I got an eye popping 42 mph max at 4200 rpms max. I understand that I should get about 10 mph faster at least on the stock 455 olds and Jacuzzi 12wj pump. I am not if the pump is cavitating. CP performance told me that if the boat does not feel like a slipping clutch then the wear ring is fine. When were running the motor in the begining we were running it dry with no water in the jet. also not sure about the impeller seems ok but not sure if it could be the culprit. currious if anyone has any input on this. I took pics of the boat today, will try to post them tommorow.
hummm? seems a bit low on speed at 4200 rpm. and if you ran the boat out of the water, and especially dry pump its a good indication that the pump was hurt. i myself do on very rare occasions start the boat out of the water but i hook up to a hose plus i squirt water in the grate while doing so. and never run it for long preiods of time or high rpm's. i hope you didnt hurt it but you may want to have it checked out.
BTW, 4200 rpm is about right for a stock olds with a good pump.
I think that is a good idea, I found out late about it being bad to run the pump dry. No problem I had it apart once and rebuilt it myself. So I am a veteran at that. Hey just curious when installing the mechanical fuel pump do you install the pump with the inlet and outlet ports where you attach the fuel lines to, up or down. I am wondering if I am installing it upside down.
ill have to take a look at mine in the morning, but i do remember the fuel pump having a long (maybe 2 inch) tube looking thing going "UP". it is offset from the center and toward the block. but if i remember correctly the fuel line was connected from the bottom side of the pump somewhat.
I had mine mounted with the fuel lines (in and out) on the bottom looking down on it. I hope that it is in upside down because i looked inside the port for the fuel pump like everone sugested and sure enough it is hitting the timing chain. If the pump was installed right then I have a timing chain issue. Let me know what you find out. I noticed you are bailing on the 455 for a 454, that might not be such a bad idea for me too. that leaves me with only one final problem, a jacuzzi pump.
You know I may be wrong here, but I don't think they are talking about the pump itself being upside down. I think they are talking about the pump lever being on the wrong side of the eccentric that drives it.
I could be wrong, I've never had the pump off of my Olds 455 (car).
I may be comparing apples to oranges here, but I'll give it my best shot.
I have a Dodge 440 in my 19 foot Anthony with a WJ pump. I ran my boat at Needles on GPS and it ran 53. Pretty dissapointing. Motor runs at 5000 RPM's.
I am running a shoe, stock (Berk)Legend "A" impeller, my bowl is modified to accept the Legend Impeller and I welded a ring on the outlet for Berk add ons. I run a Place droop, with a Hyd diverter for a Berk pump. I made my own hardened shaft that I gundrilled to fit the new impeller.
I don't know if that helps, my combination may be way off still, but I just wanted to post to say you are not alone. haha.
Brian [img]http://www.***boat.com/image_center/data/521/63droopad.jpg[/img]
[ June 15, 2003, 09:09 AM: Message edited by: wsuwrhr ]
dgie- what impeller are you running? Most WJs seem to have a B. 4200 rpm translates to around 200hp, a 455 should be more than that. My 403 Olds turned a B up to 4200. It would usually run about 47 mph at that rpm. This year the motor and pump will be new, can't wait to get some numbers.
dg,
I had a similar situation with my basically stock BBC a couple of years ago. I was only getting about 4200 rpms and about 45 mph in a 21' boat with a Panther jet. The following is what I did along with the rpm gain or loss.
dump the dual point distributor for a electronic - + 50 rpms
Switched to a Torker intake from a Performer 2-0 - very little change
swapped out a Holley 780 for a Edelbrock 750 carb - very little change
changed jetting and metering rods in carb - + 50
swapped Edelbrock carb for a Bigs built Holley - + 50 over the Edelbrock.
The engine is now getting 4350 to 4400 rpm's after those changes.
Since I didn't have any idea what cam was in the engine, I decided to pull it and do some freshening up. I put a very mild cam in it (.515 in/.525 ex) and a bit smaller than the one that came out. New lifters, rings and bearings.
After putting it together, it still ran about 4400 rpms, maybe 4450.
The next change was to go with a Edelbrock RPM Air Gap intake and gained 200 rpms.
The engine is now running at about 4650-4700 rpms and hitting 57 mph. I know it's not any kind of a speed demon but it runs real well in the 21' Tahiti.
One area you may want to check closely for is a vacuum leak. Start the engine, let it idle and spray (using a spray bottle) the joint between the intake and the heads, the base of the carb and where the linkages come through the carb. If you hear any change in rpm, more than likely you have a vacuum leak that can cause low rpm's.
My 18' Tahiti Tiger with 455 olds, berk jc pump with A impeller does 61 mph (GPS) at 5200 rpm. At 3500 rpm the mph matches rpm of 35 mph. I am thinking my pump needs a rebuild bad. The guys at CP told me if I rebuild I could get another 5 mph possibly. Is there a way to keep the same mph but lower my rpm? I hate spinning that olds to those rpms, and do not do it often. Try to always stay below 4500.
Posting Permissions
Reply With Quote