Audiofn....thanks man...i see how you R:D

I got your back!!! OOPS that did not sound good now did it.

I got ya covered!!!! OOOPS still messed up

I AGREE :D:D

Jay I have a couple questions for you

1: Is this the same motor that you had all the bent rods

2: I assume this is the same motor that pops occasionally out the carb? YES/NO??

3: If you start to see the drop in oil preasure and then you idle does the preasure come back. I am not talking about shutting down and having lunch I am talking about blasting across the water, seeing the oil preasure drop, then idleing for a bit to cool the oil down.

4: Have you pulled apart your filter to see if it is clean and free of particals, and make sure that there is no more water in your oil?

I know it sucks to hear what Audacity and I are saying right now but we are only trying to cover your butt for ya bro.

Jon

step (1) check timing (32 deg for now... don't push it)

step (2) check jetting!!! read the plugs
a new cam will run alot different than stock!!! even aftermarket exhaust alone may require new jetting.

step (3) check oil cooling
get an oil temp guage
filter clogged? get synthetic filter that wont clog immediately upon contact with water.
remove bypass, force oil through cooler, check for change in oil temp



my guess... popping means lean. lean means hot, hot means low oil pressure.........fix it before 100w wont plug that hole in your new piston. It's not too late..........



oh, audacity and ursus, you are in VIOLENT AGREEMENT ALREADY on the oil thing :D

Valvoline racing strait 40

good luck Jay. don't look at other boats... you will just frustrate yourself. enjoy this one. it's bigger than mine:)

that's ok jon....i understand!

i think i come accrossed here a lot as being a pessimist. really i'm just a realist. people hate to hear that..when i build an engine, do set-up, rigging, or dail in work...is it cheap? NO...do i turn a lot of work away due to customers having false ideas about what will do what in a boat?? YES....cutting corners sometimes will bite you in the ass....we're just trying to help you cover yours now.

hummmmm....."don't look at other boats... you will just frustrate yourself. enjoy this one"....kinda like women???....they always could use some modifications:D ....ummmmm

Okay have 2 engines in boat
Looking at the transom it is the port engine
This engine was the one that USED to be on the starboard side, they got switched in the reinstallation no big deal.
the port engine is the one that had the bent pushrods yes
Had the valve springs changed
has the oil pressure drop

Lean condition would not cause a poof though (I am not 100% sure which engine is poofing out the carb though but my money is on the same one port side engine)

To answer Audio, Okay you run down around 3200-3300 in that range with both of them and the oil PSI is 20 or thereabouts
You slow down and idle for a few minutes it is staying around 20 or so
does not drop or go back up higher
I do think the mechanical oil pressure gauge on the one engine is a damn good idea
Take the dash gauge out of the scenario and read it directly off the block
Maybe I have a crappy ground or loose wire or too badly of a corroded wire which is causing too much resistance?????
Could be a number of things but regardless that is a good place to start.
My question is what do I do with the carbs, Who sets those up?
Does not sound like engine builder does from what he said about call me back tomorrow and he was going to make a call or two.
called him and he said call back in half hour
More like he forgot and is making his calls now more or less
Unreal
Jason

One last possibility (after confirming ignition timing, and jetting are correct first!!!) is that crank main bearings were wore/spun due to running with the water in the oil.
but check the other's first.

"My question is what do I do with the carbs, Who sets those up?"....holly **** dude...the ENGINE BUILDER....show me an engine from a MAJOR builder that comes minus a carb....teague, cobra, hawk, MERC...they have all done a TON of testing on the dyno to perfect a set up....call a carb shop and ask????'s....you know what they are going to ask....CAM questions....DATA....what lift at 50????...vac.....guess what....all the #'s and data that the engine builder SHOULD have! and you DON'T go by what the cam card says!!!!...

Have you checked the possibility that you may have to much oil in the motor? If you have to much in an engine the pressure can drop at higher RPM because of foaming created by the rotating assembly spinning in the oil. To check your dipstick just switch with other engine, then check length of tube with the one on the other engine. If you know how much you put in each engine were they equal. Does it make any difference in pressure if you had a qt. less.
Your builder is correct in saying to use a vac gauge to adjust the carbs (an O2 sensor will give more accurate results but doesn't work with wet exhaust) but they need to be first calibrated for your engines. Then you adjust the mixture screws for max vac, if you go to far your vac and rpm will drop. Adjust one screw then the next and then repeat.
Good luck.

With oil pressure problems I ALWAYS check for a bad pressure sender first, especially if it is leaking oil. Use a ohm meter, swap senders or test with a mechanical gauge.

Once I rebuilt an engine because of a faulty sender. :rolleyes:

BTW Boat manufacturers don't always match the sender with the guage.

Okay spoke to engine builder
He wants me to put a mechanical fuel pressure gauge on engine.
Then take it out
He is going to try to find me an oil temp gauge to put on there as well and see what oil temps are
He does NOT rebuild carbs, he said that he is not good at it so he wont attempt it
He is going to try to find someone that is good at it and make a few calls and see if the carb needs to be done for HP increase or not. I dont know enough about carbs to tell you any of this but I do know that with an increase in HP there should be an increase in fuel delivery and with increased compression and larger bore in cylinder it should require more fuel, but lean or starve the engine of fuel and it should khonk out and studder not poof out the carb right?
Loading up I thought meant too MUCH fuel not fuel starvation
but if that is the case and it is not getting enough fuel
#1 why would it produce a poof at low (1200-1500 ish) rpm's and not up around 3100-3200-3500 area?
#2 how would fuel starvation create more HEAT in the engines oil?
#3 she only does the poof under load NOT at idle
I can rev that thing all day long and have no problem with the poof but an engine doing "work" and being under load will require more fuel than an engine just running in neutral---that I get.
Joe what is wrong with setting carb by vaccume?
I thought that was how it was always done.
Maybe im wrong or thinking of cars too much and not getting the marine setup in my head right.

I am however going to pull the oil out of there (maybe with a drill pump this time and not by hand like a fool) and put in straight 40 weight oil like everyone is suggesting.
That should increase oil pressure due to the actual viscosity of the oil itself but still may cause drop in pressure after hot but maybe not drop as low due to thickness.
If this thing stayed around 40 PSI all day I would not even think twice about it
but since it is at 20 or so that raises my brow for a WTF comment.
He assures me I wont blow it up cause im being careful and cautious and am paying attention to what they are doing and what is going on
That is a good point with the senders RickR, Every other damn thing on this boat needed to be replaced, why not this
Let me guess though, another idioit 700 dollar "marine" part LOL RIGHT?

Jason

swap the senders between the good and bad engine, use a mechanical presure guage as well and insist on a temp guage, I'll try to find one usually means I'm not gonna find one. I don't think folks were suggesting carb needed rebuilding, altho it may if its 10 years old but that it prob needed re-jeting, setting by vacum is fine for idle but the jets need to be correct in the mains and sec 1st. Lean means heat and lots of it,, one of the fastest ways to melt a piston, This is why many are suggesting here you don't find problem by self destructive testing method of just trying this then that and going out and over heating several times till you have a catastrophic failure, hence the coments to GET an oil temp guage.

Jayl

Sorry Buddy but the low oil pressure could be caused by a bad cam lobe causing the oil to overheat. That along with the puffing out the carb and the torture test it went through getting it to run I would suspect a lunched cam. If it were mine I'd pull the intake and check the cam before I ruined some pistons and scored the cylinder walls.

Keep a close eye on the oil perssure gauges. If there is a marked pressure drop a filter may be clogged with metal :mad:

The good news is oil pressure senders are only around $20

From Panchangalpina: "Have you checked the possibility that you may have to much oil in the motor? If you have to much in an engine the pressure can drop at higher RPM because of foaming created by the rotating assembly spinning in the oil. "

I wiped out a differernt new motor (less than 5 hrs) last fall due to this. Pumped down lifters and wiped out bearings. It was in fact because that motor didn't have a windage tray. I was doing the mechanical guage thing under the hatch when I finally destroyed the motor. Don't F*^k around with that too long!! Now both my motors don't have trays and I need to keep a close eye on oil level to prevent temp and pressure problems. It is quite managable though once you figure it out. My motors run like raped apes now!! Hope that is you problem.

You never answered my earlier post on if you still have windage trays?

BT :cool:

Jay

I've done similar mods to my 330's as you have. Cam, compression, head work, ect, and have spent some time getting the carbs dialed in. The first thing you have to do is richen up the secondaries. You have to change the rear metering rods to a much smaller one. The stock one is about .668, I'm down to a .440 and I'm just getting close. I'm going down lower this weekend for even more fuel. All it takes to change them is a #9 torx head screw driver and about 5 minutes per carb. You can order the metering rods at any GM dealer. Let me know if you want part numbers. I have a whole list. Remember, to rich = fouled plug, too lean = melted piston. Which would you prefer ? Let me know if I can help. Good luck, I have enjoyed following your story !

Bo

Rods and hangers...
http://www.carbsunlimited.com/rodshang.asp

Tim T.

So this fool is rebuilding engines w/o a good line carbs???WOW


"He is going to try to find someone that is good at it and make a few calls and see if the carb needs to be done for HP increase or not. "....WOW....should he not have thought of that prior to doing the engine work???

there is WAY more to selecting/setting up a carb than cfm=cid*max rpm/3456*VE

cover your ass and good luck bro

jay, just another helpful hint to save you time.

forgert the drill to remove oil. those things burn up so fast ( the cheap little pumps)

buy (sorry.....) an oil changing can/pump. They have a bycicle type pump on them. pump a vacuum into the can and watch the oil flow in. it works the best with warm oil. so much easier, especially when you have twins...

well I need to get a different oil change method
this is #5 on each engine im going to change them
All by a little hand pump
my arms are bulging and rock hard from this task
Great work out but your back from leaning over hurts like a mo fo.
Back to it
Yes he does NOT build carbs, just engines.
He stated he is NOT good at building carbs so he does not do it for people, cause it will keep coming back again and again.
Okay Cool with the honesty thing but sort of sucks that now there is going to be someone else in the loop.

The set screws I was talking about are on the primaries (front of carb) NOT the Secondaries in the back.
Just thought I would throw that out there
I also did think of something else last night, I have gas that is old in the tank. Granted it has fuel stabilizer in it which will hold it over BUT it is almost a year now (cause that is how long it has taken me to get this tub in the water)
That may have somthing to do with its performance problems as well but I doubt it.
Just because of how it reacts I would think I need to richen up the mixture a touch and add more fuel to it just to prevent detonation but Im going to do what engine builder wants me to do.
Ill let you guys know what is up when I get off of the phone with him today and see what he has to say.
So far I have been patient with him and not ready to choke him to death and he has respected me and not gone out of his way but not shruged me off or blown me off in anyway.
I dont know what is up with the carb thing but I appreciate his honesty in saying that okay I dont do carbs rather than taking them in and possibly making them worse than they were before.
Have to give the guy credit, he has not lied to me or done anything other than bailing on me to go get his harley
Then again maybe im just too nice or too dumb (Joe dont answer that LOL)
Jason

$54 at west marine. do like me. go in together with another boatin buddy. most people only need it twice a year........

On the carb thing. The two big screws on the front of the carb are nothing more then the idle mixture adjustment. On this type of carb to adjust primary or secondary you have to change rods and rod holders to adjust the mixture while running. If you are making more power now you need more fuel. Turning the idle mixture screws wont do it. Find someone who knows the AFB carb and have them tune it. Your engine is giving you signs that somethings not right. Dont ignore them.

Ron

ok then:D :D

i use a home made pump ans a industrial GE motor...takes about 40-100 secs to pump it completly out...this thing will shooot cold oil acrossed the room!....i just got sick of time involved to change oil....everyother weekend is about max life for the oil....i got it down under 5min to do both engines....


check out a place the rebuilds electric motors...they got what ya need:D

"If you are making more power now you need more fuel"

unless the efficiency of the engine has gone up???

or how about if velocity has increased....thus more fuel threw the same orifice.

I thought you could add more fuel to it via set screws on the carb
I have alot of engine knowledge but minor carb knowledge
I thought the CFM was cubic feet per minute of air right?
the 750-850-950-980-1050 was all cubic feet per minute of air NOT denoting fuel delivery
what does a just under 500 HP engine require?
I thought 750 cfm of AIR was enough to feed a 500 HP ish engine.
Now rather foul plugs than detonate engine but really rather it just run and I can be done with all this horse **** to be honest with you
If it needs metering rods that is fine but have to let someone that knows this stuff do it.
I can attempt anything that is not the problem, I can probably figure out just about anything as well BUT when it can wipe out my engine I think it would be wise to let someone do it so I dont have to go through this hell again.
Jason

real fast can someone please explain if you have fuel starvation (lean condition) why that generates more heat in the engine?
Thanks
Jason

just an aside
 

I installed a fitting/drain hose on my oil pan...run oil drain hose out transom plug, warm engine on the muffs to heat up/thin oil, drain into a pan while I work on other things...

Juat a suggestion...probably can't install now with engines in boat, oil mess to clean up. Just keep in mind if you ever pull engines again.

Zack

those drain hoses are fine if you have a single
good luck with twins being able to get that hose though the tiny hole in the stringer and out the back drain hole
Never happen with twins, cant get down there
Believe me I thought of that prior to dropping engines back in boat.
I wished that would have worked but no way no how can you get your arm down that far
thanks though
Jason

Jason,

A lean condition generates MAJOR heat...you have less fuel to burn with the same volume of air in the cylinder. Perfect ratio is 14.7:1. However, this is way too lean, especially for a boat and all things being imperfect. Max power is usually in the neighborhood of 12.6:1. Additionally, the fuel acts as a coolant on the variuos engine parts - valves, pistons, plugs, etc.

many factors...cid??...what is your max rpm??..what is the volumetric efficiency of the engine???...now factor in what it's going in??? how about cam selection???intake selection???


you oil is trying to cool the underside of the piston....which has an outragious serface tmp....exhaust tmp will range from 1200-1700 in a boat....from stuck pig rich to burn it down lean....so what do you think the the surface tmp of the source would be???HOT lol:D

Audacity is right about the efficieny. However its a general rule of thumb that to make more power you need more fuel.

The carb you have is basicaly a Cater AFB. Weber makes the marine version so its called the WFB. I think that if they came stock on 330 horse motors that they are only 600cfm. The two large screws on the front of the carb are for the idle mixture adjustment. These screws do nothing for the fuel mixture off idle. The carb is adjusted by changing the height of the metering rods in their holders. I think that you can change the length of the rods also. The Holleys use jets the AFB uses metering rods. If you suspect that you are having a lean condition at speed then you need to change the rod setting. Get someone who is familiar with the AFB to help you. They can be tuned to work properly. Most people will tell you to change to a Holley carb because thats what they know. More people will know how to tune a Holley than a AFB.

I know that you dont want to spend more money but you have got to understand that a carb for a 330 horse motor is not right for a 500 horse motor. At 600 cfm you are slightly under carbed for a 454 running 5000rpm. However the smaller carb will have better throttle response than a larger one and if drivability is more important than top speed the smaller carb can be tuned and run fine. If it were me I would buy two Holley marine 750's and start with the universal calibration that they come with. This universal calibration is usually too rich to make full power but safe for all but the most radical engines. Then you will have Holleys and every backyard hot rodder will know how to tune them. Once again you should spend the bucks to get a marine carb, ITS IMPORTANT!

Ron

Ron, I hear ya bro, But it will have to wait until next year
I have spent so much loot on this boat this year im beyond tapped.
I even spent my school tax money (I did not know that at the time though)
I wish I could toss 2 holleys on there and be done with it but I cant.
From what I was told before when I asked this on the board, I was informed that the 454-330 HP engines came with 750 Rochesters on them
not 600's
And of course it is not stamped on the side in a yellow sign hey dude im a 600 or 750 or anything either (thanks alot rochester yeah 3 thumbs up there buddies)
:rolleyes:
Anyway, Im going to call the engine builder soon around 1030 - 1045 ish and see what he has come up with
If I need longer metering rods and stuff that is fine I just need these rochesters to last me till end of this year
I can get 2 holley's over the winter time used or what not.
I see 2 on the classified section for 500 a pair which is a good deal assuming they dont need rebuilding.
I will in no way put car carbs on this thing. I agree with you there too dangerous
Hell I found a carb to air cleaner gasket on a friends boat, took that off and smelled it before throwing it away and he was like WTF you doing,
Ahhh nothing just saving you from blowing yourself up thats all

I dont play around with safety issues in a engine compartment, I might cheeze out on a few things but safety is not one of them.
If something safety prevented me from going out this year then so be it, I would be alive next year to go boating
Nuff said
Jason

simple calculation tells you this carb will not work!...toss them now! make them someone elses problem. save a ton of time and frustration...even money in the long run...go buy a holly...far less trouble...i may have a set for ya next week, by the way:rolleyes:

but first troubleshoot the ROOT cause! why buy carbs if the engine is........

I hear you Jay. Ive been there too bro. Back to the carb. If the carb has the two large spring loaded screws on the front of the carb near the base plate it is a WFB not a Rochester. The Rochester is a GM Quadrajet. They can be tuned also but not to the same degree as a AFB or Holley.

You need to find out what you have. Are the front and rear barrels the same size or are the back ones larger? If the back ones are larger then you have a Quadrajet (spread bore). I had a 1995 330 merc and it had the WFB carb on it 600 cfm. I think you have the WFB, (weber four barrel), the same as the Carter AFB, also the same as the Edelbrock Four Barrel, and 600 cfm.

Find out what you have then find someone who knows how to tune it. This is the cheapest way out. You say the engine is popping under a load and is running higher oil temps than normal. These are signs of a lean condition. Now Audacity being the engineer he is will tell you to check several other things which is correct. Ill leave all the details up to him. He seems to know his stuff.

The ideal thing would be to find a good carb guy. This guy will ask you all the specifics on your engine componets then compare that to a log book he keeps on carb settings and come up with a setting that will be close. Then if you like you can fine tune from there.

Keep the faith bro, your not done yet. When you modify an engine you become the engineer that designed the package! You are now responsible for making the engine run in a real world enviroment in all kinds of conditions.

Ron

Another thing comes to mind in determining which carb you have. GM went to all fuel injection around 1987. Because of this they stopped making Quadrajets along with all carbs. This is when Mercruiser went to the WFB carb because the Quadrajet was no longer available.

Oh and I second Audacity on the root cause. Keep this engine builder around until you make sure the problem is the carb and not him.

Ron

Well it is a spread bore and does say quadrajet on the side of the body so im inclined to say that it is a rochester :D
That being said I was told it was a 750 from board members.
Let me call engine dude and see what is going on over there and if there are any suggestions or ideas or someone else going to get involved or what not.
I do have the gasket and adapter plate for a square bore carb for my spread bore intake manifolds (came with the new intakes) so Ill be good there if I do switch to holley's or whatever
Jason

Yep, its a Quadrajunk I mean Quadrejet. Disreguard everything I told you about the AFB. The only thing I ever did with a Quadrajet was replace it with a Holley.

More bad news. If you have spread bore manifolds that will require an adapter to run a square bore carb you will need to buy new manifolds if you go with the Holleys later. The adapters are junk and have no place on a performance engine. Holley does make a spread bore carb thats great and it fits on a spread bore manifold but I dont think they make it in a marine carb. A lot of aftermarket manifolds such as Edelbrock come drilled for both a spread bore and a square bore carb and both can be used without an adapter.

What intakes are you running?

Ron

Edelbrock performers polished and it did come with a plate and a gasket for square
Jason

Jay,

Went through somthing similar a few years back when I swapped a 454 for a 502. Tried to scare up all the parts for the Q-Jet. Never did run the Q-Jet but I did get all the rods, hangers, jets from the link I posted above. I used the specs from a 502 mag from around 90 or 91. This should be plenty of fuel or at least a hell of a lot more that the stock 330 carb. I don't know where I put those specs but if you are interested Tom S. (Budman) has all the carb parts I ordered. He put them on a stout 454 with about 224/236, around 9.0 to 1, 30 over? and runs just fine. No signs of lean. PM or e-mail if you want the part numbers etc.

Tim T.

Jay,

Now that you have determined you have q-jet carbs do this now ! Go to your nearest Chevy dealer & get 4 secondary metering rods part # 7046010, size .0440 . They may not be the exact ones you need but they will richen up your fuel flow & put you in the ball park. They should cost about $30.00 for all of them. You can install them yourself in 10 minutes. Take off your air filters and using a #9 torx head screw driver remove the small screw on the secondary mounting rod hanger. This is right behind the threaded rod that the air cleaner bolts down on. Be careful not to drop the screw in the carb. Lift the rod hanger up & the metering rods come up with it. Slide the old metering rods off to either side, put the new ones on & reinstall. It's that simple, no big deal. You will feel the difference when you run the engines. If it still feels lean, popping, backfiring, hesitates or feels lazy when giving it gas you may have to richen it up more. These carbs will flow 750 cfm, plenty for your application, and work great when dialed in. Don't go the adapter, spacer, new carbs, route, you'll just have to rejet & dial in the new carbs any way and they probably won't work as good as the q-jets. Good luck !!


Bo knows

Jay, throw away the Quadrajets and get a pair of 9381 Holley`s. They are 830 cfm annular discharge double pumpers. You can usually find them at a real geed price from Jegs. You should be able to bolt these on and the jetting will be very close if not perfect.

I have had these on many boats with similar set up as yours, they work incredibly well.