81vette. No reason to feel bad.I was only educating those who want to learn.There is no debate to what I said it is the gospel.Whether it is needed or not depends on what the goal of the car owner is.All out performance requires everything to be just right. If you dont care than you can get by with less.Stock is fine for a lot of people.If that works for you great.If you want to build more power you should at least feed it to keep it safe and running to its max ability.Even on the street.Your cam choice should be determined by your driving rpm range. Better to stay on the milder side.Need alot more info than what I have.Weight,gearing,auto? engine size,cyl heads, intake/ etc

 

ask and ye shall recieve:

Im going with this setup as it appears to be the very best of the 2 427 motors that are offered. It has the streetable compression, intake and carb, so that pump gas will work nicely and I wont have to worry about stalling out every 5 seconds or not being able to start it in the winter (thanks to the ignition) but yet a large loppy cam and some serious, serious power in the top and bottom ends. Im happy with this here, but is it a little bit too much for the street still? Camwise is about the last sticking point.

ENGINE BLOCK: Motown 9.025” deck height 4-bolt main
CRANKSHAFT: Eagle 4340 forged steel 4.00” stroke
CONNECTING RODS: Manley 4340 forged steel H-beam 6.00”
PISTONS: Wiseco/JE/SRP 4.125" forged aluminum (10:1)
COMPRESSION RATIO: 10.0 to 1
PISTON RINGS: Speed-Pro
BEARINGS: Clevite H series
CAMSHAFT: Comp Cams Solid Roller. Duration @ .050 is 280 intake & 280 exhaust. Lift .657 intake & .630 exhaust. Centerline is 109
LIFTERS: Crower rollers
CYLINDER HEADS: Motown 220 Aluminum
VALVES: 2.08” x 1.600” Manley valves: Severe Duty intake & exhaust
VALVETRAIN: Harland Sharp roller rockers, 4340 pshrds., stud girdle
ROCKER ARMS: 1.5:1 ratio roller rockers (Aluminum heads utilize a .150 offset rocker)
INTAKE MANIFOLD: Motown 4150
CARBURETOR: : Hardcore 870 cfm. Hi flow 4150 style carburetor
IGNITION: MSD billet race distributor, MSD 8mm ignition wire, Accel spark plugs (416 for aluminum heads) gapped @ .035
BALANCE: Internally balanced, Hardcore CNC Balancer
TIMING CHAIN: Manley True Roller
LUBRICATION: Speed-Pro oil pump and Milodon pan
ASSEMBLY COMPONENTS: Fel-Pro, ARP and Manley
ACCESSORIES: Motown chrome valve covers; timing cover
IGNITION TIMING: 36” total @ 3000 to 3200 rpm
VALVE ADJUSTMENT: Valve lash adjustment is .028 Intake & .030 Exhaust
REDLINE: 7000 rpm

Its going to be attached to a CK Performance TH400 Stage 2 w/3200 Stall Non lock-up converter.

Im not entirely sure of what my stock gearing is...81 Vette out of Bowling Green???

 

Yassum Boss!

 

That's a loaded question!
Solid Roller don't necessarily burn gas! Cubic inches and heavy feet
do more damage on the gas tank.

I think that solid rollers free up more potential HP and are more efficient
at higher RPM's. For one, they can rev higher.

If you want a street mannered car, stay with DUR@50 below .250 so you get less mixing of intake and exhaust gases at lower RPM's.
Like I said, those large duration cams cause a lot of fouling and inefficiency if they are not frequently allowed to rev higher.

This is a topic that can be discussed for hours and people have a variety of views on it from the technical side of it. I am no guru, but have driven a few different combinations.

I did enjoy my big cam as it sounded just wonderful, but caused a lot of headaches literally as well as figuratively!

I love these questions as there are so many different views from which to pick and choose.

......

 

so anyhow, the engine is listed now hahahaha

ummm....hmmm....inefficient ALWAYS at low RPM or just inefficient if you drive downtown in 20 mph traffic for hours on end never going above 2500rpm?

 

Same thing, isn't it?

 

yea I guess....fudge....I cant really have super gross inefficiency...it simply wont work out for me. Alright then...if I had a .600/.600 solid, would it be as bad, or is just the fact that its a solid?

If I still had the same Duration @ .050 is 280 intake & 280 exhaust. Lift .657 intake & .630 on a hyrdo, would it be as grossly inefficient???

 

81Vette, BTW don't pay toooo close attention to my "technical"
posts as they are merely observations from my experience

I am sure that before too long someone will come along and rip my
statements apart

....I do enjoy learning from what others have to say and will eventually
know a lot more

 

I run twin outlets welded in the bottom corners of the fuel tank, each one feeds into a large capacity fuel filter, the same size as a large oil filter and then each into it's own high pressure holley pump. I run a 1/2 inch stainless line up to the high capacity top of the line holley regulator, not the cheap one and from the regulator into the two 850 double pumpers.
The line pressure is about 16 pounds and the carbs see 6 pounds. Each pump is on it's own switch/relay and I do a daily check that each pump is pumping on it's own before heading out.
With only one pump turned on the pressure drops to 4 pounds if pushed but with both running the gage sits on 6 pounds regardless.

 

1)My .600 (590's) solid is working great!!!No stumble, no fouling, no smell of unburnt combustion chamber gases etc.

2)Duration is duration in my opinion....solid/hydraulic does not make a difference to duration

 

The formula used by engine builders to calulate fuel requirements is:

.5 pounds of fuel per horsepower per hour for a well tuned gas engine.

For a 575 HP motor that would be:

575 X .5 = 275.5 pounds of fuel per hour.

Gas weights approx. 6 pounds per gallon.

275.5 / 6 = 45.917 gallons per hour at WOT.

We generally like to see a saftey margin of 1/3 additional. So that would give you a pump requirement of 61 GPH at 4.5 PSI.

As big632 said, after that point you have to look at high g-loads, high restrictions or any other extreme condition.

 

Alright good call all hahaha Im going to tell em to put one in...

Funny thing I cant find the comp cams cam they are using....or any other one...fudge...anyone know much about comp cams solid lifters?

 

answered my own question as usual kids,

Comp Cams 12-772-8: MECHANICAL ROLLER
Duration at .050: 248
Intake Valve Lift: 0.576
Exhaust Valve Lift: 0.582
Lobe Seperation: 110°


Now THISSSSS should be a lot better what do you think?

 

I think that you'll like that one!!

...you mean this kid didn't help at all?

 

Naaaa you helped me TONNES dude, feel free to reply to the PM though man. I definitely appreciate you sticking this one out with me to get things sorted. Cam combos are VERYYYY important, too heavy its unstreetable and smelly, too light, its a bitch motor. I think this one should be great though. Thanks again

 

Just torturing, that's all

Sorry, didn't see the PM.
You got mail!

 

Hi big632.
Sorry to hijack this thread. I knew I should have stayed out of this subject. But it`s not any argument! Many people buy parts expecting tons of power merely because it costs more but is really not necessary and more often than not, requires special maintance. I used the LS7 and L88`s illustration only because they are a special high performance engine built with all over the counter GM parts and can sucessfully be driven on the street and raced with out the use of fancy high dollar aftermarket parts. Unfortunately the unavailabity at 7-8 miles per gallon of a suitable fuel has restricted those 12.5-1 beautiful engines to an occasional cruise around the block. 93-94 octain will not work very well. I will invite you to look at a site you may enjoy if you like drag racing however. http://www.nitroalley.net

 

Ironcross. Thanks for the link.Yes you can spend a lot and get very little if not properly matched with the rest of your combo.All the parts need to work together. Nowadays making power is easier than being able to use it.My advice is from years of testing and failures.Like john force once said when asked, how can you be so humble at winning?I lost for over 10 years before I ever won.Thats how I feel about my car . I work on it all the time ,for the past 15 years it has evolved into one of the fastest and quickest dot tire cars at 7.50 at 191mph.Still able to drive it to cruises,My advice is free,take for what its worth ,if it saves you from making the same mistakes I have done than it wasnt a waste of time .We all want to improve our rides ,some more than others.

 

 

MUCH LOFFFFFING OF JOOOOO ALL!!!!


Arent forums great??? Bringing people together and answer all our happy questions. I feel so warm and fuzzy