Refreshing a tired 3.4L RWD Gen1?

[pbsch]

I have a fairly high miles (somewhere in the 150000 miles area) 3.4 that appears to have been moderately well maintained. I plan to tear it down and do a refresh at a minimum (bearings, gaskets, seals, possibly rings and inspection). Will probably do a valve job since the valves have to come out to check guide wear, etc. I guess what I'm really interested to know is what is typical in a good, but potentially tired engine. I understand I won't know with certainty until I've cracked my particular engine open and had a good look, so please give me your personal experience with other disassemblies you've been involved in
1. Will the crank journals be able to be polished or do they usually require grinding undersize?
2. Will the bores be ridge ream/honeable or will the block need to be bored and oversized?
3. Do the guides on the valves usually wear beyond tolerance at this mileage?
4. Is the cam/lifters usually shot by this point?
5. Will the oil pump need to be replaced or just checked?

Reading the forum thoroughly as I have over the past few nights, I understand that my 3.4 won't produce the same sort of power as the 3400, 3500, 3900 etc, but this is going in an 1800 pound application so i'm not concerned about all out power. I however, wouldn't mind wringing as much as i can out of this engine reliably and inexpensively. That said, I plan to do some basic gasket matching, port smoothing and flowing of intake and exhaust.
1. Will I see an increase in power if I were to have the heads milled a bit, thereby increasing combustion ratio? how much can the heads be milled before you have to start worrying about pushrod and rocker geometry issues?
2. Is there anything that can be done to the combustion chambers themselves that would improve cylinder filling characteristics?
3. Does the windage tray make a noticeable difference in either top end power or highway efficiency?
4. Anything else you'd suggest if time and skill were available but not a lot of money?

Thanks in advance for your experiences and inputs
Paul

[geoffinbc]

1.Journals will all be fine unless debris went through them.
2.When I rebuilt my 3.4L I was just able to hone it and put the stock pistons back in
3.They are cast iron guide and are usually pretty good. Bronze inserts are cheep to install.
4.The Cam in my engine was fine and I still use it but there are a lot of cases of lobe failure. The stock cam sucks compared to the COMP units so you may want to upgrade anyway. Don't forget you have to consider the cam sensor.
5. Just replace the pump don't even second guess it.

1. Decking the block would be my first approach in order to try and bring the pistons to zero deck. It will also increase compression and you will get more power.
2. Deburring the combustion chamber will decrease the chances of hot spots forming and lower the risk of detonation.
3. Top end power will be better with a windage tray but not under 5000RPM
4. Remove ALL the casting flash in the lifter valley and timing chain area of the block and cylinder head oil drain back locations. Chamfer the oil feed hole in the rear main cap for smoother flow and seal the pump to the cap with anaerobic flange sealant when you assemble it.

[pbsch]

great feedback, thanks!

A follow up - is there a particular oil pump that the engine prefers or is the one sourced at the local parts house sufficient?

[pocket-rocket]

I believe a Melling is the norm around here. Your local parts store can get you a Melling.

[pbsch]

Is the high volume unit preferred over the standard? M134 vs M134HV

[ForcedFirebird]

Mellings is a standard flow, just better than OEM.

[60dgrzbelow0]

...and if memory serves...this from "Forced Firebird" awhile back...

"Use the stock Melling M-134 Oil Pump...because the higher volume Oil Pump can put too much oil in the top end of the engine and vacate the crank case of too much of it.."

And likewise ...from "betterthanyou"...

"...as for the "over volume"...the only thing that will happen is that your By-Pass Valve will become over active at higher RPMs ...dumping the excess oil back into the crankcase that cannot be pumped through the system.."

So the GM Stock or the Melling Aftermarket M-134 should do very nicely. Just remember to use all of the necessary amounts of "Engine Assembly Lube" called for for breaking in new parts...and prior to installing the New Oil Pump...submerge it in a bucket of Valvoline Racing Oil (with ZDDP) or even Royal Purple Engine Break In Oil and crank it by hand to ensure that the air is purged out completely and it will not cavitate once the engine crank case if filled to capacity. Follow the camshaft break in procedures as well...and don't use synthetic oils that have no ZDDP to help condition the camshaft lobes by running the engine at 2,000 RPM for at least 25 minutes and then immediately change the motor oil and oil filter which will clog up with any Moly-D assembly lube and become useless. Use the proper break in oils and protective camshaft additives called for, with changes of both oil and filter at 500, 1,500 and finally 3,000 miles after the break in is complete. Change over to a synthetic oil after that like Mobil 1 in order to prevent coating your O2 sensors and CAT Converter with Zinc... rendering them useless.

Please visit my Photo Bucket and browse all the Albums that cover the Complete Engine Tear Down and Re-Build of the GM 1993-1995 L-32 3.4L V6 Engine. Plenty of engine tear down, re-assembly...specialty tools, new parts and proper part numbers for you to examine and use if you need this information:

http://s557.photobucket.com/albums/ss19/60dgrzbelow0/

Visit here to get the best video and information on Mellings Oil Pump Pick-Up Tube Installation Instructions...

http://www.melling.com/Info/TechTipVideos.aspx

[pbsch]

Great info thanks! I spent a good bit of time looking through the pics. My laptop is so slow it was painful. Can't wait to get home to my regular fast PC and my project! Oh yeah and the family too LOL...

Thanks,
Paul

[pocket-rocket]

My laptop is so slow it was painful. Can't wait to get home to my regular fast PC and my project!

I know the feeling... My laptop is a Sony Vaio I bought new back in 2000. At the time, it was pretty fast. Now the XP-M 1500+ CPU (that replaced the 800Mhz Duron) barely gets XP moving. Back when I got it, XP wasn't even out yet... At least it can still serve as a back-up pc and as something to scan OBD2 cars.

[60dgrzbelow0]

For those who must fall back on legacy PIII or even PII hardware... if you have a spare laptop hard drive... try giving the Linux Operating System flavor called "Ubuntu" that comes in a variety of lighter versions that are not as processor intensive as the M$ OS are a chance to put a smile on your face and a real look of surprise. It will give you a streamlined OS that can allow you to use Older Hardware...in new ways. Visit this forum dialog for some background and links to some Ubuntu ISO downloads that you can burn and boot up and install in a Jiffy... and give your old laptop some brand new legs to run on...

http://ubuntuforums.org/archive/index.php/t-306546.html

[pocket-rocket]

I've actually got ~5 partitions setup on my puny 80gb and have it dual booting between the Ubuntu variation called Xubuntu and XP Pro. It just sucks that 95% of software I have wants Windows and I haven't played with the Linux OS enough to learn it yet.

[pbsch]

Dang, just missed a melling m134 for $20 shipped brand new on eBay...

[60dgrzbelow0]

PB... My Apologies for the Temporary Thread Jack...


With over 15,000 applications that can rival Windoze apps...with the exception of gaming apps... the latest versions of Linux are very windows GUI-like and are so much cooler and flexible to use. Once the Distro is set up...it will pretty much fix itself on the fly daily with millions of qualified programmers funneling the latest, greatest improvements and all you do is sit back and have fun. I just built an Athlon X2 Dual Core 64 bit box based on the Fedora 12 (Constantine) flavor..and it is just superb... sleek...fast...and of course...completely forever...FREE! (Also...Free of Viruses, Trojans and Root-Kits, too)

You can learn the command line programming which is simply a modified Unix type set of commands... but it really is unnecessary to the building of a system to rival most of the 32 and 64 bit systems from M$. The other boon is that Linux will allow you to use legacy hardware that you have had to park on a shelf somewhere because of the lack of drivers to run things with each new "Layer Cake" addition on top of the bloated Windows OS with millions of lines of code that simply clog up the system and turn the processor into a code masturbation device for no actual performance gains. By the way... there is even a Linux app that can allow you to run windows applications, too... its called WINE...

[pbsch]

To tap into the wealth of knowledge on this site, I will tolerate the occasional thread hijack.

[60dgrzbelow0]

To tap into the wealth of knowledge on this site, I will tolerate the occasional thread hijack.

"I like your Styyyyyle... Dooood" (The Dude Abides..)

Here are three painless ways to try out and investigate what the Linux Operating System has to offer Windoze Users... Got WUBI?...

http://www.linuxhaxor.net/?p=817