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Discussion Starter #1 (Edited)
Hi, I have a new to me 1972 Glencoe with a engine out of a 1967 Olds 442. It is a 400 ci engine. The 455 that was originally in the boat had been taken out by previous owner and was not rebuildable. I have known the boat for 20 plus years and it always would turn a max of 4800 RPM. In looking for the same type of performance with this 1967 Olds 400 engine I changed out the original 442 cam for a Mondello jet boat spec cam and a Edelbrock Performer manifold. I am using the Holley marine carb that looks like a Q-jet and a Mallory Unilite distributor. The more I advance the timing the worse the performance. This engine will turn only about 4450 RPM. Any thoughts of something I have set up wrong? I am not an engine guru but am an OK mechanic. Also could I be experiencing a pump problem of sorts? Pump is a Jacuzzzi 12-WJ. Any thoughts or advice would be appreciated. Thanks.
 

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The 4400 rpm sounds right. My first boat had a 455 Olds and ran 4300 rpm. I sent the tach back, had to be wrong!!!! Nope, that is what it ran. Enjoy and do not go over 5000 rpm!!!!
 

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Discussion Starter #3
Thanks for the info. Another question, GPS speed says 52 MPH at 4400 RPM. Does that sound OK? Would looking at the pump help with MPH? Would like to see 60 MPH.
 

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The late 60s and early 70s boats ran at that speed. I am not that familiar with your pump or boat. But, the speed is what they ran in that era.

Speed costs money!!!! Other peeps will probably pipe in.
 

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Yeah, that sounds OK for an Olds / Jacuzzi WJ depending on how heavy the boat is?

What is your max timing? Around 36 degrees should be the best. Be nice to have it all in by 3000 rpm. I don't know much about the 400, but I'd guess it's high compression, so I hope you're running 92 octane.
 

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HOw big is the boat? That's the same RPM i get out of my 455 , never tested the speed though. So, you're probably doin ok with that setup. i usually cruise at about 3200 rpm and it stays happy.
 

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Discussion Starter #8
Boat is 18' long. There is a user on here (74Glencoe) that has a picture of the boat. Probably a splash of a Tahiti. Not sure of weight but the hull must weigh in at at least 1000lbs. Engine is heavy . I am using a 2600GVW trailer with no issues. I do use high test gas as this engine is much higher compression than the 455 was. I have been told that losing the 55 cubic inches, approx 50 hp and the same in torque may be what is my issue and I can change the impeller to match the new engine set up. The drive does have a dirverter. Acceleration out of the hole is quite strong and its gets up to speed fairly quick.
 

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Advance curve?

You said you took out the 442 automotive cam, but how about the distributor? You will, if you haven't already, need to modify the advance curve for the timing. You mentioned additional timing slows you down on top, so I am assuming you're advancing it to gain bottom. That is OK, except you may need to re set the initial lower, and curve the advance to come in sooner with less maximum advance......How many degrees are "in" the distributor? What was/is your initial setting, and when is the max all in??.........Oldsmobiles are torque monsters, but not high revers. I would hazard a guess to set initial at about 8-10*, with 24-26* "in" the distributor, for a total of 34*, all in by 2800. I also doubt you're losing 50 HP from the 55 cu inches, 455 to 400, unless the 455 had a great deal of compression and some good head work......You may have to experiment with the timing curve, initial setting, to find the motor's "happy spot" through the power curve.........Do not get discouraged, and remember boats are suppose to be fun first, and a little faster, 2nd........Ray
 

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Discussion Starter #11 (Edited)
Thanks to all who have replied. I have a Mallory unilite distributor and I need to see what it has for advance in it. The engine I have is from a 1967 442. I have put in a Mondello cam/lifter kit for a jet boat. Lynn at Mondello's was very helpful. Engine has approx 300 crankshaft horsepower. The boat has a B impeller and it turned 4800 with the 455. I think I am going to pursue the impeller selection and make sure I have the engine timing and such setup correctly. Mainly I am just going to use the boat this summer and get more serious over next winter for any big improvements. Small displacement engine just does not have the torque. This 400 because of the year (1967) will rev a little more than newer Olds 400 engines or 455 engines. (.921) lifters and such. I actually have a couple guys from Old's car club asking me if I would part with it. If I can get the money they say it is worth that would allow me to have a decent 455.
 

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Boat is 18' long. There is a user on here (74Glencoe) that has a picture of the boat. Probably a splash of a Tahiti. Not sure of weight but the hull must weigh in at at least 1000lbs. Engine is heavy . I am using a 2600GVW trailer with no issues. I do use high test gas as this engine is much higher compression than the 455 was. I have been told that losing the 55 cubic inches, approx 50 hp and the same in torque may be what is my issue and I can change the impeller to match the new engine set up. The drive does have a dirverter. Acceleration out of the hole is quite strong and its gets up to speed fairly quick.
I have A 455 olds in my boat, And from what you have said we have the same hull, If you are going to shell out the money, go away from the olds if you are looking for more speed. 5000 rpm in an olds 455 is top. Chevrolet motors are a little better in the sense of top end, but many just dont have the torqe of a 455 olds, the big block olds are known for producing insane amounts of torqe at low rpm, but there is problems with the oiling system at high rpm. Good luck with whatever you decide, and it is great to hear of another olds/jacuzzi/glencoe out there. Can you pm me some pics?
 

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Discussion Starter #13
Will be getting some pictures together soon. Probably stay with Olds as I would have to replace all the exhaust and such. Depends on what I find for deals though. I am using the boat for skiing and recreation on small lakes here in Maine. 60 MPH is plenty as you run out of lake fast. The boat will out hole shot most everything and the lake gets small before the fast prop boats can go by you.
 

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Discussion Starter #14
Found problem with boat performance. Problem turns out to be the engine. A weak coil was the culprit. Engine now turns 4800 and boat back up to speed (58-61 MPH). Not sure what else may need to be done other than some fine tuning. Going to leave jet pump alone for now and see how it works thru the next month or so. I did speak with Tom at JP who was very helpful in how to go at possible pump upgrades. Next winter plan is to put 455 back in and then look at pump.
 

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Hi, I have a new to me 1972 Glencoe with a engine out of a 1967 Olds 442. It is a 400 ci engine. The 455 that was originally in the boat had been taken out by previous owner and was not rebuildable. I have known the boat for 20 plus years and it always would turn a max of 4800 RPM. In looking for the same type of performance with this 1967 Olds 400 engine I changed out the original 442 cam for a Mondello jet boat spec cam and a Edelbrock Performer manifold. I am using the Holley marine carb that looks like a Q-jet and a Mallory Unilite distributor. The more I advance the timing the worse the performance. This engine will turn only about 4450 RPM. Any thoughts of something I have set up wrong? I am not an engine guru but am an OK mechanic. Also could I be experiencing a pump problem of sorts? Pump is a Jacuzzzi 12-WJ. Any thoughts or advice would be appreciated. Thanks.
Assuming I read all of this right , Honestly your RPMs are fairly "consistant" with the Power that motor likley makes and "limit it back" , Jet pump problems generally present as high rpms vs speed Your Glencoe WJ likley came with a B impeller ,as a rule a 455 would turn it around 4600 to maybe 4800 , I would give though to a "upgraded" Holley to replace the Qjet your early 442 400 (if all original) likely had around 10 to 1 compression and will probaly like around 36* degress toatl timing (all in at 2500) Call if I can help Tom

(ps FWIW I worked for Oldsmobile in the 70's ;))
 

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Discussion Starter #16
I have left the original manifold and Qjet off and have a Holley Marine spreadbore carb on the Performer manifold with a Holley electric fuel pump. Boat runs nice and with some fine tuning in the timing department, should perform decent for skiing and tubing. Thanks for the help Tom. .
 

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Discussion Starter #17
Been working on my 72 Glencoe over the winter. Replacing 1967 400 Olds with 1970 455 Olds. Stock rebuild but with alum pistons and Edelbrock heads. Will be breaking in on dyno and will have horsepower and torque soon. I am attaching a couple pictures from last summer of boat.
 

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Been working on my 72 Glencoe over the winter. Replacing 1967 400 Olds with 1970 455 Olds. Stock rebuild but with alum pistons and Edelbrock heads. Will be breaking in on dyno and will have horsepower and torque soon. I am attaching a couple pictures from last summer of boat.
Get that Hot rod wet ! Lets see some pics of that new power plant ! Tom
 

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Same Hull

That is the same hull as mine. I dont know about you but I love mine to death, It handles waves and wakes alot better than alot of other hulls I have been in. Mine is also built super solid, Good luck with the new powerplant, and make sure to keep us posted!!!
 

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Hey, I remember this post! Good luck with the break-in. I hope you found some good oil to run. Lots of issues with low additive oils knocking those cams out. A local engine shop is saying to look for grade CI-4+, but I know lots of guys that are special ordering "off road use only" racing oils to keep their cams alive.
 
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