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Discussion Starter #1 (Edited)
Do 455 olds with Berkley jets have problems? I just spent the day with Stardust blowing thru 40 gallons of fuel with lots and lots of full throttle. No milk shake in my crankcase. Tell me why people are doing all kinds of "enginering" to control pressure thru the engine. I understand the theory behind too much pressure and gaskets and such, but my 1970 Olds. 455 with nothing added between the Berkley and the engine seems very happy. The temp. was always low...too low, like 86 F, so that concerns me. I would like to get the temp to normal....gate valve???? Normal temp. = better fuel economy...right? I need to get a pressure guage on the engine cooling system. I have read about low pressure causing hot spots in the engine. Maybe that would explain burnt exhaust valves in the past...I am looking at past machine work done on the engine.

What are your experiences?
 

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455's are known for their oiling problems at high RPM. Never really heard of water pressure issues. With that said, it's not a good idea to push a bunch of psi through the cooling system but that can be said for any brand of motor. If you want more engine temp you can start messing with gate valves and try to find the sweet spot or there is a thermostat kit available for the 455.
 

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Do 455 olds with Berkley jets have problems? I just spent the day with Stardust blowing thru 40 gallons of fuel with lots and lots of full throttle. No milk shake in my crankcase. Tell me why people are doing all kinds of "enginering" to control pressure thru the engine. I understand the theory behind too much pressure and gaskets and such, but my 1970 Olds. 455 with nothing added between the Berkley and the engine seems very happy. The temp. was always low...too low, like 86 F, so that concerns me. I would like to get the temp to normal....gate valve???? Normal temp. = better fuel economy...right? I need to get a pressure guage on the engine cooling system. I have read about low pressure causing hot spots in the engine. Maybe that would explain burnt exhaust valves in the past...I am looking at past machine work done on the engine.

What are your experiences?
Olds motors don't neccesarily have any more propensity to water intrusion issues than others when sealed properly (primarily intakes and timing covers) , pressure controls and pressure reliefs can be a benefit to just about any marine engine application if nothing more than a failsafe mechanism to help control potential spikes, Jet boats without the thermostat systems that some folks desire and use simply run cold as far as water temp gauge readings go, water temps in those applications however are typically inaccurate , probably of greater importance to monitor oil temperature
 

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Tom summed it up nicely. Marine VS Car application is totally different. You are dealing with an open cooling system in a marine environment. Totally different set of circumstances. Don't get hung up on water temp. Are you running logs or headers for exhaust? If logs and they are plumbed properly you already have a restriction in the cooling system that is keeping you from over pressuring the engine.
 

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And the fix is..Mondello Marine head gaskets. The water passages in the head gasket are way smaller than normal...It keeps the water in the block a little longer to build a little heat...Slowing down the water flow will reduce the pressure at the water passages in the intake. I was told by a tech at mondello that olds motor tend to cool the 4 center cylinder more that the outer 4...not a problem in a car because the water circulates..Cold cylinders and car spec piston clearance could also cause a the skirts to skuff...
 

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And the fix is..Mondello Marine head gaskets. The water passages in the head gasket are way smaller than normal...It keeps the water in the block a little longer to build a little heat...Slowing down the water flow will reduce the pressure at the water passages in the intake. I was told by a tech at mondello that olds motor tend to cool the 4 center cylinder more that the outer 4...not a problem in a car because the water circulates..Cold cylinders and car spec piston clearance could also cause a the skirts to skuff...
I was just passing through looking for something else and saw this thread. The above answer is accurate. Not all Old's jet packages were the same, but they are old, like me. The Berkeley "Packajet" was the best engineered of all, but ugly and expensive compared to their SoCal competitors. The "Packajet" had a recirculating pump just like the cars and a thermostat to maintain 160 degrees (just below salt water dissociation 180 +). The Oldsmobile engineering staff did not like our crude direct water entry after the exhaust manifold passages which depending on ambient water temp could be very cold. This was hard on pistons, valve guides etc., but warranty rates were modest so the engineering staff allowed us to continue. For Ford we had to do some real testing but if we could maintain 40# block pressure at WOT we passed. We could not reach 40# with the available vane pumps for V-Drive boats so we could not build Fords without re-circ pumps. It was a small market so we just did not build them. Boat builders would buy the jet motors and convert themselves. Chevy's were no problem much like Olds. The fact this motor is still alive is a testament to their toughness. We built a 410 hp version with a Mondello oil pump and 10 Qt pan and solved the oiling problem. The big problem was in a jet you run 3300-4200 RPM which is equivalent to 100 MPH all day and the stock pan was designed to clear the trans axle of front wheel drive Toranado's so there was no clearance between the pan and crank and "roping" kept all the oil above the crank. We tried to get Olds to put the old pre-Toranado pans on but since all the engines came off the same production line they left it up to us, hence the 410. Restricting flow will raise the temp but lower the pressure and the pressure keeps the water molecules on the surface eliminating "hot spots".
 

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Just out of curiosity , do you remember any of the other specs on the 410HP motor like C.Ratio and cam specs? I assume the motors probably had Ka heads?
 

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Just out of curiosity , do you remember any of the other specs on the 410HP motor like C.Ratio and cam specs? I assume the motors probably had Ka heads?
The 410 was a stock high compression production engine (390 hp) - no cam change - and 9.5:1 compression. It had the Mondello oil pump conversion, Dooley 10 Qt. pan and an Edelbrock Tarantula manifold with a 800 cfm Holley. Old's also built a 8:1 455 cu. in. version @ 300 hp and when they dropped the 390 HP engine we stopped building Old's engines. We briefly tried marinizing the 355 cu.in. diesel when it came out for commercial boats but it was a very weak engine internally and power wise. What we were proud about were the exhaust manifolds designed and produced by Paragon for us. We eventually bought the patterns and later most of Paragons machine shop. Still the best log Old's manifold. I don't know the head classification we were never allowed to alter what came off the assembly line where they built 15,000 per day. I once asked them to build our engines without the water pump which we did not use. I received a quote that it would cost us $8.00 for them to remove the pump. We sold the pumps to a re-builder instead. We tried a cam, rocker arm and spring combo Joe Mondello developed, but it would void the Old's warranty Even though it made 425 HP we passed on production do to too small a market. Joe did well with it.
 

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The 410 was a stock high compression production engine (390 hp) - no cam change - and 9.5:1 compression. It had the Mondello oil pump conversion, Dooley 10 Qt. pan and an Edelbrock Tarantula manifold with a 800 cfm Holley. Old's also built a 8:1 455 cu. in. version @ 300 hp and when they dropped the 390 HP engine we stopped building Old's engines. We briefly tried marinizing the 355 cu.in. diesel when it came out for commercial boats but it was a very weak engine internally and power wise. What we were proud about were the exhaust manifolds designed and produced by Paragon for us. We eventually bought the patterns and later most of Paragons machine shop. Still the best log Old's manifold. I don't know the head classification we were never allowed to alter what came off the assembly line where they built 15,000 per day. I once asked them to build our engines without the water pump which we did not use. I received a quote that it would cost us $8.00 for them to remove the pump. We sold the pumps to a re-builder instead. We tried a cam, rocker arm and spring combo Joe Mondello developed, but it would void the Old's warranty Even though it made 425 HP we passed on production do to too small a market. Joe did well with it.
Did you mean Elelbrock Torker Manifold ? Mondello sold alot of those. :)Unsure
 

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Did you mean Elelbrock Torker Manifold ? Mondello sold alot of those. :)Unsure
Torker came later in production and was a simpler and better manifold but by then the Old's was gone from our inventory. We tested all available manifolds - even the Offy dual plane - (no comment). We did the same for the Harman 440 hp, 454 Chevy (Sig Erson and/or Iskenderian cam), springs, retainers, roller rockers, 800 Holley and Dooley 10 Qt. pan based on the rectangular port marine (405 advertised hp 454 Chevy but we never had one dyno over 390). A great engine: 7/16 rod bolts, forged steel crank and 4 bolt main cap block. We took over Kieth Black's dyno for a week and tested every intake manifold made. The overall winner - the stock aluminum Chevy open plenum/high rise manifold the engine came with. John Petrac the head of GM's OEM sales bet me an all Aluminum Reynolds Can-Am engine that our 440 would not make more than their factory race 425 HP 454. We made 438 hp on their electric generator dyno (the most accurate dyno's since they do not rely on water). I never got the Reynolds - oh well.

Two more things since I'm on a roll. #1. A good friend at the river had a 330 HP,(small port, 2 bolt block, 3/8" rod bolt smog motor) - the standard Chevy marine motor asked me to try a similar package on that engine. That engine had exhaust valve rotators so we had to make spacers and 3/8" rocker arm studs which were considered pretty weak. The intake manifold from the 405 rectangular engine did not fit the round port heads at all but we ran it anyway since we had time left on the dyno - 403 HP. #2: At the time we were experimenting with turbos. We built some 460 Fords, as delivered, at varying boosts up to 7# but they were not reliable (piston failure, cast aluminum). The 405 Chevy production engines had forged TRW pistons, 8.75:1 compression, good rods, great blocks and good heads. We tested at 8#(twin turbo) no inter-cooler - 700HP. And then the insurance company went ballistic. We were selling the 405 engines to Gale Banks for his conversions, and we all know how well that has worked out.
 
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