QuickVet

I talked to my machine shop a little while back and was asking about making a new motor for my vette. I told em I was interested in a 383. He seemed to think I would do just as well with a 355 as I would a 383. I was kind of turned off by this because everyone seems to love the 383s. Is there any logic to what he is saying. Does the 355 just rev up better then a 383 on the top end? do you guys think I could build a 355 that could out power a 383?
Thanks for you opinions.
Aaron

scorp508

If you go with a 6.0" rod 383 you'll have the same rod/crank ratio as a 350. :yesond:

Taijutsu

That was my goal. If you are going to make more power w/less inches you have to get the extra flow somewhere. In my case a 218-224 Hyd Rol w/1.6 rr, ported TFS heads w/backcut valves, matched up the Air Gap and topped off w/10.25 cr and 6" rods. I have forged everything and ARP 100% This will make BB power w/SB weight. Of course the 383 can do all those tricks at a lower rpm. I have 3:55 w/M21. I would go 383 w/auto. Still the 383 will use 9% or more gas. The question is "How much power can you use "safely" on the street. For me the 425 hp and 450 tq do it!

QuickVet

do you think i should try the 355 or the 383? I need to build up my motor this winter but dont have a clue what i am doing. I wouldnt know what parts to order :confused:

MoMo

A 355 is a good motor. But a long rod 383 is a better motor for street/strip. If you don't know what you're doing, please hire a good machine shop to build it up for you. The biggest danger is cutting into the water jackets while clearancing for the increased stroke. You'll also need a small base circle cam, and you can get a 383 rotating assembly to use in your 350 block at most engine suppliers, such as PAW and Speedomotive.

The 355's rod/stroke ratio is 1.63, using 5.7 inch rods. A 383's rod/stroke ratio is 1.60, nearly as good, using 6.0" rods. So they'll rev as eagerly, but the additional stroke and cubes of the 383 will make quite a bit more torque and power as a result.

Now, if you enter into the equation, a long rod 355, using those 6.0" rods, then that throws a curve ball into the argument. Because although the 383's excellent torque will haul you off the line very well, the high rev potential of a long rod 355 could be built for some serious high rpm power with a radical cam and very steep rear end gears.

I'd go with the long rod 355 for a drag race engine. Then you get a 1.72 rod/stroke ratio. build it for 13:1 compression, put a really hairy solid roller cam in it, and a good pair of large valve 2.08/1.60 heads and a Victor Jr. intake with an 850 Demon or Dominator, and you'll probably do very well. Use this engine for drag race only though. But I'm sure you'd see 11's with at least 4.11 gears, shifting at, oh, 7500 or so.

BUT ...if it's also a street car, THEN I'd say go with the long rod 383 with not as wild of a cam. If you have to live with it in stop and go traffic, you'll come to really love the massive torque and the friendlier idle.
:smash:

scorp508

Isn't it true that a normal size cam is fine as long as you go with a capscrew on the connecting rod?

RACER7088

larger engines are better for race and street for the most part. Whatever engine builder told you that is stuck back in the seventies when cylinder heads sucked.

vader86

383

Red Rocket

Running the same ET's with my 396 as the 350 although my mph is about 4-5MPH more. Can now launch at idle on street tires with the 396 and not dump the clutch at 4000 rpm's with ET Streets on the 350. Overall, I would say the car is taking less abuse on the track and is alot more fun driving on the street.

hookedup

Scorp,
Clearance depends on the brand of rod you use along with the lift, duration & installed position(advanced or retarded) of the cam.

Hope that makes sense, Dave :yesnod:

CORKVETTE1

to momo quote I'm sure you'd see 11's with at least 4.11 gears, shifting at, oh, 7500 or so.
then why not do the same thing with a 383 be confident to run mid 11s all day without breaking a sweat without breaking parts spinning that motor that high a 383 could do iy under 6000 with 3:55 gears :D

CORKVETTE1

:cheers:


[Modified by CORKVETTE1, 12:33 AM 9/16/2002]

sinistervette

If all you are concerned with is drag racing, I would go with the 355. But, are you staying with the tpi? Do you want to go to a steeper gear ratio? If you want to stay tpi, and stay with 3 series gears, then you will be better off with the 383. Tourqe/rpm is the factor for this. The tpi seems to be a great torque/lower rpm set up, therefore the long stroke/small bore will work best. If you are going carburated, and want the low gear/high rpm way of going fast, 355 is in my opinion far better choice for the $. One thing you might want to consider, go with a 406. This uses the long stroke(3.75"), but big bore! It is a killer! :D You can stay with the tpi, and make more torque and hp than the 383. Check out corkvette, and you will get my point! :cheers: By the way, 355 vs 383 with all else being equal, the 355 will rev quicker than the 383.

The Green Rocket

Bigger is better see: http://www.chevelles.com/forum/Forum4/HTML/011478.html

While he is correct in saying that you could do just as well with a 355, what he neglected to tell you is that it would take more rpms out of the 355 to match power with a 383. Even if you don't know much you should be able to see that the 355 is going to be more stressed than a 383 for any given power level. Less stress of course means greater reliability. Besides, there are tons of good 383 combos to choose from that have been posted in CorvetteForum. I'm going to guess that the engine builder you are talking to hasn't doen a 383 and doesn't want to have to learn the finer points that result in good power and reliability.

Go find another engine builder.

Thomas

jerryjfunk

I was talking to an extremely well known engine builder around here, Burkart, and he told me that a 355 would be much better for drag racing.

I'm building a 383 for the street, but it will see the strip once in a while.

:cheers:

Jerry

gkull

I owned a 9000 rpm 355 ci alky injected drag motor. Best 1/4 mile was 8.30's in the low 170's mph. We we always fixing something in the valve train. It was probably around 700+ hp. I've been told that the 358 pro stock trucks all made around 850 hp. But that's super high dollar motors.

Then we bought a 509 ci big block chevy alky injected and never spin it over 7500 rpm and it's still running today and it's a no problem 7.50 second 1/4. in the low 180's. Hundreds of 1/4 mile runs and it doesn't need a toe machine. If you don't use the chute you just drive back to the pits

Anybody that tells you to drag race with a smaller ci motor is a :conehead

QuickVet

:eek: :eek: :eek:

Alright guys. there is alot of good info here. I guess the best buy would be to go with the 383. Even if it is slighly slower, i would rather not be fixing it every month. So what is my next step. I really want a strong motor. Im planning on just doing the short block and then sitting on it untill i have the money for a really good set of heads. I was thinking Dart heads. Anyone have any suggestions on where to get "stong enough to do the job" parts at a fair price. I have seen the Eagle parts on ebay for about 1500 bucks and Bill Mitchells parts are about 1500 bucks. I am guessing that is what i have to spend for a forged kit. BUT WHICH KIT? (6.00" rod kit right?) any suggestions on heads as well? This is for my 79 Holley carbed vette with 411 gears and a 3000 stall.
thanks.

Aaron

QuickVet

and what kind of cam? :confused: thanks

vettedan

Go with the best of both worlds! "383" it has awesome torque and HP characteristics. Having a 400 cu. in. crank in a 350 c. in. does wonders. 383 would be my choice for drag racing.
Dan

sinistervette

Depends. If you want more ci, that is usually the best choice, I don't go for long stroke/small bore. To me torque is fine for street, street/strip, and is best in a tow vehicle. But if you want the long stroke, go with a bigger bore. You will gain even more ci, and have more hp in the samr rpm range if lower rpm is what you are looking for. If torque(long stroke/small bore) was the best for drag racing, almost every "pro" catagory racer is doing it wrong! :confused: I would look into a 406, with your set up(carb/4:11/3000 stall) you would be much quicker/faster and more reliable than with the 383. JMO. :cheers: