Engine Build

[citiracer]

Kicking around the idea of "building" a motor. I would like to start with an assembled short block and turn it into about 650HP wet sump so that it could be used in a modified or late model. Slightly underpowered I know but plenty of motor for tracks it will see. Also just trying to dodge the cost of a dry sump system at least for now.
I'm looking at the following short block assembly:
http://www.summitracing.com/parts/drt-03124272/overview/
I figured with the H-beam rods and 4130 crank it should be a pretty reliable piece. As you can tell, I'm more concerned with reliability than I am performance. I'd rather have 650HP last me 1000 laps than 800HP last me 500. If this build is a success we might try something more aggressive.
Then not sure on what heads but would like to stay 23 degree to keep it simple as far as matching other stuff. For sure aluminum heads for weight savings and then REALLY not sure on cam but realize that will depend on head selection. Leaning toward AFR heads for business reasons I won't get into. Suffice to say I would have to get some REALLY compelling reasons not to go with AFRs for the price I can get them.
I'd like max HP in the 650 neighborhood and would like to spin it close to 8000 RMP if necessary.
Am I on the right track with this?
Initial budget for the whole project is going to be about $12,000.

If things go right and the motor holds up, I would be open to going through it and putting 18 or 13 degree heads on it to see what it will really do but want to start basic if possible.

How much compression do I really need to make 650HP?

[stockcar5]

if it were me i'd look into a quality usa 4340 crank and rods along with a nice piston like a je, mahle ect. callies compstar stuff is nice.

as for heads i'd go with the afr 245npp heads. they should make an easy 700+ hp. i'd shoot for 13 to 1 or so compression for reliability.

[sj valley dave]

Totally agree with Stockcar5..Forget the 4130 crank and get an American 4340 crank and rods. I'd go with the AFR 235's or the 245's in a heartbeat. The 245's will support well in excess of 750 HP with the right build and parts. At least 13:1-14:1 for compression...

[citiracer]

Sorry I made a mistake on the crank material.
This Dart 427 short block deal comes with 4340 crank and con rods.
It looks/sounds like a good package. The Dart SHP blocks are only rated by Dart up to 600HP but I have seen a lot of people say that was marketing spin to keep from taking a chunk out of their Little-M base and these blocks can hold 800HP easy even in circle track applications.
Are a lot of guys building open late model motors with the SHP blocks?
I do like the idea of the shaft mount rockers on the 245 heads. I'll spend a little bit extra for something that gives me a performance AND reliability advantage.
What is a good cam for the AFR 245 head? I'm leaning toward solid roller setup. This motor (if ever built) will see mostly bull rings.
Are the AFR 245s pretty good out of the box or do they stand to gain from additional port and polish?

[sj valley dave]

There are quite a few guys on another Speed board that run the AFR 245's and they are really good out of the box. A couple of head porters have stated that if if a guy doesn't really know these heads he will hurt flow. They have a great CSA and very little pushrod pinch area for a 23* head...I'd definitely go with a solid roller, over a flat tappet...

[perfconn]

Are a lot of guys building open late model motors with the SHP block?

Absolutely not.The SHP doesn't even have steel caps.Most open motors are aluminum blocks.

[hremotors]

we have a 400 cu inch with a dart little m block crower small lounal crank oliver rods afr heads dan olson pan titian oil pump jessel shaft rockers je pistons i would say it makes 650 horse power u could buy it for 9000

[LateModel B23]

I have a set of Brodix -10's with JE domes far sale. The pistons are 4.125 bore for a 3.50 stroke and a 6 inch rod. That would give you a really good 23* 380 cu in motor.