new boat, some questions on 5.7 mercruiser

[Scott Danforth]

Re: new boat, some questions on 5.7 mercruiser

I doubt it. however if your in fresh water, aluminum is fine.

most aluminum marine manifolds are dual alloy castings - water jackets out of bronze, then over-cast with aluminum.

then again, you could always go back to cast iron.

 

[idleRelaxation]

Re: new boat, some questions on 5.7 mercruiser

I doubt it. however if your in fresh water, aluminum is fine.

most aluminum marine manifolds are dual alloy castings - water jackets out of bronze, then over-cast with aluminum.

then again, you could always go back to cast iron.

guess ill be swapping out my intake mani then, trying to remove any possible water entry points, i would imagine this would eventually be a problem in salt water? i would mostly be in salt water

 

[Scott Danforth]

Re: new boat, some questions on 5.7 mercruiser

you could also use enecon to coat the water passages of your intake. however that stuff is pricey.

there are aluminum intakes with bronze water connections available

if you had vortec heads, here is one on fleabay http://www.ebay.com/itm/Marine-Inta..._Accessories_Gear&hash=item35ba3a873d&vxp=mtr


here is a used iron intake with distributor, etc. http://www.ebay.com/itm/Mercruiser-..._Accessories_Gear&hash=item2573a641e4&vxp=mtr

 

[idleRelaxation]

Re: new boat, some questions on 5.7 mercruiser

you could also use enecon to coat the water passages of your intake. however that stuff is pricey.

there are aluminum intakes with bronze water connections available

if you had vortec heads, here is one on fleabay http://www.ebay.com/itm/Marine-Inta..._Accessories_Gear&hash=item35ba3a873d&vxp=mtr


here is a used iron intake with distributor, etc. http://www.ebay.com/itm/Mercruiser-..._Accessories_Gear&hash=item2573a641e4&vxp=mtr

both those are for vortec heads correct? just to be sure, difference is the bolt pattern, vortec being vertically mounted bolts and non-vortec being angled?

guess ill at the least pull my intake mani to check for water entry there, though my riser gasket seemed to have been the water entry point

 

[Scott Danforth]

Re: new boat, some questions on 5.7 mercruiser

the used distributor and intake is for the early Gen 1 SBC. the aluminum intake is for the vortec heads.

 

[idleRelaxation]

Re: new boat, some questions on 5.7 mercruiser

the used distributor and intake is for the early Gen 1 SBC. the aluminum intake is for the vortec heads.

sorry if this is a dumb question, but am i missing something then? bolt pattern for both those intake manis is vertical, no? i dont have vortec heads and my bolt pattern is angled

 

[Scott Danforth]

Re: new boat, some questions on 5.7 mercruiser

no, the bolts for the vortec are vertical and there are only 8 of them on an V8 vs the 12 on the earlier Gen 1's I didnt look at the used intake close enough and assumed it was older since it has the TB IV ignition in the same auction.

 

[idleRelaxation]

Re: new boat, some questions on 5.7 mercruiser

no, the bolts for the vortec are vertical and there are only 8 of them on an V8 vs the 12 on the earlier Gen 1's I didnt look at the used intake close enough and assumed it was older since it has the TB IV ignition in the same auction.

ok just making sure

come to think of it, i think i only have 8 bolts in on the intake mani, if i remember correctly i did not see any bolts in the two vertical holes on the mani, only the 8 bolts in the angled holes, sounds strange no? will take a look today

 

[idleRelaxation]

Re: new boat, some questions on 5.7 mercruiser

anywhere i can find distributor removal/reinstallation procedures? ive never done this and imagine i need to remove it to pull intake manifold

actually, found pdf showing basic steps, is there anything i can do to make reinstallation easier ( dont have to remove cap/removing entire assembly/keeping same position)? im basing this on what i found here : http://www.boatfix.com/merc/Servmanl/16/16B4R2.PDF

 

[Scott Danforth]

Re: new boat, some questions on 5.7 mercruiser

to remove the distributor, manually crank engine around to TDC on #1 cylinder. remove cap and take a permanent marker and mark where the rotor is pointing. also make a reference mark on the distributor to the intake manifold. then remove the distributor clamp. gently pull up on the distributor. when it comes free, mark where the rotor is now.

when you install, line up the rotor with the last mark, drop into the hole, the rotor should turn to the first mark. then line up the marks on the distributor with the marks on the manifold. this gets you really close to re-time the engine.

 

[idleRelaxation]

Re: new boat, some questions on 5.7 mercruiser

to remove the distributor, manually crank engine around to TDC on #1 cylinder. remove cap and take a permanent marker and mark where the rotor is pointing. also make a reference mark on the distributor to the intake manifold. then remove the distributor clamp. gently pull up on the distributor. when it comes free, mark where the rotor is now.

when you install, line up the rotor with the last mark, drop into the hole, the rotor should turn to the first mark. then line up the marks on the distributor with the marks on the manifold. this gets you really close to re-time the engine.

thank you very much! cant tell you how much this forum has helped already, really appreciate the quick responses

 

[idleRelaxation]

Re: new boat, some questions on 5.7 mercruiser

took some other pics, didnt get a chance to remove intake manifold yet and check status of runner

the block casting number is 10243880, which seems to be a 95-00 vortec block, i know it was a 4bolt main, apparently with a roller cam, much newer than i would have imagined.

confusing part is this, on the intake manifold there are 12 bolts, but on one side there are two empty bolt holes shown below


so it seems i have a vortec block with non vortec heads?

also, if the top one is the temp sender, what is the bottom sensor?


and if grounding the temp sender wire does not send temp gauge to full hot, next step grounding at gauge, if it doesnt shoot up there then new gauge?

 

[Scott Danforth]

Re: new boat, some questions on 5.7 mercruiser

one sender is gauge, one is alarm. you do not have vortec heads, however would get more bang for the buck with them.

 

[idleRelaxation]

Re: new boat, some questions on 5.7 mercruiser

temp sender was bad, ordered new one

adjusted shift assembly and now reverse engages perfectly just in case anyone ended up here seaching for this

 

[idleRelaxation]

Re: new boat, some questions on 5.7 mercruiser

also, for anyone else reading this, I took the boat out today and she ran perfect, the timing was definitely the issue, almost no time to plane out and it hit 59mph(gps on iphone) at 4500 rpms, so if your boat is running low rpm WOT check your timing if any service has been done to distributor or surrounding items

also, checked oil after running, clean as a whistle with no water or milky-ness, rather surprising after one oil change, i did use some marvel mystery oil

i think the thermostat may be busted or non existent though, boat ran rather cold, never going above 140, stayed mostly around 125-130, would i be right in that assumption?

 

[tswiczko]

Re: new boat, some questions on 5.7 mercruiser

Hi Idle, Those are about right inline with mine, it rarely gets to 150,
I have a 5.7 magnum, 23p prop 4500 wot @52mph GPS(with the wind at my back going down stream) in a 24ft./cuddy

 

[idleRelaxation]

Re: new boat, some questions on 5.7 mercruiser

Hi Idle, Those are about right inline with mine, it rarely gets to 150,
I have a 5.7 magnum, 23p prop 4500 wot @52mph GPS(with the wind at my back going down stream) in a 24ft./cuddy

i think it still has some in it, i went out on rather rough waters for WOT runs, but i just had to test all my repairs, im thinking on a day with good conditions she will hit around 62-63 trimmed

do you have trim tabs on your boat? i am definitely installing some on my baby

 

[tswiczko]

Re: new boat, some questions on 5.7 mercruiser

Yup. The trim tabs make a big difference. I can get on full plane before I hit 18 mph. But when I'm above cruising speeds I lift them all the way up and trim the motor out a little for best speed.
I would need a big block to get your speeds but 52 is respectable for about 5k worth of boat and my fuel consumption isn't bad at cruising speed. My cruise speed is between 26 and 36 mph anything above 36 and I spend a lot more than I have to on fuel. Best being closer to 26

 

[idleRelaxation]

Re: new boat, some questions on 5.7 mercruiser

Yup. The trim tabs make a big difference. I can get on full plane before I hit 18 mph. But when I'm above cruising speeds I lift them all the way up and trim the motor out a little for best speed.
I would need a big block to get your speeds but 52 is respectable for about 5k worth of boat and my fuel consumption isn't bad at cruising speed. My cruise speed is between 26 and 36 mph anything above 36 and I spend a lot more than I have to on fuel. Best being closer to 26

That's another thing, I'm very surprised with the good fuel economy I am seeing

I have a nice cruise of 30-35 but the tabs would really help stabilize the boat, especially when/if I do choose to swap in some Vortec heads to fully utilize the roller cam in my block

I did seem to have a problem keeping the motor at around 1k-1.5k rpms, I've read this can happen with non-stock cams and timing not being advance enough, should I try advancing my base up a bit to say 10? It's at 8 now

 

[idleRelaxation]

Re: new boat, some questions on 5.7 mercruiser

to be clear, i can put engage into forward and idle in forward gear, but if i try to increase throttle slightly (lets say for a no wake zone) itll bog down and turn off, but if i throttle up to say atleast above 1.5-2k rpms itll run perfectly fine

basically i cant really get a slightly quicker wake zone speed beyond idle, this is what i think might be related to my timing and cam spec since it wasnt doing this when the base timing was much more advanced than what it is now (8*)