410 stoker

-
dansuperbee

dansuperbee

Member
Joined
Mar 3, 2010
Messages
8
Reaction score
0
410 stoker in my 72 dart, dyno the other day, 312 hp , 451 ftlbs torque at rear wheels. It has eddy magnum heads on a LA block. Why is my torque so high compared to my hp?
 

Attachments

  • image.jpg
    45.6 KB · Views: 579
im not that familiar with building on mopar (yet)but as in all motors/cars its in the motor combo and it would be easy to tell that if it was motor on the dyno but seeing it was in the car then losing through the drive train could be possible also.

So those that can help you with you questions are going to require all the proper info. So post up everything you can about ur motor and drive line combo and people should be able to help.
 
Need more info, cam, headers or manifolds, intake, any porting, auto or stick?
 

Attachments

  • dart 1.jpg
    40 KB · Views: 526
It's a chassis dyno - so the convertor can also cause some error - but the "short, short" version is the engine is producing more low end power than high end power - probably due to the cam choice. But we need a lot more to go on.
 
moper said:
It's a chassis dyno - so the convertor can also cause some error - but the "short, short" version is the engine is producing more low end power than high end power - probably due to the cam choice. But we need a lot more to go on.
Click to expand...

x2

I can't really make out your dyno sheet, but what RPM were peak numbers achieved? The operating range on your cam seems fairly low, which isn't necessarily a bad thing. It'll be more of a stump puller than a drag racing engine. Sounds like you have about 1HP per cubic inch, which isn't terrible by any means.
In my experience, most 2.02 valve LA and Magnum heads flow 210-230 CFM. This is going to kill most combo's between 5- 5,500 RPM.
 
Love to know you're combination, but 5 post in 5 years as a member? See ya next year ! :happy1:
 
j par said:
Love to know you're combination, but 5 post in 5 years as a member? See ya next year ! :happy1:
Click to expand...


Well, now maybe he can make it 10 posts in a week!
Let's know exactly all the parts of the engine bud as well as what trans & read gears/tire size you have.

Long stroke engines make a lot of torque. The longer the stroke, the more torque it makes.
 
My motor combo
410 stroker kit from coast high performance, reverse dome piston -17.5
Comp. cam high energy xe274h flat tappet
Stock Eddy magnum heads 58cc
Roller rockers 1.6
Magnum eddy airgap duel plane
Hooker comp 1.625 prime 3 inch collector
2.5 exhaust end before rear axle with purple flow tech Hornies mufflers
727 with 2500-2800 stall
Rear gears 3:73, ET streets 30/12.5/15
Unlight Mallory, converted to flame thrower internals, and a msd box
 
small hydraulic cam, 1 5/8 headers, low compression...looks like you are probably about where that combo is going to put you. Looks like a stockish setup with the extra torque generated with a stroker crankshaft. (i mean this as a positive, not a negative)

not sure what you put into this engine dollar wise, but looks like a fun, torquey, streetable engine that you will probably have years of fun with from stoplight to stoplight.

keepin mind, through a 727, you're probably losing 30% through the drivetrain. Thats more like 400hp at the crank.
 
That's a 450+ hp engine all day long.

Chassis dynos are inconsistent at best. Junky converters will throw another wrench in the program.

Take it to the track and run it. See how it MPH's and don't worry about what the dyno says. The timeslip will tell you what's going on. Pay attention to RPM going through the traps.
 
In my opinion it's a little undercammed and it does seem down a bit on paper but that could all be the convertor and dyno... I've seen that before. Were the heads checked out or run out of the box? Which rockers?
Best way to know for sure is run it and get a weight on the vehicle. Then you KNOW.
 
I have about 1500 hundred for the heads, stoker kit bought in 2010 chp balanced and Delivered for 1000. Block was free from a friend come out of an old cabin cruiser , and had the block machine for free from a friend. Crane Rockers new from a friend who bought them for his mustang 100 bucks. Intake, cam, headers, pushrods, lifters, intake, timing chain oil pump , plus misc. parts 1000 dollar.Rebuilt trans with new torque converter for 500 dollars. I run last year 13 flat at 105 miles per hour. Since added new quick fuel hot rod carb and had it dyno tuned last week. Just have to wait for the track to open.
 
My 410 did roughly the same but made about 90 more hp

I made 400 hp to the ground
452ft lbs tq

410 stroker 4 speed
Magnum 306s comp cam 555lift 260@50
323 gears on a 28 inch tire
750 proform dp carb out the box
But I'm also using Indy rhs heads built by Brian at Imm engines

I was expexting a lot more hp out of mine as well at least 475 to the ground Maybe a bigger carb and some timing would help

What's the cfm on the carb ? I say the cam is partial to the problem any head work? Or out of the box were they just bolted on?
 
Here's a stoker setup I'm running:

360LA block 408 stroke
360 magnum heads
9.8:1 compression
1.92" intake
1.625" exhaust
flat tappet cam
.474 intake and exhaust
238 intake and exhaust duration
110 degrees
molly rings
hardened pushrods
750 eddy
air gap intake
 

Attachments

  • securedownload.jpg
    54.9 KB · Views: 403
105 in a '72 - so guessing around 3200lbs with you in it? That jives with your dyno result. Not great, but you did it on a budget so in terms of value you're not doing bad.
It should be a bit quicker though. I'd expect at least mid-low 12s out of an average full street car. It might be worth some basic diagnostics: a compression test & a leak down test to verify things are as they should be - that sort of thing. How does it 60'?
 
HP does seem a bit too low in comparison to TQ, but with parasitic loss its not a bad number, maybe the question should be why or how is your TQ so high? Its very good for the mild build, even for a stroker. Is this a street car that you will occasionally hit the track with? For the budget you did good, but for the same money a bigger cam could have woke your stroker up a lot more. If you don't plan to do a lot of hiway driving I would either go to a 28" tall tire or a 4.30 gear. 3.73s with a 30" tall tire plus the tight converter will hurt your 60' for sure. Have fun at the track getting it dialed in!
 
moper said:
105 in a '72 - so guessing around 3200lbs with you in it? That jives with your dyno result. Not great, but you did it on a budget so in terms of value you're not doing bad.
It should be a bit quicker though. I'd expect at least mid-low 12s out of an average full street car. It might be worth some basic diagnostics: a compression test & a leak down test to verify things are as they should be - that sort of thing. How does it 60'?
Click to expand...

I bet it's heavier than 3200 with him in it.

I'd guess ~3300 without driver. ~3450 with driver.
 
I was thinking no crash reinforcements like the later ones, and aluminum and headers on the engine. But - going with your numbers, it's making more steam - so I'd call mine conservative.
 
71 Demon, 360, j heads with 1.94 valves, ld340, 750dp, msd, dougs, 2500 converter and 2.94 gears ran 104 in 4000 foot air with a fat tune. It ran high 2.20 60's because of the 7.25 rear, it wasn't full throttle until about 40-60' out. No doubt leaving harder, it would have run 105+. Car weighed 3250 with a 200# driver on the scales in Vegas.

Engine made ~350hp on a dyno at ~ 5300-5400 rpm, 400ish tq.

Something is VERY soft in the OP's tune up/converter to run that MPH.
 
crackedback said:
71 Demon, 360, j heads with 1.94 valves, ld340, 750dp, msd, dougs, 2500 converter and 2.94 gears ran 104 in 4000 foot air with a fat tune. It ran high 2.20 60's because of the 7.25 rear, it wasn't full throttle until about 40-60' out. No doubt leaving harder, it would have run 105+. Car weighed 3250 with a 200# driver on the scales in Vegas.

Engine made ~350hp on a dyno at ~ 5300-5400 rpm, 400ish tq.

Something is VERY soft in the OP's tune up/converter to run that MPH.
Click to expand...

Did it have?: front drums, manual steering, no sway bar, full stock interior: heater, radio, stock seats, console shift.

3250 is pretty light.

I just weighed my 68 Barracuda at 3209 lbs on digital scales. But it a 12" disk, power steering, console, buckets, f/r sway bars, 8 3/4 rear, thick T-bars. But has alum heads, waterpump, radiator.
 
That is a bad graph to read, the way its scaled makes it harder. Are you intersecting points at 5250 rpms were hp should meet TQ? I'm sure the toque number is accurate and the HP is just throwing off the dyno because of the converter.
 
Ya compression and cam are small. Brian at IMM and majority of people do not even throw OOTB eddy heads on their engines. Dustya_383s car was not tuned, carb was OOTB and did that, his dyno chart was showing it was lean on top end too and could use some more timing.
 
You must log in or register to reply here.
-

Back
Top