43 mph????????

[dgie]

This is a follow up from all my earlier posts as
I am still trying to figure out why I am getting to only 43 mph at 4200 RPMs. I have a 455 with a jacuzzi 12wj pump. I took advice of some and pulled the pump apart and checked out the wear ring etc. The wear ring had a gap between it and the impeller wide enough to equal about 1/8 to 1/4 inch I was told it should have a gap between the two in the amount of .012" . I am assuming that there was some serious cavitation going on. Also there was an issue that some brought up that I am not getting enough horsepower and to check out the cam. I did not build the motor and the person who did does not remember what he put in it. So I pulled the cam and it has no marks on the end specifying who made it, part number etc., so it is a mystery cam. I ordered a Claysmith cam to include lifters and a Claysmith degreeing kit. I checked out the cam bearings and the main bearings. The first cam bearing has some wear and a little pitting. The journals on the crank shaft look good except for a little wear. I am going to get the cam bearings replaced monday so I do not mess up the new cam. I am also going to go ahead replace the main bearings while i am at it. They are not showing any copper except for on the sides of them (is that normal?)Some people say not to use the degreeing kit, just line up the marks and go with that (what does everyone else doing dereeing or not?) "Why is he telling us all this?" is probably what you are saying, well just want to know if I am on the right track or if I have left anything out and had a few questions, please let me know what you think, thanks

[Moneypitt]

Wow, where do I start? Okay, new cam and lifters, good move. Now what are the cam numbers, lift and duration, from the cam card that came with the cam? These numbers will ID the cam as to how severe it is, and this will help determine wheather or not degreeing is necessary. Although I would strongly recomend degreeing any cam instalation, for some cams in some engines it isn't totally necessary. The bearings being "coppered" on the sides is not normal unless you are refering to the thrust bearings that control end to end movement of the crank. The sides of these thrust bearings ARE copper when new, and nothing to worry about.. What worries me the most is the fact that the bottom end of an engine, especially a boat engine, is the most critical part. Errors or oversights here WILL result in having to do it all again. If you are not very experienced in this area, please go slowly, find a book that details what you are trying to do, and read it!!!!...Additionally, the cam to crank timing is critical when trying to get all you can from any engine. This is why you've been told to degree the cam into the engine. Degreeing will expose a loose chain, a bad sprocket, possible valve to piston clearance problems, and allow you to adjust the valves using the degree wheel as a reference point.. and also verify your ignition timing marks.... I've gone on long enough, please be VERY sure of the bearing clearances, and if you are un sure about anything, anything at all, STOP until you find out the answers to your questions... Either here on the boards, or from someone that has the experience required to do the job.... Do not be afraid to ask questions!!!I haven't even started on the cleaning process yet...Moneypitt
P.S. all bearings are NOT the same, research before you buy.......

[dgie]

I wish things were easy... I just ordered the cam and lifters today should be here wed. The machine shop will be open monday, so I will take the motor down there then and have the cam bearings put in, not sure if I have to remove the heads and pisons. I do not know which bearings to buy or do machine shops just use their own? Also The sides of the main bearings are showing copper on the #4 main bearing, not sure about the others. Is this bad? if so what does it mean?

[malcolm]

Was that 43 mph on GPS? You might have said before, but I don't remember. Is that a B impeller?

[dgie]

I used a GPS and while I had the pump apart I found where it was stamped on the impeller it is a "B"

[Moomawnster]

Don't do two things at once !.... If you had a quater inch gap in the impeller fix that first and see how it works THEN go to the next step if it is still "slow" , otherwise you will have no idea what was wrong :rolleyes:

[dgie]

one problem with that, I already pulled it apart.

[Moomawnster]

Oh well ... not a big deal ,I hope you get it fixed up , depending on the size of the boat you should gain quite a bit with just the impeller adjustment , my 16' Tahiti touches 60 @ 4k .

[Floored]

I use Clevite 77 bearings. Don't use cheap bearings,there is a big difference.also have you thought about since you are already apart putting in the main bearing oil restrictors.not expensive, could be good! rule of wallet- is cheaper to do once right than twice half right.take your time, you'll be glad you did. good luck

[Moneypitt]

I agree with Floored, Clevite 77 bearings seem to cover MOST needs when assembling an engine, and the olds 455 definitly NEEDS the oil restrictor to prevent all the oil from going up to the top of the engine. When I said to do some research on bearing choices, it was an effort on my part to let you decide which type of bearings suited your needs best, and WHY.. The 77s are harder, so they will take more abuse, not grab the crank under extreme use, and are more forgiving if under lubed for a split instant.. That said, there are other choices out there that also have their advantages, in other words, Learn the WHY!!!
Now that you have started this project, DO remove the heads and pistons, DO replace the rod bearings as well as the mains, DO check piston to wall clearance, and ring gaps....DO have the heads disassembled and inspected....DO throughly CLEAN every nook,cranny, and orfice in the entire motor with HOT soapy water and a garden hose prior to re assembly... I'll stop now and say again, find the proper BOOK that goes into great detail about the exact engine you are working on and read it cover to cover, you WILL be glad you did, and will find yourself answering questions for others right here on these boards in the near future........Moneypitt

[dgie]

The engine has only 10 hours on it. The oils restrictors were put in when it was built so they have been in there the whole time, I also have a high flow oils pump and a 10 Qt oil pan with baffles. I have good compression so the pistons are sealing. I am not sure about the heads, but I assume they are fine I did not see anything abnormal during the compression check. The readings were 147-155 psi during the compression check. I agree with changing out all the bearings with fresh ones, like the ones you described, the thing that really has me worried is the wear on the side of the #4 bearing, It was mentioned earlier in this thread, that if it is on the thrust bearing that is normal. what is the thrust bearing and where is it,,,as I stated earlier I am just learning.

[Moneypitt]

The thrust is on #3. Check the #3 for excessive wear that would allow end play in the crank. I don't see how the #4 could be coppered on the edges unless some foriegn matter got in there, OR the main journal was ground with a radiused wheel leaving an excess radius in the corner of the crank, (it happens all the time.) compare that journal to the others, lay a bearing from a different main on the crank up side down and see if it sits flush or rocks on the corners, also measure the thrust surface opening in the crank, then measure the width of the thrust bearing you took out while installed on the block and/or the main cap. End play on a 455 is .004-.008.

[396_WAYS_TO_SPIT]

I am going to agree with others about the loose pump. I would tighten up the pump before I would do the motor. What are the specs of the cam? You cant go too big on the lift without some headwork. My specs for my 455 are .230@.05 int/ex .490 lift, rpm is 2000-6000. Also, on the bearing clearances .002-.0025 on the rods and .0025-.0035 on the mains and it wil live. What is your oil pressure at? If you have a hi volume pump I would highly recommend restricted pushrods. They help out alot but they are a little pricey.I run a 10qt pan with a stock pump and only restricted pushrods. Also when you got the gps reading what all did you have in the boat passangers,fuel,ski's,etc(how much extra weight?).My boat is alot faster with low fuel wink Rule of thumb for a 455 olds is to keep the r's under 5000 and it will live for a long time wink Let me know if you need anything.
396

[396_WAYS_TO_SPIT]

One more thing, if your pulling it apart then have the shop mic the rods and crank to ensure trueness wink But I am still leaning tward the loose pump. Loose pump=less pressure out of the nozzle=loess speed. my nozzle has alot of blow by so I know for a fact I am loosing a minimum of 5mph on my pump.
396

[dgie]

I missed something about the loose pump, is that meaning the jet pump was loose and causing loss of speed? I am also thinking of cancelling the cam shaft and getting the cam I have checked for duration etc. to see if it will be good enough for what I am doing. If it is not then I will order it at that time. I need to start saving money here and there, but not to the point where I am doing things wrong. I like the advice of an earlier response to this thread fix one thing and if that is not it, then move onto another.

[dgie]

One more thing, it was the #3 bearing not the #4. Turns out the wear is normal being how it is the thrust bearing. What can I say I have an olds and when I see wear I get scared eek!

[dgie]

Here is a pretty cool link for main bearing inspection that I got from someone on the Realoldspower discussion forum, just in case anyone needs it:
http://www.engineparts.com/motorhead/techstuff/bearingfailures.htm#

[Moneypitt]

Dgie, if you are going to re install the old cam,(not old OLD, just the one you were using)I hope you've kept the lifters in order!!mix them up and you can almost count on a flat cam lobe in 10 or 15 minutes of use. (When you mix em up you throw it all away and replace the cam and lifters). Another thing, the jacuzzi pump should have a vertically adjustable nozzle, where is it set? could be part of the speed problem.....Moneypitt

[malcolm]

The WJs dont have a vertical adj. thats the YJs

[dgie]

I kept them in order, but like I said I am not sure, I may just go ahead and change out the cam anyways. Hell its on its way and should be here wednesday its a Claysmith cam, I guesss they are good I am also ordering a Claysmith degreeing kit and video.I would like to say I wish everyone could get together and descide on weather one should degree a cam or just stick it in, line up the marks and go. I found out today that a lot of engine rebuilders do not degree a cam. To degree or not that is the question???

[Moneypitt]

Ok, here is one PRO degree reason. In order to establish ABSOLUTE crank (not ignition) TDC you must use a degree wheel and some sort of travel indicator or a positive stop on the piston. (I use a travel indicator) Once you have established that, then you can verify the opening and closing specs on the cam, as related to the crankshaft TDC. This is important to people like me that like to bump a cam up a couple of degrees to make the valve event happen eariler to take advantage of the overlap and a tuned exhaust system. Now if the cam guy has already bumped the cam up, you may run into piston to valve clearence problems if you also bump it a couple of degrees.(4) So the ONLY way to know these things is to check them yourself. You can ask the cam guy if they ground the cam "up" any, and most grinders say no, as a matter of pride of accuracy in grinding.. Now you look at the cam card and see how many degrees btdc the valve STARTS to open,(.050) and at what degree it closes, if you have a degree wheel on the crank you can VERIFY these numbers are correct with YOUR timing chain and sprockets (or gears), as the cam guy has no control over your assembled parts or you methods of putting things together, and if you call him with a problem or a tuning question, the first thing he'll ask you is if you degreed the cam in to the motor.. If you took 2 identical engines, blindly assembled 1 and degreed and corrected the other the difference would really suprise you. Do you understand what happens at tdc piston dwell? and the reason that tuned exhaust boosts HP and Tq?.........Moneypitt

[dgie]

no, I am new to all this, and need to learn it. Along with the degeeing kit I am also getting a video on how to do it. Just out of curiosity How do you bump up a cam a couple of degrees?

[Moneypitt]

Depends on what kind of motor, and what type of drive you're using. Some gear drives are adjustable, some lower gears (crank gears) have more than one keyway, (this isn't considered advancing the cam as in fact you are retarding the crank, same effect though), and if the cam is located by a dowel pin, you use an offset pin and elongate the mounting holes to adv the cam. None of this is possible unless you know where you really are..... Moneypitt
P.S. I'll go into benifits in a minute or two.

[Moneypitt]

OK, you know the basics of an internal 4 stroke engine. the intake stroke, comp st., firing st.,and exh.st... Now go back to the first one, and understand that the intake opens, the piston goes down sucking fuel in (vaccum) as it goes. Somewhere around BDC the intake closes, and the piston comes up compressing the fuel into the combustion chamber, and firing it to make the power, forcing the piston down, then the exhaust opens and the piston forces the burnt exhaust out..simple really...But suppose you could actually pack more fuel in the cylinder? Well, you can! with a high perf. cam you have what is called overlap. This is the time that the exhaust is closing, but still open, and the intake is starting to open.. Your cam card will tell you how many degrees of crank rotation both valves are open. As the ex. is closing there is a suction created by the tuned exhaust, (collector) that will actually suck some of the waiting fuel in the intake port(as the intake is opening) into the combustion chamber,as the ex. valve slams shut BEFORE the piston starts down, so we've loaded the chamber CC volume without the use of the piston moving (dwell time) as the crank comes over center, Now as the piston starts down in its normal vacuum stroke, we will load what it pulls in to the cylinder, PLUS what the overlap allowed the exhaust to pull in, and this results in a better packed cylinder that will be compressed into the chamber for firing.(more fuel=bigger bang) You must understand that all of this is done in a split instant of time, to much overlap and the fuel will explode as it comes in contact with the exhaust gases, (back fire in the intake)so all of this has to timed to a Gnats ass. So, during this piston dwell time, we are using the exh. suction to charge the CC volume of the chamber, at high RPMs we are talking about such a short period of time for this to happen, that a few degrees of advance in the cam timing allows the valve event a head start to perform this overlap function. Remember that at this critical point, your conection between the crank and the cam, regardless of the type of drive you use,is stressed to the max, and if the cam falls just a tiny bit behind the crank, you lose this split instant in time when this fine tuning can work for you...I'll stop now, I hope this helped. The decision about degreeing YOUR motor is YOURS to make.......Moneypitt
P.S. did you find and buy THE book about YOUR engine?????

[dgie]

I did get a book, and have had it for some time. The only think I don't like is it covers many diffrent vehicles, well my engine is in there so thats good. I am ordering the cam and degree kit through cp performance. I am wondering if I could go straight to clay smith and get one from them and save by cutting out the middle man.

[dgie]

I also have the Mondello book.

[Moomawnster]

One Thing At A Time ! :rolleyes: Sounds like you are getting the good stuff from these guys! ... keep up the good work and Have A Reason for all you do ..... when you know more about your boat you can make improvements cheaply and effectively ...Throwing money at it is OK too but KNOW WHAT YOUR DOING ! :D Oh yeah ... If you haven't tightened up the pump yet DON'T ... Do the motor and see what happens , even if you have to put the pump back the way it was .... really you'll be glad for the knowledge ...
Moo......
[ June 30, 2003, 02:59 AM: Message edited by: Moomawnster ]

[dgie]

I went ahead and ordered the wear ring for the pump and the cam etc. from cp performance. I am going to get it all done at once even though I should have done one thing then the other. Seeing how everything is out of the boat and taken apart, better to do it now. Also It seems that going straight to clay smith to get the cam and degreeing kit does not really save you any money. Cp seems to have pretty good prices.

[Squirtcha?]

dgie:
Also It seems that going straight to clay smith to get the cam and degreeing kit does not really save you any money. Cp seems to have pretty good prices. When I was doing my shopping around for motor parts, I found the same thing to be true. It seems (second hand info here) that at least some of the manufacturers will agree NOT to undersell their retailers/distributors. This will typically result in their prices being slightly higher than what you pay for it at Summit or Jegs etc.
In fact I started some stuff by accidently while on a phone call with a retailer/distributor, telling them that the manufacturer was going to sell it to me cheaper than they could. The dude got real pissed and told me they weren't supposed to do that (that's where I found this out). He finished up with me quick like, and I'm betting he was getting back on the phone with them to bitch about it.
Anyway whether it's true or not, I don't know. Kinda interesting though.
[ June 30, 2003, 10:19 AM: Message edited by: Squirtcha? ]

[Moomawnster]

Ahh Hooey ! I have switched impellers 4 times just experimenting with the pitch and shims It ain't hard and I KNOW why my boat works ....You are asking questions that require technical answers , now your gonna void any knowlege you might have gained by doing this right , I hope it works for ya :rolleyes: :D Moo .....