Dart Big M 9.8 short deck

[DAREDEVIL]

Any idea how many hours were on the old engine? Also, look for scuff marks on the sides of the piston...

I'm running a 6.70 rod in my 580's compared to the normal length rod... Downside it it's harder to get pistons off the shelf and it puts the pin up higher in the skirt but it's a better rod angle ratio. 250 hrs on refresh and the pistions were perfect!

But u can't compare your talldecks with these !
What bore size and stroke are your 580's ????

[Velocity Vector]

Any idea how many hours were on the old engine? Also, look for scuff marks on the sides of the piston...

I'm running a 6.70 rod in my 580's compared to the normal length rod... Downside it it's harder to get pistons off the shelf and it puts the pin up higher in the skirt but it's a better rod angle ratio. 250 hrs on refresh and the pistions were perfect!

Not sure of the hrs but from my understanding, "Dare Devil probably knows more about it" but I have heard they tear them down after every race or 2 maybe and check everything swap out rockers, rod & cam bearings, that is if you want to be a contender in the next race.

[Geronimo36]

But u can't compare your talldecks with these !
What bore size and stroke are your 580's ????

Not really trying to compare, just letting him know that sometimes it's ok for the pin to be higher up in the piston.

4.530 bore, 4.50 stroke, 6.70 rod, steel heads, 93 oct.

Not sure of the hrs but from my understanding, "Dare Devil probably knows more about it" but I have heard they tear them down after every race or 2 maybe and check everything swap out rockers, rod & cam bearings, that is if you want to be a contender in the next race.

On The Chip ran their supercat engines pretty relentlessly (Curtis is an animal) with minimal maintenance through out the race season.

Brings back good memories!

[DAREDEVIL]

Not sure of the hrs but from my understanding, "Dare Devil probably knows more about it" but I have heard they tear them down after every race or 2 maybe and check everything swap out rockers, rod & cam bearings, that is if you want to be a contender in the next race.

SOME DO, SOME DON'T and are still lucky .....LOL

[DAREDEVIL]

Brings back good memories!

INSTIGATOR ( Peter Meyer ), the guy that went the wrong way here ..LOL,, he had REAL supercat engines in that boat !!!! 7800 RPM !!!!

[Geronimo36]

Not sure about instagator, other than me having to waive them back on track but good thing Peter didn't pass on my stern side cause my cousin would have needed to DQ him.

[Velocity Vector]

Thats cool

[DAREDEVIL]

Not sure about instagator, other than me having to waive them back on track but good thing Peter didn't pass on my stern side cause my cousin would have needed to DQ him.

LOL

[Velocity Vector]

Anyone with experience building 11.1 Dart Tall deck pro's/cons vs 10.2 I'm fixen to start building engines for the 35' OE Cat project and would like some input on engines using the 11.1 Dart blocks as the foundation. N/A VS Blown. I'm thinking around the 1100-1150 HP range with gobs of torque should do the trick. Can I get that much N/A. I bought #6 SSM wet 1.35 ratio drive's for this project.

[MERPerformance]

The 11.100" deck height block is going to allow you to run more stroke and lower the rod angle, by reducing the side load on the cylinder wall. Depending on what stroke, rpms you will be running is going to limit you. The mass of the rotating assembly is still a factor.

[DAREDEVIL]

I know for a fact, a 660 CI Donavan engine N/A Hydraulic roller with a 1050 Dominator and a reg intake ( don't know any specs on internal parts ), made 960 HP and 1020 FPT @ 5800 RPM on the DYNO !!!!!!

THE DONAVAN BLOCK IS A 11.200 SUPER TALLDECK !!!!!!!

The cheaper and maybe easyer way is a 572 ( 10.200 ) blower engine , twin 800 carb and mild should do ~ 1000 HP and 850 + FPT @ 5800 RPM.

IT always comes down to MONEY !!!! LOL

[Velocity Vector]

Donovan 800 CID 180 lbs. Looks real pricey to me.

Donovan Engineering HC 800 Standard
Weight 180 pounds
Maximum CID, 5.0" Spread Bore
Cam Raised 1.0"
Pan Rail 3/4" Wider Than Stock
Deck Height 11.000" to 12.000"

[Velocity Vector]

The 11.100" deck height block is going to allow you to run more stroke and lower the rod angle, by reducing the side load on the cylinder wall. Depending on what stroke, rpms you will be running is going to limit you. The mass of the rotating assembly is still a factor.

Those darn factors, you got to factor this and factor that and if you do this you got to factor this in and you can't do that cause we already factored this in. I hate'm them factors.

[PatriYacht]

Brodix makes a 10.4 deck block that would make a nice 632 with 6.800 rods. Other than the block, everything that goes inside would be off the shelf items.

[Geronimo36]

I guess it's personal preference but I think you'd be better of with a 565" or 598" blown with a 10.2..... You get gobs of torque and HP and lower RPMS and parts that are readily available from all the aftermarket companies should you have a failure.

Just my opinion!

[Velocity Vector]

Thanks guys I am all about off the shelf. I'll go 10.2 and that will do exactly what I want it to. No use making it harder than it is. Plus the cost is about 1/2 going with this set up vs the super tall with custom parts list..