opinion on R3/W8 340 (358ci)

-
3

340kid

Well-Known Member
Joined
Mar 2, 2010
Messages
179
Reaction score
2
came across this engine that we are considering to put in a 73 Scamp drag car
motor was built somewhat to nascar specs.
340 R3 48 degree block - 358 cubic inch
Bryant crank 3.30 stroke
carillo rods 6.25"
diamond 4.155 flat tops -
crane solid roller - duration 266/270 @ .05, lift 726/610
Jesel pro series rockers 1.65 int 1.5 exh
12 to 1 compression
dry sump oil system
w8 heads 2.18 int, 1.625 exh, nextek springs, titanium retainers etc
w8 MP intake
crank trigger / MSD distributor
dyno sheets show max torque 523 at 5800 rpm,
max HP 685 at 7500 rpm

would this be ideal in the Scamp ?
 
dyno sheet
 

Attachments

  • dyno-1.pdf
    69 KB · Views: 227
"Is it ideal?"
We don't know anything about the car to answer that. The car won't know it's a "nascar" oriented motor which IMO is a little down on power, I'd think around 730-50 would be correct for what those motors were. Will it be a blast? Hell yes it will!
But be prepared for a lot of plumbing with the oil system and headers will be a compromised piece if you still have a factory K member and steering. Nothing a little time and money can't cure.
 
That's my concern, headers and dry sump location, dry sump is located just below 1&3 cylinder banks, does anyone make 2"+ headers for w8 r3 blocks that fit a Scamp..
The scamp is a 73 with a full fiberglass 71 Dart nose, hood, fenders and bumper, has 8 pt cage, no rear seat, front racing buckets, tubbed with 29.5 x10.5 slicks, 5.13 8.75 rear with spool, 727 with dynamic 9" converter 4500 + stahl, goal is to be low 10 seconds
 
I prefer the "observed" numbers, but either way in a 3000lb well sorted out car, low 10's should be a breeze with that engine. The fitment issues will be the toughest to deal with for sure, and something I can't help you with. I'd bet though that a custom header is probably in your future. But hey, you gotta pay to play :D.

Good luck, she'll be a fun ride!
 
Speaking of headers, what size primaries was it dyno'd with? I suspect a 2"? At least...

That torque curve upstairs is really nice & flat.....That thing will hum with the right converter, probably a custom built 8" for maximum performance in my opinion. Once it's right though, pull the belts tight & hold on. :)


P.S... Oh, and if all the stars align, you may be a little over geared. I'm thinking a 4.88 gear set will still let you pull hard on the top end. I'm looking at low 130's mph & 7500rpms?
 
340kid said:
That's my concern, headers and dry sump location, dry sump is located just below 1&3 cylinder banks, does anyone make 2"+ headers for w8 r3 blocks that fit a Scamp..
The scamp is a 73 with a full fiberglass 71 Dart nose, hood, fenders and bumper, has 8 pt cage, no rear seat, front racing buckets, tubbed with 29.5 x10.5 slicks, 5.13 8.75 rear with spool, 727 with dynamic 9" converter 4500 + stahl, goal is to be low 10 seconds
Click to expand...

You'll be making everything. The craftsman stuff didn't have a large port, probably don't need a 2" header here, you can buy flanges and adapt a Hooker 1 7/8" header but you will be modifying them due to the dry sump (I'm guessing it's a 5 stage pump and as a bonus one stage is probably a vacuum pump) nothing about installing one of these is simple.
I know of a 3.30 stroke 4.185 bore truck motor that was raced with a glide and a 4500 stall moving 2850lbs and it was an easy 5.70 car to the 1/8 with a 9:1 CR. These motors just plain RUN! That was shifted at 8000
 
The dyno sheet shows 2" headers stepping up.... You would be spending in the upwards of $1600+ to have headers built I'm estimating from personal experience. Looking at the HP/torque vs headflow numbers you'd certainly have room to grow in the future. I wouldn't want to work around that combo and a stock front end.... I don't like torture. Some do...
 
You must log in or register to reply here.
-

Back
Top