SoCal Jet Boats

Tech Talk => Engine Mechanical / Electrical => Topic started by: 79charger on July 24, 2010, 09:41:13 PM

Title: Wont Idle???
Post by: 79charger on July 24, 2010, 09:41:13 PM: I just got my new motor in today , 460 with d3ve heads,mild cam roller rockers , 9.5.1 pistons balance and blueprinted . Anyways it fired right up and i held it a 1750 rpm for around 15 minutes to break in the cam . I am having a difficult time getting it to idle . Am i chasing a fuel issue or a timing issue . It runs great at 1500rpm or above . My carb is 750 single pumper holley . It worked fine on my last motor which was closer to stock . I have the timing set to 33 .Thanks
Title: Re: Wont Idle???
Post by: GT Jets on July 24, 2010, 10:57:17 PM: Timing set at 33 degrees locked out?

What is the base timing?

It almost sounds like a vacuum leak.

As for it being a carb issue or a timing issue, the best answer I can give you is .....Yes. :-\

GT
Title: Re: Wont Idle???
Post by: 88CARRERA on July 25, 2010, 12:47:12 AM: what intake?
Title: Re: Wont Idle???
Post by: quick olds on July 25, 2010, 12:57:36 AM: Check fuel pressure?
Title: Re: Wont Idle???
Post by: SS-201 on July 25, 2010, 03:59:20 AM: Check for vacunm leaks and set the corner screws in and the out to 1 1/2 turns out. Be sure the air bleeds are clear, spray them with wd 40.
Title: Re: Wont Idle???
Post by: 79charger on July 25, 2010, 07:24:34 AM: Ford cobra jet Manifold . I will re torque and retry . Thanks
Title: Re: Wont Idle???
Post by: 88CARRERA on July 25, 2010, 07:40:13 AM: spray brake clean all along where manifold bolts to head with motor running and see if it revs up, sounds like a vac leak
Title: Re: Wont Idle???
Post by: 79charger on July 25, 2010, 01:08:21 PM: I retorqued all the manifold bolts . And it still dies when it drops below 1500 rpm . Sounds like it runs out of fuel i will try the carb cleaner at the base but its sort of hard to hear the engine rev up if i have to keep it at 2000 to keep her on. My engine builder put the intake on so he will be fixing it monday
Title: Re: Wont Idle???
Post by: enginedoctor on July 25, 2010, 03:55:09 PM: Sounds like a Vac problem. (leak) ;)..Do you have a vac. guage on it? What cam specs? ???

doesn't sound like a fuel press. prob.Carb maybe.
Title: Re: Wont Idle???
Post by: 79charger on July 25, 2010, 05:33:25 PM: I sprayed ether over the manifold edges and the idle rose substantially. So either the manifold was not torqued right , or he used the wrong gasket . I have a cobra jet intake and typical 460 gaskets dont work . The one with sheet metal covering the valley . But now it has me wondering , I had to get new heads because mine were cracked . My old ones were port matched to the cobra manifold . These werent . I wonder if that will give me a sealing problem .What do you guys think ???????? Hope not i am out of money and leaving for Parker Thursday . Btw the boat will be at the engine builders bright and early tomorrow am .
Title: Re: Wont Idle???
Post by: electrowoman on July 25, 2010, 09:19:34 PM: With the cobra jet ports in the manifold you'll need the cobra jet intake gasket. Bigger gasket seals over smaller ports but smaller gasket won't seal over bigger port opening :sly:
Title: Re: Wont Idle???
Post by: IRRebel on July 25, 2010, 09:29:28 PM: Quote from: 79charger on July 25, 2010, 05:33:25 PM
I sprayed ether over the manifold edges and the idle rose substantially. So either the manifold was not torqued right , or he used the wrong gasket . I have a cobra jet intake and typical 460 gaskets dont work . The one with sheet metal covering the valley . But now it has me wondering , I had to get new heads because mine were cracked . My old ones were port matched to the cobra manifold . These werent . I wonder if that will give me a sealing problem .What do you guys think ???????? Hope not i am out of money and leaving for Parker Thursday . Btw the boat will be at the engine builders bright and early tomorrow am .

Just a thought, but if any substantial material was removed in decking the block, the intake will need machining to match as well. Dave would be the one to ask on that though.

Could also be that the intake was machined correctly for your old heads if they, and/or the deck, were resurfaced before, same issue. Fel-Pro makes a marine intake gasket kit that I use, and I also cut up the tray from the old gaskets to still use it. Just no end seals, RTV above and below the pan.

Ray
Title: Re: Wont Idle???
Post by: SS-201 on July 26, 2010, 04:07:26 AM: Did you use the center metal valley tray gasket? It takes up space that obvious you have, not only vacumn leaks but throws oil out everywhere.
Title: Re: Wont Idle???
Post by: 79charger on July 26, 2010, 08:31:44 PM: MY WIFE HATES ME RIGHT NOW AND THE ENGINE BUILDER!!!!!!!!!!!!!

I took the boat back to the engine builder today and we came to the conclusion he used a non cobra jet gasket on a cobra jet manifold . He gladly replaced the gasket and the motor than idled . I was happy , he was happy so I decided to go to the lake . I wanted to test the motor before i hauled it all 300 miles to Parker thursday. That is where my story turns sad . The boat ran like crap on the water . It was missing down low and would not even clear out on top .Like it was running on 3 cylinders after idle It is the same carb that i was using sucessfully with my last motor . And then nursing it back in the oil pressure dropped from 70 to 25 at 1500 rpm . I dont know if that is just the motor breaking in or throwing in the towel . The water temp stayed between 180 and 200 . I have the timing at btdc 33 degrees like the cam guide suggested . I checked compression when i got home 170 all around . The spark plugs are turning a chocolate brown My engine builder wants me to pull the motor for him to inspect .......Any ideas why it would run like crap . Here is the last two things i am unsure of .

I purchased a new holley 80gph fuel pump . When I went to unhook the fuel line gas squirted out everywhere like it was over pressurized . Should I have a regulator ?????

When i pulled the carb which is a older holley single pumper i think 660 or 750 there was alot of gas in the intake if the carb is
flooding the motor wouldnt the plugs be wet and would it miss ?

My last heads were port matched dv3e to the cobra jet intake . These new heads arent . Since they wont flow as well would i have to rejet accordingly .....enough to make it run this poorly

Thanks alot everyone for your knowledge . If i cant get this going i will be the loser at the sandbar with the rental boat on it for my bachelor party next weekend lol ....
Title: Re: Wont Idle???
Post by: GT Jets on July 26, 2010, 09:07:48 PM: FWIW most of the smaller Holley fuel pumps are set to 6lbs....Not saying you don't have a problem there, but just a tidbit...

What exhaust are you running? Also why was it running so warm? she should have been running around 140-150 degrees....

Relax, hopefully it's something lame....

GT
Title: Re: Wont Idle???
Post by: 79charger on July 26, 2010, 09:19:45 PM: Running Harman marine logs, and was idleing most of the time . It usually drops to 150 when i am moving .
Title: Re: Wont Idle???
Post by: IRRebel on July 26, 2010, 09:30:50 PM: The oil pressure would concern me. Dealing with the aftermath of a similar issue on that. To quote Lakesonly on my debacle, "Ray, anytime you lose substantial oil pressure, shut it down, and tear it down". GT has some good questions as well. I run about 120-160 on Moo with headers, Pickle, with logs, 110-130 all day long. :screwy:

Still trying to understand the "Cobra jet" manifold gaskets. These are not Cobra Jet heads?? What difference would THAT make?

Also, I don't think port matching in the intake side is of any real importance in this case. The 460 Ford heads are genereally very good on the intake side, it's the exhaust side that needs all the attention from what I understand. My D2OE's that were on Moo had substantial exhaust port work done, but only minor blending and contouring on the intake side. Considering the same setup using C9's and getting with Lakesonly on those. (Rivertard is challenging me I think for the Columbus Day get together! News at 11 on what I actually do. Shortblock should be ready this week... :sly: ).

If your oil pressure dropped that much, running like crap, pull the engine and at least have the builder take a looksee. Couple of hours to pull the engine, at most. Cost savings if somethings wrong and caught in time, priceless.

Ray
Title: Re: Wont Idle???
Post by: GT Jets on July 26, 2010, 09:41:22 PM: DID I EVER MENTION I HATE DOING SHIT TWICE??

:banghead: :banghead: :banghead: :banghead: :banghead:
Title: Re: Wont Idle???
Post by: IRRebel on July 26, 2010, 09:54:47 PM: Quote from: GT Jets on July 26, 2010, 09:41:22 PM
DID I EVER MENTION I HATE DOING SHIT TWICE??

:banghead: :banghead: :banghead: :banghead: :banghead:

LMAO! Exactly what I am going through Glenn! :thumbup: Granted, my own fault, on at least two issues I know of right now, but THAT is siggy line shit!

Ray
Title: Re: Wont Idle???
Post by: Marcsrollin on July 26, 2010, 10:46:42 PM: Sounds to me like you might have a stuck needle and seat and the carb is flooding.
Title: Re: Wont Idle???
Post by: 79charger on July 27, 2010, 09:51:10 AM: I guess its possible .I am getting a new carb today since mine is worn and very outdated . I am still concerned about the mismatch between my intake and heads . The cobra jet manifold ports are larger than the ports on the d3ve heads .
Title: Re: Wont Idle???
Post by: SS-201 on July 27, 2010, 01:11:02 PM: Better check your oil to see if is contaminated with fuel, if it is drain and relpace . Besure to check fuel pressure 6-7 lbs is all you need. If the pan is loaded it would account for the oil drop however better to check to see if ithere is damage to the engine.
Title: Re: Wont Idle???
Post by: 79charger on July 27, 2010, 02:09:08 PM: what does fuel in oil look like ? And what do you mean by my pan loaded ?
Title: Re: Wont Idle???
Post by: Marcsrollin on July 27, 2010, 02:10:29 PM: Quote from: 79charger on July 27, 2010, 02:09:08 PM
what does fuel in oil look like ? And what do you mean by my pan loaded ?

Smell it! If there is gas in it you will know.
Title: Re: Wont Idle???
Post by: 79charger on July 27, 2010, 08:13:36 PM: new carb didnt work , so i pulled the intake and the cam is gone . Metal in the lifter valley .....Real Nice . My builder says he will rebuild it again . Hope fully he knows where he went wrong .
Title: Re: Wont Idle???
Post by: enginedoctor on July 27, 2010, 08:20:21 PM: Good luck 79'.... There are posts on this site that can help you...Sorry to hear about the cam.
Title: Re: Wont Idle???
Post by: propless on July 27, 2010, 08:34:48 PM: Quote from: 79charger on July 27, 2010, 08:13:36 PM
new carb didnt work , so i pulled the intake and the cam is gone . Metal in the lifter valley .....Real Nice . My builder says he will rebuild it again . Hope fully he knows where he went wrong .

I had a feeling, but didnt want to jinx you.

BTW, did the oil smell like fuel ? That will wipe out a new cam real fast, dont ask how I found that one out. :banghead:
Title: Re: Wont Idle???
Post by: 79charger on July 28, 2010, 01:49:47 AM: no , oil was clean for the most part .I think he used the wrong lifters or pushrods .....
Title: Re: Wont Idle???
Post by: torquer460 on July 28, 2010, 06:07:16 AM: Quote from: 79charger on July 28, 2010, 01:49:47 AM
no , oil was clean for the most part .I think he used the wrong lifters or pushrods .....
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be sure and add a breakin additive that has zinc in it. i also run a heavy duty diesel motor oil in my 502 bbf because it still has the
additives needed to lube flat tappet cams. most oils now days do not. it is very critical on a new cam. be sure and run the cam
manufactors lifters or ones they suggest. run it at 2000rpms for first 20 minutes. be sure cam and lifters are installed using the cam
lube supplied with it.

ps: is your boat made by charger? mine is a 77 charger 21'
Title: Re: Wont Idle???
Post by: 79charger on July 28, 2010, 01:58:11 PM: I used rotella which has zinc in it and ran the motor for 2000 rpms for 25 minutes . As far as cam lube goes i would hope the builder used it .
Title: Re: Wont Idle???
Post by: torquer460 on July 28, 2010, 04:14:16 PM: Quote from: 79charger on July 28, 2010, 01:58:11 PM
I used rotella which has zinc in it and ran the motor for 2000 rpms for 25 minutes . As far as cam lube goes i would hope the builder used it .

Rotella is good. You might ask him about spring pressure, I seen where to much pressure (at enitial startup) can cause problems along with bad
valve train geometry and/or to much preload can cause excessive wear.
Title: Re: Wont Idle???
Post by: 79charger on July 28, 2010, 04:35:35 PM: Yes , spring pressure was a concern of his ....