Something Trickey

[gmcgruther]

Ok Guy's and Gals, My brother-in-law owns a 1987 Baja Islander with a 350 Chevrolet:eek:. The 350 is not the stock engine. The boat orginally came with a 305 Chevy:nonod:. This is what has been done to the engine, 1986 350 block,rods, and crank. The pistons are Speed-Pro Forged .125 dome and teflon coated pistons, stock bore size:eek:. The cylinder heads are the center bolt valve cover heads before GM went to a different intake alignment:cool:. New cam bearings, New Summit retro thumper cam, 316 Advance duration, 260 @ .050 duration, .504 to .508 lift:thumbsup:, High volume oil pump, Old Style weiand X-celerator intake(looks like a Victor-JR), Eldenbrock 750 CFM Carberator, Alfa 1 drive with a 14 1/2" 17 pitch medium cup prop. He replaced water cooled exhaust manifolds with new ones. Runs damn good in the begining:thumbsup: but after 10 minutes under load, the oil gets so damn hot it damn near boils:eek:! The Temperature gauge reads 180* F. after 10 minutes under load! It screws up the Valve lash badly:nonod:. I have built engines for 20+ years and I'm stumped on this one. I did not build this engine:nonod:. My brother-in-law did:eek:. I was thinking maybe the Machine shop installed a couple of the cam bearing wrong (Misaligned the hole):(. He has tried everything to get the oil from boiling, but no luck:(. Does anyone have any insight one this:thumbsup:?

[gmcgruther]

Come on guy's I know someone know's something! I have been on here way to long to know you guy's. Please help. This is not my Boat, I'm visiting my family here in michigan for two weeks and he would like to get his boat on the water for family.

[Euroski]

I don't think 180 is too hot for the oil. What grade(wt) oil is being used? What temp does the engine run at? Just a suggestion as I been away from V8's a long time...

[gmcgruther]

I don't think 180 is too hot for the oil. What grade(wt) oil is being used? What temp does the engine run at? Just a suggestion as I been away from V8's a long time...

the oil boils when engine temp hits 180*F.(Water temp). 10W30 Castrol synthec full synthetic , this engine has me baffled, after 20+yrs in automechanics and almost 7 yrs in automachining.

[racer]

How much load/rpm, does it have an oil cooler or just a power steering cooler?

[Superbender]

What t stat does he have in it?drive, i'm assuming its a mercruiser that has a new pump.water temp seems too high unless its fresh watercooled,does the t stat hsg have those blow off balls sometimes those springs get jammed up,also you may want to check the coolers to see if they have debris in them.

[luv2gofast]

You say the valve lash gets screwed up??? You mean the lash goes up? If that is the case you better check the oil and filter for metal. It sounds like the cam/lifters is going away. You could also check the lift with a dial indicator or even calipers to see if you have a lobe going flat.

[DavidW]

What does the oil pressure look like.

[gmcgruther]

The oil pressure at cruzing speed is 40 to 50 psi and at ideal 25 to 30psi, The out drive is a mercruzier Alpha 1 unit. The oil he has changed several times do to over heatin the oil and it comes out negative for metal particals, It breaks the oil down to the point of no viscosity and that is whats screwing up the valve lash, the valve lash returns to normal when she cools down. The boat has a deep haul not deep V! I told you all this engine is throwin me for a loop and I personal can't figure it out.

[gmcgruther]

How much load/rpm, does it have an oil cooler or just a power steering cooler?

At cruzin speed it's at 5600 to 5800rpm the cam is good for 1500 to 6200rpm. It has a the orginal mercruzier power steering cooler as a oil cooler.

[racer]

Power steering cooler is not very big, you may need to look into a large thermostatically controled cooler. You can get these with a seperate area for the steering. I have one on a 565 and it works great. Assuming everything internally is good.

[service860]

If it has a large capacity oil pan and the water circulating pump is bad(even if it is new lol) i have seen the oil overheat before the coolant like u r describing.

[flabum1017]

I agree with the cooler. The small blocks don't come with engine oil coolers from the factory and when you beef them up and spin them harder, you'll need a good, big cooler. The water temps are a bit highm but not overheating. Generally 160 - 170 is the norm. I'd be checking the sea pump and hose in the gimball. If a cam bearing or something was misaligned, you be seeing metal by now.

[flabum1017]

Another thought, that 1986 block might have some rust built up in it. we had a big block years ago that did the same thing. It had a layer of rust sitting at the bottom of the water jacket. It was so deep, you could pull the drain plugs and no water would come out even after trying to clear it.... After we cleaned the water jackets out, it ran great.....

[gmcgruther]

Thank you guy's I will suggest all that, and tell him he has some work to do:eek:! Thank God he bought a good runnin CheckMate 20':thumbsup:. I'm trying to talk him in a different prop but he likes it the way it is on the checkmate:(!