shamby

While I've got the engine out of the car I'm thinking about going ahead and stroking it out. I stroked my 4.0 jeep wrangler and it made a world of difference. Does anyone know what kind of numbers a 383 will make over a 350. Right now I'm running edelbrock Performer RPM kit. I know kinda a loaded question, but just a rough estimate.
thanks
Scott

SanDiegoPaul

The big thing is real-world feel. Day to Day driving with a stroker displays more torque, and makes for a much more fun ride.

It is completely impossible to even guess what numbers you're going to put down on the pavement until/unless a plan is made and components chosen.

shamby

that's kinda what I thought. It made my jeep a real stump puller. With 455 gears and a 4.6 stroker the only thing that will stop it is the junk rear end.

Right now I have edelbrock Performer RPM 64CC heads, Weiand stealth intake, holley 750 double, Comp XE268, all bored 30 over. I think I could stroke it for around a grand. Trying to decide if it's worth it. At some point you need to say no.

Rmorgan&11

You can get some pretty good rotating assy's from CNC Motorsports or Competetion Products

shamby

I know the block has to be machined for clearence, different flex-plate and harmonic balancer. To my knowledge that is all correct?

RoadsterGuy

That depends on the kit you buy.
Both Scat and Eagle make kits for 3.75 stoke in a 350 block that are internal balanced and use cap screws rather then bolts and nuts on the rods. The cap screws give enough clearence in most blocks to clear without grinding.

MotorHead

Look at it this way, for an easily driven on the street motor 350-400 for a 350ci and for a 383 you can go 450-500HP. These are just guidelines based on my own personal experience building motors we all know you can build a 600HP 350ci. And I am also not saying 33 more cubic inches is going to give you 100HP, these motors would have different components in and on them

billla

Two thoughts:

1. If you're doing an overhaul, you'll end up having to turn the crank or buying a new one...so the cost of a 383 is virtually zero.

2. There's no substitute for CID - at 1 HP/CID, you'll build...33 more HP and more than that in TQ. A 450HP is fairly rowdy, a 450 HP 383 is just getting started.

Start with a budget and work backwards to what you can achieve.

Rich's'78

Watch your compression ratio or you may be in detonation territory.

hugie82

Even if you go low compression, cast, mild cam and stock heads. I think you will see a big improvement off the line and all around kick in the pants fun Only in America!!!

shamby

The kits I've been looking at will put my compression ratio right at 10.7. I should be good with that. As long as I keep it under 11.1 I should be good right?

OzzyTom

Cam choice will need to be carefully chosen for that compression ratio
you'll need a bit of overlap to bleed off the compression to prevent detonation (pinging)
in other words, you will need a lumpier cam...
Which isn't a bad thing if performance is your goal

you will need to determine the dynamic compression ratio

shamby

The cam I have is Comp Cams 268H-10.

Intake Duration at 050 inch Lift 218
Exhaust Duration at 050 inch Lift 218
Duration at 050 inch Lift 218 int./218 exh.
Advertised Intake Duration 268
Advertised Exhaust Duration 268
Advertised Duration 268 int./268 exh.
Intake Valve Lift with Factory Rocker Arm Ratio 0.454 in.

I have not even opened the box yet, so if the cam is wrong I can always send it back. I'll have to do a little home work to determine dynamic compression ratio
Thanks for all the post

MotorHead

You need a bigger cam to run that compression ratio, I am somewhere around there and have a cam that is 248/254 dur @ .050"

shamby

Good thing I didn't open the box. Also I think my dynamic compression ratio is 8.33:1. Thanks again for all the help. Can you grind the block your self for clearence?

hugie82

Yes you can clearance the block but I would see how much your machine shop would charge. If its another $100 I would let them do it..IMO

MotorHead

8.33 is on the edge and if your calculations are off then you could be in trouble. With that DCR you need the best high octane gas available, shoot for 8 or slightly under. I forget exactly where I am but I am not over 8:1 and I can run 91 octane and still make 600+HP

shamby

Thanks Motorhead, that 10.7 compression was using flat top pistons. If I went with a dish piston the compression will drop to 9.8. So just to be safe I guess I need to stay with the 9.8

glen242

My 383 w/aluminum heads and a CC XE274H cam has a calculated static 10.3 CR, and a calculated dynamic 8.3 CR.

I have been running 89 octane BP since I built it 4 years ago, without a problem.

BTW, timing is 34-35* all in by 2600 rpm.

MotorHead

What are the specs on the motor, bore dia., stroke, pistons cc's + or -, combustion chamber volume, compressed gasket thickness, head gasket bore diameter, and piston to deck clearance ?

I'll figure out your DCR, I don't like giving out the wrong info to others and if you say what you have is there and it works out to 8.3 DCR then I will have to edit my post.