tearing down the 502s

[harbormaster]

I got my pair of 502's and am getting ready to tear them down.

So far I have found out:

The blocks are #14096859...502..Gen.V, HO

The Intakes are GM #6269318 454 72 Holley Rectangular port - Aluminum

Heads #14097088...91-up...rect...OPEN...Gen.V 454/502 HO, 118cc chamber

This all sounds like a good stock combination. Any comments?

Now I have to cleanup the garage to work on 'em....

[olredalert]

Scot,

-------Under the valve covers you will find the magic numbers........Bill S

[harbormaster]

Thanks Bill. I found it on further snooping around.

[Shark in the Pond]

Sorry so late but what you doing with them 502s and what are they going in ?

[Shanghied Again]

I Know Iknow, But I am not saying anything until the Harbormaster does

[harbormaster]

They are going into a 31' Scarab Viper.

Do any of you motorheads out there know of any cheap, easy tricks to get more HP?

How would you build them if you were on a budget, wanted some more HP BUT did not want to sacrifice reliability/longevity?

[mphatc]

Try this

:D :D :D
http://www.holley.com/HiOctn/ProdLine/Products/NOS/NOSNS/BigShot.html


Reliabity . . . .
eek!

MPHATC

[Donzi Blackhawk]

Hello Harbormaster and welcome to the Registry! As you spend time here you should meet a lot of nice people. :D

Cheap horepower? eek! At low cost and high reliability? :D Man...you are killing me! :D

Balance those bad boys, K&N filters, headers and re-map the ECM. If these mods don't do it for you, hook the blue bottles up to them! eek!

Bryant

[RickR]

If you're going to stay with the flat tappet cam and silent choice?

And you have 4cc domed pistons

Raise compression to around 9.5 by

Deck block .020
Mill heads .025
Felpro marine head gaskets .041

Mill intake .020 and .040

Change valve train to adjustable (rockers, pushrods and studs).

3 angle valve job with brass inserts and teflon seals

Cam around 226/230@.050 (Contact me if you need a cam)
Springs retainers and locks.
BREAK CAM IN WITH SINGLE OUTER OE SPRINGS

Make sure you check for correct rings, some pistons have a shallow oil ring land.

Check ALL clearances.

Polish crank
H type bearings
HV oil pump with hardened shaft
Stainless Marine exhaust

[MOP]

Did anyone say 540? Plus the above and no Blue bottle.

[MOP]

I know I know NOT CHEAP but effective!

[Team Jefe]

Scot - I can't help with all the fancy Mill intake .020...Change valve train ...3 angle valve job with brass inserts and teflon seals, stuff.

BUT, I can work a wrench, ain't afraid of getting my hands dirty, and...

I call "Shotgun" on the maiden voyage of The Mad Cow.

....No, No, No....all you jake-legs get in line. I called it. :D :D

[BigGrizzly]

Gen V should be a Roller system. Cheap is realitive. If the block is realy a HO thab you have a good bottom end. Heads are fine and work well. A deasant cam and Stainles Marine exhaust and your in the ball game. If you need moe specifics Give Me a jingle.

[Woodsy]

Scot...

While you have them apart, Balance the rotating assy... cheapest way to reliability. If these motors were mine...

Balance rotating assy,
Cross drill & chamfer cranks
ARP rod bolts
HP500 cam or equiv (KEY TO HP HERE)
C&A gapless rings
HV pump.. not High Pressure
clean up existing heads, add adjustable valvetrain
Stainless Marine Exhaust...

tune & break in on a dyno if possible... saves lots of headaches later when motors are installed in boat...

The down side, is that with twins everything costs twice as much....

If you plan on doing these yourself, pick up a copy of Dennis Moore's book on Big Block Chevy Performance. Also, if these are the first motors you are building yourself, I suggest you have the machine shop put together the short blocks for you...

Woodsy

[harbormaster]

I cut my teeth in the 70's building 396's.

I am curious about one point that was raised more than once.


Change valve train to adjustable (rockers, pushrods and studs)Why over what it has now?

[JimG]

What are those engines rated at, stock?

[harbormaster]

I believe that these are rated at 365 hp stock.

[KMLFAMILY]

Harbormaster:
I cut my teeth in the 70's building 396's.

I am curious about one point that was raised more than once.


Change valve train to adjustable (rockers, pushrods and studs)Why over what it has now? Scot, I believe the point was raised with the milling suggestions on heads/block.This could alter valve train geometry and cause coil bind on the valve springs& valve/piston clearance issues.

[smoothie]

Harbormaster,,,heres a few "Cheap tricks" you can do that will add a few ponies... add a lifter oil baffle to keep the intake running cooler,a windage tray for the oil at high RPM's,and bore notch (http://hometown.aol.com/valakoraceheads/page1.html) the block,If you decide to increase the compression ratio,you may want to have new pistons made instead of all of the machine shop work,I did mine and pistons were the the way to go for price. Wiseco Piston (http://www.wiseco.com/)

Have fun :D

[RickR]

Yep, what KM said :D
Changing valve train geometery and cam lift over .540 (Dennis Moore) requires an adjustable valve train.

Kits are available with studs that screw into existing 3/8" threads.