Thread: dyno estimate

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Well here it is good or bad.
3.766 bore
3.48 stroke
1.84 int valve
1.5 ex valve
5.7 rod
56 cc heads
8 cc d cup pistons
.015 steel head gaskett
deck height .025
single plane eddybrock
600 cfm 1406 eddybrock
rams horns
xe 262h cam .050 218int/224 ex
intake valve closes at 57 abdc
462 int lift/469 ex lift
rhodes lifters which bleed off 10 degrees of duration and .060 of lift untill 2500 to 3000 rpm
HEI distributor with module and coil upgrade
electric fan
electric fuel pump
straight up timing
approx 9.4:1 static compression
approx 8.4:1 dynamic compression
Thnx for any desktop dyno numbers or any comments!!!
My hope was to get 275 hp and not have to mess with the motor all the time for a weekend cruiser.I am just about ready to fire it up and would like an estimate on hp numbers soo when the first thing everyone asks is how much hp!!!I can tell them a realistic number and I am curious myself since I will probably never have it dynoed.

I can't figure the exact effect of the rhodes lifters but safe to say you'll get more low end torque. With the figures you supplied assuming 3.766 bore on the head gasket and 8cc dish pistons, I get 9.92:1 SCR. This gives 299hp@5000/359tq@3500. This is assuming stock cylinder heads with no porting, etc. High flow single plane manifold and high performance ex manifolds.

-Chris

Thnx for the estimate!!!!!If I get those numbers for real I would be more than happy!!!Should be close to exactly what I wanted out of this motor.Wonder why vol efficiency is soo low ?
Thnx again for the dyno numbers!
Anyone else have different dyno software....curiouse at the difference in estimates .I have another dyno estimate at 288 hp@5000 and 359 ft lbs @3500.

Nice combination shawnlee. You have covered the bases with the leak-down lifters. Good move.

How bout this one...

400SBC
4.125" bore
3.75" stroke
5.565" connecting rod
461 camel hump heads 1.94/1.5 valves, 160cc intake runner, pocket ported and valves deshrouded 62cc chamber
9:1 static compression with stock dish pistons
252H extreme energy cam(212,218@.050 .447,.454 lift on 110LSA)
1 5/8" headers with 3" collector
edelbrock performer intake
650cfm carb
Mallory distributor... blah blah blah

Now here's something I wanted to experiment with...

I have a 1.52 ratio roller rocker which makes .453 and .460 lift but I was wondering what the 1.65 rocker would do for power... it would make .492 and .499 lift. Thanks for the help. I predict a torque monster!! either way!!

Originally Posted by techinspector1

Nice combination shawnlee. You have covered the bases with the leak-down lifters. Good move.

Thnx Tech,the outcome has alot to do with all the good advice I have gotten on this forum from everyone!!
As soon as I do a once over I am going to be starting it for the first time!!!!!!!Soo far all checks are good,the electric fan comes on and the electric fuel pump also makes noise like it is suppose to.When I turn the key the starter engages and all other systems check.Last thing is to put in fuel and check for leaks which should be easy to do since the fuel pump can pressurize the system with out starting the engine and risking fire.Then fill the radiator with water and aluma seal ,then dump the second bottle of E.O.S. in the oil and prime for the last time. .......keep your fingers crossed all goes well....may even have video!!!!

Originally Posted by 69elko

How bout this one...

400SBC
4.125" bore
3.75" stroke
5.565" connecting rod
461 camel hump heads 1.94/1.5 valves, 160cc intake runner, pocket ported and valves deshrouded 62cc chamber
9:1 static compression with stock dish pistons
252H extreme energy cam(212,218@.050 .447,.454 lift on 110LSA)
1 5/8" headers with 3" collector
edelbrock performer intake
650cfm carb
Mallory distributor... blah blah blah

Now here's something I wanted to experiment with...

I have a 1.52 ratio roller rocker which makes .453 and .460 lift but I was wondering what the 1.65 rocker would do for power... it would make .492 and .499 lift. Thanks for the help. I predict a torque monster!! either way!!

Well the short rods suck to be honest.
I have a 55 gallon drum about 1/2 full of the 5.565 rods.
I would run a 5.7 or 6.0 rod to get a better rod ratio.
The better rocker arm ratio will help to open the valves quicker and make the cam appear a little larger.
The down side is the extreme rocker arm ratio really puts exta pressure on the rocker arm stud.
If you don't have screw in studs and just have press in studs I would never try it.
It would make a great engine for a tow vehicle.

Well wish me luck ,I am goin out right now to add water and fuel and pressurize both systems to check for leaks...... .....might even get brave and fire it up!!!!!I have been paranoid about cam break in and have been stringing out this first fire deal now for a while for fear of cam failure......might wait a couple more days and build my confidence up more...

Good luck on the cam break-in, as long as you keep the engine revving at 2,000rpm for a good 20-30 min. and the cam lobes are lubed up with moly, you should be good.

Originally Posted by erik erikson

Well the short rods suck to be honest.
I have a 55 gallon drum about 1/2 full of the 5.565 rods.
I would run a 5.7 or 6.0 rod to get a better rod ratio.
The better rocker arm ratio will help to open the valves quicker and make the cam appear a little larger.
The down side is the extreme rocker arm ratio really puts exta pressure on the rocker arm stud.
If you don't have screw in studs and just have press in studs I would never try it.
It would make a great engine for a tow vehicle.

Well, the 5.565 rods are great for making torque, but not for high rpm. Which is why I chose a cam that only revs to 5,000 rpm. The 400 is bone stock. I'm just going through it to see what I can get out of it without replacing the pistons and rods. And yes, If I do the 1.65 rocker ratio I will be putting bigger springs and screwin studs to accomadate the extra pressure.

Anyone with a desktop dyno wanna try the 400?

Well the high tech swivel water neck housing leaks like theres no tomorrow!!! A little form a engine and let it set ,soo looks like tomorrow for the first fire!!!Fuel system checked out and was easy to test with a electric fuel pump.Hopefully the water leaks will be fixed by tomorrow and maybe get to fire it then.{form-a-engine has to set 24 hrs}Good thing I was testing it all first,as I have heard many horror stories I figured it better to check too much than not enuff.