: How hard is it to change valve seals on a 5.0 brougham



shorty rocks
06-17-08, 04:13 PM
gotta brougham with a 5.0 liter 305. im loosing oil, NO leaks, white smoke when i start up, my coolant level is fine, im not loosing any. im hearing it the valve seals, how hard is it to change em yourself in a driveway? i looked in the Haynes manual , and it looks like a pain in the ass. said u gotta stuff the cylinders with rags:banghead: and use air so the valves dont fall in, and also said u gota turn the motor as u change them. is there any way to do it with out turning the motor, etc??? thanks for ur help by the way..

carnut
06-22-08, 02:15 PM
The book is correct except for the rag. Each piston is brought to top dead center, then an air hose is screwed into the spark plug hole and air is pumped in to hold the valve shut. Then a special tool is placed over the valve stem once the rocker arm is removed. Remove the spring then the seal. Replace spring and rocker arm. Once all eight are done then you must adjust all the rockers like an old V/8 Chevy. most times the failed seals are the intake valves only. So most people only replace those. Good luck!

N0DIH
07-07-08, 03:09 PM
Spend $500 and toss on a pair of Vortec 350 heads..... :)

shrike77
06-21-10, 12:32 PM
Spend $500 and toss on a pair of Vortec 350 heads..... :)

I am curious,
How different are the benefits from stock?
Are we talking about a carb'ed engine?
any other mods required for this?

Stingroo
06-21-10, 12:40 PM
You also need a Vortec intake. It can be done for carbed engines or TBI.

It's what I want to do for the wagon. :) Supposedly good for a fair amount of horsepower too. :devil:

N0DIH
06-21-10, 12:45 PM
Vortec heads. On a 350 are a pretty easy and dirt cheap 50hp gain. Remember a 350 vortec has a smaller ca
m than the 350 it replaced and still was 45 hp stronger. A wet EFI like the L05 and L03 has some nice intake air cooling benefits over a dry intake.

Don't use rags. Use ONLY compressed air. I have a broken piston on my 455 back in 1992 from a rope I used. Use air........

I have read many people mod the stock intakes to work. But an aftermarket intake overall is prob a better idea.

Stingroo
06-21-10, 01:32 PM
Whoa whoa whoa. Hold the flippin' phone.

So if I dropped about $700 (edelbrock performer RPM vortec 350 intake is like $190) into my car I could gain 40-50 hp?

How mechanically involved is this? I know its obviously some amount of work, but like.. if I brought the parts to a local shop what do you think they'd charge to install? (College campuses are hardly good for work space :lol:)

I'm definitely listening now. lol

N0DIH
06-21-10, 03:03 PM
do you have 305 or 350?

The L03/L05 heads suck bad, they have the ski ramp down one side and block off nearly 50% of the airflow.

The Vortec heads flow pretty darn good for stock castings, they are low cost too. NEW low cost.

Personally any 350 should have them put on, they cost per $ is hard to beat.
Toss in a LT1 350 Z28/Vette/TA cam and there is no reason that 270-280 hp would not be realized. The L05 cam I would bet is larger than the stock LT1 and Vortec 350 and HT383 cam. So it wouldn't be a bad thing.

Upgrade exhaust to duals and good flowing manifolds or better yet, headers and a 300 hp should be easy.

You will need PCM tuning, but I am all setup to do that, I can do PROM based cars/trucks no problems.

N0DIH
06-21-10, 03:11 PM
Here is what Fast305 said on Fullsizechevy.com (http://www.fullsizechevy.com/showthread.php?200280-Vortec-Heads)

After seeing the cam specs, they are pretty lame, probably a 275 hp LT1 cam swap would be well worth it, they are cheap on craigslist, often $20-$30. Being you have a roller, no worries. I have one for a stock LT1 out of a Fleetwood, just still in the engine, but I plan on swapping it out anyway. It is a 260 hp LT1 cam, stout cam for heavy cars, but lacks upper rpm power (over 5500 rpm....), but stout for torque....


Vortecs heads by themself do not give huge gains on a LO5. From GM the vortecs got MPFI, a hotter roller cam, dual cats, less restrictive exhaust, the vortecs, and better ECM tuning. All togather it was worth 45 Net FWHP and 30 ft/lbs of torque. The vortec cam is a large part of that. Even more signifigant than the heads. Headers, full exhaust, bigger cam, a better intake, and a good chip will really wake up a stock L05 and give better gains than swapping to vortec heads and leaving the rest stock. The 193 TBI heads do not pose a restriction until around 300 FWHP in stock form.

And I found this on another forum called hotrodders.com (http://www.hotrodders.com/forum/chamber-cam-compression-l05-132228.html)


:It seems like there are 3 different versions of the L05:
1. Low compression truck version.
2. Police version (availiable on Caprice's only).
3. The version used on all other L05 cars.

Since my engine comes from a Buick Roadmaster, I must have the third version and this is what I've found out about it. Apologize the caps look, but I just copied it down from an internet page:

2 BOLT MAIN 1 PIECE CRANKSHAFT SEAL BLOCK( NO MECHANICAL FUEL PUMP PROVISION)NODULAR IRON CRANKSHAFT
POWDERED METAL CONNECTING RODS
FLAT TOP HYPEREUTECTIC PISTONS
9.6:1 COMPRESSION RATIO
SHORT WINDAGE TRAY
SINGLE ROLLER TIMING CHAIN

HYDRAULIC ROLLER CAMSHAFT
INTAKE LIFT-.359" * EXHAUST LIFT.384" *
INTAKE DURATION @.050-186.5 * EXHAUST DURATION @.050-193.8
LOBE CENTER SEPERATION -110.3
CAMSHAFT MECHANICAL SPECS:
INTAKE VALVE OPENS @ -16.9 BTDC * INTAKE VALVE CLOSES @ 23.4ATDC * INTAKE LOBE CENTERLINE - 110.3 EXHAUST VALVE OPENS @ 25.6BBDC * EXHAUST VALVE CLOSES @ -11.9 ATDC * EXHAUST LOBE CENTERLINE - 110.3
CYLINDER HEADS:
CASTING NUMBER 14102193
SWIRL PORT INTAKE PORT DESIGN
65.3cc COMBUSTION CHAMBER
1.94" INTAKE 1.50" EXHAUST VALVE self-aligning rockers.

Stingroo
06-21-10, 04:46 PM
Now I'm even more confused, lol. I don't really understand all the camshaft lingo.

I just want more power out of the wagon on the (semi) cheap, but without doing anything totally ridiculous.

shrike77
06-22-10, 09:23 AM
Mine is a 307 carb'ed (1987)
What are the gains that I could expect with these modifications?
I don't want crazy power but if I can get around 200 horses with not too much money thrown at it I would be happy.
Also would it affect gas mileage?

sven914
06-26-10, 01:17 AM
Mine is a 307 carb'ed (1987)
What are the gains that I could expect with these modifications?
I don't want crazy power but if I can get around 200 horses with not too much money thrown at it I would be happy.
Also would it affect gas mileage?

I think N0DIH confused himself... He was telling you how to improve the Chevrolet engine you don't have, and Sting just made it worse by getting all excited about his Chevy.

But as Carnut said, the procedure in you manual is correct (I just confirmed it in my Cadillac Factory Service Manual). If you want to find out some information about making your Oldsmobile 307 a little more powerful, go to performanceolds.com (http://performanceolds307.tripod.com/). They Have some good info on what heads and modifications you need for more power.

N0DIH
06-26-10, 02:19 AM
The original post said 305/5.0. Not an Olds 307/5.0....

I don't think I am too confused am I?

brougham
06-26-10, 04:51 AM
It looked like shrike77 had a 305 too until he said he didn't. That's what confused everything.
shorty rocks problem doesn't look like valve seals anyway. That's usually dark smoke and there shouldn't be enough oil getting past them to make any noticable difference of oil level.