. Check out the Help & Suggestions section for the Image Posting FAQ.

wow that looks nasty. Sorry to say but I don't think you'll be able to do a complete overhaul for $200-$300. You'll probably be near that in gaskets alone

Nice guuk! How much of the internal work are you doing yourself. An extra $200-$300 is worth it IMO just for the experience, if you have the time. Keep the updates coming.

wow that looks nasty. Sorry to say but I don't think you'll be able to do a complete overhaul for $200-$300. You'll probably be near that in gaskets alone

im pretty sure he meant 200-300 more than buying a cheap crate motor that was made in mexico, just going by what i read into his post.

im pretty sure he meant 200-300 more than buying a cheap crate motor that was made in mexico, just going by what i read into his post.

yes, that is exactly what i ment. perhaps i worded that alittle awkwardly. its rather comical now because the build total is now more than double what a crate motor would have cost. anyone reading this thread and contemplating doing their own rebuild.....run, do not walk, to your nearest engine supplier and just get a crate. the warrenty and lack of headaches is worth it alone. no dealing with shady machine shops, parts delays, interchangability issues, etc. if this were a normal run of the mill small block i could have built it with parts i already had. im going to post up the rest of this thread probably later on today when im back on highspeed (the pics take forever on dialup). this project has been nothing but headaches from the get go and i highly regret not just popping a new set of gaskets on and giving it a flush and calling it a day. oh well, you live and you learn i suppose.

Goes to show why you shouldn't mix dex cool with regular antifreeze. Looking forward to seeing the rest of this. I am thinking about picking up a spare motor to rebuild, and it is always good to see what I might face before I actually get there.

Dexcool and "regular" coolant mix is not a problem, that gunk looks like "sealing" compound that was added over time....I have been running a mix for years....

Yea, I agree about just buying a crate motor from a reputable builder. But I gotta admit, I am very entertained by the pics! more please!

I trust my machine shop and any engine given them for overhaul gets it's warranty. I would never go for a cheap crate engine "Made in Mexico".

Over here a crate motor is expensive anyways no matter where it comes from around 4'500 $ while a rebuild costs about the same.
So I'll not bother risking to get a "Made in Mexico" when I can do it at the same price decently with material as good as OEM or better.

I'll probably do that in 1 - 2 years using the engine on my scrap Blazer and have it rebuilt.

As I can disassemble and re-assemble everything myself i'll get cost down to 2'000 or 3'000 $ - and do some nice things to the engine such as a proper porting job, balancing everything starting with pistons, rods, and crankshaft, then balance all together with the flywheel and maybe add 0.05 to 0.08 bar to the compression.

When it comes to engines nevertheless my heart beats for an older Alfa Romeo 4 cylinder DOHC or V6 - these are real nice engines and make the one in my Blazer look like a tractor.

Nice work though on your Blazer. Thanks for the pics very interesting and good quality to get an idea what it looks like below the spider.

hey guys sorry about the long hiatus from posting, i actually forgot all about it to be honest. the project has been finished for a few months now and oh boy am i glad to report that. this project was such a pita! everything that could possibly go wrong pretty much did. ok so where did we leave off......

well after tell my padre his options he opted for a full rebuild(lucky me). so i got to work yanking the motor out then broke it down to send out to the machine shop. i was going to add the rest of the pictures right now but photobucket doesnt seem to want to cooperate with me while im at work on a dialup connection so i will post them up in a few hours....

here they are guys

http://i27.photobucket.com/albums/c189/timbevis/DSCN9861.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN9862.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN9863.jpg

supported the trans with a jack

http://i27.photobucket.com/albums/c189/timbevis/DSCN9868.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN9872.jpg

slowly started to lift it out being careful not to snag anything on its way up

http://i27.photobucket.com/albums/c189/timbevis/DSCN9875.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN9876.jpg

supported the bellhousing with a piece of barstock that spans the frame rails

http://i27.photobucket.com/albums/c189/timbevis/DSCN9877.jpg

bolted up the engine stand to get it ready for disassembly

http://i27.photobucket.com/albums/c189/timbevis/DSCN9879.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN9878.jpg

more pics in the next post fellas...

Nice progress! Keep the pics coming!

alright well after it was bolted to the engine stand, i started to disassemble the motor. make sure you label all of your parts and bolts to make sure it all goes back together properly. i used a spring loaded center punch to mark the main caps and connecting rod caps as well with dots corresponding to the cyl # or main cap position ref the front of the motor.

http://i27.photobucket.com/albums/c189/timbevis/DSCN9880.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN9885.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN9883.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN9882.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN9886.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN9892.jpg

do the same thing when you mark the rotating assemblies, cam to balance shaft more importantly

http://i27.photobucket.com/albums/c189/timbevis/DSCN9887.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN9890.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN9893.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN9891.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN9896.jpg

thats my blazer on the left

http://i27.photobucket.com/albums/c189/timbevis/DSCN9894.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN9898.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN9899.jpg

and off she went to get boiled and cleaned out of all that gunk. the heads were rebuilt and the block was taken .030" over.

http://i27.photobucket.com/albums/c189/timbevis/DSCN9971.jpg

now just a note to you guys rebuilding your own motor.... take your time and make sure that you are paying attention. unfortunatly i was working on this motor in any free moment i had and around 1am i was pushing the last piston into the #6 cylinder and something went very wrong...apparently i did not have the ring compressor square to the block and the bottom oil control retainer ring was not fully compressed and scored the heck out of the cylinder wall. i carefully removed it and surveyed the damage after a lot of yelling and some not so PG rated words were uttered

http://i27.photobucket.com/albums/c189/timbevis/DSCN9965.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN9967.jpg

heres the ring compared to a good one i stole from the 4.030" ring set i was saving for my 355

http://i27.photobucket.com/albums/c189/timbevis/DSCN9968.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN9970.jpg

after that little mishap i went out and bought a sleeve style ring compressor and i regret not doing it even sooner! this thing was amazing!

http://i27.photobucket.com/albums/c189/timbevis/DSCN9972.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN9973.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN9980.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN9974.jpg

after that little hiccup the rest of the assembly went kind of smooth....until the next speed bump. stay tuned

oh yeah i know i didnt really go into detail with that score in the cylinder but i did clean it up and hone the crap out of it before i reinstalled the piston with a new ring just for the record.

http://i27.photobucket.com/albums/c189/timbevis/DSCN9982.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN9983.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN9984.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN9985.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN9987.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN9986.jpg

and the lovely torque to yield bolts required the torque angle gauge (sarcasm much?)

http://i27.photobucket.com/albums/c189/timbevis/DSCN0008.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN0010.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN0012.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN0011.jpg

Love all the pictures, it takes dedication and time to stop during assembly/tearing apart anything to stop and take pictures!

Love all the pictures, it takes dedication and time to stop during assembly/tearing apart anything to stop and take pictures!


Thanks man, it is difficult to stop and remember to take pictures. i didnt stop and take pics while assembling the rotating assembly and the measurement/plastigage stage because i was on such a roll. that was until i scraped the hell out of the cylinder wall. after that mess i decided to document the rest of the build extensively so it could serve as a guide to anyone else doing a rebuild themselves. just a few tips i forgot to mention earlier....put 2 pieces of fuel line over the bolts on the connecting rods to prevent any scratches on the cylinder walls (ironic much?), from what i gathered speaking to several engine builders if a fastener has a torque spec that preloads it with a set torque and then requires it to be turned to an addtional angle, that fastener is most likely a torque to yield type fastener. now i know there is some arguement here and people have gotten away with re using fasteners without issue, but with my luck i would be the guy to hve the bolt break because it was already stretched once and i ended up listening to the wrong advice. so by my logic, yes its an addtional cost, ~$40 for new main bolts and $14 per side for new head bolts, but id rather pay that $68 any day of the week and have the piece of mind knowing that my hardware is just fine. hmm what else.... oh well be sure to use the proper sealant/lubracant on the bolts especially on the head bolts as they go into h2o jackets. follow all torque specs and orders. that about it i guess as far as advice goes. ill post of the pics of the rest of the build now

after the cam was in i realized that the timing set i got had a different sprocket set up so i had to pull the bottom one off and put the correct one on

http://i27.photobucket.com/albums/c189/timbevis/DSCN9989.jpg

through all of my searching for a timing kit with the correct gear i came across a service bulletin from chevy. apparently there was a problem with some rattling coming from the stock timing chain so chevy had the dealers add this timing chain tensioner kit. i was going to ignore it but i figured eh what the hell. so about $270 later i got the kit and installed the nylon tensioner that rides along the side of the chain

http://i27.photobucket.com/albums/c189/timbevis/DSCN9992.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN9993.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN9995.jpg

make sure you dont switch up the plates for the cam and balance shaft

http://i27.photobucket.com/albums/c189/timbevis/DSCN9996.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN9998.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN9999.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN0001.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN0002.jpg

then it came time fore the oil pan to get secured after the front cover was put on. i opted for a new timing cover as per the instructions from chevy, the seal is molded into the the cover itself and it doesnt stand up very well to time.

http://i27.photobucket.com/albums/c189/timbevis/DSCN0013.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN0026.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN0028.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN0029.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN0032.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN0034.jpg

while the motor was out and there was some creepy looking coolant gunk i decided to do another heater core just in case to prevent any clogs

http://i27.photobucket.com/albums/c189/timbevis/DSCN0019.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN0022.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN0021.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN0024.jpg

decided to go with some comp cams 1.6:1 ratio roller tip magnum rocker arms to up the duration and lift since we decided not to go with one of those "computer friendly" cams

http://i27.photobucket.com/albums/c189/timbevis/DSCN0016.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN0017.jpg

had a big DOH moment once i went to go install them though, i found out when the pivot balls wouldnt fit that i had to replace the rocker studs....no fun. good luck trying to find metric on the bottom and SAE on the top for a v-6. several speed shops looked at me like i had 3 heads when i asked for them. but i finally tracked them down from ARP and had them overnighted to get the motor done

alright where did i leave off.....rockers! thats it. well had a bit of a problem with the lifters. when you have people helping you out make sure they know what they are doing...rather than making the assumtion that they know how to properly install rocker arms, double check that they dont find a "rocker" torque spec in the haynes manual and go ahead and just torque them all the way the eff down. more on this later....

here are some more pics for you guys

http://i27.photobucket.com/albums/c189/timbevis/DSCN0035.jpg

paint

http://i27.photobucket.com/albums/c189/timbevis/DSCN0030.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN0034-1.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN0040.jpg

my dad went and ordered a set of OBX headers off ebay, really cheap too....but i found out why they were so cheap later on too when they leaked like crazy

http://i27.photobucket.com/albums/c189/timbevis/DSCN0060.jpg

the #3 tube loops out and around the steering shaft for clearance. cool design but PITA

http://i27.photobucket.com/albums/c189/timbevis/DSCN0064.jpg

sneak peak of it all installed

http://i27.photobucket.com/albums/c189/timbevis/DSCN0085.jpg

ready to swing. i always cover everything up whether it be a carb hole or in this case the entire lifter valley with cardboard and some shop rags on the rockers to prevent anything from falling down in there and making a big oops

http://i27.photobucket.com/albums/c189/timbevis/DSCN0041.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN0048.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN0050.jpg

the good ole' fashion way to find TDC lol. just thought it was a cool pic

http://i27.photobucket.com/albums/c189/timbevis/DSCN0053.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN0070.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN0073.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN0075.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN0079.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN0095.jpg

in the middle of all of this the rear on my 98 decided to blow. my ex always told me i was good at killing spiders but i somehow doubt this is what she ment....

http://i27.photobucket.com/albums/c189/timbevis/DSCN0127.jpg

following the trend of this build something went wrong when i swung the motor too. i caught the wire loom and ended up squashing it between the motor and trans.

http://i27.photobucket.com/albums/c189/timbevis/DSCN0090.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN0091.jpg

put the refurbed spider onto the intake

http://i27.photobucket.com/albums/c189/timbevis/DSCN0058.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN0059.jpg

once again. a problem. intake bolt snapped when in/lbs were confused with ft/lbs

http://i27.photobucket.com/albums/c189/timbevis/DSCN0106.jpg

success! got it out

http://i27.photobucket.com/albums/c189/timbevis/DSCN0109.jpg

break bolt-check! lol

http://i27.photobucket.com/albums/c189/timbevis/DSCN0116.jpg

new bolts and we were in business

http://i27.photobucket.com/albums/c189/timbevis/DSCN0115.jpg

made a checklist and just went at it full force hooking stuff back up...

http://i27.photobucket.com/albums/c189/timbevis/DSCN0123.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN0118.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN0120.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN0121.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN0136.jpg

http://i27.photobucket.com/albums/c189/timbevis/DSCN0137.jpg

wow great detail in those pictures. how long did the whole process take?

Nice work!

wow great detail in those pictures. how long did the whole process take?

haha longer than id like to admit. it took about 5 weeks with my work schedule and all the other projects i had going on. i started out thinking it would take only 2 weeks. oh boy was i mistaken.

Nice work!

thanks man, never again though. if the motor dies in my 98 it will either be time for a crate/junker or hasta la vista baby

nice write up man

I kind wish you woulda painted it orange! But great job otherwise.

nice write up man

thanks, its always helpful to have lots of pics to look at if your doing the rebuild and hopefully others can learn from my mistakes or learn a tip or trick to make it easier on them

I kind wish you woulda painted it orange! But great job otherwise.


i wanted to go good old chevy orange but my dad didnt want it. i did however do my last project in chevy orange....

http://i27.photobucket.com/albums/c189/timbevis/DSCN0406.jpg

it put out just a little more horsepower than the 4.3 lol. heres some proof

http://i27.photobucket.com/albums/c189/timbevis/th_burnnnnnout.jpg (http://s27.photobucket.com/albums/c189/timbevis/?action=view&current=burnnnnnout.flv)

Great write and pics.

wow! nice, thats a ton of work. ive never seen a 4.3 so naked.

Good story and well displayed! Bravo!
Good luck :)