The elusive 224/3.7 MerCruiser banger

Wasn't it an old standard estimate that another 50% power is reasonable from a moderately boosted engine? That would fit with your figures.

Rpm will be one limitation, Randy ran some* of his mercruiser engines 6500 rpm, but the ford 460 was not so much a high rpm engine. as were some smaller engines. Dick C. made 9,000 rpm 2300cc ford engines and they lasted well, I read that the Pinto engine needs a lot of boost to make power.

As I see it, a good approach is to make use of the good torque that a 470 has to offer.
If detonation can be kept to reasonable levels, a blower would capitalize on torque, and is a very reasonable way to build power.

* I know that Randy ran at least one short stroke mercruiser. It may have been his high rpm motor. More recently he has run smaller Japanese motors and reports excellent power from them.

All in all. the 470 is a pleasant motor with a few simple deficiencies which can be easily taken care of. It has proven to be a great motor for a light car. There are always other options, I've a friend who has been making[ on and off] a Hyabusa powered mg midget.

 

dennis,

If the 470 can produce 225 hp with the addition of the performance head and the roller rocker arms that I will install and I can get a 50% increase in hp then the mercruiser should produce about 335 hp.

Not bad for a 224 cu/in 300 lb enginewith minimal internal modifications. Just a change of pistons and a Turbo.

Dick
.

 

According to Wicopedia they didn't make an 83 Buick Grand National but called it a T-Type that was rated at 190 hp at 1600 rpm. and actually pulled its maximum torque at 2400rpm.

Another source stated that the carburated pull through turbo engined 3.8 Buicks produced 200 hp at 4000rpm and 299 ft/lb of torque at 2400 rpm.

Go figure. But either way I believe that the mercruiser will greatly benefit from the turbo.

But I still intend to build most of these engines with the regular Mercruiser 4 barrel manifolds QuadraJet carbs non turbo.

I might even build one with the Mercruiser 2 barrel Rochester set up.

Dick
.

 

dawford,
If your stock engine has the same general parameters as the stock 3.8L the swap should work ok. But..... modifying your engine will change the match between the turbo and engine. A better head will have the effect of making both the compressor and turbine sections of the turbo seem smaller to the engine. Depending on the characteristics of the turbo and how it was originally sized/matched to the engine, what I said may or may not be a problem. Things you most want to avoid are putting the compressor into surge, and excessive backpressure. Both of those things can happen when a turbo is too undersized for the application. Properly matching a turbo to an engine requires some calculatiuons, then some real world adjusting/changes. Sometimes people get by with slapping turbo "A" on engine "B" and things work well enough. but that is a roll of the dice. If people successfully put the GM performance heads on 3.8Ls that have this turbo that would be an indication that the turbo might work ok on your engine with a better head.

 

Al,

Thanks for the advise. There are turbo upgrades for the Buick and I will probably go to one of the So. Cal. Turbo Gurus for advise before the final installation.

The advantage of living here in So. Cal. is that there are all kinds of people and products available locally.

The way I stumbled onto the turbo idea like a lot of other things that I have decided to try is that I saw a picture and post of someone who installed this setup on a 225 slant 6.

Imitation is the best form of flattery.

My style of building is to put together many other peoples engineering into a unique package that takes advantage of the totality of their talents.

These days few things are totally new but most are built by making incremental improvements on previous made incremental improvements.

Anyway the 225 slant 6 has always been a good platform for performance and can be made to perform at high RPM so I figured that between the original Buick 231 cu/in V6 and the Plymouth 225 ci/in slant 6 that the performance of this turbo would lend it's self to the 224 cu/in Mercruiser.

If necessary the Buick GNX used a Garrett ceramic turbo that had quick spool-up characteristics.

The GNX is said to have had an underrated 276 hp and 360 ft/lbs of torque and was reported to do 0 to 60 in 4.7 seconds.

That setup also used fuel injection but I doubt that the injection was that much more of a factor than the 750 cu/ft/min QuadraJet that is used on the earlier turbos. It also had an inter cooler and was a blow through design which would add too much complexity for my application.


Dick

 

I just got the Buick GN turbo and lined it up with the 2 barrel Mercruiser intake manifold.

It looks like all I will have to do is make a flat aluminum adapter plate with 4 bolt holes to match the intake manifold and three studs to match the turbo base and drill a 2" hole to match the turbo to the intake manifold.

I will also have to fabricate a couple of braces to the engine or intake to distribute the strain and prevent breakage of the turbo 3 bolt flange.

There will be oil, hot water and vacum lines as well as a couple of sensors.

I will have to find out what the plumbing was all about on the Buick GN.

Here are a couple of pictures of the turbo setup sitting on the Mercruiser intake manifold.

Dick
.

 

Dick,
Cutaway Al brought up the compressor surge issue.

It is extremely important that surge not take place. It gets destructive fast.
I've seen turbo maps showing the surge area in their potential operating ranges,
That chart is essential in planning your system.

As the Mercruiser is an uncommon engine, you may have to get data for a ford 460 biturbo setup.

dennis

 

Your copper colored pneumatic actuator is very important to keeping boost under control.
It is essential to run it connected.

Thinking about the merc manifold:
mine is heated, but that is not to say yours couldn't be water cooled . Where to get the cold water would be another thing to solve, perhaps a heater core mounted up front and a little electric pump

 

Your exhaust pipe to the turbo will act to as a brace to dampen lateral vibrations , but in heating it lengthens placing a strain on the manifold .

 

Dennis,

I actually cut the water heater jacket off a couple of my 2 barrel manifolds before I realized that they were necessary on the carburated engines.

So I will use them for this application.

The turbo manifold under the QuadraJet actually has it's own hot water jacket.

These are called Hot air turbos and in order for them to opperate properly in a daily driver they need the warm manifold to help vaporize the gas.

Cooling the mixture after the compressor is not a good idea as it tends to condense the fuel.

Thus no intercooler. Intercoolers are only used on the blow thru setups and go between the compressor and the carb or the injectors.

The upside of the pull through Turbo is that the compressor helps vaproize the mixture.

The downside is that without the intercooler the mixture is less dense.

Dick

 

You are getting use of them. and they are smaller but they seem to flow well. As the turbo heats the fuel-air mix, you may not need the heating so the stock heated manifold could be converted into a cooled manifold if that would be of any benefit.
Anyway they are good manifolds...by comparison, I've made a few bad ones. The worst one didn't line up right, really causing problems ,an internal dispute [in the motor] as to how fast it was supposed to run.
really hurt fuel economy as half the motor was running too lean and the other half ran too rich.


dennis

 

Dick:
Your first turbo photo shows a 1/2" 2 bolt flanged hole. I think it is the oil return. Orienting that downward lets the oil drain out resulting in less oil burning in the turbo and less residue there.

dennis

 

Yes, one of the problems of the early turbos was that after some high turbo use when the engine was turned off without letting the turbo come down to a normal temperature the oil in the turbine would boil and coke up restricting subsequent oil flow.

Good synthetic oil solves the problem.

Before I put this engine together I will consult a good turbo shop to make sure there aren't some upgrades or better turbo combinations available.

Dick
.

 

If the engine is run hard and shut off, heat from the red-hot turbine wheel can travel through the shaft and damage the bearing. Synthetic oil doesn't eliminate that problem. That issue is why some turbos have water cooled center sections/bearing housings, that are often set up to circulate coolant through the bearing housing for some time after the engine is shut off. I other cases it is standard practice to let the engine idle/cool for a short time before shutting down.

 

CutawayAl,

You are right I should have said that synthetic oil helps and that letting the engine cool at idle solves the problem.

Fords new Ecoboost twin turbo V6 uses coolant water to cool the bearing and that lets the engine be shut off after full speed sessions.

They ran the engine ten minutes of peak power (355 hp, 350 foot-pounds of torque.

Then the engine and all cooling were abruptly shut down. This process was then repeated 1,500 times without an oil change.

Then they ran the engine at full power continuously for 362 hours straight.

After the engine is shut down the water just boils and is thermo siphoned until the temperature reaches the boiling point of the coolant which well below the point of any damage to the bearings.

Some things come full circle. Henry Fords first Model T's had water pumps until he decide to save the money and let thermo siphon do the cooling.

Dick
.

 

Ford also thermal shocks their engines in testing. They get them to the verge of boil over and then abruptly change all the coolant to below freezing temp in a matter of like a couple seconds. They repeat this over and over and tear them down to see how it handled it.

 

No these are aluminum blocks cast by Mercury Marine that use some Ford 429/460 parts (Head,Pistons and rods the cam and crank are also made by Mercury Marine along with the intake/exhaust manifold

 

Funny, at least 3 people who have posted to the HAMB are running the combo you seem to think won't work, and I know if at least a couple others who don't post here. I haven't taken pics of my set up yet, but it's got a Kaase Boss9 head.

 

this is my lousy typing skills showing up!I'm trying to say that the Head ,Pistons and Rods are Ford parts and that the block, crank,cam and intake /Exhaust manifold are Mercury Marine parts.it was in answer to someone saying that this engine is built from a cut in half 429-460 Ford motor!

 

So I just got a call to pick up one of these motors that has supposedly been rebuilt for around 500, any one interested in it?

 

anyone ever get one of these running?

 

Randy Dupree raced one seven years and finally blew his up after completing a 187 mph one way at the salt flats.

Sarge Nichols from inliners has built 3 of them for the drags.

dennis g has one in his speedster and likes the way it performs.

There are at least 25 or 30 of them currently running in cars and many more in the process of being Incorporated into project builds.

Dick

 

thanks i think i found him on face book....

I am really seriosuly looking at doing one of these in my turbo pinto once the 2.3 blows...

chris

 

do it, do it. do it.

zero deck it, cut the cam's front end off & change waterpump and alternator. Mill the block's rear end 5/8" if using an old chevy manual tranny. aluminum chevy bell housing, ford pressure plate chevy clutch disk Everything fits. Otherwise make spacer to fit an automatic tranny.
It is a good engine, torque is only about 20 ft lbs lower than a ford 289.
dennis

 

that may take a while. as the 2300 stands abuse well. Friend of mine set his up to run 9000 rpm [no boost] It stood it all racing season and the next too. then he sold it and it was still running some time later.

 

Most dealers hate them as they had too much compression as delivered and the only 'authorized' fix was to pull back the timing which made them horrible to start and run like dogs. The trick is to drop the compression and put the timing back where it needs to be..........


By dropping compression I take it you mean replacing pistons and rods.
Any idea what pistons and rods would do this , and what sizes would fit.

Also where would the new timing be

 

kevdavO,

You are right if you are running a 470 in a boat with low octane fuel, however in a car it is another story.

These engines were designed in the mid 80's when gas still had lead and 100 octane was still available so when the gas went south so did the timing.

However there are a lot of differences in how they work in a light car.

The main difference is in how much resistance they are up against at FOT (Full Open Throttle).

They are designed to run at FOT all day long if necessary, that is to say that they are run at 4600 to 4800 rpm pushing a boat through water.

If the rpm exceeds 4800 rpm they recommend putting a bigger propeller on the outdrive. That means that the engine is always up against maximum resistance at FOT.

That is like running up a steep hill all day long.

In a light weight car they have to push a car through air and they can be run up to what ever is considered a safe rpm.

They are not required run at that speed for any significant time.

One of my first cars was a 1953 Chevrolet 210. My father thought he was doing me a favor by taking it to his company mechanic for a tune up.

When I got it back it was a dog. He had timed it with a timing light and set the timing to spec.

I loosened the distributor and advanced the timing to where if I floored it in second gear at 15 mph it pinged. 15 mph in second gear was lugging the engine and caused the preignition.

After tightining the distributor it ran a lot better for a 235 6 and didn't ping when driven properly.

Four things exacerbate preignition, high compression, heat, lugging an engine and early timing.

I suggest using the stock pistons and an aluminum head with the 95cc combustion chamber which will provide the standard 8.8 to one compression ratio.

With that combination in a Model A Ford I do not expect to have any problems using regular gas.

If I use the early Grand National Buick turbo I expect to use premium fuel if it is necessary.

Despite the liberals in Sacramento our California gas is not that bad.

Dick

 

Thanks Dawford what you say makes a lot of sense.
Do you have any ideas for an aluminium cylinder head(model etc) with pedestel fit for roller rockers. It is for marine use , i always felt there was some way of getting more HP out of these engines

 

kevdavO,

The aluminum head that I am using on my first build cost about $500.00.

I got it off of ebay.

They were sold as :

2 Brand New set of cylinder heads for your big block Ford, these heads are for your big block Ford with 290cc intake runners and 95cc combustion chambers. These heads have studs with a guide plate making them ready to install.

for $999.00.

I just asked them if they would sell me one for 1/2 the price. I drove to Riverside Ca. and picked it up.

I have seen them for even less at times on ebay.

After I get the first one worked up the way I want it I will buy them in pairs anyway.

The aluminum roller rocker arms work on the same studs that come with the head and were purchased from the same supplier.

The best and easiest mod is to upgrade to the Mercruiser QuadraJet manifold and carb if you don't already have one.

I don't know how you would use the Buick turbo in a boat but I am sure it could be done.

The exhaust manifold would have to be scrapped and a header would have to be made to hook up to the turbo.

The exhaust and the hot water would have to be ejected out much like other high powered boats do it.

I have several boats right now that I am removing the engines from but I have no intension of trying to salvage any of them for use.

The government rules regulations and fees have ruined boating and fishing for me.

I remember when these agencies were there to help people enjoy these things in a reasonable manner.

We now have to speak out to keep them from further infringing on Hot Rodding and auto ownership rights.

Dick

 

kevdavO,

I forgot to mention that If you want to use the aluminum performance head in a boat as it is set up by Mercruiser you would have to drill a hole in the front of the head for the water return pipe and you would have to modify the intake manifold to cover the water jacket holes in the intake side of the head.

The holes are larger on the aluminum heads than the cast iron heads.

The aluminum head on a boat engine might have unexpected consequences in that the exhaust ports flow more and that might effect low rpm torque.

In a small light fast bottom boat I would suspect that one of these engines might surprise people at how fast it could be made to go.

If engine longevity were not a priority they could probably be made to turn 6500 to 7000 or more rpm and put out a lot of HP.

Remember, Randy Dupree made one go 187mph at the salt and that one didn't have a turbo.

Dick