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1986 need new engine, whats best?

ptrparker

ptrparker

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I think that I need a new engine or a rebuild. I use this as my everyday driver, not off road. I was thinking of upgrading, but I need the most reliable option.
I seem to be leaking oil into the pistons because every couple months I have a fouled spark plug at #8. Its caked with oil and will not fire. It eats a lot of oil. My other problem is that I live in California and I have to obey smog laws...
Any suggestions?
1986 K5 350
 
How many miles are on the engine? Do you blow blue smoke on start up after sitting overnight? I am assuming you have a TBI system being an 86.
Depending on what you are looking to spend a GM crate motor is a good way to go. Good warranty and reliable. Not a whole lot you can do with a TBI motor to make easy HP gains anyway. Since this is your daily driver you want it to be as reliable as possible. Being in CA limits you options even more.
 
Hello RollinKaos,

Thanks for the reply. Its carb and has 112,000 original miles, and yes to blue smoke..
 
Blue smoke usually indicates valve stem seals leaking. Pretty common for GM motors. I would run a compression test and consider doing the valve seals if the compression is OK.
 
ok, if I have the heads rebuilt....I will have an opportunity to add headers and new intake manifold, carb etc. any advantage to add a better intake and carb but maintain reliability? Should I add rolling lifters etc..then again I am up to about the same price as a new motor...any advice will be appreciated.
My goal is to increase power, but maintain reliability and pass smog...
 
FMS (foreign machine service) in Pasadena, on Walnut Ave. west of Altadena

JMS racing engines (johnson machine service) in Monrovia, on Peck Rd south of Arrow Highway

those are the only machine shops I know of in the area
 
nope .

air adaptor for spark plug hole to hold valves up.

spring tool to pop springs off on head.

pop seal off and put new on .

reassemble and go to next cyl till done.
 
I would pull the heads to do valve seals--done them before using the air or rope trick to hold the valves shut,but its a tedious back busting procedure,and I have had engines blow a head gasket just weeks after doing the valve seals,so its probably just as well to remove the heads,do them on the bench and inspect them good for cracks and or bent,burnt valves while they are off,and put new head gaskets on it at the same time.................................................................................................Due to the fact chevy V8's slant to the rear,any sludge build up in the heads can prevent oil from draining back into the oil pan,if the passages get clogged in the back of the head--oil will then puddle up around the valve stems and get sucked into the combustion chamber,and eventually will foul the rear most plugs and they'll stop firing...cleaning the oil returns often improves or eliminates that condition............................................................................................I have done valve jobs on a few engines,then had them smoke horribly after assembly,because now that the valves are seating tightly,any wear at the rings is magnified a lot...sometimes its best to do the whole engine over at the same time,due to that...I've found it easier and cheaper in the long run,to drop in a good running low mileage salvage yard engine than trying to rebuild an old one....you can blow a ton of cash at a machine shop,and still wind up with a crappy engine..
 
I agree with Diesel. Pull the engine and get it "freshened up". Throw a new cam in while it's apart for a little more power.
 
Definitely, If you are going to pull the heads then do the whole motor. I am against doing a top end on a worn bottom end. It nevers pays off. You almost always have to go back in shortly afterwards and repair the bottom end now that the top end is holding compression. Freshen up the bottom end, do a valve job and get a little bigger cam. Being in Ca. will definitely impact what you use as a cam though, you dont want to bring those idle emmission numbers up too high.
 
When you're talking about all this time and money involved in a complete rebuild, you're probably just better off saving time and buying a Goodwrench crate motor. You get a brand new engine, not rebuilt, for just a little more than the typical cost of an average rebuild. For a daily driver where reliability is a concern, and in CA where your modification options are limited, that really might be the best option.
 
Need more advice ...for my 1986 K5 Sliverado
I have a quote from Jegs for a 1985 GM LB motor with 290 HP, with intake, distributor, $2300. They said this is the best option, but will need to replace the flex plate. my carb is good.
1. has anyone done this?
2. will engine match up to tranny( I read that I have a single rear main seal and is only on 1986)
3. do I have to do any additional modifications to make it work?
 
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If it comes with an intake (center bolt angles on the intake changed with the engine when they went to a single piece main seal) then yup, all you should be needing is a new flex plate to have the proper balancing and bolt pattern.

The engine will have the same bolt patterns for the bellhousing and on the flex plate for the torque converter. No other modifications should be nessessary.

That said, have you considered swapping to a newer fuel injected engine? Doesn't have to be a fancy 6.0L, even a TBI or Vortec 350 would be a step up from a carb!
 
havnt thought about got to TBI..
What are the advantages and what would be needed?
Trying to keep it simple and easy...
 
GM had a problem with the intake gasket leaking oil into #6 and #8 cly's. Because of the EGR valve. You just mite only need to replace the intake gasket to fix your problem. I would do a compression check and if all the cly's are about the same. I would bet the intake gasket is the problem. A new motor Always sounds good, But if it's a DD and your tight on Money. I would do the compression check First. Just My 2 cents
 
I'm just going to throw this out there. If your only problem with this motor is valve seals, you are crazy to do anything other than fix those, and leave it alone.

There is NO point in messing with a perfectly running motor. You are only inviting headache and cost that you don't need or want.

Just saying. Nothing against anything other people have said, but you start digging into a good running motor, by the time you are done, it won't be running as good. Murphy's law.
 
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