Ok, i am going for most power from 0 to 120... So its a WIDE range of a power curve i need. I will drive it daily so not looking for drag ONLY.

I am boring prob .5 to .6 unless someone says otherwise to go bigger or go down. I am doing custom mods to my head such as sanding in certain areas to get smoother air flow. I plan on getting my head worked on as well with increasing air flow. I dont mind price. Also need these parts to be able to handle a turbo as well, i have a turbo kit built and ready to install, I already tested it but until i get my fuel injection system tuned i cant use it. I have someone willing to do it as well. So let the parts list begin. I would rather have the low end power if anything though. I am really digging the isky 256 cam though.. i want most power OFF the line.

 

If you're going with a turbo don't bore anymore than you need to. No need to thin down the walls. Bore .010 over and go with a quality forged, low compression piston

if you're doing the turbo no reason to get a header really. Use the log manifold and just weld up a turbo flange, cummins style

With a turbo you really need to contact a custom cam grinder and have them spec out what you need. an off the shelf will never really work right

besides, you don't mind price, right?

 

Price isnt an issue. I have cash to spare. The largest part i run into though is can the stock valve springs and rings and rods handle that extra boost. I figured i would do a rebuild and create a fresh motor to add this turbo to in reality. So far i feel i have used a dino before and after adding it and it approximately gained 124hp and 134tq without any other modifications with everything being stock. I pushed 10 PSI just to be safe and i tried 13 but i saw my valves start to lift so i cut off. Any other ideas?

I understand the custom Cam. The biggest issue i run into there is i know VERY LITTLE about cams besides its function and what the different size does in general for the power of the motor and how it affects the tq curve etc. Where would i go to get this done?

 

How would you figure out your grind?

 

Don't waste your time responding.

 

Haha, well said

 

I wasn't asking for a smart remarks all i'm asking is how do you even figure out a baseline to start at?

 

I've been using desktop dyno just playing with cam grinds on our motors and so far I've found that a rv/pulling cam works the best with a boosted application, surprisingly. I don't know how accurate it is in the real world but it does make alot of sense. I wouldn't think you would want a lot of valve overlap with a turbo or a supercharger. But come to think of it desktop dyno won't tell you if it will detonate or not. I really wish my program would tell you cylinder pressure. So I really don't have a clue what you would have to run for a compression ratio. Also I've only been putting about 3 lbs of boost to my model engine. I've put more to it and I really doesn't raise the performance level enough to chance blowing a motor in real life.

My test subject is a stock ford 300 with a 600 cfm carb, 7.5 compression ratio, a rv cam from isky and, small tube headers with mufflers:
198 hp @ 4500 rpm
274 torque @ 2000

Boosted with a roots- BDS 471 (street) limmited to 3 lbs :

228 hp @ 4000 rpm
321 torque @ 3000 rpm

Looks Like a good build to me for being a stock setup but I bet you would have to run that sucker off of race gas

Like I said I've tried to put bigger cams into the program but they really don't preform all that well when even compared to a stock cam. So I'm betting a Rv cam would be you're best bet. But who am I? I just have too much time with desktop dyno...

 

Thanks for responding tpyroboy where did you get your program from?

 

Look around for desktop dyno 2000 It's no the best but it will give you an idea what you can do. by the why I really can't remember how I came across that program I think a buddy in the navy gave me his copy because he installed a newer version.

 

By the way My test motor according to my program would so whoop up on it.
Bore 4.050 Stroke 3.980
Combustion space: 106.35cc Compression ratio 8.90
750 quardrajet clifford 4 barrel intake
small tube headers with mufflers
140H Ford 240-300 Hydraulic Lifter Camshaft from schneidercams.com
Port on the intake side and port and polish job on the exhaust with chevy small block valves with the stock rockers.
Yields the torque monster motor:
344 ft lbs of torque @ 2500 rpm
277 HP @ 5000 rpm

But I'm dreaming as of right now I really don't have accurate measurements to go off of right now to prove I can really deliver this right now. But, I hope to have a long block here before too long to start really dialing every thing into the program. I'm really concerned about making valves clear. But really until I get a motor torn apart to start doing some measurements this is all a pipe dream. I really don't want a big hp motor I'm really looking for the torque.

Good luck man I really hope you find some kinda answer in all of this...

 

Have you tried that with the Offenhauser Dual port I think that would increase torque.

 

I can't find a file to upload the intake into the program so I'm just using a single plane for right now. I really want to get the numbers into the program and then go get the motor dynoed somewhere and see how it turns out but this is all a long ways off. If I could get close to those numbers I really would be a happy camper. But this will be the first port and polish job I've ever done on a motor so we will see soon...

 

A turbo cam usually has less exhaust duration and overlap...no sense blowing pressurized fuel/air through the chamber and out the exhaust.

Every intake for an inline six is essentially a dual plane manifold. On a V8 it fires every 90 degrees of crank rotation; an inline six fires every 120 degrees. Dual plane V8 manifolds separate the cylinders to keep that pulse 180 degrees apart - inside cylinders from one head share a plenum with the outside cylinders on the other. That reversion is no worry at 6,000+ rpm where a single plane is made to work.

The DP and Offy C both have all cylinders on the same plenum like a V8 single plane, only the DP splits the primaries and secondaries into their own plenums/runners. The Offy C doesn't act at all like a single plane on a V8. I've never driven a DP-equipped 300 but my truck didn't lose anything off-idle with a C vs. stock. But it sure as heck gets through low rpms quicker. And pulls at least 1,500 rpm farther. The factory log is a single plane, unlike every Ford V8. Of course, designing for a 1-bbl carb doesn't give you many other options.

Those dyno programs are fun but don't put too much faith in one. What head flow data are you using? 300 heads are very restricted. Even fully ported they couldn't sneeze at an off-the-shelf pair of Chinese aluminum 302 heads. Within reason, anyway, for a street engine. And a 302 is only filling 38ci cylinders vs. 50. You won't see those big numbers up top.

 

I was using just the generic most restrictive head flow data off of a early 60's ford small block. Good point I really don't mean to hijack this man's thread does any one have some bench flow data for a 300 head?

I will admit and I should have I really don't have much experience in using this program but I am quickly learning. I really didn't mean to lead someone on to false data. What I've seen is just from playing with the program...