Planning a new 383 build that is now going to be a 400

busterrm · Dec 1, 2012

Re: Planning a new 383 build!

We are looking at about 93 % volume efficiency, I think it will do well with a Holley 700 cfm carb. The formula equates out to be 625 cfm, but I would rather have more and tune it to the engine rather than not enough. What do you guys think?

grumpyvette · Dec 1, 2012

Re: Planning a new 383 build!

don,t get so worried about matching a carbs flow rate almost any of the better 650-750 cfm carbs can be easily tuned and theres generally not 5-6 hp difference once they are, remember as the vacuum reading changes so does the effective flow rates, that one reason vacuum secondary carbs work rather well.
I generally find a good 750 cfm vacuum secondary holley with dual inlet fuel feeds and just tune it to the application.
yes you can easily spend three times as much and get a better carb that makes a bit more power but youll have a hard time getting more value per dollar spent than on a basic 750 holley, on a street application for a 350-406 sbc

http://store.summitracing.com/parts/hly-0-4779c

Indycars · Dec 1, 2012

Re: Planning a new 383 build!

busterrm said:
Block is here(we've had it but was at mach shop) had the machine shop check all the stuff. (1) Boring of the cylinders is fresh, with the sonic testing he got with the block I feel confident we have a good block. Mains are straight, decks are square, lifter bores are good. This block has all five mains with four bolts. We have decided on a crane roller cam for it. Even though we have aluminum heads, I wanted to keep the dynamic CR down around 8.25, some of the cams we have been looking at were pushing it up in the 8.35-8.45 range. The rotating assembly is going to be forged he kept wanting to go cast steel and I pushed him to decide on forged. It should be here in the next week or so. (2) The block is already clearanced for 3.75 stroke but I am going to do a mock up assembly when the cam gets here to check all the clearancing points. The rod and main bearings are going to be clevite coated bearings.
(3) Hey Rick when you did your 400 did you use plastic gauge on both sides of each bearing to check the journals? What I mean is, did you check on the rod and block sides then on the rod caps and block caps? With the bore we have I am going to get a ID mic from work and check the bore and pistion sizes for clearances. Will check the pistons with my standard mic. With the crank and rods being new I suspect my clearances are going to pretty close like they should be, but going to check them anyway.
Once we check all the block clearances and bearing clearances, off to the machine shop for rotating assembly balancing.

(1) What was the lowest cylinder wall thickness on the Bowtie block ???

(2) How are you going to get in there to check clearance between the rod and camshaft ???

(3) I'm not completely sure what your asking, I think maybe your asking about checking
for taper or out of round on the journal. I only checked once for each bearing like I show below.

To get accurate clearance check from plasti-gauge, be sure to use 2 feeler gauges to take up
all the rod side clearance while you are torquing the rod bolts. Check out the next to last picture.

The rubber fuel line will stop the crank from rotating while you are torquing the rod bolts. Only
tighten the rear main cap enough to prohibit the crank from rotating, It won't take much.

busterrm · Dec 1, 2012

Re: Planning a new 383 build!

Answers in order:
1 Thinnest spot in the bores was at the bottom of # 6 and it was .229. Thinnest spot in the middle of the bores was .246(#4), and thinnest at top of bores was .249(#8).
2. I will probably use some .08 silver soldier I have in my toolbox. If I remember right you did yours with 12 ga electrical wire? Am I right?
3. What I meant was did you check on the block side of the main bearing and the main caps also. Same with the rods, side of the bearing that is the rod itself and then the rod cap.

Indycars · Dec 1, 2012

Re: Planning a new 383 build!

1.) Shouldn't have to worry about that block then.

2.) Yes I used 12 gauge solid wire to check. Bytor used solder and should work even better, I just got lucky that my clearances weren't closer than the copper. The copper would not have compressed letting rod slip by like the solder will.

3.) Ok I see, no I didn't check each bearing twice.

You headed this way any time soon.......I have good supply of Cherry Brandy in stock !!! :lol:
But I get to pick the movie this time!

busterrm · Dec 1, 2012

Re: Planning a new 383 build!

The plasticgauge question I asked was because, I have always done it on both sides. Something my dad used to do when he rebuilt engines. I was just wondering if others do it. With doing this build with all new parts I was going to do it on one side and if it checked out let it go.

I may be headed that way in late january or early february. Keep the brandy ready! As far as movies are concerned, hell I have about 600 or so here, I could bring a few John Wayne movies I have.

busterrm · Dec 3, 2012

Re: Planning a new 383 build!

rotating assembly got here today. will start checking clearances this weekend probably. Should there be any gap at all in the file fit rings?

Indycars · Dec 4, 2012

Re: Planning a new 383 build!

busterrm said:
Should there be any gap at all in the file fit rings?

Unless they are of the gapless design, then yes. There should be instructions in the box.

I used ( Top / 2nd / Oil ) .022 / .024 / .018 and I have a 4.125 inch bore.

grumpyvette · Dec 4, 2012

Re: Planning a new 383 build!

read thru these related threads, posted below, youll find a good deal of info, on installing pistons and rings.

viewtopic.php?f=53&t=509&p=12277&hilit=gapping+rings#p12277

viewtopic.php?f=53&t=5454

viewtopic.php?f=53&t=4630

viewtopic.php?f=53&t=2795

viewtopic.php?f=53&t=2837

viewtopic.php?f=53&t=852

viewtopic.php?f=53&t=3897

viewtopic.php?f=51&t=588&p=869&hilit=hone+plate#p869

busterrm · Dec 4, 2012

Re: Planning a new 383 build!

Okay, I will have to look at and read carefully the instructions with the rings.

Indycars · Dec 5, 2012

Re: Planning a new 383 build!

If you are still using the Mahle Power Pack piston set like you posted on the
first page, then that's the very same piston and rings that I used.

The ring end gap info starts on page 23 and goes for 3 page.

viewtopic.php?f=69&t=3814&hilit=ring+end+gap&start=220

busterrm · Dec 5, 2012

Re: Planning a new 383 build!

Yeah the pistons are mahlee. I was looking at the literature today at lunch.

busterrm · Dec 11, 2012

Re: Planning a new 383 build!

Rotating assembly back from machine shop. Will start checking and rechecking all the tolerances(clearances) on bearings, gaps on rings will be file fit them. Thanks Rick for the posts on rings, I will be using emory cloth to smooth the filed ends of the rings. I am working long hours at work, so the work will be on the weekends. I am also going to use your Dart SHP build as a basic guide. Since the heads aren't here yet, we will work on the short block for now. Tommy has been deburring the block, and once all the checks and rechecks are done we will clean up and bag the pistons/rods, crank. I am going to label and bag each set of rings for each cylinder. Prepping the block for painting looks like it could be long time consuming process. But as I saw when I visited Rick, its worth the effort for a good looking block when its done. Oh yeah Rick was it Glyptal Red that you used internally on your block?

mathd · Dec 12, 2012

Re: Planning a new 383 build!

before balancing did you got the piston to wall thickness clearance checked/set?

Indycars · Dec 12, 2012

Re: Planning a new 383 build!

busterrm said:
I will be using emory cloth to smooth the filed ends of the rings.
..................

Oh yeah Rick was it Glyptal Red that you used internally on your block?

I found it somewhat easy to chip the moly inlay, but then I was using an 8X power eye loupe to inspect the ends after filing. Be sure to stroke the ring toward the inside to minimize chipping the moly. That damn eye loupe has cost me more time and money.....everything looks BIG when you looked at it with 8x power magnification! :lol:

The only paint I used on the engine was the Por15 Engine Enamel in silver and black. The Glyptal is about $50 quart if I remember right, so I used the Por15. To prepare the surface I degreased it, applied "Por15 Prep & Ready" and then painted.

busterrm · Dec 12, 2012

Re: Planning a new 383 build!

mathd said:
before balancing did you got the piston to wall thickness clearance checked/set?

I thought that was done after the balancing is done? Well crap, will it cause any failures if I do it after the balancing?

busterrm · Dec 12, 2012

Re: Planning a new 383 build!

Indycars said:
busterrm said:

I will be using emory cloth to smooth the filed ends of the rings.
..................

Oh yeah Rick was it Glyptal Red that you used internally on your block?

Click to expand...

I found it somewhat easy to chip the moly inlay, but then I was using an 8X power eye loupe to inspect the ends after filing. Be sure to stroke the ring toward the inside to minimize chipping the moly. That damn eye loupe has cost me more time and money.....everything looks BIG when you looked at it with 8x power magnification! :lol:

The only paint I used on the engine was the Por15 Engine Enamel in silver and black. The Glyptal is about $50 quart if I remember right, so I used the Por15. To prepare the surface I degreased it, applied "Por15 Prep & Ready" and then painted.

Did you use Por15 on the lifter valley also Rick?

mathd · Dec 12, 2012

Re: Planning a new 383 build!

busterrm said:
mathd said:

before balancing did you got the piston to wall thickness clearance checked/set?

Click to expand...

I thought that was done after the balancing is done? Well crap, will it cause any failures if I do it after the balancing?

Well i really have no clue, since you have quality piston i guess they are size/weight matched very close.
I know grumpy will enlight us

Am pretty sure it just dont matter, i asked if you did because i wanted to know if thats required.

grumpyvette · Dec 12, 2012

Re: Planning a new 383 build!

your piston diameter and block bore diameter will not change due to balancing the rotating assembly,you need to talk with the piston manufacturer and find out where on the piston you measure its diameter and what the clearances should be because pistons are NEVER ROUND, they expand very un-evenly as they heat up.
most are slightly oval and wider below the ring grooves
you need to contact the piston manufacturer to find WHERE and HOW to measure the piston diameter, in many cases they choose a spot 1" below the piston deck and 90 degrees from the piston pin center-line. all rods and all the pistons in that engine will or at least should be modified if necessary to weight the same amount , the crank, damper and flex-plate or flywheel and if its a manual the pressure plate, generally get balanced also.
generally the small and large ends of each rod is weighted and the heavier rods ends are belt sanded on the ends until all connecting rods in a set weight the same on both ends, after the rod caps are numbered to prevent parts beings swapped between rods, the piston pads under the pin boss are milled to get the pistons to the same weight and the cranks counter weights are milled, drilled or have weights welded into drilled holes to add weight

if the engines EXTERNALLY BALANCED theres off center weights added to the balancer and flex plate or fly wheel to compensate for the lack of extended counter weights on the crank shaft

the areas with green Xs are milled to balance piston weight

mathd · Dec 13, 2012

Re: Planning a new 383 build!

but i was wondering, will it change the balancing if he take a piston and change it say from cylinder 1 to cylinder 6? do it matter wich piston is in wich cylinder as far as balancing go or you can just put any piston in any cylinder and it wont change the balancing?

Wondering if the mahle piston are high silicon(4032)? those expand less and have smaller piston-to-wall clearance(less cold engine piston slap). little more prone to cracking under detonation but last longer on a street engine and more scuff resistent.

Planning a new 383 build that is now going to be a 400

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