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View Full Version : boat cleaned up today,engine upgrading plan.



fasttrucker
11-02-2002, 04:01 PM
well spent today cleaning up the 28zx.i removed the snap in carpeting,for cleaning next week.found a missing earing,that my wife lost. :rolleyes: i bought a full cover from boatcoversdirect.com it was $300 not $1000. that the local canvas shop wanted. :p it fits pretty good.i then washed the donzi it was 45 degrees out so that wasnt a lot of fun. :( we are pulling the motor next week.iam missing a lot of oil so we are going to drain it down to see if its the rings/valves.so ive decided to do a head valve job installing larger valves,springs,retainers,keepers.roller rockers+pushers.hdy.roller cam "custom grind" edelbrock victor jr. manifold w/hp750 holley carb. this should put me at 520-540 hp.i then try a bravo-1 26in prop.? :confused: :cool:

Bryan Tuvell 33ZX
11-02-2002, 05:57 PM
FastTruck....
Glad to hear your doing good.
I am starting to think you should have bought an older ZX for a total engine rebuild! :rolleyes:
That new stock 502 should be fine, low oil? :(
A stock 502 can be a quart low after a very hard day and say 20 hours on the oil.
How low are we talking here????

Prop, I can push a 26P B1 to 4700, a labbed one to 5000, if you do all that you will need more than a 26P B1...
Bryan

fasttrucker
11-02-2002, 06:23 PM
well,couple weeks ago 1/2 qt, then 1 1/2,this morning i noticed below the add mark.so not really sure.what do u think the picth should be? 28?

Bryan Tuvell 33ZX
11-02-2002, 07:06 PM
Truck, that can be normal oil use in a 502.
How many hours since the last change?
I start to use some oil at 20 hours and we change EVERY 20 to 25 hours.
What oil are you using???

I would be skeptical on pulling the motor to look for a problem over this, especially on a one season 502, she is still stock mechanically right?
B

Greg Maier
11-02-2002, 08:41 PM
Bill,
I have read that a 502 will burn more oil than you would expect due to the forged aluminum pistons. I can burn up to a quart in a couple of hard days of running. Also, when I spoke to you, you said that you are using 30 weight oil. That could also have something to do with you burning a lot of oil. I would expect the lighter oil has an easier time blowing by the piston rings. The 502 calls for 40 weight oil in normal summertime temps. By the way, I really enjoyed running with you a last weekend. Your 28ZX really moves.

harbormaster
11-02-2002, 09:52 PM
I had heard once that the 454 was designed to burn some oil. The oil lubrcated the valve guides and was burned afterwards.

fasttrucker
11-03-2002, 06:29 AM
boat is a 98.it had 120hrs on it when i bought it.last owner said he changed the oil one time.it looked ok on the dip stick so i put about 5 to 10 hrs on it,then did a oil change when i did my tune-up,installed stainless marine,ect.after i ran last week w/greg i lost 2?/3? qt.s???so i dont think thats normal,since mech is pulling motor for the cam,ect he might as well check it out.will keep u updated. wink

Sam
11-03-2002, 06:50 AM
For what it worth I have twin 454 Horizons (215 hrs) in my go slow boat. On long cruises I always burn some oil. When I asked Merc about it they said it's the nature of the beast.

Sam

Shanghied Again
11-03-2002, 07:53 AM
Bill with 540hp you are going to more in the 30pitch area, test a 28 pitch first, My buddys is at 580hp and is running a 32 pitch in his 28ZX
Oh by the way 502s love to burn oil.

BigGrizzly
11-03-2002, 06:33 PM
Bn't know how hardyou run her but a tock 502 run at 3800 burns oil like crazy, My own boat doesn't because it was done from the new block and not stock pistons or rings I have real valve seals and other stuff.

Bad-Tat
11-03-2002, 06:44 PM
My owners manual say the 502 will burn 1 qt for every 1-5hrs of operation at high rpm. Mine doesn't burn that much running on AMSOIL.