3.0 Mercury marine question

I want to build a hot 4 banger to run in a T bucket or roadster ( I've been looking at the Speedway motors kits ) I was thinking of a 3.0 Mercury marine( 181 Chevrolet ) I was wandering if anyone ever built one? I was told you can use the 153 Chevrolet head so you can use the Clifford performance 4 barrel intake.

Larry at Clifford recommends the 151 Pontiac Iron duke other people I've spoke to say the 181 is better. Any thoughts? Thanks Todd

 

I am running one in my 1932 Ford roadster. It's been in there for 25 years and I love it. I am using the 181 block and the 153 head.

Charlie Stephens

 

Fab up a manifold for the 181, much better head 8 port and bigger valves. Got a 181 all bulit on the stand waiting for me to get off my ass and put it in my 27 T to replace the 153 that is in there now. Fab'ed up a 2 one's manifold out of 2X3 tube for it. Ports in the 181 are MUCH bigger than the 153 has.

 

A better idea is the 3.7, 470, or 488 Mercruiser. Look it up in the archives. There is a guy in NJ not far from you that has one in parts, and several complete ones on Craigs at this very moment. Yes, I want to put one in my Fiero.
Good Luck!

 

Thanks for the replies. Todd

 

Wow dude, unlucky choice of a username...hotrodtodd of the Hellions CC just passed away recently...I'm glad nobody is using that name for a sick joke (which is what I thought this was going to be before reading it), but it's still a little creepy to see his name posting here so soon...

 

Saw a Mercruiser 4 cylinder derived engine in a roadster recently.......It was larger displacement than the 181 version........same as I used to have in a boat years ago.......uses some 460 Ford parts......this guy even had an aluminum aftermarket 460 Ford head on it.......nicely finished and detailed...used a commonly available bellhousing that fit all but one bolt as I recall, a really cool and unusual (around here anyway) powerplant......very refreshing to see something besides SBC

 

I didn't know the other hottroddtodd. Hate to hear of anyone passing. I hope to live a long time...

 

Ya, that took me by surprise to see the name...
HOTRODTODD was one of our club members/brothers killed one week from, shit, one hour from now! You are welcome to use the name at your own risk, but if you choose to do so...
Please use with the utmost RESPECT!

 

i hope you live a long time too, but it would show mad respect to change your user name. it appears you just joined so it shouldnt cause you too much hassel. He was a great friend and all around great guy...if you knew him you would unerstand where we are coming from...

 

R.I.P. brother...

 

there is no "other" hotrodTodd, he was IT. He is my cousin, and has a bunch of friends, family, club members on this site, out of respect, change your name.

 

The motor that uses 460 parts is a half of a 460. Its turned 30 degrees I guess, so the head sits level. I have heard good thing about them from boat owners who have owned them. Most of the complaints come from people who never had one, go figure.

 

It was actually called a 470, 3.7 liter

 

Please change your name . . .
All to soon and way to weird.
Please consider our fallen brother and change your username.

 

I contacted Ryan and had him change my name to autocartodd.

 

Hey..lets get this thread going again....is it true the Mercruiser 181 is half a 327....if so would all 327 performance parts work for a 181? I need a prescription for a mild 3.0 hop-up rebuild. Any suggestions out there??? Also, what is the best automatic to use with this motor Thanks HAMBer's

 

"is it true the Mercruiser 181 is half a 327"
No.

 

Well, not exactly, but one box of 327/350 piston rings did re-ring TWO 181's! Same bore and ring widths used on slugs.

 

Hello all, I have one of these 181 Mecruiser engines and want to turn it into the powerplant for custom build, I have questions !!! many, many, questions lol.

Head? which one can be swapped ove ror do I need to do this?

Cam, being a boat engine it has a "marine" profile, where would i go about finding such a cam or do I need to?

I have spent a little bit of time trying to find answers and they have led me here...

Thank you all in advance for any suggestions/advice.

Muddi1

 

I will do the best that I can to answer some of your questions. I’m no expert on any of this, but I just spent the better part of 2 years resolving all of the issues you will go through to make this engine work on the street, so I do have SOME experience.

I recently completed a 181 swap into my ’28 pick up and have it on the road. I managed to drive it for about a month before putting it away due to nasty Jersey weather, but it does work and is a fun driver.

Head: As stated on this thread, the stock 181 head is a better design with larger ports and breathes much better than a 153. The downside is there is NOTHING available for it, with regards to intakes or headers, ANYWHERE, so a custom build is required. It took me two generations to make mine work, but it’s in, it works and I couldn’t be happier! Plus it looks cool!! I have no experience with the 153 head, but if it bolts up, there is plenty of aftermarket stuff for intakes and exhaust out there. Your fabricating ability, budget, and expectations out of this engine will dictate the direction you want to take your project.

Cam: The stock marine cam is still in my engine. It has specs of 204 duration @ .050 lift and a valve lift of .498 with the 1.75 to 1 ratio rocker arms. The listing in the Isky cam shaft web site,for the Nova 153 inch motor, shows this cam has specs right between Isky's first 2 street cams which have durations of 202 and 208.

Pistons: Stock units are fine to use, but since my engine needed to be bored and the head decked, we decided to play a little. Pistons used, in the rebuild have no valve relief. They are the flat tops for the propane model of the motor. Decking was done to true the surfaces, which pushed the compression up to or slightly past 10.0 to 1.

Block: The block was boiled, .020 off the block to repair the deck, then bored to .030 over sized. New camshaft bearings and brass casting plugs installed. The head was also decked to true it. This took off .015 from it's surface, and a 5 angle valve job was done. New valve guides were machined to allow the use of new type sealed power valve seals but the crank shaft was still standard size so it simply got polished to clean the journals and reused.

Internally, that is pretty much all we had to do to get this little guy back into shape.

Externally, spark from the stock point and condenser type system was heaved and replaced with a full electronic marine/forklift kit for a more dependable and hotter system.

One of the bigger issues to resolve was the oil pan. As this motor, in both marine and industrial models, uses a front sump oil pan, while test fitting, we found the sump hit the tie rod and drag link, so the search went out for a rear sump pan and oil pick up. We discovered that an old early 60's Chevy K10 box van was needed. I found one in Minnesota and had it shipped. It literally is a complete reversal of the Mercruiser part and bolted into place.

Carb wise, we used the stock Mercruiser unit, basically a Rochester, but had to put in smaller jets as it ran rich. Down sizing the jets from 1.45mm to 1.35 mm gave us the perfect plug color and a proper running engine. The smaller 1.35mm jets are used for this carb in higher altitudes due to thinner air. But the catch was, they were no longer available from Mercruiser. We located a set in Seattle that were NOS! Searching the web we found that motor cycle jets from both Keihin and Mikuni carbs are perfect matches both in size and thread, so there are fresh supplies out there.

The bellhousing is GM so anything you can put behind a V-8 will go behind this little guy.

It’s a fun driver so far. If I can answer any other questions for you, I’m more than happy to do so. Also. My buddy Charlie, who was instrumental at doing the engine build is wealth of knowledge and is on the HAMB under ‘Jersey Greaser’. He has volumes of sites and specs that may help you out.

 

"One of the bigger issues to resolve was the oil pan. As this motor, in both marine and industrial models, uses a front sump oil pan"

There are several other applications which used a rear sump:
68-70 Nova, small Postal vehicles (I have a '71 engine) and the first couple of years of 151 engines in Pontiac Astre & Sunbird, (77-78) and 78 Chevy Monza, Olds Starfire and optional on 78 Vega. All of these are probably just as rare as the van 4 cyl.
There was a change in the oil pan rail, I think sometime in '79, which makes the later pan different.

"Externally, spark from the stock point and condenser type system was heaved and replaced with a full electronic marine/forklift kit for a more dependable and hotter system."

The Astre and Monza used a 4 cyl HEI but the distributor location on the later '79-1/2 engine was different than on the 153s. I don't think it would take much to adapt to the earlier engines.

 

ok guys! i'm lances mechanic. mercruiser did for some time make it's own 3.8 liter 4 banger.believe me it is a royal POS merc cast their own alloy block used a 460 ford head. gear drive water pump. mechanic worst night mare.

the 3.0 L 181 inch is the chevy nova.gm industrail motor. in marine trim it make 140 hp with a carb or MPFI. but has 8.25 to 1 compression,
the industrail model makesa very low hp something like 73 at 2200 rpm. has 10.5 to 5 compression other wise from the bell back it is small block chevy,
here is a low down on doing the job, a brand new crate motor
http://www.helmarparts.com/product_p/85890-gm.htm.costs $2.450.00. this should be the 8 port head with the raised ports. comes with all the parts listed. here is the gm info link
http://www.gm.com/vehicles/innovati...lized/industrial/REV_2011_3000_Industrial.pdf

you need to change the camshaft to a marine, "thanks sealed power for a after market" get from a gm industrail dealer parts for a first design 1991 to 1993 3.0 l 181 inch rear sump oil pan part number 93419742, pick up screen part number 03915988, main bearing stud part number 03852870

helmar also sells a gear reduction starter brand new http://www.helmarparts.com/product_p/5800779-57-new.htm. if you use the cast iron manifolds they have a down pipe for $18.00,http://www.helmarparts.com/product_p/3eb-03-22110.htm

motor mounts and alternator can also be obtained cheaply. fuel supply the marine fuel pump remains the best move as a fuel filter is built into it. you could still use a electric pump if you wanted i simply like the on board filter with the marine pump.

 

"first design 1991 to 1993 3.0 l 181 inch rear sump oil pan part number 93419742"

Does that pan fit the 153 motor?

 

sorry but this number is for the newer 181 inch motor with the 1 piece rear main seal and a 1 piece pan gasket,

for your 1971 motor you need to get lance to pm you his place in MN for a pan off a p10 box van from the 1960's that used the nova 153 engine, as lance states they also sent him the needed pick up/screen, you will also need a main bolt with the stud built onto it.
you can use one from a small block v8 by cutting off a 1/2 inch of thread.


try calling these guys http://www.atlantaliftruck.com/index.php they may have a rear sump pan and can for sure supply you with a cast iron intake/exhaust combo manifold for the 6 early 6 port head like you have.

word of warning here, and i do mean WARNING! fit the pan and trim the baffle as needed! if you don't that baffle gets hit by the crank shaft counter weight.

the pontiac motor is a odd ball,it's not really a 153/181. so the ignition from one will not fit, but this kit will as it's made for the chevy.gm industrail marine engine
http://www.michiganmotorz.com/delco-voyager-marine-electronic-distributor-p-120.html

here is where we got the rebuild parts for the motor,
http://greenbaypartsworld.com/index.htm

 

I built a 151 for my model A coupe. I built a two X two sheet metal intake for two 97's and use a Cliffords Performance header. Bought a chevy to early ford three speed V8 trans adapter off of E-bay. This setup works with the 1930 rear axle with no mods required. It will cruise at 80 MPH with ease.

 

Here is a few pictures of my setup.

 

I have three GM 3.0 bangers out of....forklifts! Must be the 181 version.

 

"for your 1971 motor you need to get lance to pm you his place in MN for a pan off a p10 box van from the 1960's that used the nova 153 engine"

The reason I was interested in the oil pan was because my postal engine came with a seriously dented oil pan. I've stored the engine for years (since 1986) waiting for just the right project.

I'm kind of guessing that the motor is a '71 postal engine. The only number I've been able to trace is the alternator number which is a '71 GM number.
The engine and its accessories look just like my old '62 ChevyII engine, right down to the
1 bbl carb with hand choke.