[jarrettandroski]

i was wondering if anyone had a dyno program and if they had any spare time or ambition to check a combo for me chevy 355 with afr 195cc street eliminator heads and a crane energizer cam with 286 adv duration and a gross lift of .465" with a edlebrock performer intake and eldlebrock 750 carb and hooker headers

[spitnl]

Yes I've got Engine Analyzer pro, and I don't mind running it for you.
But I will need some more info to get better results:
- Compression?
- quench?
- Size of the headers? 1-3/4?

Frederick

[jarrettandroski]

oh sorry about the lack of info its 10 to 1 compression with 1 3/4 headers but i do not know the quench?

[techinspector1]

You can guesstimate the squish depending on whether or not the block has been decked and what kind of piston you used, along with the compressed thickness of the gasket.

If you used a cheap, rebuilder type piston, then the piston compression height is probably around 1.540" and the squish will be in the toilet with a virgin, un-cut block and a standard 0.040" compressed gasket.

Add up the stack. Half the crank stroke is 1.740". The rod is 5.700". The piston is 1.540". This adds up to 8.980" Subtract this from a virgin block deck height of 9.025" and you get the piston down in the bore 0.045" at TDC. Add a standard 0.040" gasket to this and the squish (or lack of squish thereof) comes out to 0.085". If this is what you put together, chances are that the motor will detonate on pump gas at 10.0:1

If you used quality pistons that were manufactured with a piston compression height of 1.560" (or 1.561" in the case of KB hypers), then you may slide by with a squish of 0.065". If you used 1.560" pistons and a head gasket thinner than 0.040", you should be fine on pump gas.

As a side note, in my opinion, you did a good job of matching the cam to the c.r. You should also get a nice rump-rump out of it with the 106* LSA.

[OHD]

What info do you need? I would like to see how close the program comes to actual pulls.
I will list the motor I have on the stand now.

[jarrettandroski]

i am going to be using seal power hypers if that is what the machinist said or something similar to that with moly rings which he says they dont need to be worked as much as the kbs the deck has not been milled and 0.040 head gasket

[techinspector1]

You might talk with him about using a thinner gasket such as the GM 10105117 to improve the squish a little.

[spitnl]

OK got the results.
I am not very familiar with chevy's but a 355 is a 350 bored 0.030" over, correct?
The results are valid for testing the engine on a dyno:
- No exhaust system
- Electric waterpump and fan

Dynamic compression: 7.72
Theoretical cranking compression: 192psi
Idle vacuum: 11,7" Hg


Info you minimally need for a decent result:
Block:
- bore x stroke
Head:
-flow for intake and exhaust
-valve sizes
-compression
-squish<0.060" yes/no
and preferably port lengths and diameters at faces
Intake:
-type of manifold
-cfm of carb
and preferably port lengths and diameters at faces
Exhaust:
-primary pipe diameter
-primary pipe length
Cam:
-type of cam
-open and closing events @0,050"
-cam lift
-rocker ratio
and further type of fuel if not gasoline

[SBCfan04]

Where do you get the desktop dyno program?

[spitnl]

Originally Posted by SBCfan04

Where do you get the desktop dyno program?

http://www.proracingsim.com/purchasejac.htm

[techinspector1]

I just purchased the DynoSim Advanced with Pro Tools software. It's on sale for $99.95 and was too good to pass up.
http://www.proracingsim.com/purchasejac2.htm

[jarrettandroski]

thanks alot for you time i appreciate it that made some nice torque and some decent horsepower ill probabaly go with that cam and i am probabaly gonna buy that desktop dyno yea a 355 is a 350 bored 30 over

[PatM]

Jarrett
Just a note. I think that he used a program called Engine Analyzer Pro. This is from Performance Trends. They have a "light" version for considerably less money, called simply Engine Analyzer. Desktop Dyno is an entirely different (and dare I say, IMHO less effective) program. I am not familiar with DynoSim advanced, as mentioned by TechInspector.

Pat

[techinspector1]

Originally Posted by PatM

Jarrett
Just a note. I think that he used a program called Engine Analyzer Pro. This is from Performance Trends. They have a "light" version for considerably less money, called simply Engine Analyzer. Desktop Dyno is an entirely different (and dare I say, IMHO less effective) program. I am not familiar with DynoSim advanced, as mentioned by TechInspector.

Pat

Hi Pat, here's the rundown on DynoSim products. The one I bought is the fourth column from the left, headed up DynoSim Pro Tools....
http://www.proracingsim.com/enginesimfeaturetable.htm

[spitnl]

Yep I used engine analyzer pro.
Sorry SBCfan04 I thought you were talking about desktop dyno specifically.

You can download a demo here for both the normal and pro version of engine analyzer.
http://www.performancetrends.com/download.htm#eapro
The demo's work for 10 days.

I have also used camquest and desktop dyno, but I think engine analyzer pro is alot better.
No experience with dynosim.
Just my 2Cents.