SoCal Jet Boats
Tech Talk => Engine Mechanical / Electrical => Topic started by: Stevecat on July 28, 2009, 12:31:50 PM
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Hi. I am starting to talk myself into buying '73 Glastron boat with an Olds in it. The seller says that the Olds 455 is probably the original. Block is a '73 casting is F. Heads are G. He thinks it has a marine/rv/performance cam but no specs on it. He replaced stock rockers with Mondello (sp?) rollers. Eldebrock performer intake w/ 750-1406 carb. Logs were upgraded to 4". HEI MSD ignition.
I would be using the boat for cruising and towing skiers and water toys. Not wanting to go over 50mph.
I am aware of all the "issues" with Olds and oiling. I have an "extra" 455 hanger queen from out of a '74 Laveycraft. I'm just not that into tearing apart motors nor becoming an expert on Olds.
My question is: since nothing is a sure bet and we are talking about 30 year old metal, I understand all the risks. But if I use the boat like it was designed for in the 70's instead of trying to rev it over 5k, is this motor combo likely to be OK for me? What additional questions can I ask the seller about the motor?
Thanks for your help!
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Not so much an Olds expert but...
Find out if he knows if the engine has been overhauled, and how long ago.
Find out how long it has been setting unused.
Find out if it has been serviced recently or at all. (copies of receipts)
The engine block being 30 years old doesn't make as much difference as much as how it was maintained in that time.
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My float is a 73 and I have no reason to believe the motor has ever been opened. The hour meter broke over 10 years ago with 463 hours on it. Starts and runs like a champ. Compression is still good but does use some oil. Probably no more than 225 hp though and that sux. Run it until you can't, what do you have to lose?
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Do a compression check, check for water in the oil, and leaks, if it passes those, buy it and run it til it/IF it breaks!
I wouldn't get into block castings, etc, on the Olds. Only a couple real hot numbers in there, and I don't think any of them were 455's. (Been awhile, and memory is fuzzy at best on that). There were some pretty good heads, but again, I doubt very seriously many of them woulda found their way into a boat.
Many people have run the Olds for decades with no issues, some are even active members on this site! For a cruiser as you describe, sounds just fine to me. The majority of the rest of us are, for lack of a better term, self-motivated idiots that don't really know when to leave well enough alone! :screwy:
(https://www.socaljetboats.com/proxy.php?request=http%3A%2F%2Fi673.photobucket.com%2Falbums%2Fvv95%2FIrrebel%2FWeiand1.jpg&hash=7839e9092ee82af086dd6b6a29c1ad398e12b794)
Ray
BTW, the oiling issues are really only a problem with sustained useage above say 5000 or 5500 rpm. (Has much in common with it's Pontiac and Buick brethren). You'll probably find it's set up with the impeller, hp curves, etc to max out around 4500 or so and won't go no further.
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There is absolutely nothing wrong with an Oldsmobile 455, especially in a cruiser, my dads Spectra 20 had an Olds and was a good runner and I only had a hard time getting the exhaust system tight, the siamese center cylinders are a tad leak prone on old manifolds, found some used Glennwoods at a swap meet and they made all of the difference in the world.
As far as the oiling woes, they are easily kept under control, either by TLC while in use or by modifying the oil return holes and adding restrictors to keep some of the top end oil in check...A larger oil pan never hurts, even on a MOPAR, Ford Or Cheverolet.
I would not call the Olds bulletproof, but pretty tough. Berkeley built them to 390 HP and they ran 4600 RPM all day long.
I will however recomend synthetic oil and a really high quality oil filter (this also helps slow some of the oil flow)..The smaller the micron rating, the more filter media, the more restrictive... ;) (that's a secret, dont tell anyone :sly:) ;)
GT
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Listen to what Glenn's sayin'. He's right, but basically, the "problem" with all older BOP (Buick/Olds/Pontiac) engines is not necessarily a "problem" with the oiling system, it's more to do with drainback, cavitation of the oil pump and foaming around the pickup tube.
The oiling system, really, is fine as it is. Drainback is the primary issue. Limiting top end oil is one way to cure it, kinda, I don't agree with it, personally, but to each his own. Controlling and aiding drainback and adding a better pump pickup/pan combo, I beleive, is the better method on these engines, IMO.
Part of the reason they run so long (in miles) is because of the top end oiling engineering. Why mess with that?
But we're way ahead of ourselves, and you're building a mild cruiser so leave it as it is! IMHO. Bear in mind these 'gremlins' only rear their ugly head under long, sustained High RPM usage on these engines. Keep it under 5000 rpm, it'll live and run forever! Honestly, when I used to get asked about Poncho engines and where to get the most bang for the buck? Windage tray. Did a world of difference in those engines, from a durability standpoint. Second was deburring the lifter valley. You're gonna be fine with what you got!
But what do I know? I'm an old hot rodder! Boats is sumpin kinda new to me!
Ray