40 hour then rebuild dual HP500 advice sought
08-02-2015, 04:35 PM
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40 hour then rebuild dual HP500 advice sought
Smart enough to know I dont know.
Not smart enough to not waterski and tube behind 34ft 5 ton Scarab.
So likely have brought alot of this on myself.
Last time they dynoed, came in around 570 each.
Rebuilt both after dropping a valve when trialing some 28p screws.
After about 40 hrs of mixed running ( quite a bit of WOT during launch skiers etc)
Both engines have run bearings and cranks subsequently failed crack testing.
Blocks back in having mains bored / honed.
No intention of chasing higher out put with these engines in future, well not with this Excel hull.
Any suggestions way forward on cranks?
Like the compstar price, first headed towards the dragon slayers but may be overkill in reality.
Bearing clearances?
Had both engines rebuilt by local machinist, later informed he had no experience with BBC.
Thats all cool, my mistake.
Couldnt get him to agree with blanking off oil chk valve so was running with that and HV pump.
He not so clear on the bearing clearances also.
Yeah so i was a dumbass, trying to fix that.
Just want to get it right this time and maybe learn a bit more respect for the engines when running.
My cook hasn't got over the cost of first rebuild so need get this one correct so can have hot meals again, and maybe she will talk to me somewhere other than the hallway.
The blocks are Gen 6.
Other than the normal Carbed HP 500 bits,
Dart Pro one 310s, Iconel valves etc.
Scorpion endurance Roller rockers and followers.
SRP 4.530 pistons, Compstar 6.385 H rods.
The last cranks were scat or eagle I believe, 4" stroke.
Appreciate any suggestions, mainly on the engines if possible.
cheers
dave
Not smart enough to not waterski and tube behind 34ft 5 ton Scarab.
So likely have brought alot of this on myself.
Last time they dynoed, came in around 570 each.
Rebuilt both after dropping a valve when trialing some 28p screws.
After about 40 hrs of mixed running ( quite a bit of WOT during launch skiers etc)
Both engines have run bearings and cranks subsequently failed crack testing.
Blocks back in having mains bored / honed.
No intention of chasing higher out put with these engines in future, well not with this Excel hull.
Any suggestions way forward on cranks?
Like the compstar price, first headed towards the dragon slayers but may be overkill in reality.
Bearing clearances?
Had both engines rebuilt by local machinist, later informed he had no experience with BBC.
Thats all cool, my mistake.
Couldnt get him to agree with blanking off oil chk valve so was running with that and HV pump.
He not so clear on the bearing clearances also.
Yeah so i was a dumbass, trying to fix that.
Just want to get it right this time and maybe learn a bit more respect for the engines when running.
My cook hasn't got over the cost of first rebuild so need get this one correct so can have hot meals again, and maybe she will talk to me somewhere other than the hallway.
The blocks are Gen 6.
Other than the normal Carbed HP 500 bits,
Dart Pro one 310s, Iconel valves etc.
Scorpion endurance Roller rockers and followers.
SRP 4.530 pistons, Compstar 6.385 H rods.
The last cranks were scat or eagle I believe, 4" stroke.
Appreciate any suggestions, mainly on the engines if possible.
cheers
dave
08-03-2015, 03:55 AM
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Is the oil pump higher volume than stock with the stock lines? Sometimes that will cause the pump to dump excess pressure back into the pan and cause cavitation so that you're sucking a good deal of air through the oil system regardless of #30 bypass valve.
08-03-2015, 05:24 AM
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my buddys been running 80+ psi oil pressure for years on that system with no issues....
I am a fan of bigger clearances and more oil pressure.... my rods are .0025-.0026, mains are .0030-.0034 and rear is .0038 I run Melling select with 80PSI cold after 5 miles of full throttle run I see 30-35 at idle and 70 running hot oil, been a proven recipe for me so I stick with it, I built a set once with less clearance and wiped bearings, if you run tight clearances you MUST run a thinner oil... I like 20-50.... hence loose clearances...
I am a fan of bigger clearances and more oil pressure.... my rods are .0025-.0026, mains are .0030-.0034 and rear is .0038 I run Melling select with 80PSI cold after 5 miles of full throttle run I see 30-35 at idle and 70 running hot oil, been a proven recipe for me so I stick with it, I built a set once with less clearance and wiped bearings, if you run tight clearances you MUST run a thinner oil... I like 20-50.... hence loose clearances...
08-03-2015, 12:35 PM
#5
my buddys been running 80+ psi oil pressure for years on that system with no issues....
I am a fan of bigger clearances and more oil pressure.... my rods are .0025-.0026, mains are .0030-.0034 and rear is .0038 I run Melling select with 80PSI cold after 5 miles of full throttle run I see 30-35 at idle and 70 running hot oil, been a proven recipe for me so I stick with it, I built a set once with less clearance and wiped bearings, if you run tight clearances you MUST run a thinner oil... I like 20-50.... hence loose clearances...
I am a fan of bigger clearances and more oil pressure.... my rods are .0025-.0026, mains are .0030-.0034 and rear is .0038 I run Melling select with 80PSI cold after 5 miles of full throttle run I see 30-35 at idle and 70 running hot oil, been a proven recipe for me so I stick with it, I built a set once with less clearance and wiped bearings, if you run tight clearances you MUST run a thinner oil... I like 20-50.... hence loose clearances...
JK! At least you are not running 100+ PSI like Borgie's motor. Man, that's a lot of oil pressure!
08-03-2015, 02:55 PM
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Yes, was a HV aftermarket pump in both.
What spring is in them is unknown at moment.
trying track down a pump dyno shop at moment.
When first assembled both engines held 60 psi at idle.
What spring is in them is unknown at moment.
trying track down a pump dyno shop at moment.
When first assembled both engines held 60 psi at idle.
08-03-2015, 03:08 PM
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Blocks are in at performance engine shop to assess blocks for mains boring or honing.
Checking wrist pins as well as the rods have seen two rebuilds, third with this current one.
Likely going with the Compstar cranks. nothing to the contrary asking around, for applications in this HP range.
Checking wrist pins as well as the rods have seen two rebuilds, third with this current one.
Likely going with the Compstar cranks. nothing to the contrary asking around, for applications in this HP range.
08-03-2015, 03:15 PM
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New 4 inch oil coolers being priced now, from local company that supplies our big River jet boating community.
Oil temperatures would often reach 240, engines never run for more than minute wot.
Any thoughts on what thermostat should be run in the oil filter block?
Looking forward to getting salt water away from the Dart ally heads and inlet manifold.
Have the Mercury Gill type coolers, flushing and pressure testing over next few days before go to ceramic powder coating. The manifolds will retain raw water cooling at this stage, read about the coolant boiling in manifolds before thermostat opens on block?
Oil temperatures would often reach 240, engines never run for more than minute wot.
Any thoughts on what thermostat should be run in the oil filter block?
Looking forward to getting salt water away from the Dart ally heads and inlet manifold.
Have the Mercury Gill type coolers, flushing and pressure testing over next few days before go to ceramic powder coating. The manifolds will retain raw water cooling at this stage, read about the coolant boiling in manifolds before thermostat opens on block?
