383 recipe

[Rustyrodknocker]

Guys, I'm looking for some input on an upcoming 383 build. Its a 1965 that will be going into a Newport 4dr sedan. I believe it is a factory 2brl.

I know their was a compression drop in 65 and a resulting lower hp. Was this do to changes in the heads? Or did they go to a dished piston?

I intend to run the stock heads as they are brand new. Factory cast iron 4 barrel and an Edelbrock/Carter carb. I have all the carb variations to choose from, in that platform.
I have a few random Holleys but I can't remember exactly which I would need to do some digging.

I was think 67-72 hp cam maybe or a modern equivalent.
I'm looking for a power upgrade for a completely stock car and I want it to look stock under the hood. Maybe a performer intake painted to match.
But basically stock in appearance. But be the equivalent of a 63 330hp or a little more

That's where I am for now.
All input is welcome.

 

[furious70]

I'd love to see a dyno test on those early 383's like was done with a magnum spec one. Always wondered how the early ones could be rated that high with those heads, intake, carb, and exhaust.
The best things you could do would be the carb and intake as you suggest.

 

[Rustyrodknocker]

They were measuring flywheel hp. They were likely 30% lower. The 330 hp was probably a 290 net.

 

[Davea Lux]

The '65 2BBL engine was a 9.2 comp ratio and this engine ran dished pistons. The 4BBL engines were rated at 10.1 comp ratio and had flat top pistons. The 2BBL engine ran a milder cam .392/.390 intake/exhaust lift. The heads are the same closed chamber style for both engines. The older 383 2BBL engines had more horsepower due to the fact that they were 10.0-1 comp ratio and ran the same cam as the 4BBL variants.
The 440HP cam is a pretty good choice for all around street use. Be sure to upgrade to dampered valve springs if going that route. If rebuilding the engine go for pistons at 9.5-1 comp ratio as that is about all you can get away with on pump gas. 600cfm Holley or equivalent Carter AFB or AVS would be a good choice for a street engine coupled with a high flow intake. Exhaust is restricted by the log manifolds, but you won't notice much difference until over 4k rpms. In a perfect world, headers with large diameter exhaust would be ideal.

Dave

 

[CBODY67]

There are some videos at Nick's Garage YouTube channel.

The '65 383 4bbl was 315 horsepower, but still had the "2bbl cam" with 252 degrees and .390" lift. The earlier 383 4bbls had more like 260/268 duration and the lift Dave stated. And, it was a single exhaust engine, too. The factory HP cam would be a good upgrade with a 4bbl intake.

Enjoy!
CBODY67

 

[Rustyrodknocker]

Well that has me curious now. I'm not sure of the condition but if its pretty good then it would be a real bonus if its a 4bbl. If it needs a rebore then it will get a kit with flat tops anyway. I thought I read that the head gaskets were thinner? I figure I could bring down the c.r. if I had to with some different gaskets. I have had good luck doing so on motorcycles with the Cometic MLS gaskets.

 

[Davea Lux]

Well that has me curious now. I'm not sure of the condition but if its pretty good then it would be a real bonus if its a 4bbl. If it needs a rebore then it will get a kit with flat tops anyway. I thought I read that the head gaskets were thinner? I figure I could bring down the c.r. if I had to with some different gaskets. I have had good luck doing so on motorcycles with the Cometic MLS gaskets.

The Mopar engines of that era ran steel shim head gaskets. The modern Fel-Pro or equivalent gaskets are thicker and will drop the comp ratio about a half a point.

Dave

 

[Rustyrodknocker]

The '65 2BBL engine was a 9.2 comp ratio and this engine ran dished pistons. The 4BBL engines were rated at 10.1 comp ratio and had flat top pistons. The 2BBL engine ran a milder cam .392/.390 intake/exhaust lift. The 4BBL engine was .430/.430. The heads are the same closed chamber style for both engines. The older 383 2BBL engines had more horsepower due to the fact that they were 10.0-1 comp ratio and ran the same cam as the 4BBL variants.
The 440HP cam is a pretty good choice for all around street use. Be sure to upgrade to dampered valve springs if going that route. If rebuilding the engine go for pistons at 9.5-1 comp ratio as that is about all you can get away with on pump gas. 600cfm Holley or equivalent Carter AFB or AVS would be a good choice for a street engine coupled with a high flow intake. Exhaust is restricted by the log manifolds, but you won't notice much difference until over 4k rpms. In a perfect world, headers with large diameter exhaust would be ideal.

Dave

By dampened spring, do you mean variable rate/ progresive wound?
I'm not sure what springs they went with Ill check that first.

 

[CBODY67]

Seems like I saw somebody that still, or has re-started, making the .020" steel shim gaskets again? But the tech behind the newer FelPro composition gaskets is better, to me.

Just some thoughts,
CBODY67

 

[CBODY67]

By dampened spring, do you mean variable rate/ progresive wound?
I'm not sure what springs they went with Ill check that first.

Valve springs with a flat-wound (damper) spring inside of the normal (outer) spring. Higher pressures result. According to Nick, you do the cam break-in with only the outer springs, then add the inner damper afterward. Not sure if that's the way Chrysler did it at the engine plant, though.

CBODY67

 

[Rustyrodknocker]

Valve springs with a flat-wound (damper) spring inside of the normal (outer) spring. Higher pressures result. According to Nick, you do the cam break-in with only the outer springs, then add the inner damper afterward. Not sure if that's the way Chrysler did it at the engine plant, though.

CBODY67

Got ya I didm't realize that was the job of the flat wound spring. Makes sense. I assume its doing its work at low lift transitioning on and off base circle.

 

[Rustyrodknocker]

I have not watched much Nicks gzrage but my father inlaw was telling me he replicates some factory builds and puts them on the dyno to see if they meet the published data

 

[cbarge]

I agree with Dave's recommendation.

You can do more work on the inside and still look stock.
You can massage the heads by opening up the bowls and port match the intake and heads.
Back cut the valves while you are at it.
A windage tray is a cheap investment that pays in spades that frees up a few extra ponies and with reduced resistance a wee increase in MPG.
My 383 looks stock--but far from the truth.
Like yours,Mine started life as a 2bbl engine.
I am running a Comp Cam 268H (with the recommended matching valve springs) which is the max for a stock convertor.
I am also running a 750 Eddy (already had it and no cash to buy a 650) on the Eddy Performer 383 intake. I removed the "Edelbrock" and painted the intake to match the engine.
Despite having to bore my block and buy new pistons,we retained a 9.2/9.5ish Compression.
The TTi system works very well even with the log style or HP manifolds (which I have).
Restrictive?
Maybe but makes gobs of torque--which is what you need to move a big heavy car.
My old NYer I kept the logs and ran the TTi. It ate 5.0 Mustwangs all day!

For reliabilty,go with a Cloyes timing chain set and a Melling oil pump.

But as mentioned before in other threads,do your homework to see what works well TOGETHER!!
I had seen and fixed cars where owners bought "the best of the best parts " but none of the parts gelled and the engine was a dog.

Finally,the fine tuning,of ignition system and carburetor is where you get the most out of whatever "combo" you choose.
Hope this helps.

 

[Rustyrodknocker]

I agree with Dave's recommendation.

You can do more work on the inside and still look stock.
You can massage the heads by opening up the bowls and port match the intake and heads.
Back cut the valves while you are at it.
A windage tray is a cheap investment that pays in spades that frees up a few extra ponies and with reduced resistance a wee increase in MPG.
My 383 looks stock--but far from the truth.
Like yours,Mine started life as a 2bbl engine.
I am running a Comp Cam 268H (with the recommended matching valve springs) which is the max for a stock convertor.
I am also running a 750 Eddy (already had it and no cash to buy a 650) on the Eddy Performer 383 intake. I removed the "Edelbrock" and painted the intake to match the engine.
Despite having to bore my block and buy new pistons,we retained a 9.2/9.5ish Compression.
The TTi system works very well even with the log style or HP manifolds (which I have).
Restrictive?
Maybe but makes gobs of torque--which is what you need to move a big heavy car.
My old NYer I kept the logs and ran the TTi. It ate 5.0 Mustwangs all day!

For reliabilty,go with a Cloyes timing chain set and a Melling oil pump.

But as mentioned before in other threads,do your homework to see what works well TOGETHER!!
Finally,the fine tuning,the ignition system is where you get the most out of whatever "combo" you choose.
Hope this helps.
View attachment 439505

Thats the look I'm after. Ill probably run my hybrid chrysler distributor/ pickup with a hidden hei module. That is if I do away with the points.
And I'm considering trying to build a high flowing single exhaust. I have been plotting that for a different 4dr sedan I"m chasing.

 

[furious70]

Couple things

Having owned several mustangs I'd line up in a 5.0 against the run of the mill 383 boat


Second, the oem style .020 shim gaskets held 12psi of boost in my 383 just fine, can't imagine why y'all would have any issues using them.

 

[cbarge]

Thats the look I'm after. Ill probably run my hybrid chrysler distributor/ pickup with a hidden hei module. That is if I do away with the points.
And I'm considering trying to build a high flowing single exhaust. I have been plotting that for a different 4dr sedan I"m chasing.

Some may disagree but get rid of the points.
Why stick with a single exhaust?? Is the noise level a concern?
The TTi dual system with the H pipe is quieter than you think.
They spent a lot of time engineering their system and I installed 3 of them so far with good results.
I am afraid the time and expense engineering a "high flow" single exhaust may not be feasible.

 

[cbarge]

Second, the oem style .020 shim gaskets held 12psi of boost in my 383 just fine, can't imagine why y'all would have any issues using them.

I forgot to mention I am running them and no issues.

Love your car and hope to see you again if they ever open the borders.

 

[Rustyrodknocker]

Some may disagree but get rid of the points.
Why stick with a single exhaust?? Is the noise level a concern?
The TTi dual system with the H pipe is quieter than you think.
They spent a lot of time engineering their system and I installed 3 of them so far with good results.
I am afraid the time and expense engineering a "high flow" single exhaust may not be feasible.

I may do away with the points. Mainly because when they sit around they go to hell. Especially if they are cheap *** points. But I'm not sure how long I'm going to keep this car. And my bastardized hei module system is not a selling point. But it is great for a driver. Thats what I run in my main car.
The single exhaust project is for another sedan that I am chasing, a plymouth. Its just something I want to do on a 4 door car. And I hope to get the plymouth
This car kind of fell in my lap or is going to. I have always wondered if it might but it is a one family car, not my family. So I never really thought it would be available.

 

[furious70]

With any luck I'll get back to Iowa enough to get it together before the show!

 

[cbarge]

I may do away with the points. Mainly because when they sit around they go to hell. Especially if they are cheap *** points. But I'm not sure how long I'm going to keep this car. And my bastardized hei module system is not a selling point. But it is great for a driver.

Reliability is a huge selling point on these old cars..
There are a lot of people who want to drive an old car without old car headaches.
The HEI-Or a Mopar ECU conversion kit.- when installed neat and tidy,buyers appreciate your effort knowing that they can drive the car..