PeterC3

I know squat about engines... Actually I'm being generous... I know diddly squat about engines and this is my first 'vette. The PO, I'm second owner, of my 81 does not have any data on the 383 stroker or the 700 R4 he had installed back in 2000. He did tell me that he instructed the engine shop to give him a 383 stroker on the lower end of the power scale because the car was his daily driver and he didn't want to burn a ton of fuel. He thought the engine put out about 300ish horsepower but it was never tested. I am curious to know how much power is getting to the wheels though. There are no emission thingies to hinder engine performance. Is worth putting the car on a dyno? Or do I have more money than brains?

drwet

If it was my car and I had access to a dyno, I'd love to know what kind of power it was making. Not sure what you are going to do with the information, though. If you don't know what is in the engine, you don't have any idea what to change to improve it.

ddawson

Get it on a Dyno and find out. It's not very expense at all. They results will be what they are.

Scottd

Have you verified that its a 383? My concern is when someone tells you they instructed a builder to make them a 'mild' 383...when a decent 350 would do the same for a lot less money. Just a red flag, worth looking into. Cant hurt to be cautious....I know guys who thought they were buying a 383 or a 350 and wound up with a 305. (I personally bought a 'freshly reworked 350, .030 over, 4 bolt main with aggressive cam and domed pistons' from a friends brother. I trusted the source. The ONLY thing he was telling me the truth about was that it was a 350....(worn out bearings, stock internals)

Do some homework, run the block numbers. 300 HP seems awfully low for a 383. (I say run the block numbers because you will be able to tell if it was a crate motor or at least give you a starting point, it wont verify if its a 383, but some custom engines have their own stampings when they are rebuilt)

Buccaneer

300HP on a 383 seems rather low at the motor, but maybe he meant at the rear wheels? If you have access to a dyno, I'd go for it and find out what you have and go from there. Is your motor still a carb motor or did he go EFI or what? EFI is the way to go if you have a choice.

PeterC3

Well the only one disappointed with the stock '81 vette was the original owner. He complained about getting smoked by subcompacts. Not sure if he's exaggerating. He did say the 383 was a crate engine. I'll get more details, block numbers etc but I am inclined to believe him. And he is a neighbor, I've invited him to witness his babies restoration, I can always ping him for more info.

This is my first car with any muscle, so I am easily impressed with the acceleration. Especially after I had the kit installed that allows me to reach manual 1st gear in the 700R4. I like gearing up manually for fun, but use the breaks for slowing. And I have pegged the silly 80mph speedometer numerous times running up a mountain road.

I'd like to know the realized HP just for my reference more than anything else. I love the driving the car, its primitive, throbbing nature is really appealing after driving these electronics laden, excessively nannied, computers on four wheels.

jb78L-82

What ever the motor is, the engine is from 2000 and much has changed with components that can make big HP since then. Just because it is a 383 does not mean much in terms of HP without knowing the components on the motor. A properly built 355 with decently high compression (10-10.5:1), high flowing heads, and high lift cam will smoke a 383 with inferior parts all day long. Cubes alone really tell you nothing about the HP of the engine. GM offered a SBC 400 back in 1972 with 170 net HP, as an example from the factory, no less.

Jebbysan

Can't beat a dyno......who knows, you may have power on the table still.
Correct timing and jetting can do wonders......

How about some engine pics?

Jebby

PeterC3

Well is wasn't looking for a fire breather, just a daily driver with umffff. But I do plan to let the car loose on the local track so I don't loose my license.
I'll post engine pics soon, the body is being refurbed... that's another $tory....

Jebbysan

A correctly tuned engine runs much more efficient and crisper......starts easier and runs cooler......not just about the power.

Jebby

PeterC3

Someone suggested that this super-tuning could be done during dyno? If so is it significantly different than the local Chevy dealer tune up?

ddawson

Dyno tuning is very different. They take a base line run monitoring stuff like timing and air/fuel ratio.

As they adjust thing the dyno show if they are going in the right or wrong duration. You would have to find a shop that knows carburetors though.

Jebbysan

Yes...as stated above, a dyno tune is jetting and timing set.
Do not confuse this with a "tune-up" which is wore out components replacement.
Find a dyno near you and have it done.

Jebby

PeterC3

The PO also mentioned that he had the 700R4 "beefed up" somehow so he could manually shift.

Does this sound legit? I have a lot of receipts for extensive work done way back, but the tranny records were lost in a firestorm (he lost his house) in this area in 2003.

The tranny shop warned me about down shifting to slow the car, bad. Brakes are cheaper. The PO had the tranny set up for hwy cruising at about 1400rpm for fuel economy. The lugging is kind of annoying in the city though so I manually shift a lot. To be honest I would rather have a manual tranny, but ya gotta love the one your with.

Jebbysan

Probably had the "Vette" servo put in....a common mod....this and most likely a shift kit.
It is EXTREMELY important that the shift down (TV) cable be properly adjusted.....it is the lifeline of these transmissions.....google up the procedure....it is easy.

Jebby

Alwyn678

You need to have the car gone through. A Dyno is a Great start. I have a 350/365HP and I also have a 700R4 with a 3:73 gear ratio. Everything Must work TOGETHER.

PeterC3

I had a local tranny shop install the mod to the gear selector so I could reach manual 1st gear. I'm hoping they checked the TV out at the time but I'll check and I'll research the mods. thanks.

PeterC3

Roger that, but I'm a nube, can you be more specific?

I have to admit that I put a lot of faith in the fact that the PO's had done everything right. He told me he breast fed the beast. But I did go into this eye wide open, knowing I was going to have to refre$h the car to prep it for its next 35 years.

Alwyn678

I understand......Never, Ever buy cars from friends or relatives. Doing business with either is a hornets best you are about to lay on.

Since you are not mechanicly inclined, find someone that is and have them to a thorogh inspection. Ask for All the specifics and have them Dyno your car.

This will be invaluable for Vette ownership.

Good luck

PeterC3

Was finally able to get some engine block #'s:

148207N and S207.