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Philip47
08-07-2002, 06:31 PM
How many hours should you be able to put on a moderatley built BB? Assumimg propper maintaince, oil changes @20 hrs and not running WOT all the time?

I ask because as I go through the expense of building a engine I am looking for a idea of how many hours I can get before freshening the engine.

I am building a fully machined, balanced and blueprinted 454, (bored and honed with a torque plate) Crane Hyd roller, forged pistons, Eagle H beam rods and 4340 forged crank, fresh valve job, springs,etc. Inconel and stainless valves.

Being assembled by a very good builder, taking time to fit the bearings properly etc. All parts are new with the exception of the bare block, bare heads, intake, oil pan, and roller rockers

RickR
08-07-2002, 07:02 PM
With my experience the first thing to go is the valve seats. On a flat tappet hydraulic cam engine I would do a leak down test around 500 hrs (and expect to do a valve job). A hyd roller should last longer.

My 1995 Gen V 454 w/500 hrs was in excellent shape when I tore it down last winter except for valve seats and cylinder wall damage due to a leaky riser gasket.

Bryan Tuvell 33ZX
08-07-2002, 07:20 PM
Great Topic:
I wonder what will go first in my stock 502 Mag???
Not to worried with the 5 year warranty and we do ALL fluids every 25 hours, but from what I have read exhaust manifolds won't make it 3 seasons! And the ZCare warranty clearly states it won't cover damage from them going bad etc. And Boot/Bellow at year 3.
So what will go first at 200 hours a season???
Bryan

Philip47
08-07-2002, 07:53 PM
I would be pleased with 500hrs, and per dollar spent need to see 500 hrs, my risers are Gill, not stainless but Gillvanized as they call it and should last 5 years.
Will post Dyno sheet when done

MR MAGOO
08-07-2002, 07:53 PM
Just last week, I sold my 28' Baja 280 with twin 330hp/454`s and Bravo drives. I bought it new in 1991 and it had 768 trouble free hours on it. I changed the oil EVERY 20 hrs or less. It ran just like the day I bought it and burned no oil whatsoever! I did run her pretty hard at times also!

Bryan Tuvell 33ZX
08-07-2002, 08:15 PM
I plan to redo my stock manifolds (when needed) with Mercs when the time comes since there is no performance gains on an exhaust upgrade only to a stock motor, cheaper too...

Over 700 hours, I would say you certainly got above average longevity.
Cool.....
Bryan

Rodger
08-07-2002, 10:19 PM
I built my turbocharged BBC in 1988. I used The original 330 HP block and converted it to 4 bolt mains & bored it 30 over, Chevy rods & forged crank, Merlin heads with Faria SS valves, TRW forged pistons, Speed Pro rings individually gapped per cylinder, TRW bearings, and a flat tappet cam with SS roller rocker arms. I have almost 1200 hours on it and shows no noticable deterioration in performance and doesn't use oil. I use a 14 qt. Gill oil pan and full flow the oil filter plus I use a separate filter for the oil going to the turbos. I have two oil coolers: one picks up water from the cooling system and the other one gets water from a pickup on the bottom of the hull from forward motion of the boat. I have an oil temp guage and let the oil get up to at least 160 degrees before I go over 2000 RPM. I also use synthetic oil.

MOP
08-12-2002, 10:17 PM
What are the thoughts on how high an RPM you can run on the BB's.

HyperDonzi
08-12-2002, 10:30 PM
not running wot all the time, how much time is to much at wot?

Lil Grizz
08-12-2002, 10:41 PM
I have the 7.4 mpi and limit my max RPM to the 4600-4800 range. A reliable source told me the BBC has some bad harmonics around 5000. I run up there quite often and after 2 years the engine still runs like the day i bought it. I leakdown and compression test it at least once a season and the thing still appears to be like a brand new engine. I run synthetic oil and never had any failures or issues whatsoever.

fasttrucker
08-13-2002, 11:45 AM
my stainless marine exhast system has a 5 yr warrenty.tony has a performance set up on one of his boats thats 14yrs old.ive gained speed+power for sure!but i also did k+n flame arester,sent my ecm comp. to az speed for reprograming and other tune-up stuff.so i cant say for sure my power grains are from my exhast system,iam thinking about a fresh water add on/performance heads"alum" +cam blue print=bal the lower end of motor.or procharger my 502.

fasttrucker
08-13-2002, 11:48 AM
i was told max rpm is 5400.if u do lower motor mods.iam just under 5000.with the new prop, bravo-1.

Lil Grizz
08-13-2002, 11:59 AM
What I meant by the harmonics thing was I was told not to stay in the 5000-5200 range, either go above it or stay below it.

fasttrucker
08-13-2002, 03:46 PM
dont know much about harmonics? did more reserch found that a 502 mpi rev-limiter should hit at 5050 rpm.so they are saying 5000 rpm trimmed out with light load is best. :rolleyes:

HyperDonzi
08-13-2002, 06:13 PM
how much time is to much at driving an engine at wot?

MR MAGOO
08-13-2002, 08:25 PM
I have a pair of 750 hp Hawk motors in my 38 Top Gun, they were built and propped for 5800 rpm.

Music to my ears :D although some neighbors want me hung this season eek!

BigGrizzly
08-13-2002, 10:02 PM
The origional stock motor in My Criterion had 600+ hours on it and its still going strong- its my spare now. Philip I assume you ment hours on a rebuilt engine not a brand new stock motor. If this is the case I have over 735 hours on my Corsican, which I built and bored myself with oil changes at 50 hour intervals. There is one catch --Its a closed cooling system.
You have learned well Lil Griz. The harmonics thing is a real thing. It really affects high HP engines worse. On the dyno my blown 502 really shakes at 5050-5075- you can't see it or feel it but the sensors show it real well . So I don't spend time at that Rpm. The answer to the next question is Yes my engine is completely balanced by one of the best shops.
Bryan, on the exhaust thing --stock motors do bebefit with after market exhaust systems. I have seen it on the dyno and in real life. Merc exhaust are one of the worst on the market. True gains may not be great, in your case 10- 25 Hp but fuel usage will be better. Your only problem is the salt enviorment your in. Cast iron will last longer than aluminum.

Randy

Randy

HyperDonzi
08-13-2002, 10:18 PM
i have somewhere in the neighborhood of 1200 hrs on a 4.3 sb

Philip47
08-14-2002, 07:22 AM
Big Grizzly,
Would a Fluid Dampner, (harmonic Balancer) help the vibration at that RPM?