[Geo71]

Would disagree a bit on the clearance issues. I'm building one right now and notched out on the pan rails for connecting rod clearance. Maybe it just denpends on the parts you're using...And not that this had to do with a 383 specific, but I've had to make mods to my timing cover just to clear cam button and bolts. Had to do some clearance work to make my oil pan and baffle clear journal studs. Guess it just depends on what setup you're running when it comes down to it,

Which block are you using? Which rods? We are just getting started on mine, hoping to not run into too much trouble. I'm sure something will come up somewhere though.

I went with a late model roller block but using a two pc crank / adapter. scat 6" I beams with the cap screws for rods. Still deciding on the oil pan....

 

[blue_69_malibu]

If I was to guess I would have to say 475 on both HP and torque, Customer back out on the dyno LOL. It does run very strong Like I said it runs better then I thought.

GM/crane actually makes a HR cam that is one step up from the Hot Cam and is just as reliable. It's 222/230@.050 with more lift than the Hot Cam. It's actually used by GM in their ZZ383 and is a great street cam IMHO.

What doesn't get mentioned often enough is that a modern 383....with newer, aluminum heads and a HR cam....can crush many an old school BBC. We're talking about high 11s and low 12s in full street trim....so long as the driver can hook up.

Ciao. Back to Italy. I don't know how Oliver69 drives his Chevelle with all of the crazy scooters and motorcycles in Italy.

 

[Notalent]

thats 430 at the flywheel right

There is no way for a builder to no RWHP Horsepower as its not in a car and there are to many variables with parasitic drag.

Typically an automatic trans should be 15-20% loss and a manual 10-15%, but those are loose numbers.

 

[cozmacozmy]

There is no way for a builder to no flywheel Horsepower as its not in a car and there are to many variables with parasitic drag.

Typically an automatic trans should be 15-20% loss and a manual 10-15%, but those are loose numbers.

You mean rear wheel horsepower. We don't need him anymore confused than he already is...

:wink2:

 

[Notalent]

You mean rear wheel horsepower. We don't need him anymore confused than he already is...

:wink2:

Got me confused! lol nah, just a typo rushing it

 

[pntballx1]

It all depends on what you want and what you're doing with the car. We have them starting at about $5000 carb to pan, dyno tested/tuned for 430HP with free shipping. Members get a discount too

Very interested, Sent you a PM

Jim

 

[CPMotorworks]

Thank you! Seeing as to how this is what we were talking about... a 450ish horse 383 block.

On OEM blocks cam tunnel placement, lifter bore placement some times not even close to blueprint and not having seat timing events happen when they are suppose to be can cause HP lose.

Next 400 blocks are hard to achieve ring seal. I think the 400 block Joe used had a couple of sleeves in it because cylinders were cracking it way he went to an after market block. Sleeves are not the hot set up in 400 blocks cause they are so weak.

40 horse I can see that.

Here is a good pic of a 400 block with blowby all the way down to the oil rings. There is more then a 5 horse lose right there

This is a stock block 383 @ 450hp, not a 775hp Stock block 400ci turning 8000rpm.
That 40hp (775hp to 815hp) total Joe Sherman had was a 5.2% gain....that would be a 9% gain @450HP....
You'd think we see several threads on 490hp 383's with just a block change..

 

[CNC BLOCKS N/E]

This is a stock block 383 @ 450hp, not a 775hp Stock block 400ci turning 8000rpm.
That 40hp (775hp to 815hp) total Joe Sherman had was a 5.2% gain....that would be a 9% gain @450HP....
You'd think we see several threads on 490hp 383's with just a block change..

How many guys change a block building 383 come on use your head !!!!!!

 

[cozmacozmy]

How many guys change a block building 383 come on use your head !!!!!!

Well according to you they would be wise to as they would gain a 40hp boost.

Oddly it doesn't ever happen though... as it doesn't gain them 40hp.

 

[artmalibu]

Well according to you they would be wise to as they would gain a 40hp boost.

Oddly it doesn't ever happen though... as it doesn't gain them 40hp.

The point CNC is trying to make is why the hell would you buy an aftermarket block to build a 383? It would be crazy to build to build anything under 420ish.

 

[CPMotorworks]

By using a decent aftermarket block you will see as much as a (nominal) 40 HP gain over a production-line casting.

If you do go with a block I would definitely go the 4.125" bore with the 350" mains?

The 383" platform should get you close to 500 HP and the 400" platform (if you choose, with the aftermarket block) close to 600, maybe even more?

Thanks, Gary in N.Y.

P.S. That 40 HP difference I mention above is using all the same parts with ONLY the "better" block substitute.

There is NO 40HP (nominal) gain on a 450hp 383ci SBC from stock block to aftermarket. Not even close to being factual or hinted at.
The whole 40hp (nominal) gain story credit goes to Joe Sherman...who actually did the testing..... ON AN 775HP, 7700RPM, 13.5:1 406 based on a stock block. That would put the 40HP (nominal) gain in context..we all know how weak a stock 400 block is..and if you don't Carl will tell you

This is where Carl gets distracted by my 400 comment...but this isnt about a 400. This is about a 450hp stock block 383.

On OEM blocks cam tunnel placement, lifter bore placement some times not even close to blueprint and not having seat timing events happen when they are suppose to be can cause HP lose.

Next 400 blocks are hard to achieve ring seal. I think the 400 block Joe used had a couple of sleeves in it because cylinders were cracking it way he went to an after market block. Sleeves are not the hot set up in 400 blocks cause they are so weak.

40 horse I can see that.

I agree that in the case of an extreme example like Joe Shermans there is a power to be had just by the increased block stiffness. Nothing to do with crappy machine work as shown in Carls photos.
Again, this isn't about a 400..

This is a stock block 383 @ 450hp, not a 775hp Stock block 400ci turning 8000rpm.
That 40hp (775hp to 815hp) total Joe Sherman had was a 5.2% gain....that would be a 9% gain @450HP....
You'd think we see several threads on 490hp 383's with just a block change..

How many guys change a block building 383 come on use your head !!!!!!

I already made the point...there isn't 40hp/ 9% gain to be had on a 450hp 383 from a stock block to a Dart, World, etc.
Implying there is 40hp to be had just by using a aftermarket block is a crock and misleading information. There is a context to taken into consideration, and by simple math its obvious your not going to see a 9% gain @ 450hp when the one example showed 5.2% @ 775hp.
Carl you better bring the Wine to PRI this year...I'll bring the Cheese my Friend!:laugh:

 

[cozmacozmy]

The point CNC is trying to make is why the hell would you buy an aftermarket block to build a 383? It would be crazy to build to build anything under 420ish.

I know what point he was trying to make.

 

[artmalibu]

I know what point he was trying to make.

You posted it wouldn't gain them 40HP and the displacement alone should net that...

 

[cozmacozmy]

You posted it wouldn't gain them 40HP and the displacement alone should net that...

How would you gain displacement from going from a 383 to another 383?

If we are to compare apples to apples... wouldn't the displacement stay the same?

 

[artmalibu]

How would you gain displacement from going from a 383 to another 383?

If we are to compare apples to apples... wouldn't the displacement stay the same?

Apples to apples and dollars to dollars ok, for the same price you can choose to buy a block with a 4.125 inch bore or 4 inch.

 

[CNC BLOCKS N/E]

carl you better bring the wine to pri this year...i'll bring the cheese my friend!:laugh:

lol

 

[grr456]

I dunno...I've built quite a few engines. I didn't have any real parts for an SBC and when I looked into it, by the time everything was said and done, I couldn't beat the price of a Blueprint 383 Engine thru Jegs for my 64. The complete longblock with Aluminum heads, roller cam and newer block with the 1 piece rear main was on sale last summer for $3200 including shipping. I think they are now about $3500. This included all brand new parts, dynoing, oil pan, valve covers and a 50,000 mile warranty. The only thing not new was the block. It made 450 HP and 470 TQ. I had an original 70 Z/28 intake, carb and valve covers from my 70 Z I bought in 1974.

I really couldn't find anything cheaper because I looked for a while. While there were some locals who would rebuild your core in their garage, nothing included a dyno sheet or warranty.

Just my .02....grr

 

[cozmacozmy]

Apples to apples and dollars to dollars ok, for the same price you can choose to buy a block with a 4.125 inch bore or 4 inch.

That is the whole purpose of what's being discussed here. Can you gain 40hp from just changing to a stronger aftermarket block for this 450hp typical 383.

Which many here including me have said, no.

 

[Geo71]

This is my personal experience, I built ONE 383 sbc out of maybe something like 50-60 engines so far in my life, this is way to much work and money even for the cheap guy like me who build his own stuff on extreme budgets.

I will not build another, I would rather build a hot little 350 sbc with vortec heads or build a standard 400 sbc. The 383 in my own opinion is just dumb. The cost does not out way what you get for performance when you do stuff on a budget. I would rather just bypass the dumb idea of a stroker 383 and go straight to cubic inches and just do a 400 sbc.

I grew up in the time when 383 stroker was a big deal, but I was already "better" than that, I was playing with bbc's, So forward many years later and someone wants a cheap 383, so I build one, ya not impressed, money can be spent elsewhere, hell I could have built a bbc 454 cheaper than a stroker 383.

So I say if your on a budget stick with a stand cubic inch engine that don't need no fancy parts and requires no grinding to the block or have to take apart a millions time because the machine shop say the block is cleared and then rotating assembly hits the cam too..screw that I have no patients for that kinda garbage. Specially when the machine shop say the block is good and these rods work well and then at every turn, crap was hitting crap

So as you see the 383 really pissed me off with many of the clearance issues. it did get built for under 2k most of the money went to the machine shop. They already had block and crank they pawned off on me ready to go......right

Like I said this was my own experience, I'm sure the 383 is a nice engine, but for even an experience back yard mechanic, this build really ticked me off, so I think if one is going to possibly build there own motor, just do a standard build, polish the stock crank, bore, do the standard stuff where you know the parts will fit right back in where they came from.

Just wanted to bump this up. Ive been working on a 383 build and wanted to relay some info. Using a "880" factory roller block and a set of Scat 6" ibeam rods / Scat 9000 crank we didnt have to do any block clearancing. The rods and cap screw rodbolts cleared no problem and also plenty of room for the cam.

With an older block probably some issues, but at least with the roller block all was good.

 

[Jake Wade]

Wow! No clearance work on the block? Strange, must be some differences in 880 blocks.

A couple of years ago I done one with the same Block casting, crank, and rods and had to relieve the bottom of the cylinder bores here and there.

I am doing one now using a "638" block but using the 5.7 rods and have had to do more clearance work than ever before on the block at the bottoms of every cylinder, 16 spots.