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dpage
06-22-2001, 09:54 AM
2 years ago I bought a '76 jet boat with a Jacuuzi and an old 455.
The last time I took it to the lake in 2000 while running full out (~4000 rpm ~ 50 mph) I noticed the oil pressure dropped from ~40 to ~ 20 psi. I backed off immediately and at lower rpm it seemed to maintain pressure ok
Last year I found water in the oil.
Some guys on this forum told me about Mondello and I ordered the catalog and manual and found out about the oiling problem.
This spring I ordered Mondello's complete 8qt system, pulled the engine out and was going to install.
Cut the oil filter open just to check for any "bad stuff" and found substantial babbit material.
Tore the entire engine down and found 6 out of 8 rod bearings had worn into the copper. 4 or 5 of the rods on the crank end appear to have gotten so hot they have turned black/blue. ( I have some pics I could send if anyone is interested)
Mondello is recommending installing the R104 (I beleive) oil restictors-- anyway the more restricting inserts.
A friend of mine is a Chevy engine builder and is concerned that with the restrictors the top end won't get enough oil.
Finally, my questions:
1. Can anyone that has experience with the 455 help me understand if my friends concern is valid or if not why (either at high OR low rpm) assuming I install the restrictors, do some grinding on various passages as recommended by Mondello, use the Mondello 8 qt. system? Also should I use the restricted push rods? I have an Isky Cam (Y90A 6 08 270 HL HYD 691)
2. Is the wear on the bearings likely caused by the lack of oil to the rod bearings?
I want to hold cost down as much as possible while getting a fix that will last.
Any assistance would be appreciated.
Dennis

Eric
06-22-2001, 11:54 AM
Short answer: Listen to Mondello. Nobody knows the 455 as well.
I would also be concerned with the blued rods. If you are planning to reuse them have the rods resized and check the crank clearances very closely. I spun a rod bearing on a 455 once and came very close to spinning a main. The main was blue/black on the block and cap from heat as you described, and when I laid the new crank across the mains without the caps I could teeter-totter (technical term) the crank on the blued main. The heat had caused it to swell, nothing that couldn't be solved with a line hone though.
Eric

GL360
06-22-2001, 01:16 PM
Follow Mondello's advice and use the restrictors in the main saddles. I've used them and they work! Any serious Olds engine builder uses restrictors in the main saddles. Dave Smith Engineering (Corona, CA) is another good source for Olds advice.
As for water in the oil, you are probably putting too much (water)pressure to your engine unde full throttle. Use a bypass kit (www.hi-techperformance.com) and you'll keep the water out of your oil.
I like my Olds, but it definitely has some quirks. Use oil restrictors and a by-pass kit and you'll eliminate 95% of your problems.

montrone
06-22-2001, 01:40 PM
i have an 11 qutr oil pan on my olds,
would i still need the restrictors?
should i take off the J heads and put the C heads i bought on?

SuckMyWake
06-22-2001, 05:19 PM
dpage,
I have a 1976 Taylor with a 455 olds with a 'B' impeller. I run 40-50 psi of oil at 5000 rpm all day. The restrictors definitely do the trick. I only run a 6 quart pan and have had no problems.
Thanks,
-Todd
Montrone,
The C heads are the best, however, the real gains are in separating the exhaust ports from one big port for two cylinders and also filling the EGR passages with aluminum. Then porting extensively. Mondello "C" heads are worth 100HP over other factory castings. Also, the marine "K" castings are quite good.
If you have the time, port the C heads and put them on, you'll still get a pretty good HP increase.
-Todd

oldphart
06-24-2001, 09:53 AM
I had similar problems on a 455 went to restricters, 4 not 5 and 11 qt pan. had to clearance the sides of the rods too. thats a problem for Ols's. While I,m on this soap box heres a heads up for you OLDs guys. I wanted more performance for my Tahiti and being a Ford guy was going to pull that GM lump and install a 460. The local speed shop convinced me that with the addition of edelbrock heads, Mondello jet cam an bigger carb I'd be set. Bought the heads $1400.00, They had to have special rockers $170.00,
Special Head bolts $100.00,longer push rods $130.00, taller valve covers $110.00. Put her all together and she blowed up. Hydrauliced 2 cylinders bent 2 rods. Replaced the rods, reduced the pressure to manifolds, and surfaced manifolds put her all together and she blowed up. hydrauliced 3 cylinders bent 3 rods. This time called edelbrock, no help. Started checking everthing having to do with water and found that in 4 corners Edelbrock had drilled the water passages into the intake ports. Called Edelbrock they said we ported them too far. We explained we didnt port them only took them out of box and put em on. they picked them up at the speed shop and left us a new pair. Put her all together and she blowed up. Crank was broke from the other tramatic experiences. Tore it down installed new crank, Eagle rods Aries forged pistons, 11 qt oil pan & Pickup & put her together again she runs like a striped assed ape but the only thing olds is the block and I flinch every time I hit the gas. Just sign me; never another Olds!

W I P P
06-24-2001, 07:05 PM
I have an olds 455 the only thing I've done was a bassett 10q oil pan and windage tray runs 4600 rpm with edlo 750 cfm carb and AA impeller. But I burnt rods or mains out of 3 engines before the big pan and tray, $100 for the first 2 engines out of old deltas. The big pan really helped out I wish I would of found this site earlier.

SuckMyWake
06-24-2001, 07:29 PM
Hey Oldphart,
So your 455 ran fine before the head swap, then you had a bunch of problems due to the defective cylinder heads. Now that a good set of heads is on the motor it runs very well. Don't knock Olds because of Edelbrock. The stock nodular iron crank and the stock forged steel rods (all 455 rods are forged) will last forever as long as water does not find its way into the cylinder!!
Olds engines are just not the norm, and you have to know waht it takes to make them run. Stock C heads work real well, but those edelbrock heads are pretty sweet.
my 2 cents,
-Todd

455Olds
08-09-2003, 06:55 AM
My Olds 455 runs 40 lbs when she starts but drops to just 25 the first time you tromp on her and stays there all day... no lower, but 25 just don't seem good. The block was a build from Wausua Crank in WI just this spring... less then 10 hours. Has a 6qrt pan because outside of a dry sump I can't find anything to fit. My fingers can barely squeeze between the pan and hull as it is. The builder told me stay with the standard oil pump... no high velocity, and no high volume because he said olds engines like to hold all the oil high often starving the pump. Any truth to that? Any and all help appreciated!

Back Forty
08-09-2003, 07:34 AM
If you would like to open a door into the Olds world, try here:
www.realoldspower.com (http://www.realoldspower.com)
Don't mention Mondello to much. They like a good linching over there. argue

Moneypitt
08-11-2003, 09:52 PM
Dpage, what ever else you choose to do to that olds, Throw the blued rods in the trash!!!and try to find a good Hardin Marine crank, I know some, if not all of them, were crossdrilled. This is just one of the things you need to do to make the olds live. You might also consider pinning the lower rod bearings, and use aftermarket rod bolts. After all is said and done, remember, olds motors aren't chevys, they don't like major rpms, but they will make some awesome power if treated right!!....my .02 ....Moneypitt