[jmayabb]

Well we finally got the Mercruiser 4 cylinder motor in the car and running. The owner of the car let me drive it at the track for its debut and I have to say that it is one bad 4 cylinder. We had some bad luck with the motor but hopefully it didn't hurt anything. The cam pin broke in the motor.

Here are some specs. 4.390 bore Diamond pistons, offset ground 4.050 stroke stock crank, 6.800 GRP aluminum rods, reground flat tappet camshaft, Ford Motorsport Super Cobra Jet head, 4 barrel intake, and a 740 cfm alcohol carb. Our intentions are to turn it around 6500. The car is an open wheel modified with a bert transmission and weighs around 2300 lbs. I don't have much circle track experience but when I made a few good laps it would pack the left front wheel all the way down the straight. I honestly think it will be competitive in the V8 class when everything gets straightened out with the motor and the car.

The class is called Outlaw 4 cylinder. The only rules are 2000 lbs with a naturally aspirated 4 cylinder motor. The biggest competition are all aluminum Esslinger engines. I think it should have no problem competing when everything gets lined out.

 

[kid460]

what the hel* is that like a 460 cut in half or wut?

 

[jmayabb]

It is a Mercuiser boat motor that pretty much uses all 460 components. It is a pretty neat setup.

 

[G-Code]

It is a Mercuiser boat motor that pretty much uses all 460 components. It is a pretty neat setup.

Cool build. I know a guy who has one in a a dune buggy lightly modified. Some years ago Dan Crower and I talked about building one like you did with a Cobra Jet head and a roller cam. Bruce Crower had one at his shop it was a forgotten project of his.

Congrats on the build, are you ever going to put it on a chasis dyno ? I wonder the power it put out.

G-

Jon

 

[jmayabb]

We were hoping go get between 325 and 350 out of it but we will never know. If we ever do another one we plan on putting a roller cam in it somehow or another. The way the lifters are designed, there is no way to put a roller in it without some major engineering.

 

[8liter]

I'll bet it sounds like the devil...

 

[G-Code]

We were hoping go get between 325 and 350 out of it but we will never know. If we ever do another one we plan on putting a roller cam in it somehow or another. The way the lifters are designed, there is no way to put a roller in it without some major engineering.

What do you think is a safe rpm to rev with that block? That's one of the biggest questions we had, as to where we'd drop the crank out the bottom of the block.

G-

 

[jmayabb]

I don't know what is safe. We are going to turn this one around 6500. Hopefully it will last at this rpm.

 

[BIGBLOCKB2]

Suprised this thread didnt go farther.....Ive heard of these but never saw one close up

 

[parkclay]

Cool Build

This is cool. I started out running 6 cylinder modifieds at Black Hills Speedway in Rapid City SD long ago. No where near this high tech.

Clay

 

[turbo2256b]

There was a fellow that ran one in a swamp buggy racer a few years back. No budy knew what is was. I figured it out as I have worked as a boat mechanic. He would have won the hole thing that year but in the final run against the guy that won in the unlimited class. The 4 cylinder was way ahead and hit a hole wiped out his front suspension a few yards befor the finish line.

What should happen in your case as I have run a 6 cyl Gremlen in circle track against V8s. We were top points holder for 2 years straight. The tires wont heat up like a V8 tires will and loose traction. After 2 years they figured how to factor us out of the winners circle. Later in a different division we did the same thing is a 300 six in a Ford.

 

[iadr]

Is that the later Kaase design head or the earlier one with the conventional valve locations?

What kind of cam figures did you end up with? Compression ratio?

 

[iadr]

The way the lifters are designed, there is no way to put a roller in it without some major engineering.

How do you figure? Tie bar-style should work, no? (I have one literally under the bench that's headed to become a winter project)
I think if I guy fronted the money to get steel cam cores made, he'd get it back over a year or two. Just not really sure I want to be the guy..lol

 

[jmayabb]

It has a plate that bolts on the outside of the block and the bolts go through right between the lifters so a bar would not fit. To put the lifters in, you have to remove that plate so you don't have to take the head off. If you machined that part of it completely off and did away with the plate I think roller lifters would work.

 

[iadr]

Hmm, well, I don't know about keyway lifters in an aluminum block, but that's another option,

or more likely, doing the GM dogbone fixed guide plates in the lifter gallery. I forget if there is a Ford .874 diam dogbone lifter in anything OE... aren't some 5.0's that way? They have that sheetmetal "spider", right, rather than the GM thick dogbone.
I'd have to look at a sample to see if the average lifter could be cutdown to run that style of "guide". I think the lifters are likely spaced further apart, but I'd rather use the actual OE parts if there was any chance they'd work, due to proven metalugical compatibility (no wear)

I understand you are racing it and might not want to say, but any word on CR and cam, even by PM?

 

[jmayabb]

Cam is .252 and .258 at .050. Lift is .665 on a 114 lobe center.

Compression ratio is around 13.5.

 

[wayney]

what bellhousing pattern do these motors have?

wayne

 

[jmayabb]

They have a chevy pattern. It has a reverse rotation starter with a bert transmission.

 

[iadr]

Cam is .252 and .258 at .050. Lift is .665 on a 114 lobe center.

Compression ratio is around 13.5.

You got that reground onto an original core? That's good lift! With that compression I can see it really working.

 

[jmayabb]

Yes that is the original core. A guy named Steve Demos (Demos Cams) in Georgia did the cam for us. Great guy to deal with.