The elusive 224/3.7 MerCruiser banger

Anyone know if there is an aluminium cylinder head that will take pedestal fit scorpion roller rockers. Ive tried everywhere but no0 luck so far

 

for a car one is far better off to zero deck the block. Although this raises the compression the engine is now knock resistant. I run the cheapest gas available and my merc 470 has never knocked in 700 miles.

 

Yes and he would have gone faster but a door blew off his car screwing up things.

 

Anyone know if there is an aluminium cylinder head that will take pedestal fit scorpion roller rockers. Ive tried everywhere but no0 luck so far
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Check the points plate in your distributor if your Mercruiser 470 is experiencing engine stopping after it runs a little.

My engine did that 3 months while I searched for the cause. I found that the bottom of the breaker plate had a thick oxide layer where it touched the distributor housing. It was enough to stop the engine after the plate and housing warmed up.


The screws that hold the plate down don't conduct as they are isolated from the plate in rubber. I discarded the rubber and screwed it down directly after cleaning the plate. When I finally found the problem I had replaced the coil, the condenser and the wiring so it has a nice new ignition system.

As the plate is thin, it does not take much torque to strip out the threads in the holes that mount the condenser and points. (Guess what happened.) I silver soldered a nut below the mount hole for the points as it needs to have a wave style lock washer [a conventional one may not work] and be tight. The condenser screw is not as critical so I just tapped that hole for a 8-32 screw.

 

How tall is this engine? I'd like the measurement from the bottom of the sump in front to the top of the valve cover if possible. If it is short enough it might fit in an MGB, which would almost be funny, making it possible to run with the big dogs on a 4 banger. Or more conservatively, have very good performance with a near stock appearance. For carbs, a dual Webber setup would seem nearly ideal.

JB

 

Jim,

I went out and measured the one of mine and it is 25" high.

The only other measurements that could be problematic are the total length of 29.5" with the stock harmonic damper (from front of pulley to bell housing flange).

You might get it down to 28" by machining 5/8" off of the bell housing flange and using an after market zero balance Harmonic balancer.

Machining the bell housing 5/8" also makes them more adaptable to a T5 or 200R4 overdrive transmissions.

The full length sump is 23.5" and it could also interfere with the cross member or steering.

On my projects I am engineering them to avoid any problems in the overall dimension areas.

Anyone who knows what an MGB engine looks like will know right away that you have grafted in a much larger 4 cylinder engine.

Not many non MG people know what an MG engine looks like anyway.

I am putting my engines in Model A Fords and in a Volvo 544.

The 544 will be a European sports cars worst nightmare.

The Model A's will probably shake up most flathead and many V8 hot rods.

225 hp. out of a 300+ lb. Carbureted engine in a light weight car is a formula for success.

Even if you can't beat them you should be able to surprise them.

Dick

 

The crossmember will be an issue, as will the height. The length, not so much except potential interference with the steering. Let me ask this: Is it a skirted block and how far below the crank throws is the pan bottom? Also, will a 460 pan fit it, and where is the oil pick-up located?

For this to work, there is nearly 4" of height at the front of the motor that must be accommodated, either by cutting the crossmember or the pan, either of which are fairly routine as long as it doesn't use a front pick-up.

JB

 

Jim,

The oil pump is in the front and the pickup tube runs to the back.

A short tube pickup could be made to work in the front and the pan bottom clearance to the conrod bolts is only about 1.5".

The oil pan is different than a 460 ford pan and they do not have the same or similar bolt patterns.

I have taken some pictures for you showing the pan and the recessed main caps.

The oil pump extends about 5" down into the pan but is slanted toward the front of the pan therefore it occupies only about the front 5" if the pan.

I have never considered altering the pan to make the engine a front sump pan but I can see that it would be easy to do.

The oil pump drives off of the distributor shaft at the front of the engine.

I am not familiar with an external oil pump setup so I would not know how to set up a rear sump.

Dick
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Probably won't work then, not enough hood clearance. It was an interesting thought though.

JB

 

Do not give up easily, I recently changed engines in a car and had a surprising amount of room, mostly as it was in the chassis 3" lower than the old engine.
There was a cross member in the way so I removed it and put in another a foot forward.
I prefer to place engines completely behind any cross members or steering.
Granted that there is not a lot of room under the hood or in the footwells of British cars, you may still be able to relocate the center section of the firewall rearward to provide room for a larger motor. Another thing which is done to gain space is to move the engine transmission and driveline to the right. The engine can be tilted over to the left if height is a problem.

I leave 4" ground clearance under the sump.

 

People reacted to my engine that way, on seeing my engine, two said "that's NOT a small engine"
dennis

 

Thanks Dennis, but really I was investigating the possibility of this engine choice as an alternative on behalf of the new guys coming over to the "Dark Side" and wanting to know what the best choice would be for their application. We have well established V6 and V8 swaps and a number of other choices and initially I was intrigued by the thought of a big inch 4. But on reflection I have realized that this swap would be well beyond the skill and means of most owners. Not to say that it couldn't be done, but sort of like our 455 project, it would require the abilities of an expert. And to be honest, I don't know anyone who has the skills to pull it off, who is also that much of a 4 banger enthusiast. There may be one, and I'll suggest it when and if I think the idea may get some traction, but I'm not going to do the swap unless things change in a major way., as I have other projects in the works. Still, I really appreciate the time and effort you and the others have put into helping me to investigate the possibilities. There's really no telling where that might lead.

JB

 

Jim,

Sorry to hear that you don't figure that this engine will easily fit in an MGB.

MGBs don't have very large engine compartments. Restrictions in all directions.


You are probably correct. However not easy are challenge words to many in this hobby.

Good luck with your other projects.

Dick

 

So I have a question for you guys that have a running 3.7 in a car. How's the fuel usage? Is the engine thirsty? Thrifty? Or just so-so?

Would a 200R4 with 4.10 gears and 28" tires in a 27 T tall coupe be a decent running setup?

 

"Not easy is a challenge..."

I couldn't agree more. I'm just putting the finishing touches on an MGB with a 455 Buick and Jag IRS that is just a fantastic car, beautiful ,easy to drive, great handling and just massive power: http://forum.britishv8.org/read.php?2,166,page=73

And I'm closing in on completion of my blown, injected and intercooled 340 Buick powered MGB, also with Jag IRS but also with an 8 speed automatic, forward tilt hood assembly and many many other custom features: http://forum.britishv8.org/read.php?2,274,page=19 (both cars also have air bag front suspension)

So you see, I'm no stranger to a challenge. But the car in the shed is more likely to go plug-in-hybrid. I've got an old Samurai that I use here like a golf cart, put gas in it about every 3 months and I like the idea of a fun car for local trips that I never (or rarely) have to take to the gas station.

JB

 

I have not yet completed one of my 470 installations due to knee problems.

I have now had both knees replaced and my recovery has let me start to resume working on my projects.

One of the reasons that the 470 engine has intrigued me so much the fact that so many boat owners who have used these engines reported that they got excellent mileage in their boats.

On boat Internet sites they have reported that their boats got considerably better mileage than similar boats that ran 6 or 8 cylinder engines of nearly the same hp.

One recently said that he ran the 190 hp 470 and that he marked the throttle control handle where the 4 barrel QuadraJet just started to open the secondaries.

He then ran the engine just under that threshold most of the time unless top speed was really necessary and the resulting mileage was impressive.

On the QuadraJet carburetor the primaries are 1.475" while the primaries on the 165/170 hp mercruiser used the 2 barrel Rochester with 1.775 venturis.

I intend to run my cars with the 4 barrel QuadraJet, a 3.08 or 3.55 rear end and a T5 5 speed so that when I am cruising I can short shift it and when I am on the Freeway I can cruse at 70 without using the secondaries.

These engine will produce 250 ft/lbs of torque which is enough to pull the light cars that I am making very easily.

I expect to get way better mileage with these engines in my model A's than what I have gotten with the 40 hp stock engines.

They currently get about 15 mpg at the speeds that I have to go to keep up with traffic.

Dick
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dawford,
You wouldn't happen to have an extra quad manifold you would part with? I have searched all the boat shops around here and find nothing but 2 bbls. I have 3 of these engines and grandios ideas.

 

Mine gets 15 mpg consistently in an 1800 lb car running 3.07:1 rear end and 6.00 16 tires, 2bbl carb, torque cam. It got 22 one afternoon when something was wrong with the timing. I had expected more but it is a lot better than it's preceding engine which got 7mpg.

I'd see more benefit in turning the engine slower as it has lots of torque and is a low rpm engine. A 3.07 ratio easily makes both tires smoke in low. An automatic would be convenient as there is no linkage to fool with. I've a 3 speed manual transmission.

 

Babyearl,

I am sorry that it has taken me so long to respond to your inquiry about a 4 barrel manifold.

I usually keep good track of this thread but somehow missed your reply.

I do not have any of the 4 barrel manifolds that I don't have plans for.

I have bought mine off of ebay and I have had to pay as much as $300.00 plus shipping.

I regards to dennis g and his experience with gas mileage I suspect that some of the modifications that he has made to the original Mercruiser engineering have effected his mileage greatly.

Carburetor, camshaft and manifold changes make a big difference in the delicate balance that has to be just right to get the best mileage.

That is why I suggest only changing the necessary components of the otherwise well engineered original Mercury Marine engine.

The water pump and water plumbing.

The alternator, cylinder head and the exhaust system.

Dick

 

Hi Dick,
You could not have been more correct about the manifolding.

On my Allis Chalmers engine one manifold I made was destroying its mpg...it got 3mpg which with careful jetting changes I got up to 7 mpg.

That head had siamesed ports and the manifold that I made for it did not match one hole very well. That uneven restriction caused two cylinders to run rich when the other two were lean, hence 3mpg. As flow rates changed with rpm, I could see the mixture change erratically with my oxygen meter.

So I used a stock 2bbl merc manifold as it looks like a well designed manifold.

The comparisons to other motors was probably made at high power outputs and
that is where it was designed to run. The sixes and the eights being car motors, had their roots in mainly low rpm operation.

As our application is automotive, I have attempted to adjust the optimum engine rpm parameter downward hence a milder cam. (An RV grind.) I'm using a stock Autolite 2bbl carb and as it is capable of delivering 28mpg consistently for 289 v8 fairlanes and mustangs on the highway.
I would expect a mpg increase with the compression increase that I made.

The cam is an unknown.

Maby I'm timing it wrong.
I remember mercury retarding the timing, but I do not know if the figures that I see are the normal timing figure or the retarded one. I time mine at 33 degrees advance at 2000 rpm
It advances to 36 or 37 degrees by 3000 .

I know that intake valve diameter does make a difference and the stock ford valves are big, so that is one factor for lower fuel consumption.

I welcome suggestions.

dennis

 

I'd expect shorter stroke engines to be more economical as the internal friction and pumping losses are much lower.


It is a big bore, long stroke engine with large intake valves so I'd not expect magic.
Jets are easy to change and I may jet it slightly leaner as it is right at 14:1 on the road,
I didnt do that earlier as the radiator was too small then.

That being said, Mine has excellent power and I'm really happy with it. At 60 it turns ~2200 rpm at 90 it is at 3000 and is just entering the rpm band where it makes most of its torque.

 

Dennis G, Does your distributor have vacuum advance ? If not you should investigate adding a vacuum cannister. At light loads the engine will tolerate a lot of advance and this will dramatically improve your gas mileage, throttle response, idling, starting, everything !!!

Boat distributors don't have vacuum adv because they are always under a heavy load. Might take some heavy thinking to make a vacuum adv dist for this motor but it would be worth it imo.

 

rayjay
I have read that the mercruiser 470 distributor is an adapted chevrolet distributor.
If so, modification to vaccum advance would be quite easy.
My engine is only lightly loaded at 60 mph and at that rpm is advanced to fire at about 33 degrees.
When cylinders are large dual plugs give an advantage as the flame front travel is shorter. I do not know if there is any practicality for this with a bb ford head, but an airplane engine runs a couple hundred rpm faster with 2 plugs firing versus 1 firing.

 

Your engine should tolerate at least another 10 degrees of advance when cruising under light load. This will make it run dramatically better. With the proper vac can the second you start applying the throttle the vac will decrease and the extra advance will disappear so the engine won't ping. Also with a the vac hooked to direct manifold vac you will have a lot more adv at idle which again makes the engine very happy. I have a link to a distributor set up article that I will go find.

The link is below. In a prior life I had a Sun dist machine and did a lot of distributor recurving and customizing [ how about a cast iron Chevy dist with an HEI pick up and reluctor ???]. There is nothing more critical to performance than having the spark occur at the ideal time; whether at idle, cruising down the highway or WOT.

http://www.hotrodders.com/forum/distributor-tuning-theory-part-1-a-59033.html

 

ray-jay,

What effect would Turbo charging have on the Vacuum advance distributor?

Dick

 

I apologize, I didn't realize Dennis g's motor was turboed.

 

raj-jay.

I don't remember if dennis's 470 is turboed or not.

I was asking because I have an early Buick 3.8 V6 hot air turbo that I am planning to use on one of my 470's.

I do agree that the carbureted 470 might run better and more economically with a vacuum advance distributor.

But I still wonder how the turbo would effect the vacuum advance distributor.

Maybe I should look at the Buick 3.8 V6 distributor that goes on the early Buick turbo's.

I am also wondering about the Buick turbo's use of a QuadraJet Carburetor on that setup.

How does the vacuum of the pull through turbo effect the vacuum secondaries of the QuadraJet.

I will look into what it will take to get a vacuum advance setup installed on one of the carbureted engines.

Dick

 

Why apologize? It is not turboed at the moment. I do have one ready for it if I need that much more power,

Your suggestion is a good one, it presently will advance to about 37 degrees at 3000rpm. a vacuum pullback would not hurt it at all.
It did get 22 mpg one afternoon when the points were moving around so it looks as if more mpg is possible.

I can not use an HEI distributor as there is barely enough room for its regular small distributor is right up against the manifold at some adjustment points . I move parts around so that does not happen. {filed off some obstructing bumps too}

Wasn't the distributor was modified from a 4 cylinder chevrolet distributor.

 

I have never even ridden in a turbocharged car and would like to mess with one and have done a bit of reading up on them. It seems you have two options -

#1 is a 'ghetto' turbo. This would be a suck through turbo with a carburator and a distributor. Going in you know this will be an extremely compromised set up. The engine will never run to the potential of the individual parts. It will use more gas, be more tempermental, less reliable, and prone to expensive failures. Fun but .....


#2- Electronic fuel injection with a distributorless ign. This will add a lot of complexity to the equation but the info is out there. I have read a lot of Mega Squirt postings and it's really intriguing. Steep learning curve for a carb & distributor guy like me but NO MORE GAS ON YOUR HANDS FROM MESSING WITH CARBS !!!! YA HOOOO !!!! No more messing with springs in the dist, welding up or filing longer the advance limit slots, no more advance compromises due to an OD tranny. Hook up the laptop and program the changes you want. WOW, a hot rod that runs troublefree like a new car. O2 sensor, TPS sensor, crank sensor, boost sensor, manifold pressure sensor, high pressure fuel pump, injectors, etc. Lots of wiring but once the wiring and hardware are mounted the tuning is done with the laptop while driving down the road. Cool.