383 L31 V8 Ole Yellar build

[1Gary]

I have for a long long time insisted on certain parts based on extensive research.One of those items was Mahle dished pistons which is a special order item with a cost of $639.95 plus 18.00 S&H.

I got a package today:



You know life is full of compromises.I talked for a longtime with a experienced engine builder and my machine shop.We all came to a conclusion that is nice to have a want,but more importantly it is much better to build towards my needs and intended use without giving up reliability.A very good compromise is these pistons.









They are Icon's a forged piston top dished with a 72cc RHS head @ 0 deck will give me a C/R of 9.4 using a 040 head gasket.The desk top dyno along with the rest of the combo will give me these numbers.Torque of 2000 RPM 460 to 480 at 3500 and HP of 340 RPM of 3500 to 4500.Those numbers will be refined as I get closer to the final build.Reason being is as a example I found one series of RHS heads we thought came in a 72cc head and a 170cc intake runner is no longer available.So we will sub in a set of 72cc heads that have a intake runner of 180cc.That will move the band ranges around a little bit.I am still seeking "that" balance point between torque and hp.I am very please with the torque numbers and I do admit they seem to be high VS the HP ratings.

Bottom line.The pistons are going to the machine shop to have us start machining the block and over time get this build back on track.Cool thing is ICON sends a spec sheet given the use for clearances.Towing included.Not sure you can made this out.The ring gap is .0045 and we add .0002 to that.



More to come as we get things done..............

[astroturf]

They're...

Made in Mexico???

[1Gary]

Finished machined here with very tight verifiable tolerances.The final hone sizes confirm that fact while fitting the pistons.Off the build sheet I'll give you that result if I can.

[6spd_monte]

I'm excited for you, Gary!
Nice pictures, too.

[1Gary]

Thanks James.Still got a ways to go,but it is a start.The rings are next.Looking to get the Mahle plasma molly rings.

[Cobra]

cool awesome to see this long awaited engine being built

[Mr_Roboto]

Wow, good price on the slugs for forgies. I hope you mean 4.7 thousandths per inch of bore. Your finals would be 18.894 for the top ring which seems tight to me actually. I may be wrong I'm not exactly the person who's looking at N/A builds for things like this. Are you just going to use stocker Vortecs cut or something else for the heads? Also what length rods I'd think 5.7 but you may have gone with some 6es or 5.85s.

[1Gary]

The rods are I bean Scat's 5.7 with ARP 7/16 bolts profiled for a stoker with a Howard's track smart forged crank.The heads are iron RHS Pro Action 72cc with a 180cc intake runner.C/R works out at 0 deck to be 9.4.Rough estimates is 460 to 480 torque from 2000 rpm to 3500 rpm and 350 hp from 2800 rpm to 4800 rpm.I want to upgrade to comp cams roller lifters with will raise the rpm limits over the stock lifters/spider lifter retainers,so the hp ratings as subject to change.The block I am using is a 1995 four bolt main that came threw with the bosses for a roller,but was a flat tappet,so the upgrade is a natural step anyways.The cam is a custom grind for torque.The rings are Mahle plasma moly and the bearing are Kings.I am thinking Edelbrock air gap and I will need your help for a 600 CFM TBI.

[Mr_Roboto]

The rods you're talking about are the capscrew style ones right? Supposedly they make swapping a ton easier than if you just stuck to standard stock style rods. Nice choice on components depending on cam choice I could see 350 being like shooting fish in a barrel with the cubes, heads etc.

[1Gary]

Yes the capscrew ones.I need your assistance on a 600cfm TBI/air gap Edelbrock manifold combo.Could you please give me a refresher on that topic??.

[1Gary]

Here is the computer dyno numbers I had a friend from another site run on this build:

RPM HP TQ
1000 68 358
1500 116 408
2000 172 452
2500 225 472
3000 264 462
3500 301 451
4000 334 439
4500 352 411
5000 348 366
5500 310 296
Peak BMEP 186.1 @2500

[astroturf]

Here is the computer dyno numbers I had a friend from another site run on this build:

RPM HP TQ
1000 68 358
1500 116 408
2000 172 452
2500 225 472
3000 264 462
3500 301 451
4000 334 439
4500 352 411
5000 348 366
5500 310 296
Peak BMEP 186.1 @2500

Interesting...

Can he also generate some for a factory fresh 05 4.3?

And then run some more numbers on the two motors mpg?

Thanks, Jim

[LiftedAWDAstro]

Max torque at 2500 is perfect for towing! Wish my truck made anywhere near that at 2500!

[1Gary]

Dean-here is the RPM calculator @ 65mph with 3.70 rear end gear,29" tire,1 to 1 in third gear:

http://www.csgnetwork.com/multirpmcalc.html

About 2750 RPM.

Peak hp in O/D without the trailer is 140mph.

Can you imagine going 140 mph in a shortie Astro with a high top???.


No I can't either.

[1Gary]

Here is the computer dyno numbers I had a friend from another site run on this build:

RPM HP TQ
1000 68 358
1500 116 408
2000 172 452
2500 225 472
3000 264 462
3500 301 451
4000 334 439
4500 352 411
5000 348 366
5500 310 296
Peak BMEP 186.1 @2500

Interesting...

Can he also generate some for a factory fresh 05 4.3?

And then run some more numbers on the two motors mpg?

Thanks, Jim

Jim,

The numbers for a new 4.3 I would think are published on the net somewhere.

With the tune on the 383..........the goal is 18 to 20 mpg.


Jim-you know you want to build a V8.Got's to get wifey's support first of all..........then give up texting,cable tv,high speed internet and go to dial up,the cell has to go,shop for food at Aldi's,the money is there. Oh yeah no fast food stops.Nothing but the food you bought that is at home.