Engine rebuild ?'s

[Deuling]

I have an 85 k5 with a 305... Lol ryhmes haha. Ive had this low oil pressure problem and was told to try thicker oil. (it has a nock when oil pressure is so low at idle unless i rev it to about 900).

Well i changed the oil, put rotella 15w40 in and a bottle of lucas. Driving oil pressure increased, but after i drove it and let it idle went back down and still makin that clunk noice, dangit. I guess ill try an oil pump first but if that doesnt solve it, the engines just gotta last another 2 or 3 months till winters over so i can get the van out. Then i think ill pull the engine and rebuild it. I want to spend the least amount of money possible, i found a rebuild kit with seals and piston heads for $180. I want to make it bone stock though as far as cam, what is the numbers for a stock cam?? unless a bigger one will not hurt gas mileage?? I want to rebuild it and be able to get the best mileage possible. And im sure a rebuild will give me alot more power anyways than what i have now. The only upgrade i wanna do is the gear drive timing thing. I love that whining sound and they are only like $85, so ill put one of them in, unless its a bad idea.

Any tips on a rebuild would be awesome thanks, Adam

 

[4xcrazy]

My opinion, that 15/40 is still some pretty thin oil, i ran it in a car once, only because i got it for free, the car had well over 100k miles on it, and within a couple thou miles, it wiped out the cam. Guessing the cleaner oil broke all the dirt deposits loose and ran all the crap through the engine.

I never run that stuff even though alot of guys on here swear by it.

again, just my opinion, that oil was designed for Diesels, leave it for the Diesels. If it is such a good oil, i wonder why the dealerships don't send their new cars out with it in them, even the higher end sports cars. They usually run a good quality synthetic.

By running a thicker oil i would try 20/50 wt, stay away from Quaker State. I ran that for awhile cause i was told it keeps the motor quiet, lifters and such, which it DID, but it also burns and leaves carbon deposits throughout the engine.

Just saw you're in Michigan, ya may want to wait till alittle warmer weather though th run a 20/50 wt oil, may have a rough time starting with that thick of an oil at those real cold temps. Maybe run a straight 30wt. or 40wt.

 

[Deuling]

Idk i dont think its the oil causing the issue though. I should be able to run whatever i would think and not have that noise. Plus i put a bottle of lucas oil stop leak crap, idk i thought maybe it would seal something up, but that stuff was soo thick it took like 5 min to get down the funnel. I put one quart in so that should have made it thicker.

 

[76zimmer]

It sounds like a rod, maybe a main that's bad, if its a low end knock. Are you sure its not a lifter tick, or a fule pump pushrod? Do you have a mechanics stethoscope?
If thats an 85 engine in there it needs some cam additive like CompCams cam breakin lube....the oils now don't have the zinc and phosphorus that is needed by a flat tappet cam. So if you want to save the cam add something specific for flat tappet cam protection.
Doesn't matter if you use 5/30, Rotella-15/40, or 20/50, they don't have those properties in ithem anymore. Although the thicker oil should increase oil pressure slightly.
Your running on borrowed time here, but just take it easy on the engine, and let it warm up some before driving it. It might make it 20 miles, it might make it 20,000 miles, just keep your idle high enough to provide 15-20psi at all times, and change your oil and filter every couple thou til you can throw that engine away....its just a boat anchor anyway...

 

[Fordum]

You can run 20/50 in pure synthetic. It will pour and circulate fine when regular oil will barely pour out of the bottle in cold weather.
I like Amsoil, but most any one should work. Just stay away from the blends in that weather.
Everything I have put the synthetic in, has gotten better oil pressure, especially when warmed up.
Even if the synthetic was the same weight.

Problem is, do you want to put that much money in that engine??

 

[Deuling]

So i shouldnt rebuild it?? I kinda like the idea of a smaller engine for mileage purposes. Im not like most guys on here. I dont want a ton of power, just enough to have some fun at the dunes, but have a nice daily driver that doesnt kill my wallet.

 

[Deuling]

Problem is, do you want to put that much money in that engine??

Idk do you think its worth it?? Im not looking for super performance. Mostly a daily driver with enough balls to make it up the sand dunes. I want it basically bone stock as far as internals on the engine. Just a nice driving truck.

 

[Fordum]

Slight misunderstanding. I meant the price of the synthetic oil, not a rebuild.

As for a rebuild, if you like the engine size, then stick with it. But the only way you are going to be able to tell about rebuilding the one you have, is by at least pulling the heads and miking the bores.
If they are too egg shaped or worn, a rebuilt one might be a better idea.

 

[Deuling]

Slight misunderstanding. I meant the price of the synthetic oil, not a rebuild.

As for a rebuild, if you like the engine size, then stick with it. But the only way you are going to be able to tell about rebuilding the one you have, is by at least pulling the heads and miking the bores.
If they are too egg shaped or worn, a rebuilt one might be a better idea.

Lol oh yah no prob with expensive oil haha.

Yah idk, if its a good engine then i will stick with it. And yah i would check it out first so i dont rebuild a junk block. I just dont know exactly what i should get as far as parts to keep it simple. And what are pros/cons of the timing gears instead of the chain drive?? I like that sound, but would it take alot more parts to do/ would it hurt mileage.. Basically i want rebuild info for what i wanna do, what should i get, and to keep price low.

 

[Fordum]

Not "up" on the 305, didn't even know that timing gears were a option on that engine.
Both gears and chains will do the job. A gearset will usually outlast a chain, and stay accurate longer.
No chain stretch after high mileage.

As for gas mileage, that noise you hear is energy being taken from the engine that is not producing torque and driving you down the road.
So theoretically, gas mileage should be less with gears than chain due to more friction.
But, I'm not sure if its noticeable.
On the other hand, don't forget that there is a reason most car-makers have gone to belts over chains.
Belts drain off less horsepower than chains, and chains less than gears.

 

[Deuling]

But, I'm not sure if its noticeable.
On the other hand, don't forget that there is a reason most car-makers have gone to belts over chains.
Belts drain off less horsepower than chains, and chains less than gears.

Belts seem like they would stretch/slip/break the most to me idk.
I just love that gear whine, i think its the coolest sound haha.
And yah summit has a 305 kit for $86

 

[shovelbill80]

i really liked the 305 in my '85, worked fine.....till i wiped out the cam at 126K.
the truck i have now has about a seconds worth of rod knock at cold startup and my valve seals are shot, 170K on the clock. runs good otherwise after the good tune up and exhaust i just did. MPG difference? too early to tell.....
i'm researching a new motor now though. one thing i do know is i'm going with a "mild" roller motor with better heads.

that intake setup you have would better suit a 350 anyway....might want to look into a more "modern" 350 shortblock someone has laying around or a complete donor TBI truck (be good on the dune too i think) too.

a double row chain is plenty....gear drives are generally prone to parasitic loss .....and in the new twin cam Harleys, they have too much runout on the crank (pinion shaft) to run gear drive cams. everything has to be trued and balanced. i'm not sure about how gear drives actually effect our type motors though (lash and such), just food for thought. personally i don't like that whirring sound.

 

[Fordum]

Belts seem like they would stretch/slip/break the most to me

They do. Thats why you have to have them changed every so many thousand miles.
Actually, due to the fibers in the belt, plus the way the tensioners are used, stretching is not much of a problem.
And they are cog belts, so they don't usually slip.
But, they do break. And in a lot of engines, it destroys the engine. Thats why the owner's manual says they must be changed every so often.

 

[Deuling]

i really liked the 305 in my '85, worked fine.....till i wiped out the cam at 126K.
the truck i have now has about a seconds worth of rod knock at cold startup and my valve seals are shot, 170K on the clock. runs good otherwise after the good tune up i just did. MPG difference? too early to tell.....
i'm researching a new motor now though. one thing i do know is i'm going with a roller motor and better heads.

that intake setup you have would better suit a 350 anyway....might want to look into a more "modern" 350 shortblock someone has laying around or a complete donor TBI truck (be good on the dune too i think).

Im lookin to ditch the intake mani for a more daily driver setup. And if i can find a smaller carb. That thing is rated for 1500-6000 rpms or something lol. I need one thats rated for idle and up haha.

What do you mean by the roller motor??

 

[Deuling]

They do. Thats why you have to have them changed every so many thousand miles.
Actually, due to the fibers in the belt, plus the way the tensioners are used, stretching is not much of a problem.
And they are cog belts, so they don't usually slip.
But, they do break. And in a lot of engines, it destroys the engine. Thats why the owner's manual says they must be changed every so often.

Well eff that noise haha. I wanna put it in and never worry about it lol

 

[shovelbill80]

Im lookin to ditch the intake mani for a more daily driver setup. And if i can find a smaller carb. That thing is rated for 1500-6000 rpms or something lol. I need one thats rated for idle and up haha.

What do you mean by the roller motor??

i know about that intake
a roller camshaft is what i meant by roller motor.....better lifter/cam setup. i like roller rockers too, less side loading on the valve and guide. the lighter and stronger the valve train the better. pick parts that work well as a complete system.. i'm a srong believer in balancing and blueprinting all rotating components as well.

 

[Deuling]

i know about that intake
a roller camshaft is what i meant by roller motor.....better lifter/cam setup. i like roller rockers too, less side loading on the valve and guide. the lighter and stronger the valve train the better. pick parts that work well as a complete system.. i'm a srong believer in balancing and blueprinting all rotating components as well.

Do you think you would mind putting up some links to a good rebuild setup for my 305?? And at the cheapest price you think is still good lol. And im not planning on different heads or anything. Aluminums would be sweet, but are much to pricey.

 

[JPOutfitters]

And in a lot of engines, it destroys the engine. Thats why the owner's manual says they must be changed every so often.

Mostly because they are "interference" motors where when the timing slips/breaks the piston slaps valves!

 

[shovelbill80]

Do you think you would mind putting up some links to a good rebuild setup for my 305?? And at the cheapest price you think is still good lol. And im not planning on different heads or anything. Aluminums would be sweet, but are much to pricey.

i really haven't been looking at rebuilding kits, but if i run across anything i'll post it up.....i completely understand the want for "cheap", but i prefer to wait and save than "cheap out" on something as important as an engine build or rebuild. if i can upgrade something after it fails then that' what i'll always choose to do......when possible. a full, proper rebuild will cost as much as a good new short block anyway.....more if you don't do the due diligence

 

[Deuling]

i really haven't been looking at rebuilding kits, but if i run across anything i'll post it up.....i completely understand the want for "cheap", but i prefer to wait and save than "cheap out" on something as important as an engine build or rebuild. if i can upgrade something after it fails then that' what i'll always choose to do......when possible. a full, proper rebuild will cost as much as a good new short block anyway.....more if you don't do the due diligence

But if a stock motor goes 200000 miles, why not keep it that way?? Wouldnt a "cheap rebuild" be better than what ive got now?