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RJ16
03-26-2014, 10:20 PM
Greetings,
I’m sure this has been discussed a number of times, but my track just started to allow UMP motors and was wondering what kind of motor combination I should look into building to be competitive. Will a Dart SHP block be sufficient? Should I go with a 23deg. 18deg. or 13deg cylinder head? Gas or alcohol? Any other advice would be greatly appreciated.
Thanks, RJ

jsf74
03-27-2014, 01:07 AM
650 horse with a smooth power band will get it done "most" places.

Anonymous24
03-27-2014, 05:35 AM
650hp sounds like a good starting point. Once your able to effectively hook that up, jump up in HP would be okay but not really needed unless your running large fast tracks such as Eldora for example.

JustAddDirt
03-27-2014, 07:44 AM
4.125 bore
3 5/8 stroke crank
6 inch rod.
14:1 compression
or

4.125 bore
3 7/8 stroke
6 rod
14:1 compression

you will get so many different opinions on here about engines. The 2 I have are stated above.
one is an 18º the other is 23º.
one has more power than the other, but both are very competitive everywhere I have went with them.

JR. MECHANIC
03-29-2014, 10:02 PM
^^^^ 388 and 414 to help you guys out.
Bore x bore x stroke x .7854 x number of cylinders = cubic inch

RJ16
03-30-2014, 11:34 AM
Thanks for all the help. What is the thoughts on gas vs alcohol?

jsf74
03-30-2014, 12:23 PM
Gas
Less percentage change.

JustAddDirt
03-31-2014, 07:39 AM
on the fence on fuel.
alky will net you more torque, and horsepower, no overheating worries, just run a 180º thermostat, so motor will be up to temp before you run it, (less likely to flood oil with alky.)

price of alky is cheaper, even if you double the usage to gas (which it is like 1.5 :1 for me) it is still cheaper.

if you run a lot of long races... say 50 laps Gas me be the way to go
less rear % drop, but not that significant, for a 20-25 lap feature.

Lizardracing
04-09-2014, 12:17 PM
Gas ranges from 6-12/gallon and if you figure in the specific alky/gas parts as part of the cost my math says Alky is a little more work but a little less expensive overall.