Planning a new 383 build that is now going to be a 400

If I remember correctly the ignition is set to run at a max of about 6000rpm, and your running a hydraulic cam thats not likely to make great power over about 6200rpm, thus the AIR GAP is very likely to prove to be a better match! than the single plane intake,
as a general rule you'll find single plane intakes on a SBC generally work best on engine combos with at least a 245 duration cam at .050 lift and with 10.7:1 or higher compression and solid lifter cams that can operate efficiently in the 5500rpm-7000rpm PLUS power band and geared to operate in that same 5500rpm-7000rpm PLUS power band most of the time.
this also requires a short block assembly designed to operate in that upper rpm band, now as the engine displacement is increased, like in the larger displacement BBC engines port and runner air flow speeds will also increase so the effect is that a larger BBC engine can use more, or longer cam duration at a given rpm band, due to its larger cylinder volume to valve curtain area requiring more time, for effective cylinder fill and scavenging .

thus a 2.02 valve sbc reaches max flow near .505 lift
thus a 2.19 valve BBC reaches max flow near .5475 lift

Calculating the valve curtain area
The following equation mathematically defines the available flow area for any given valve diameter and lift value:
Area = valve diameter x 0.98 x 3.14 x valve lift
Where 3.14 = pi (π)
For a typical 2.02-inch intake valve at .500-inch lift, it calculates as follows:
Area = 2.02 x 0.98 x 3.14 x 0.500 = 3.107 square inches


For a typical 2.19-inch intake valve at .550-inch lift, it calculates as follows:
Area = 2.19 x 0.98 x 3.14 x 0.550 = 3.714 square inches

a typical 383 sbc with that .500 lift cam, has 47.875 cubic inches of volume in a single cylinder, divide that by the curtain area of 3.107 and you get 15 cubic inches of cylinder volume for each square inch of valve curtain

a typical 496 BBC with that .550 lift cam, has 62 cubic inches of volume in a single cylinder, divide that by the curtain area of 3.714 and you get 16.69 cubic inches of cylinder volume for each square inch of valve curtain, or about 11% less available air flow even with the larger valve and higher lift cam, to compensate use of a tighter LCA is frequently used to allow a longer, and more effective cylinder scavenging time frame in the big block combo

Junkman2008 said:

Hey Grumpy, you always hear that headers give you more horsepower. How does that work and what formula can you use to determine the horsepower gain that a given set of headers may bring?

Click to expand...

that questions a bit like asking how good a girl might be in bed based on the color of her hair brush, yes theres a mathematical formula , in fact several, but theres a whole bunch of factors that determine the results, like cam timing, compression,cylinder head flow, back pressure,engine displacement , header primary and collector length and diameter,exhaust temps,etc.
the more back pressure the exhaust system beyond the header collectors has the less effective the headers will be, but if you have a low restriction exhaust and a ram tuned intake with a matched cam timing, a tuned header can in some cases produce gains in excess of 60 hp.
as a general rule Id say your safe expecting a 25-40 hp increase in peak hp from good long tube tuned headers over stock cast iron exhaust manifolds that come on most passenger cars, but with properly matched components on a high compression engine more can be gained.

READ THESE

http://victorylibrary.com/mopar/header-tech-c.htm


http://forum.grumpysperformance.com/viewtopic.php?f=56&t=495&p=613#p613

http://forum.grumpysperformance.com/viewtopic.php?f=56&t=1303

viewtopic.php?f=56&t=572&p=35352&hilit=rams+horn#p35352

http://forum.grumpysperformance.com/viewtopic.php?f=56&t=185

http://www.chevydiy.com/chevy-small-block-engine-guide-exhaust-systems/




I find this graph very useful, it shows stock corvette exhaust manifolds vs headers on the same 496 BBC engine dyno test

http://garage.grumpysperformance.com/index.php?threads/port-speeds-and-area.333/

http://garage.grumpysperformance.co...alves-and-polishing-combustion-chambers.2630/

http://garage.grumpysperformance.co...lsa-effects-your-compression-torque-dcr.1070/

http://www.enginebasics.com/Advanced Engine Tuning/Intake Runner Length.html

Went back to the shop and did some work preparing the car and mock up block and tranny to put in the car, and found one of my snafu's. When I made the front mount for Rick's T Bucket and my car I made some miscalculations and mine will not work unless it is modified. But, the amount I would have to take out would weaken it to a point I am not satisfied with, but, I made a set for Rick before the current one he has was thought up. So, I dug them out and bolted them in place and whallaw.... I also got out my leveler to hookup to the mock up assembly and couldn't find my chains for them so I had to improvise. Here are some pictures, take in mind that on the one piece support the black lines aren't all that was going to have to come out. The radius at the bottom of the mount is wrong and have to be widened, I must have marked wrong when laying it out in the flat. It should be a 6.625 inside diameter, but instead its 5 inch inside diameter. I have no earthly idea what I was thinking when I made it, I just fugged up! So on top of the notching that you will see there would have to be 13/16 more cut out along the inside radius. I was afraid it would warp if I touched it with a hand torch and thus fuggin it up even more.

90% of the art of hot rodding cars is in the ability of the skilled mechanic,
or owner, too look at a potential area of the build,
regardless if its body,frame,suspension or drive train related, or a sub-system,
and realize you have an issue that needs to be inspected,
measured, investigated, defined and if possible IMPROVED UPON.
just the fact you found an issue, can define exactly what needs to be changed,
and have the skills to both realize it needs to be changed,
and that you have the skills and knowledge to correct it puts your well above average.

That looks exactly like what I did except I needed the center section to hold
one end of the alternator adjustment bar. The center section was cutout of
the original mount that had the engine too high in the frame.

I may still be able to use it, I am going to look at the actual engine going in the car and take some measurements. I am guessing right now but the radius around the bottom may not be critical, bottom of the timing cover gets drastically small below the center line of the crank. I am going to cut out the areas in the pictures the test fit it.

I did some looking at the 400 and bolted the mount it and I am in the clear, I did some recalculating off of one of your schematics of SBC's Grumpy and figured its good to go, plus I had a old timing cover in my pile of OEM parts and did some measuring off of it also. I laid out the mount differently than I had it yesterday and found another snafu of mine. The part of the mount where the pedestal for the rubber biscuits will be is in the same area where my alternator and PS pump will be located, so that will have to come off. But, I will wait to do that when the mockup is in the car, so I will know where it will end up being mounted. In the picture I have lines where it will probably be cut off.



On another note, it's so nice to have my compressor back up and running, air grinder and air rachet's are so cool to have available and it makes working a lot more efficient.

http://garage.grumpysperformance.co...asic-engine-size-measurements-weight-info.11/

http://catalogs.speedwaymotors.com/publication/?i=146130

I have the mock up in the car and ran the cooler lines, everthing looks good there, I will probably add a soft mount just above the suspension idler arm and one farther back on the cross member later. Now my focus is on getting the front mount and midmounts fabricated and ready for the new engine and tranny. I may be okay with the front mount, I still have to flip it when I get the block tacked down in the car. I have already made piece flat plate that is bolted to the second main journal register directly over the cross member and I will tack a piece between it and the cross member to hold the block in place, then I will unbolt it and remove the stock mounts to free the area up and then fab the front mount and pedestal, then move on to the mid mounts, I am thinking of using set from speedway motors. They also have a set of biscuit mounts for these types of applications that are relatively inexpensive. Here are a few pics of the mockup in the car.









You can see the lines in the last picture, they are actually not touching anything but I a still going to put in a soft mount on the cross member just to keep them safe.

It's going to be interesting to see how you get everything to fit. It's a bit
hard to visualize from words.

When you say flip, do you mean the motor mount tabs (where it attaches
to the frame)will be pointing to the back?

Yes exactly, not sure I may have to shorten the height of the mount. I think made it too tall, I am thinking I may to cut it apart and shorten it bout 1 1/2 inches.

I ran into a problem, I can't get the frame bolts out so it looks like the mock up is going to come out so I can get rid of frame mounts. I will be good at putting the engine and tranny in while this going on. Oh well, glad the weather is good.

I am going to pull the block and leave the tranny in, in the next day or so, I have done some preliminary measurements and I am going to move the pedesal in 1 1/4 inches on each side and move the driver's side down 3 inches and the passenger side down 5 inches. Passenger side has fuel pump in that area, that's where the 5 inches down on that side. I will have to install the fuel pump after the engine is in the car to avoid any damage to it.

I had to drop the drivers side also due to involvement of the PS pump. I did solve a problem I was worried about. With the front support thickness I was going to have to trim 1/4 inch off two pieces of billet aluminum. but instead integrated the back part of the PS pump bracket into my support and eliminated that bracket altogether. The first two pics are mounted on the 400, last one is after I made all the needed mods and did some bracing on the fuel pump side.







Now I just have to get the OEM mounts out of the way and start fabricating the pedestals on the frame I will be in good to go. I will clean it up and get it ready and primer it .

These are the parts I am going to order and use to finish the mounts. I am not capable of drilling a 1 inch hole, not really expensive.
http://www.speedwaymotors.com/Universal-Bolt-Through-Engine-Mount-Cushion-Kit,1199.html
http://www.speedwaymotors.com/1928-1934-Ford-Frame-Adapters,77.html
http://www.speedwaymotors.com/Steel-Rear-Motor-Mounts-Chevy,3278.html
Once they are here, I am going to get this thing done and finish up all the stuff for the tranny lines and be ready to work on the engine and also do some refurbishing on the tilt steering column.

Thanks for posting the ,useful links!
BTW I LOVE THE PICTURES YOU POSTED,IT MAKES IT FAR EASIER TO SEE WHAT YOUR TALKING ABOUT RATHER THAN GUESSING,
I know many of the younger guys don,t know that theres several old school speed shops other than SUMMIT and JEGS and just curious, why can,t you drill 1" holes?

http://www.speedwaymotors.com/Universal-Bolt-Through-Engine-Mount-Cushion-Kit,1199.html
http://www.speedwaymotors.com/1928-1934-Ford-Frame-Adapters,77.html
http://www.speedwaymotors.com/Steel-Rear-Motor-Mounts-Chevy,3278.html

http://catalogs.speedwaymotors.com/publication/?i=146130

http://www.herbertcams.com/herbert-cams-crate-engines/

http://www.jegs.com/

http://www.shop.speedunlimited.com/

http://www.hawkinsspeedshop.com/

http://jbaspeedshop.com/

http://garage.grumpysperformance.co...ng-at-the-circle-track-suppliers-helps.10978/

Well for one I don't have the bit, two my drill press won't turn slow enough, three those brackets from speedway already have the 1 inch hole slotted like I want them.

http://www.amazon.com/Champion-CT7-...63246&sr=1-32&keywords=hole+cutters+for+steel

http://www.amazon.com/CRC-03400-Tru...452463485&sr=8-1&keywords=drill+cutting+fluid

Grumpy said:

http://www.amazon.com/Champion-CT7-...63246&sr=1-32&keywords=hole+cutters+for+steel

http://www.amazon.com/CRC-03400-Tru...452463485&sr=8-1&keywords=drill+cutting+fluid

Click to expand...

Also, the frame bracket is designed to work with the cushion set from speedway.

Hey Grumpy, I was wondering what is the rpm range of a edelbrock tm1(tarantula) single plane intake?

3500-7500 effectively making that intake less than ideal for your application
I think a great deal of the marketing appeal was based on having something OBVIOUSLY VISUALLY DIFFERENT WITH THE ANGLED CARB LOCATION, BUT IN YEARS OF TESTING IVE FOUND THESE TM1 INTAKES RATHER LESS THAN IMPRESSIVE

http://victorylibrary.com/mopar/edel.htm

I have YET to find a single application where the edelbrock tm1 produced the same power as either the EDELBROCK 2925 or HOLLEY 300-110
its only advantage's I can think of is the TM1 is easy to find cheaply used and its lower carb mounting pad height allowing better hood clearance.

http://www.summitracing.com/parts/HLY-300-110/

THE newer EDELBROCK 2892 has larger ports than either of those intakes and its a newer design, (THATS NOT NECESSARILY BETTER) but if I was building an engine for use with NITROUS PLATE USE thats the option ID go with

http://garage.grumpysperformance.com/index.php?threads/carb-intake-test.58/
http://m.summitracing.com/parts/zex-82040

http://garage.grumpysperformance.com/index.php?threads/octane-boosters.613/#post-38309

http://garage.grumpysperformance.com/index.php?threads/faq-on-nitrous.59/#post-72

http://garage.grumpysperformance.co...trolers-and-control-software.9633/#post-35731

http://garage.grumpysperformance.co...rogrammable-box-info-needed.10491/#post-44250

http://garage.grumpysperformance.co...-big-a-fuel-pump-do-you-need.1939/#post-35934

http://garage.grumpysperformance.com/index.php?threads/setting-up-your-fuel-system.211/

http://garage.grumpysperformance.co...ting-a-port-size-and-intake-for-nitrous.4930/

http://garage.grumpysperformance.com/index.php?threads/carb-mounting-studs-or-bolts.1037/

http://garage.grumpysperformance.com/index.php?threads/carb-plenum-intake-design.4362/

http://garage.grumpysperformance.com/index.php?threads/cooler-denser-air.8961/

http://garage.grumpysperformance.co...-the-holley-4150-and-4160-series-carbs.10736/

http://garage.grumpysperformance.com/index.php?threads/hobbs-switchs.10129/#post-39717