pasky

Just got it back today .

pasky

Eagle 5130 5.7 SIR Bushed rods + -3.4cc forged sealed power pistons

pasky

Piston close up.

pasky

6.3 liter 383 CI 95 LT1 block

GOnna have a 11.54:1 static compression and
forgot the dynamic but it was 8.xx:1

cam is:

230/244 .544/.574 (1.6 rockers) on a 112 LSA

Ported heads flowing:

.100 72/54
.200 138/110
.300 195/144
.400 245/187
.500 262/202
.600 262/208

and 42# injectors

Im looking to put down 420rwhp and about 480-500 at the crank.

Gonna be one hell of a ride when I get it done over these next weeks, will keep this updated .

ME Leigh

What ported heads are those?

Air_Adam

That looks like an LT1 block to me, so I'd guess either LT1 or LT4 heads are going on it...

pasky

https://www.thirdgen.org/techbb2/sho...ght=ported+lt1

Mkos1980

iTrader: (8)

Be careful with those rods, I had a set and they were so out of round from the factory due to a problem eagle was having. They were not torqueing them to spec when aligning. I ended up returning them and eagle set me a net set direct and they were still bad. I emailed them and they sent me a set of H beams instead for the same price.

StealthElephant

Nice healthy looking cam there, looks like that things gonna be a lion on the street, can't wait to see the finished product.

pasky

The bearings seem to be sitting fine on these . I have two on the crank right now and it looks good to me. Thanks for the heads up though.

thirdgen88

I'd measure them to be for sure...

pasky

*** Update ***

Slowly but surely im getting it done. Going to pull the blown lt1 out of the car tomorrow and start swapping things over (timing chain, cam, headers, intake, etc...).

Pics of the new shortblock and my 1991 RS:


http://community.webshots.com/user/pasky13

Matt87GTA

Should get pretty close to that 420 RWHP number you are looking for... I would guess closer to 400-410 than 420 though.... The heads appear to be your weak point but then again the cam is matched fairly well to the head's flow... Should be a nice fairly mild 383 with good street manners.

Parrydise7

iTrader: (1)

The next time you should probably think about spending some serious money on an engine.

pasky

Im not followin you....

Eats5.0's

iTrader: (1)

I'm thinking it was a joke. Nice to see another 383 going together. I wish I would have gotten my pistons coated. Too late now though.. Can't wait to see it together.

Parrydise7

iTrader: (1)

It was a joke. Not a very good one, but a joke...

Matt87GTA

Well the reason nobody got it is because he isn't spending that much.... Definately a lot less than I did!!!!!...lol.

pasky

about 1900 total for the rotating assembly and machine work.

Rembrandt

How did you come up with a dynamic compression number?

Are we thinking of the same thing?

Dynamic compression doesn't have a number, it is transient. Transient=dynamic.

For each difference in volumetric efficiency throughout the RPM range for a given throttle position, and even for a given cylinder since they won't breathe equally, there is a different dynamic compression.

If 100% volumetric efficiency would be the static compression, what would your dynamic compression be?

Peak volumetric efficiency x static compression ???

Or some average?

Either you don't know what that means or you have a special sense of the word.

pasky

Dynamic meaning the compression ratio after the pressure is bled off from the came lobes opening the valves. The more overlap on the cam, the more compression you can run without running into detonation.

Example:

http://www.wallaceracing.com/dynamic-cr.php

Now im not sure on the stock head gasket bore thickness so I did two calculations

4.030 bore
0.039 headgasket thickness
4.125 headgasket bore (also did 4.025, not sure the actual number)
3.750 stroke
-3.4cc pistons
5.7" rods
58cc combustion chambers
0.023 piston deck

4.125 headgasket bore gave me 11.48:1 static
4.025 headgasket bore gave me 11.54:1 static

Cam card for my cam:

http://www.compcams.com/Technical/Se...umber=07-306-8

intake valve closes 73* ABDC

With both calcuations I figured:

4.125 headgasket bore size @ 0 ft.: 8.57:1 dynamic ratio
4.025 headgasket bore size @ 0 ft: 8.62:1 dynamic ratio

I was told by my engine builder you can usualy move a decimal point over to the right on the dynamic ratio and that would be the minimum octane to run.

I.E.:

8.57:1 = 85.7 octane minimum necessary


Are we on the same page?

*** Edit ***

Ahhh crud, just noticed the 73* ABDC is for .006 lift.

Gotta find the damn spec .050 or find a calculator that uses .006.

Parrydise7

iTrader: (1)

Dayum! (This is intended to be, and is, an expression of approval and admiration).

pasky

This oughtta be fun, just called comp and its 43* ABDC at 0.50

10.53:1 dynamic. Weee race gas.

Actually, I think im doing something wrong =/. I know of two people running higher compression than myself and getting away on pump gas (93 octane here).

hoogabooga

iTrader: (1)

hey pasky i'll take one too.

Thomas Aquinas

iTrader: (14)

hey Pasky,
This site has some good stuff on DC. Download their VB program and it works like a charm.


Dynamic Comp.

hopefully it works...

pasky

Cool thanks, figured I was doing everything correctly because you do not calculate at 0.050, by then their is pressure already being bled off since the valve is opened. My original calculations were correct.

Thomas Aquinas

iTrader: (14)

Yea, you take advertised numbers. hahaha, a 10.5 DCR would be out of control! With an LT1, 8.5 is liveable, use some 92-94 and it should make some sweet power.
Good luck!

Rembrandt

I'll be danged.

That makes sense.

pasky

Alright then .

HalfInchWrench

How many folks think you are Muslem cause they think you are from Packistain. "PACKY"

You dirty packy!

But then the same folks might be Indian from India and wonder WTF you are talking about.


The packies might know what you are talking about.

ME Leigh

Um WTF

HalfInchWrench

You wouldn't understand. Too upright and stiff. The Mechanical Excuse you have in what ever your job is has nothing to do with SBC's. Us mere motals would never understand your pure brain power.

pasky

Oooooooookay...

Matt87GTA

I'm guessing there is some drama that I missed somewhere here between ya'll????

Because there is definately no tech involved in those last few replies....

pasky

Uhhh, none that I know of. Thought it was just a bad joke.

pasky

Valve Train is done. I had a set back of about a week because my rods were hitting the cam with the added stroke so had to take it back to the machine shop to re-balance and clear them.

More photos added of the long block:

http://community.webshots.com/album/323874290BmlIfb

Shooting to drop this in this Thursday/Friday. I hope .

AJ_92RS

FWIW, you are doing something wrong.

Using the calculator that Thomas Aquinas posted you'll have a threoretical dynamic compression of 9.34. You'll be pushing the limits, but it may be doable.

pasky

Im still getting 8.62:1, like I said, know a couple of guys here running 12:1 static on pump gas.

Thomas Aquinas

iTrader: (14)

Pasky, how much did you have to clearance the rods? What is the clearance now? 0.050" ? Did you go with a small base circle cam? Also, do you have a pic of one of the rods with the grinding?

The engine looks like its coming along, do you have plans for dyno tuning or a custom chip?

pasky

Yup, rods now have 0.050 clearance between the rods and the cams. Sorry no pics of the clearance it was very little near the rod bolts. Believe it was the #2 and #6 that hit.

Thomas Aquinas

iTrader: (14)

Did you use a small base circle cam?

pasky

Oh, nope, regular size. If I did, it would have cleared just fine.

Thomas Aquinas

iTrader: (14)

Cool, thanks, I'm going to be building my first 383 in the next couple weeks and have been reading up on clearance issues with the rotating assembly. My main concern is the cam and rod clearance. I've been debating on whether or not to get a small base circle, but I should be able to get by with stock size with my rods.

WhiteLightnin83

ok i got a few questions for you 383 specialists since i just built this one and i have no idea what i'm doing exactly! well here is a bit of what i have and then i'll ask the questions. i have an eagle 3.75" stroke crank with KB flat-top -7cc dished pistons that are rated at a static compression of 10.9:1 with 64cc heads. the block is zero decked and bored to 4.030". hydraulic crane cam with 234*/244* and .488/.510 lift. the heads are edelbrock aluminum rpm heads. 64cc chambers with 2.02/1.6. weiand intake. hooker long tubes. edelbrock 750 cfm. i think thats about it. anyways what do you think i should run for timing on this thing? i'm gonna put it on the light tonight and i'm also wondering what plugs i should get. i bought a set of platinum 2s and my friend said they are junk so i'm wondering what your imput is on these and if i should get new ones which ones should i get? thanks in advance!
Dustin

Matt87GTA

Run standard copper plugs with a .035" gap and one heat range colder than stock (not sure what style plug those heads use). I use AC Delco if they are available but have also had good results with Autolites. Platinum plugs are for cars you don't want to change the plugs for 100,000 miles but don't care about performance (platinum is harder than copper and thusly lasts longer, but it is also is poorer conductor of electricity and is more expensive).

I would say timing should all be in by about 3200RPM and be somewhere near 36-ish degrees total but you really need to play with it some and find out what your engine likes as they are all a little different. Get it on a chassis dyno and play with different advances and total timing amounts and go from there...

WhiteLightnin83

awesome, thanks a lot... guess i'll just throw the platinum two's in my little beater car or something and get some ac delco's... what is 36* overall? on the light i have it set to about 15ish... is that too advanced?

Matt87GTA

Well you have to look at your distributor settings and add whatever the total advance is to the base setting (15* in your case) to get your total advance. However, IMO, the ideal way to set timing with a mechanical advance system is to have an adjustable light that you can dial whatever total advance you want into it. With the light set, you have an assistant rev the car up past the RPM where full advance is acheived and adjust it from there. With the light dialed in to 36* you would actually set it to 0 on the tab at high RPM and that way you would know that you have exactly 36* of total timing. Otherwise there is a chance that it could be slightly off. But doing it your way and setting the base and then taking into account the advance amount will get the job done as well and will be pretty accurate.

What kind of distributor do you have in it and what kind of advance curve setup is in it?

WhiteLightnin83

hmmm... well all i know about the distributor is that ist an accel supercoil HEI.... does part number 14007 or something like that sound right? i dunno, maybe that number is coming out of my *** but i dunno, its in my head for some reason.... or something relatively close to it...

Matt87GTA

So it's a stock HEI distributor, non-computer controlled?

WhiteLightnin83

correct... i like computers, and i love cars.... i just don't like computers in cars!