468 build

[muddtruck]

First off I'm not a mechanic, I have a 468 bbc in my 4x4. 6272292 ovals and edelbrock intake with flat tops. its big and heavy all one ton of fun. Its a 5 speed with lockers n boggers. I take it out mudracing a few times a year, other than that its a toy. I'm after more power of course. I bought some 188 casting rectangle heads and an edelbrock performer rpm to match. I have 1-3/4" jba shorty headers and a 770 street avenger carb. Also gonna add some 20cc dome pistons to up my compression. Any cam suggestions to make it all work together and give me more power? too vague?

 

[Indycars]

The accuracy of your answer is directly proportional to the detail you provide as input.
Garbage in , Garbage out so they say!

If you don't know what type rotating assembly you have, how do you know it's been
stroked/bored to 468?

Please make in LIST FORM everything you know about your truck and parts you have
along with budget and goals. You said budget of $2000, any leeway?

Car
Weight:
Rear Gear:
Tire Diameter:
Trans Ratios:
Budget:
Time Frame to Complete:

Motor
Carb:
Manifold: Dual or Single Plane?
Headers Dimensions:
Combustion Chamber CCs:
Camshaft Desired Characteristics, Any Research so Far, Brand Prefence........:
Camshaft Timing Numbers: REQUIRED if known, IVC most important
Rocker Ratio/ Type:
Fuel Line Size:
Fuel Pump Rating:
Fuel Pump Type (Elec or Mech):
Radiator Sufficient Now or Need Upgrade:
Aftermarket Heads Possibly ??? One of biggest determination of power.
Fuel Octane To Be Used
Etc:
Etc:
So on and so forth!!!

Tools and Skills
Basic Hand Tools, Pliers, Sockets/Rachet
Die Grinder for Matching and Polishing.....etc
Micrometers
Dial Calipers (Digital)
Dial Indicator and Magnetic Base (Even a cheap $40 one will work)
Torque Wrench
Feeler Gauges
Piston Ring Compressor
Built Any Engines Before
Can you fabricate a bracket if needed
Welder Available
Good machine available

Just because you don't have something above, does not mean you are out of luck. It's just
means taking a different path. Tell us everything in one place, it's going to be used over
and over and over when making recommendations.

The discussion about SCR/DCR or Static/Dynamic Compressor Ration is normally a lengthy
discussion. Look at the calculator below and provide as many numbers as you can. Remember
the Intake Valve Closing angle has a very big effect of your performance and fuel requirements.
Rows 9 & 10 have very little effect and can be left as is, just provide the best info you can, we
usually narrow in on the final answer as we get closer to the final configuration.

Best Damn CR calculator in Town:
http://garage.grumpysperformance.co...comp-ratio-cranking-pressure-calculator.4458/




Good luck, were here to help!!!

.

 

[muddtruck]

I'll get more info and list it so its easier to read, thanks alot

 

[Grumpy]

no one is a born mechanic, but many of us have a knack for working with and understanding how the laws of physic can be used to our advantage while modifying and improving the efficiency of machinery, and most of us can learn those traits and skills from the others if we have any interest in doing so!

INVESTING THE TIME AND EFFORT IN PURCHASING AND READING A FEW BOOKS WILL BE VERY COST EFFECTIVE, AND SAVE YOU MONTHS OF WASTED TIME AND THOUSANDS OF DOLLARS

http://www.dragzine.com/tech-stories/en ... ine-block/

"http://garage.grumpysperformance.com/index.php?threads/magnets.120/#post-49772

 

[muddtruck]

Truck
1992 k2500 single cab longbox 4x4
Dana 60 front axle 4:10 gears w/detroit locker
14 bolt ff rear 4:10 w/detroit locker
Weight probably 4500-5000lb
Trans 5 speed nv4500 hd
Tires 38.5"x15 swamper boggers
Budget is around $2000ish for dome pistons and camshaft kit

Motor
468
4.31" bore
4" stroke
No details on crank and connecting rods yet
Heads: 14096188 rectangle port 116cc chambers
Intake: edelbrock performer rpm dual plane
Carb: holley street avenger 770
3/8" fuel line mechanical pump runs on premium gas
Headers: jba shortys 1-3/4" primarys
3" collectors
Exhaust: 2-1/2" duals and bottles
Radiators a 4 core, electric fans wanted later
I'd like a cam that will have strong mid range to high rpm
Trucks not a daily driver and I like to mud race it.
As far as tools go I have most listed, I do all of my own work on my truck besides the motor work, and gear setups. For that I have a mechanic buddy to help. Im just hoping I can make a good performing combo with the proper cam. Hope this helps thanks for any replies. I'll get some more info for the cr calculator above when i open it up later

 

[Grumpy]

without knowing the compression ratio its going to be difficult to do the calculations but its obvious with 38.5 inch tall tires and 4.11 gears that your not going to be spinning the engine to super high rpms.
Ill do a few calcs and post in awhile

 

[Indycars]

I don't think he is running in high gear when he is racing the 200 foot mud pit.

Quote from Introduction Thread:
"I do race a 200' mud pit in 4 low 3rd gear held to the end....it revs a bit high for what it is."

Shane:
What RPM are you twisting the motor at the end of the mud pit?

 

[muddtruck]

Its spinning 5500 rpm plus by about 3/4 of the way thru. I race in 4 low 3rd gear. After work I'll take some measurements for compression ratio. I did take the pan off for a good look at the rotating assembly....cast crank, stock connecting rods, cylinders look great honing marks visible and its a 2 bolt main. Pistons are sealed power flat tops (domes going in their place)

 

[Indycars]

Just wanting to throw some numbers out there to start the discussion. First I need the
IVC (Intake Valve Closing) for a camshaft in the right RPM range (2000-5800) so I picked
this Crane 139771. The cam card doesn't show the IVC directly so I had to use the calculator
to get there, see graphic below.

Also the cam card did not provide the LSA (Lobe Separation Angle) so that can be calculated
by using the lobe centerlines and dividing by two.
(109+119)/2 = 114°.

Advertised duration can be read directly from the cam card and that is 292°/298°.




Plug the above numbers into the IVC Angle Calc-2 page and you get 75° ABDC for the
closing angle.




Now I can get at the DCR using premium fuel, the ratio should be in the neighborhood of
7.5-8.0. To get there I played with the piston dome size, which seemed to dictate a number
between -24cc to -32cc. This provided a range of DCR's of 7.54 to 8.09.

Questions about how I got there???



I invite you to confirm all the numbers used. Please assume something is wrong until you
yourself have confirmed them to be accurate.

 

[Grumpy]

a great many people ignore or don,t understand how to use this chart posted above,
but calculating the results, it suggests and using the info when selecting your cam,
will tend to produce a better resulting engine build

if we take those 188 heads
http://www.mortec.com/bbc.htm
theres a very good chance they have 2.19 intake valves
468 /8=58.5/2.19=26.6 so a fairly tight lsa will work best

something similar to this,
http://www.claysmithcams.com/bbc-47...r-990s-promaxx-or-rhs-320s-max-rpm-5800-6200/

• Part. No.160-3106
• Adv. Dur 292/302
• .050” Duration233/243
• .200” Duration152/158
• Lift .620/.600
• Centers 103/111
• LSA 107

YES IT REQUIRES ABOUT 10.5:1 compression or a bit more
working with that cam timing , work back wards and get the 8:1 dynamic and then static compression required
youll find these useful

http://www.rbracing-rsr.com/runnertorquecalc.html

http://garage.grumpysperformance.com/index.php?threads/crowers-valve-timing-charts.4299/

http://www.gmhpclub.com/performancecalculators.htm

http://garage.grumpysperformance.com/index.php?threads/very-brief-big-block-chevy-history.951/

http://wallaceracing.com/Calculators.htm

http://www.bgsoflex.com/auto.html

http://users.erols.com/srweiss/

http://garage.grumpysperformance.com/index.php?threads/big-block-chevy-info.710/

http://garage.grumpysperformance.com/index.php?threads/precision-measuring-tools.1390/#post-52466

http://garage.grumpysperformance.com/index.php?threads/checking-piston-to-valve-clearances.399/

http://garage.grumpysperformance.co...ectly-and-get-it-to-last-cam-install-info.90/

http://garage.grumpysperformance.co...uild-the-engine-to-match-the-cam-specs.11764/

YES YOU NEED TO VERIFY CORRECT CLEARANCE ,
INSUFFICIENT CLEARANCE LIKE THIS GUY HAS

CAN RAPIDLY BECOME VERY NOISY, ANNOYING , & EXPENSIVE STUFF LIKE THIS

LEAVING YOU

 

[Indycars]

Mission accomplished ..... got Grumpy off his little hiny and suggest a camshaft made
by Clay Smith.

With this change the IVC will be 69° ABDC. This brings the piston dome more inline
with what Shane had originally suggested in the range of -18cc to -26cc.

You can still play with the advance and maybe set it to zero, but then you will need a
larger dome to compensate for the later IVC of 73°.





That hamster is just too funny !!! LOL!!!!

.

 

[muddtruck]

thanks alot for taking the time to post this info! i've got some reading to do. with the existing flat top pistons in it i calculated about 7.5-8:1 compression. when i bought the motor i was told 10.5:1, i was kind of dissappointed to find that not true but i'm happy he was right about it being 60 over and the cylinders look nice still. my goal is to clear the 525 hp mark, i'm thinking i had about 325-350 hp MAYBE with my old setup. with the low compression and stock heads. my intake, carb and headers were the only power adders. stock is 270 hp. the torque of my bb impressed me and won races, cant wait to see what it feels like next year with some more ponies!

 

[Grumpy]

look into the cost of new pistons bearings rings, a balance,probably new connecting rods,
I personally would never reuse stock 3/8" rod bolt big block rods in any serious performance application being that the rebuilt cost far exceeds the cost of new 7/16" ARP rod bolts SCAT,RODS
stronger aftermarket connecting rods, and youll generally find that a complete rotating assembly will cost you about 45% more than the pistons, rings, and bearings, alone, thus the new crank and rods cost only 45% more!
now think about that! the old crank and rods have hundreds of thousands of stress cycles on them and stress is cumulative, the newer SCAT components, even the cast steel cranks are stronger than the cast IRON factory chevy stuff, and the 4340 forged stuff is MUCH stronger (true EXPENSIVE) but if something comes apart at 6000rpm how much are your feet worth?
yeah DAMN LINKS AND 90% OF THE INFOS IN THE $%%^&* SUB LINKS SO IT REQUIRES READING CAREFULLY
http://garage.grumpysperformance.com/index.php?threads/types-of-crankshaft-steel.204/
http://garage.grumpysperformance.com/index.php?threads/a-brief-look-at-clutches.447/
http://garage.grumpysperformance.com/index.php?threads/another-496bbc.5123/
http://garage.grumpysperformance.co...onable-cost-454-bbc-upgrade.11064/#post-49202
http://garage.grumpysperformance.com/index.php?threads/a-mid-range-454-bbc-build.8215/
http://garage.grumpysperformance.co...sic-454-big-block-chevy-build.1211/#post-6714
http://garage.grumpysperformance.com/index.php?threads/cheaper-454-chevy-build.4620/
http://garage.grumpysperformance.com/index.php?threads/489-bbc.8383/
http://garage.grumpysperformance.co...increase-a-454-displacement.10589/#post-45343
http://garage.grumpysperformance.co...-600-hp-out-of-mark-v-block.10548/#post-44903
http://garage.grumpysperformance.co...bbc-muscle-car-engine-combo.10084/#post-39412
http://garage.grumpysperformance.com/index.php?threads/big-block-chevy-info.710/

http://garage.grumpysperformance.com/index.php?threads/popular-hot-roddings-509-bbc.3437/

http://www.claysmithcams.com/bbc-47...r-990s-promaxx-or-rhs-320s-max-rpm-5800-6200/

 

[T-Test]

thanks alot for taking the time to post this info! i've got some reading to do. with the existing flat top pistons in it i calculated about 7.5-8:1 compression. when i bought the motor i was told 10.5:1, i was kind of dissappointed to find that not true but i'm happy he was right about it being 60 over and the cylinders look nice still. my goal is to clear the 525 hp mark, i'm thinking i had about 325-350 hp MAYBE with my old setup. with the low compression and stock heads. my intake, carb and headers were the only power adders. stock is 270 hp. the torque of my bb impressed me and won races, cant wait to see what it feels like next year with some more ponies!

Refresh and add a blower and keep it under 5500 rpm and you'll love it, I garuntee!!

 

[muddtruck]

Thats another option to check in to

 

[muddtruck]

A guy I know has a brand new roller cam thats collecting dust and said I could have it if it'll work for my combo...I have no idea if it will or not. Can I get someones opinion on it? kind of a tough card to read sorry

 

[Grumpy]

230/239 @ .050 lift duration
.548/.575 lift.
108 lca
all fall very close to what your trying to do, I 'd sure grab and use that even if I had to pay for it!
as long as its new in the box and reasonably priced, and free!! grab it and buy the guy a big steak dinner with enough red wine that he forgets who he gave it too.


notice its not that different from what I suggested
http://www.claysmithcams.com/bbc-47...r-990s-promaxx-or-rhs-320s-max-rpm-5800-6200/
a bit lower lift and duration, I doubt there would be 15 hp difference

• Part. No.160-3106
• Adv. Dur 292/302
• .050” Duration233/243
• .200” Duration152/158
• Lift .620/.600
• Centers 103/111
• LSA 107

HERES A VAGUELY SIMILAR COMBO PREVIOUSLY POSTED
ENGINE COMBO #2

454/475 CID 7.8 LITRE GM CHEVROLET ENGINE (BORED)
570 HORSEPOWER (425KW)
585 POUNDS TORQUE

- RE-MANUFACTURED 454 CHEVY BLOCK, FULLY SHOTPEENED BACK TO VIRGIN STEEL
- MAGNAFLUXED
- SONIC CHECKED
- VIRGIN GM CAST CRANK; WET MAGNAFLUXED; SHOTPEENED; GROUND .010 .010
- CON RODS; VIRGIN GM 3/8 TRUCK RODS, WET MAGNAFLUXED; 3/8 ARP ROD BOLTS RESIZED; SIDE POLISHED; SMALL ENDS CHECKED FOR PRESS
- HEAD WORK: VIRGIN GM 1973/1974 “049” or “781” OVAL PORT CASTINGS; BAKED; SHOTPEENED; MAGNAFLUXED; NEW HONED BRONZE VALVE GUIDES; FULLY PORTED AND FLOWED
- 9.5:1 COMPRESSION RATIO
- ISKY SOLID LIFTER CAM: 550 LIFT – 230 230 @ .050 – 108
- EDELBROCK PERFORMER RPM AIR GAP INTAKE MANIFOLD
- TORQUE PLATE HONED DECK AND SQUARED ON A BLOCK TRUE FOR A ZERO DECK
- ALL HOLES TAPPED
- LINE HONED
- LIFTER BORES HONED
- ALL HOLES TAPPED
- KING BEARINGS
- MELLING OIL PUMP
- DURABOND CAM BEARINGS
- MAHLE ROD & MAIN BEARINGS
- FORGED KB PISTONS
- FELPRO GASKETS
- SMITH BROTHERS PUSH RODS
- CLOYES DOUBLE ROLLER TIMING CHAIN
- MSD PRO BILLET DISTRIBUTOR
- 850 CFM HOLLEY CARBURETTOR

*A real Dyno tested 570 HP, 585 Torque!

 

[muddtruck]

Cool, that'll save me a little coin for other things on my list. Planning on at least 10:1 compression. Do you think that will get me to 500+ hp?

 

[Grumpy]

the answer to that depends on several factors and other parts selected,but the cam won,t be a big problem,or restriction

 

[muddtruck]

Thats good enough for me, I'll grab it and keep collecting parts. Thanks again