MERC 500HP FACTS, FICTION, ????'S AND ANSWERS...

[707dog]

White haired guy mid-60ish, wife about 10-15 years younger, and 2 springer spaniels?

hell i thought you were describing ol 2FF

 

[2FORCEFULL]

so what I'll do next is gap the new plugs @ .035,,, they came pre gapped...LOL.. .043 they'd probley run like that, but maybe get blow out...so then I would have a high speed miss, instead of cold idle...I'll button it all up, grab a vac. gauge, a timing light and go to the lake,... then I can check the float level and set the timing... at the lake..

 

[LargeOrangeFont]

So in summary:
It’s a great motor to start a build.
Once you upgrade all of the weak links.

Cliff notes of summary -

Great motor once you replace everything.

 

[Dalton]

2FF- what do you think about the hp500 "bulldog"?......holygrail?

 

[2FORCEFULL]

2FF- what do you think about the hp500 "bulldog"?......holygrail?

the 540 motor?

 

[Dalton]

the 540 motor?

yes

 

[2FORCEFULL]

The Merc Bulldog is an exceptional platform for upgrades. Many of these were contracted to the military, hence the overkill on the hard parts. Below are the specs on the engine.

541.9 CID
GM MK 4 tall deck (cast# 14044807)
Block clearance to accommodate 4.375” stroke
Siamese Bore, reinforced decks with blind head bolt holes.
Deck 10.2”
2 pc rear seal
Bore 4.44”
Stroke 4.375”
(With a factory recommended bore range 4.250’- 4.560” there is plenty of room for upgrades)
SCR 8.6:1
4340 Lunati crank
Piston is Wiseco (Merc part #)
Connecting rod is Manley +.400" / 6.535"
Dart Single Plane Intake Manifold

Crane Camshaft Specification Card
Part Number: 13H000036
Grind Number: H-240/329-2-10 T1.2


The cam rates on a 110*LSA, 5* advance
Lift .329” Lobe .559” Valve
Lift .340” Lobe .578” Valve

Specs:

@.0042"
................Opens..........Closes............. C/L...........Duration
Intake.....43.0 BTDC.....77.0 ABDC......105*..........300 °
Exhaust...88.0 BBDC.....42.0 ATDC......115*..........310 °
85* overlap

@.050"
................Opens...........Closes...........C/L.........Duration
Intake.....15.0 BTDC.....45.0 ABDC.....105*.........240 °
Exhaust...60.0 BBDC.....10.0 ATDC.....115*.........250 °

Camshaft Is Ground with .0012" Lobe Taper

 

[2FORCEFULL]

http://www.mercuryracing.com/sterndrives/engines/540-2/


540
The 540 features a CNC machined cylinder block packed with Mercury Racing designed components, including a balanced crankshaft, forged and shot-peened I-beam connecting rods and forged aluminum pistons.

A carburized hardened camshaft is used for enhanced durability. Performance cam profiles, combined with larger valves, flow more air through the engine for greater power and torque. Increased displacement, combined with enhanced airflow, results in unprecedented mid-range punch and consistent pull through the engine rpm range.

The 540 complies with EPA emissions requirements. CARB (California Air Resources Board) emissions compliant models are available upon special request.

 

[2FORCEFULL]

check this out, big baller stuff, merc says rebuild the 1550 @ 25 hrs...


Highlights

• Rebuilt by Mercury Racing Technicians
• Factory original parts
• Choose either a new or a reconditioned long block
• Qualified on Dyno – full power run and system check
• Factory warranty on all purchased parts for non-competition (1100-1550) models

QC4v Refresh & Maintenance Interval Schedule
Model Refresh Time Maintenance Intervals (Hours)
Max Hours Valve Lash Oil Change
860 300 100 50
1100 200 25/75^ 25
1350 200 25/75^ 25
Dual Cal 1350/1100 200 25/75^ 25
1550 25—100* 25/75^ 25
*Maximum hours for refresh at 1550 mode is 25 hours; a total of 100 hours when combined with 1350 mode run time.

^Recommended adjusting the valve lash after the first 25 hours and every 75 hours afterward

 

[2FORCEFULL]

so, I believe this to be correct, merc says to rebuild the hp 500 at 300 hrs....correct???

 

[guest hs]

I have seen Gill manifolds make huge improvements over stock manifolds. Much better then Imco or Eddie Marine. Don’t forget about the valve spring height issue with Merc. 500 engines so there is clearance for those short valve covers they use.

 

[2FORCEFULL]

I have seen Gill manifolds make huge improvements over stock manifolds. Much better then Imco or Eddie Marine. Don’t forget about the valve spring height issue with Merc. 500 engines so there is clearance for those short valve covers they use.

I dropped the prop off on fri on the way to the lake...hope it works for you...

 

[2FORCEFULL]

Monitoring to each cylinder is less important and not the same as delivery to each cylinder. EFI with port injection and decent injectors will deliver equal fuel to each cylinder at a given load. A single carburetor can not.

pretty sure, though didn't see it with my own ly'n eye's... that merc has a pretty elaborate dyno and they read AFR to each cylinder... that's how they knew to do staggered jets on the carb...what I do,,and what I did fri at the dock... I start the motor,,,and let it warm up running at the dock....it's easy with the gil exhaust... if you touch down by bottom of the manifold, each cylinder will start getting heat,,.. that lets you know each cylinder is firing... after letting it run, I still had 3 ports cool to the touch...that told me I had 3 dead holes so I just loaded up and came home...I do the same test on header motors, but only I do it with a wet rag...tube headers will burn the shit out you... it's kinda like the shop towel fan clutch test... some of you might wanna watch it done first....lol... when I used to race alcohol motors, we would run the motor till you felt heat in the heads with your hands before making a pass, in the pits the same process , then run the valves..and at the same time I could do a exhaust port test to see that all holes were firing

 

[2FORCEFULL]

a well known problem with that engine is the rings going away.

leak yours down.

seen them go away after just 250hours.

I don't know if its because of the ring package merc uses, or possibly the hone finish on the cylinder wall, or the excessive fuel merc tunes throw at the engine that shortens ring life.

and yeah...there is a world of difference between the modern port injected 8 channel systems vs the one size fits all approach merc runs.

I've had 502's leak down over 75% and on the same motor bring it up to less than 10% just running marvel mystery oil ...and I sudjest to every one to run marvel in their oil, and lucas in the fuel...marvel WILL re seat rings...although all my plugs were fuel fouled, I was happy to see them all black,, one white would have ment pull the heads today..I'd like to get through this season,though it's time for a tear down, I wanna go back with aluminum heads, and of corse valve train up grades...I did the head swap to aluminum on my last hp 500 and was able to go up two prop pitch sizes...

 

[2FORCEFULL]

The problem with boats and motors, is the boat owners, and the lack of general knowledge... it's wallet race...it's like going to the drags, walking over to the pits, and finding no one has a tool box.and they are all out there comparing spray wax, no one has spark plug,or knows how to run the valves..no one checking any thing, goes out the next round and murders the motor..
as far as my boat.... it has a higher value to the general public... it has a stock merc motor that still has the factory lead seals
and has never been touched... but to those few in the know... the 300 hrs raises the red flag..the blue merc racing motors are just that,,they are a motor that needs to be owned by a wrench....when you tell some one they should pull the heads on there motor at 300 hrs, you might just as well told them their kid is ugly.. a good boat mech. can have your motor out and on the ground in less than and hour, and have the heads off while you go make a run to mc donalds through the drive through...but, getting back to the general public... they just don't wanna buy a motor that's had a wrench on it..so my advise to those in the majority.. stay away from the race motors,,,get a 496 ho... they are throw away motors, go lots of hours with just and oil change, pretty much junk componites , and when the rotating assembly goes... just get another one and be a happy boater...they are monitored to be murder proof and will just shut down when something is not right...sure, you can lean on them and make them have more power, but the longevity goes out the window,and with a lot of luck, you might not window the block and throw the rods out the pan..

 

[2FORCEFULL]

I went away from my norm, when I bought this boat, the "FUGLY DUCK"... I just couldn't get up the want to have wrench sex with it... it's fugly..and wrench sex on a boat motor in the boat is like sex with a crack hoe, you'll end up on your head before you're done.. and my bad for not bringing it home , pulling the plugs and doing a leak down... so bash a way... my bad is gonna be my response, and deserve the lashing...I said this about others, what a dumb ass , hauled the boat 45 miles to go find out the plugs were fuel fouled....but, all I can say is, I know what I need to do,pull the heads...but, I thought i'd just be the regular joe that just goes out there and runs it...lol...I'd like to finds a good mechanic that has the time to do a tare down head swap, but most everybody is booked way out there, so my thought was to limp it easy through the summer.. and have it for a winter project.. one of the 2FF's needs a good ass whomp'n for not doing this last winter..it's kind off a Russian roulette deal. lots of history that shows it is good insurance to pull the head around 200-300 hrs,.. even though it's running perfect... and there is also the history of those that will say,.. I have 600 hrs on the motor and never had the valve covers off..

 

[2FORCEFULL]

my lake mead dyno,LOL ...I pulled the heads off this motor @ 200 hrs,... just to have wrench sex and she what she looked like stripped,.. beautiful Hallett 270, pulling a 26p with aluminum head swap

 

[707dog]

keep the input coming some people will be like what the fok is the geezer rambling on about... then guys like myself who have spent the $$ building a motor mocked after the blue ball 500 motor pay attention and enjoy the reads. although i went with the HP 525 efi cam for my build the same maintenance stands and have already left that money in my engine builders tool box to take care of the heads when its time still have 150 hrs to go

 

[2FORCEFULL]

on that 270 hallett, I pulled the heads @ 200 hrs, this is what I found,it was bout to suck a valve, and if you look close it was about to cut a hole between 5&7... I've pulled these motors down to find where it looks like some one took a cutting torch and cut a groove between these cylinders... got to this one in time so it saved to motor..

 

[2FORCEFULL]

keep the input coming some people will be like what the fok is the geezer rambling on about... then guys like myself who have spent the $$ building a motor mocked after the blue ball 500 motor pay attention and enjoy the reads. although i went with the HP 525 efi cam for my build the same maintenance stands and have already left that money in my engine builders tool box to take care of the heads when its time still have 150 hrs to go

Hope all is well up your way, hows the legs doing..? like I said in the first post,,there'll be a lot of people that disagree... and jaws dropping, some people will argue with the sign post and take the wrong road home...I think they put the valve covers on top of the motors to make it easy to take them off, while most think it's so they can put pretty ones on easy ....lol.. good to hear from you... when's havasu trip, and as you know, you and the family are welcome at my havasu or vegas home anytime..

 

[707dog]

had hope to down there for the hallett dealio this year but other people beat me to putting vacation in for around that time but still working a angle it maybe a smash and crash drive tp spend 2 days there but we will see. legs are great back to work and coaching kids sports 100% and taking long family bike rides keep them working good too keeping up with the youngsters

 

[farmo83]

What is a siamese bore ? I've heard the term but have no idea what it means.

 

[wsuwrhr]

What is a siamese bore ? I've heard the term but have no idea what it means.

It means the bores are joined together at the sides with no water in between where they are touching.

Brian

 

[wsuwrhr]

The cylinderwalls have become so big of a diameter on a block that was designed with a finite bore center so eventually what happened is they have increased to the point there is nowhere left to go.

If that makes sense.

Brian

 

[guest hs]

I dropped the prop off on fri on the way to the lake...hope it works for you...

Thanks Steve i will give it a whirl. I actually ran a Mirage plus on my boat this weekend and boy did the boat like it! I finally got the engine to spin 5K and the speed was way up there and the idle speed wondering at the wheel i use to have is almost non existent now.

 

[wsuwrhr]

Which describes every build on every motor ever done.

Disassemble, throw away damn near everything but the crank, bare block and cylinder heads, valve covers, maybe the rods and oil pan are reused.

....and maybe a handful of bolts.

Start over.

Brian

Cliff notes of summary -

Great motor once you replace everything.

 

[Bigbore500r]

Which describes every build on every motor ever done.

Disassemble, throw away damn near everything but the crank, bare block and cylinder heads, valve covers, maybe the rods and oil pan are reused.

....and maybe a handful of bolts.

Start over.

Brian

Seems like factory motors have come a long way, stock components are pretty stout these days. Hell - the head gasket of choice for 25+ lbs of boost on a LS Motor, is a factory head gasket!

Typical LS3 N/A build

-swap camshaft and springs , retain stock lifters
- Tune it
- Beat on it for years / 7000rpm

 

[wsuwrhr]

Right.

Suit yourself.

Years. Noted.

Well until 10s, or 100's, of thousands of LS motors are in hotrodded boats and cars for 50 years, I guess the jury will still be still out.

Brian

Seems like factory motors have come a long way, stock components are pretty stout these days. Hell - the head gasket of choice for 25+ lbs of boost on a LS Motor, is a factory head gasket!

Typical LS3 N/A build

-swap camshaft and springs , retain stock lifters
- Tune it
- Beat on it for years / 7000rpm

 

[Bigbore500r]

Right.

Suit yourself.

Years. Noted.

Well until 10s, or 100's, of thousands of LS motors are in hotrodded boats and cars for 50 years, I guess the jury will still be still out.

Brian

“Until 10’s of thousands of LS motors are hotrodded” - lol

I thick that milestone was eclipsed In 1997? This is a 21 year old platform at this point . Your more likely to find a LS in a fox body mustang that you are a 5.0 anymore, and THATS saying something

 

[wsuwrhr]

You're. Yoooor, yore, yoooorreee, please.

Think.

It is??? Considering the "5.0" was always a POS, since prolly 1964, I don't think it is any benchmark to rest an accomplishment on. With it's piss poor rod ratio and a short deck to boot. Aint worth fuck for nothin.

Brian

“Until 10’s of thousands of LS motors are hotrodded” - lol

I thick that milestone was eclipsed In 1997? This is a 21 year old platform at this point . Your more likely to find a LS in a fox body mustang that you are a 5.0 anymore, and THATS saying something

 

[wsuwrhr]

Sorry,

Forgot the venerable, lol.

Youre.

It is??? Considering the 5.0 was always a POS, since prolly 1964, I don't think it is any benchmark to rest an accomplishment on. Piss poor rod ratio and a short deck to boot. Aint worth fuck for nothin.

Brian

 

[bocco]

So I've got one of these motors right at 300 hours. 1997 gen 6 with the seals still on it. I've got three seasons on it with nothing but basic maintenance. It runs great and I really don't want to F with it. But it's probably wise to start to thinking about it. that being said, the valve train is kind of noisy in my opinion but I have heard that that is the nature of the boast.

I'm not looking for more power so whats the minimum to get me another few seasons? Obviously the heads need to go to the local machine shop for a valve job and springs. If the rockers look OK are they good to keep running? Lets make a list of required parts to replace assuming the short block stays in the boat. I'm just enough of a wrench to do the work myself with a little help from the RPD knowledge base. When I break down and do this I don't want to spend more than I have to but I want to use good parts that will hold up?

Head gaskets for sure. Which ones are recommended?

Head bolts? Studs? Reuse?

Which springs keep the correct height?

If the valves look good do they need to replaced or just a good valve job?

Rockers?

Push rods?

Lifters for sure. Which ones will quite things down a little bit.

Timing chains don't seem to be a problem.

 

[LargeOrangeFont]

So I've got one of these motors right at 300 hours. 1997 gen 6 with the seals still on it. I've got three seasons on it with nothing but basic maintenance. It runs great and I really don't want to F with it. But it's probably wise to start to thinking about it. that being said, the valve train is kind of noisy in my opinion but I have heard that that is the nature of the boast.

I'm not looking for more power so whats the minimum to get me another few seasons? Obviously the heads need to go to the local machine shop for a valve job and springs. If the rockers look OK are they good to keep running? Lets make a list of required parts to replace assuming the short block stays in the boat. I'm just enough of a wrench to do the work myself with a little help from the RPD knowledge base. When I break down and do this I don't want to spend more than I have to but I want to use good parts that will hold up?

Head gaskets for sure. Which ones are recommended?

Head bolts? Studs? Reuse?

Which springs keep the correct height?

If the valves look good do they need to replaced or just a good valve job?

Rockers?

Push rods?

Lifters for sure. Which ones will quite things down a little bit.

Timing chains don't seem to be a problem.

Compression and leakdown test. If that is all good swap valve springs, lifters and perhaps rockers and pushrods if they are showing wear. Then run it.

 

[Bigbore500r]

You're. Yoooor, yore, yoooorreee, please.

Think.

It is??? Considering the "5.0" was always a POS, since prolly 1964, I don't think it is any benchmark to rest an accomplishment on. With it's piss poor rod ratio and a short deck to boot. Aint worth fuck for nothin.

Brian

“Mopar or no-car” is all I’m hearing

 

[LargeOrangeFont]

Right.

Suit yourself.

Years. Noted.

Well until 10s, or 100's, of thousands of LS motors are in hotrodded boats and cars for 50 years, I guess the jury will still be still out.

Brian

Volvo Penta V8s are LS based. I’d/yoood/anyone would have zero problem swapping a cam and valvesprings to get a 500 HP LS in a bote.

 

[wsuwrhr]

Never said a word about a motor preference, so if somehow you are "hearin it", it was all you sayin it, bringing up fords and I slammed dunked it over the top of you. I don't even know how that was so easy.

At this point Ive got as many Chevys in the family as there are Mopars.

lol.

I thought the thread was about he HP500?

Brian

“Mopar or no-car” is all I’m hearing

 

[wsuwrhr]

Great, now the thread is going off the rails from the OPs request and somehow rd is going to blame me for it. lol.

Volvo/Penta....another benchmark accomplishment in the boating world, but you go swapping your roller(prolly) cam onto your used lifters and run it.

Lets get back to 2FF stroking his love/hate deal with the HP500.

Brian

Volvo Penta V8s are LS based. I’d/yoood/anyone would have zero problem swapping a cam and valvesprings to get a 500 HP LS in a bote.

 

[guest hs]

So I've got one of these motors right at 300 hours. 1997 gen 6 with the seals still on it. I've got three seasons on it with nothing but basic maintenance. It runs great and I really don't want to F with it. But it's probably wise to start to thinking about it. that being said, the valve train is kind of noisy in my opinion but I have heard that that is the nature of the boast.

I'm not looking for more power so whats the minimum to get me another few seasons? Obviously the heads need to go to the local machine shop for a valve job and springs. If the rockers look OK are they good to keep running? Lets make a list of required parts to replace assuming the short block stays in the boat. I'm just enough of a wrench to do the work myself with a little help from the RPD knowledge base. When I break down and do this I don't want to spend more than I have to but I want to use good parts that will hold up?

Head gaskets for sure. Which ones are recommended?

Head bolts? Studs? Reuse?

Which springs keep the correct height?

If the valves look good do they need to replaced or just a good valve job?

Rockers?

Push rods?

Lifters for sure. Which ones will quite things down a little bit.

Timing chains don't seem to be a problem.

I have seen many of the 500 carb and 500 efi engines go well over the 500 hour mark with proper maintence. The rockers arms seem to be the weak link and i cant tell you why because they are a good quality Crane roller rocker arm. But everyone of these engines i see fail these always broken rocker arms. It really depends on do you babby your boat or run the piss out of that will be the deciding factor.

 

[LargeOrangeFont]

Great, now the thread is going off the rails from the OPs request and somehow rd is going to blame me for it. lol.

Volvo/Penta....another benchmark accomplishment in the boating world, but you go swapping your roller(prolly) cam onto your used lifters and run it.

Lets get back to 2FF stroking his love/hate deal with the HP500.

Brian

It is always yoooore fault Brian.

 

[wsuwrhr]

It aint my first ro-da-o sir.

It is always yoooore fault Brian.

 

[Bigbore500r]

Great, now the thread is going off the rails from the OPs request and somehow rd is going to blame me for it. lol.

Volvo/Penta....another benchmark accomplishment in the boating world, but you go swapping your roller(prolly) cam onto your used lifters and run it.

Lets get back to 2FF stroking his love/hate deal with the HP500.

Brian

If your trippin on re-using roller lifters....wait till u see me sliding in a reground cam! . #itgetsworse

 

[28Eliminator]

The 2 biggest problems with the HP 500 were the heads, and the cylinder bores.

Stock heads were 325cc runners, IMO too big for that engine to provide enough port velocity for a proper carb signal, causing incomplete/insufficient fuel vaporization.

The Cylinders were not honed with deck plates by Merc, resulting in bad ring sealing/failure.

Fix those, and they’re solid engines!

 

[Racey]

I start the motor,,,and let it warm up running at the dock....it's easy with the gil exhaust... if you touch down by bottom of the manifold, each cylinder will start getting heat,,.. that lets you know each cylinder is firing... after letting it run, I still had 3 ports cool to the touch...that told me I had 3 dead holes so I just loaded up and came home...

I would imagine that if you had 3 dead holes you'd hear it, and you'd feel it, Dry headers in a car, absolutely we check em with the infrared all the time during initial EFI setup and shake down, wet rag too is fine, hell even just getting your hand close you can feel if it is hot or not without even touching it. But on it's almost impossible to gauge runner temp on a manifold that is heavy walled aluminum surrounded by a water jacket wicking heat away by touching it. There is a ton of water flowing through there and the whole temperature differential is dampened by that. Depending on where the water is coming in from, and the flow through the manifold. I would never rely on that as a full proof method of telling whether or not the cylinder was firing in a marine application with a cast and common jacketed manifold.

 

[buck35]

A few cheap inline spark testers will tell you if you are getting fire to the plug, and its not too difficult to see if said plug is firing.

My question is who and why were the plugs installed with an .022 gap ? This makes no sense at all ...
also , what became of the spaghetti steering lines and slop.

 

[LargeOrangeFont]

The 2 biggest problems with the HP 500 were the heads, and the cylinder bores.

Stock heads were 325cc runners, IMO too big for that engine to provide enough port velocity for a proper carb signal, causing incomplete/insufficient fuel vaporization.

The Cylinders were not honed with deck plates by Merc, resulting in bad ring sealing/failure.

Fix those, and they’re solid engines!

So you are saying it is solid after tearing it completely down, re machining the block and putting all new parts in it .

 

[LargeOrangeFont]

If your trippin on re-using roller lifters....wait till u see me sliding in a reground cam! . #itgetsworse

China head studs? Say it isn’t so!

 

[Riverbottom]

A few cheap inline spark testers will tell you if you are getting fire to the plug, and its not too difficult to see if said plug is firing.

My question is who and why were the plugs installed with an .022 gap ? This makes no sense at all ...
also , what became of the spaghetti steering lines and slop.

Probably someone who runs a magneto, shouldn't be .022 for much of anything else.

 

[Bigbore500r]

China head studs? Say it isn’t so!

Dont get me started...my last 408 had Chinese RPM rods and crank lol

I’m done threadjacking - sorry 2FF

 

[28Eliminator]

So you are saying it is solid after tearing it completely down, re machining the block and putting all new parts in it .

Exactly [emoji16]


Sent from my iPhone using Tapatalk

 

[wsuwrhr]

Cams are reground All. The. Time.

If your trippin on re-using roller lifters....wait till u see me sliding in a reground cam! . #itgetsworse