cv67

Musta had one hell of a converter on that vortec 383
Mph makes no sense to me but hey never know right

Ditto on manifolds with a good performance head working on the rams horn is a waste of time been there done that. Just get headers enjoy the motor who cares what some car show snob thinks.

A 383 witha 6 in rod has the same rod/stroke ratio as a 350 mine will touch 7k no problem and revs just fine'thats just tuning. Like you are wanting, built mine to run more upstairs and NOT make so much low end torque. Its a kick in the azz (and very controllable) let me tell you. Drag radials are a blessing or learn to modulate that right foot

The lever action of the 383 may be a little harder but who cares a half decent rod isnt much.

Back on topic....oops!

TCracingCA

I am a polarizing type person!

But hogging out ram horns, they will crack eventually and die!!!! You need to leave the meat on them as designed and you will never get out of the 300 range with them.

Well, I forgot what else I was going to say. That has never happened while typing on the computer, just in real life!

Ok I remember, I am just not a fan of 383 built in the conventional way with cast parts, unforged parts, and non-high quality rods. The Rod angle is a little much for RPM's is my slam!!!!! But if you work in longer rods and stronger components, then the 383 can be a beautiful high rpm singing engine!!!!!

Darn, now I forgot what else I was going to say!!!!!! I will probably have to PS later!!!!!!!!!!

ohiovet

A while back I installed a GM Ramjet 350 in a 62 Corvette and it ran great.
I ued ram horn 2 1/2" headers, round mufflers ,etc.
Ran it on a chassis dyno and the dyno guy told me I could gain 30 to 40 HP with headers.
So...

00fxd

There was a guy on here a while ago that was makin' big power with ported rams horns... Hope he chimes in - it was interesting ...

cv67

Like to see it.
Few yrs ago I did a set for a member here and went as far as I possibly could with them from stem to stern
327 voodoo cam replaced the solid Wesmigletz tuned it to perfection.
Owner who I believe is an honest guy said he felt zip in the butt o meter dept so if there was any measureable gain imo not worth the money he spent. Dont know if headwork could have helped or not perhaps that was/wasnt the bottleneck

427Hotrod

Do a search on 632C2. Steve Barker has done some incredible work with iron manifolds on his 383" C-2 and later the 542" engine he dropped in same car. Both had tons of work to make them appear "stock". The small block made 400+ RWHP and ran 11's. The BBC made over 700 RWHP...through manifolds!

JIM

MikeM

I don't usually get mired down in these Ricky Racer threads but my take is, if you're going to use the bug cubes (383/400) and stick with the stock intake/exhaust manifolds/mufflers/carburetor, the best thing you can do to get the most bang for the buck is to slip in a mild cam in that engine and go with factory cast iron heads and forget about a high winding big cube engine with the aforementioned OEM components.

I have done several big cube engines with stock heads, LT1 intake, 780 Holley, rams horn exhaust, and L 79 cam and none of them would crank or even want to crank over 6K but they pulled like a freight train.

All I'm saying is, if you are building a big cube SBC and you want high rpm, forget the OEM intake, exhaust, heads, etc. Keep the rpm down and the factory stuff still works.

BWTFDIK?

joebobbilly

Much for RPM's ?

Is 6,500 too much for a 1.50 rod ratio? A 383 w/a 5.7 rod is 1.52, better than 1.5.

Here's a 1.50 rod ratio:


Low 8's all steel except for hood and decklid. All real glass, bumpers, horn, blinkers, tail lights, head light, high/low beam the whole nine yards.



And that's foot braking/hand shifting and not even pulling a tire.

TCracingCA

I just """like""" a higher rod ration is my preference. Not saying that guys aren't doing it with shorter ratios (thus don't get a short complex, please!). And we aren't talking all of the magic race car combinations, but about the OP's street car! But Is your bottom end built??? You didn't say??? Do you have higher end rods?, upgraded rod bolt hardware? Forged Crankshaft???? Like I recommended with a 383, I bet you do! And that is a super cool and fast looking car!!!!! I like it! You have good tastes!

A lot of people slam that rod ratio!!!! Don't just burn me at the stake or tar and feather me only. Oh ya! For some reason, everyone from NASCAR to F1 and such seem to lengthen the rods!!!! There must be some intelligent life form in those series, that causes that to happen!!!!!!

TCracingCA

Is that Extrude Hone process! I have mixed feelings about that stuff, but to some degree it makes sense. To take a pair of iron boat anchor weights and burn up grinding stones and such for a gain, OK are you honestly that darned bored!!!!!!!!!!!

Thus maybe this process, but I can't see how you can control the distribution on this process. I can see the material hitting an obstruction point or choke point and removing more here or there and less here or there! But maybe something like that would be cost effective if that was your path in life!

Headers Headers Headers! is so much easier!!!!!

TCracingCA

Join us ricky racers! The force literally in HP is stronger!!!!!!!!!!!!!

joebobbilly

I know a lot of people slam that rod ratio. I could always see them in my mirror. The vortec 383 I did for my friend, like I said and you can look back and find it, it was a 5.7 rod....a powdered metal rod...factory rod. One of those cheap cast steel cranks and for the guy that commented on the convertor, it was one of those cheap $200 9 inch deals, sorry to inform you.

Sure the nascar/F1 like a different ratio, but they are running 9-12K rpm. It's the flame travel that is important, not the rod ratio.

And fyi, the 1.5 ratio was with a 4130 eagle crank/rods, and stock block.

With today's aftermarket selections, making big power is easy....if you know what parts to slap together.

OP can do what he wants to do. He wanted real life experience opinions, and I gave one. I was running that fast 20 years ago on a budget. Nowadays, it takes much less talent to go fast if you have the wallet.

DucatiDon

What is the combo that you are running?

Imstarting to look at headers now, as I dont want a mack truck vette...Id like to spin the thing a bit. And i can put them on the car now, while I am building the 383. I "could" do the same with the heads too I suppose...

Comparing McJacks long tubes to Hooker Supercomps, Stainlessworks and Dougs... McJacks has the best price point... which fit the AFR .25" raised port angle plug heads the best?....still unsure.

cv67

billybob was referring to stall speed I didnt clarify


don probably not what most would want to drive
11.5:1
Some out of date Dart Conquest heads by Mamo they are exactly 230cc now
Isky solid roller 260/268@050 640 lift 108 lsa
Fully ported Team G with 1 in spacer
AED 850
What most would consider mismatched (its in an A body, 6 spd). Flat out rips

Where exactly do you want yours to come on and let up at?

With todays parts you could make even more power with a modern head and a smaller cam also.

claysmoker

I have Hooker SC's on the engine I am currently running on my test stand and they clear the RHS angle plug heads just fine. Raising the holes 1/4" might cause some issues with the #6 spark plug.

Westlotorn

We built Cast, Hypereutectic and Forged pistons used in 383's in the early 90's, at first these were known to only last 40-60,000 miles before you saw block problems, mains cracked through the webbing, piston skirts cracked from the high side load when using the factory 400 5.65 rods. When the 5.7 rod pistons started being used in the mid 90's the blocks stopped failing and the piston skirts were fine, short life spans were eliminated and the 383 became an engine upgrade of choice.
The 6 inch rod versions allowed even more, ability to rev higher and less side loading of the pistons. A much better 383 for all purposes.
A good crankshaft is needed, the factory 400 crank had it's limitations as do many of the aftermarket cast cranks.
BTW the powdered metal rods mentioned in this thread tested to be stronger than the OEM 1970's Pink Rods. Those powdered metal rods held up really well once they got the bugs out of them. Some of the early attempts had rod failures but that was worked out and most OEM's use powdered metal rods today.
They save money vs forged rods. With any forged part you only get so many forgings and the dies need to be replaced, this makes all things forged more expensive.

TCracingCA

With the raised ports, there probably is just enough of a difference in them vice the 461's that I wouldn't mock them in yet, until you have the AFR's on the block and in the car. I can't make recommendations on those models, your config is different. On one car (my C2) I have old Vintage Hooker sidemounts with 1-7/8 and 4" collectors on STD Bowtie heads and on the other (my C3) I have old no longer available Hedman 65330's which are under the car 1-7/8 and 3-1/2 collector units also on the same vintage heads. I am sure the topic of best to pick has been covered on the forum in the past. I bought one set painted black to save a bunch of money, and prior to firing the engine, fitted them and did the special flange, and then took them off to send for Jet Coating.

But back to my project of trying to get a gun rack into the hardtop of my C2!!!!!!!

Nicola

Good buddy who happens to be licensed class A mechanic, said I should try running regular 87 fuel in in my 66 327/300 hp/ p/g with a/m electronic ignition. I was quite surprised with his recomendation...so I tried it.
This was 2 years ago...never looked back...no pings, no bucking, no bucking, no snorting.
I do drive my car for about an hour just about everynight between May and into Nov. weather permiting. Does make a difference in the fuel bill.

DucatiDon

OK I've been convinced. Z28 intake and 1.75 long tubes. Now I need to decide on heads...195 or 220cc. And straight or angle plug....any suggestions on which will be best with headers?

joebobbilly

the Z28 intake has decided the heads for you....but you do what you want to do because there will be far less informed opinions that trump hands-on experience of 'ricky racers' such as myself