post me some questions

[grumpyvette]

I can understand that... Do you have any recommendations? Also in going from a solid lifter to a hyd lifter.. what differences in performance do you think I might see?

 

Thank you again!!

 

youll kill off valve train control over about 6300rpm, swapping to a hydraulic I WOULD STAY solid lifter

[deMideon]

Damn.. I will definitely follow your advice!! Thank you!!!

[deMideon]

If you don't mind... what do you think of the Isky 20154 cam?

[grumpyvette]

http://iskycams.com/timingchart.php?product_number=201546

 

you really have not posted enought info for me to make intelligent suggestions, in comparing cam grinds but if youve got decent heads with the necessary clearances, a low restriction exhaust,a single plane intake, about 11:1 cpr and a decent rear gear ratio like a 4.11:1 or so that you can use the cams potential , sure jump on it

Edited May 7, 2009 by grumpyvette

[deMideon]

That's true.. sorry about that... Yes I do... canfield pocket ported heads, 11.5:1, Vic jr intake, block hugger headers, dual 2 1/2 in exhaust, So it sounds like it will work well! Thank you!!!

[a6t8vw]

grumpy im converting my 350ci sbc to Turbocharged MPFI useing these parts

The goal is 700hp

.

 

 

 

 

Whats the rule of thumb when choosing throttle body size?

The intake elbow opening is 90mm should i just get a 90mm tb to put on there? Will a 90mm tb support 700hp?

 

You know i just realized i need to look at the cfm my engine requires vs the flow of a 90mm tb! any input on would be great tho. thank grumpy

[grumpyvette]

with a TURBO, your cramming high pressure air thru a throttle body, not relieing on outside air pressure to fill the void formed in a cylinder by a rapidly desending piston to fill the cylinder, 90mm will be fine in your case, certainly not a huge restriction with a turbo on only 350 cubic inches of displacement, or put another way,a throttle body with a 90mm bore has a cross section of approximately 6375 sq mm of area, while a dual 58 mm throttle body used on my corvette has about 5293 sq mm of area, or only 83% as large and I know of several guys that are well over 800 hp with turbos on engines running those throttle bodys.

90mm - 1287 CFM

rated flow BEFORE you go using a TURBO to cram air thru it, in theory with about 20 psi of boost that throttle body size should very easily support over 1500hp

Edited May 7, 2009 by grumpyvette

[G-rib-73-240z]

hey grumpyvette,

 

would an unknown spec running 289 freshly rebuilt be worth 800 bucks?

like i said unknown specs but it was built for a ss malibu, and it apparetly "hauls" in the malibu. wasnt engine dynoed or anything just seat of the pants tested. But the guy said 800 bucks for everything but the intake and carb. i asked my friend to askem what the actual specs are and he could take me overthere to talk to him in person. What do you think?

[grumpyvette]

are you talking about a ford 289 sbf or a slightly over bore size 283 chevy?

also, Id point out that a running engine for $800 if your looking for transportation may be a bargin , but if your looking for performance a 283 based chevy v8 would hardly be a good basic starting point

Edited May 9, 2009 by grumpyvette

[deMideon]

I have another question for you.... my engine should be putting out around 500 hp, I will be using it on the street, a lot all sorts of driving, hwy, in town stop and go all of it. I have a very good radiator and electric fan. I also have Canfield heads (aluminum), is it safe to use the Mr Gasket ultra-seal head gaskets (5801) ... they do not have the steam holes?

[grumpyvette]

generally having heads with steam holes and a matching head gasket is the best route with an engine based on a 400 block with its siamesed cylinder bore casting, yes youll find lots of guys running 400 base engines with a decent radiator and aluminum heads, a high volume water pump and yes they get away with it. that doesn,t mean it won,t tend to run cooler with the steam holes in the heads and the correct gasket.

[a6t8vw]

thanks for your help grump -andy

[G-rib-73-240z]

are you talking about a ford 289 sbf or a slightly over bore size 283 chevy?

also, Id point out that a running engine for $800 if your looking for transportation may be a bargin , but if your looking for performance a 283 based chevy v8 would hardly be a good basic starting point

 

 

yea the 283 chevy my bad i got confused for a minute. would it be worth it for a runner for the car? 800 bucks for a running motor?

[grumpyvette]

if your only looking for a running engine thats an option, heres a different option

 

http://store.summitracing.com/partdetail.asp?part=NAL%2D10067353&autoview=sku

 

http://www.rustpuppy.org/chp/

[rsicard]

Grumpyvette: I believe you are the one that purchased a Milling Machine. If so how are you coming along with it just curious. I purchased a Metal Lathe and am in the process of getting it tuned up and getting the proper tools for it. Please respond. Thanks.

[grumpyvette]

IM still buying , table vices, cutting bits, bit holders, coolant pumps, coolant oil, drill chucks etc and teaching my sons (verbally as I watch and instruct them)how to set it up and use it, my old leg and back injuries make doing most things required on the machine myself very difficult or totally impossiable at this time, so I need to relie on my sons at times to get things done for me.

as Im

sure your aware the milling machine is just the basic tool, and theres a good deal more expence in the accessories necessary to get it to function, and trying to instruct a new guy when you can,t acctually demonstrate things at times is fustrating

 

heres the machine they get to learn on

http://www.grizzly.com/outlet/Shop-Fox-Vertical-Mill-9-x-49-/T20828

Edited May 15, 2009 by grumpyvette

[rsicard]

Grumpyvette: I took my SBC block to the engine machine shop, to have the tops of the lifter bosses milled for clearance for the link bar on solid roller lifters. It had a hydraulic cam and solid roller lifters and was told that solid roller camshaft is different than hyd roller camshaft and the two should not be used together.

 

In your experience what is the difference between the two camshafts with the same specs such that they must be of the same type? Please advise. Thanks.

[grumpyvette]

the roller cam lobe ramps are designed differently,between the two cams, you can run hydraulic roller lifters on only MILD solid roller cams,with low spring load rates (usually under about 235 -240 duration at .050 lift) but verify with your cam manufacturer, before you mis match components and spring rates, most manufacturers have a cover your butt attitude and will suggest you only use parts matched to run together just as they are reluctant to suggest a differant manufacturers lifter can be used on thier cam or thier lifters on a different manufacturers cam,........... you can run solid rollers on almost all billet core hydraulic roller cams (PROVIDED THE CLEARANCES AND SPRING LOAD RATES ARE REASONABLE FOR THE APPLICATION) cast cam cores tend to wear very rapidly under high spring loads, so thats rarely even an option

your clearance issue would make me suggest swapping to a different lifter design rather than milling the block for clearance

Edited May 15, 2009 by grumpyvette

[John Scott]

Hey Grumpy, thanks again for fielding all the questions.

Question: I have 383, isky solid roller, 244 385 lobe lift, 108 degree, afr 195s, vic jr, srp flat tops, figuring about 10.6:1. In past I've run a 4150HP 750, but had to jet it down nearly 8 steps in rear, three in front to get it running right. 1 3/4 header shorties, dual 2.5 into single 3". Track is nearly 6000', DA usually 8000+ in summer. Confirmed by plugs and afr gauge running WOT.

Today I threw on an old Speed Demon 650, which hated my cam duration, so I reconfigured with all bleeds, orifices to a Drag Race Demon specs, smaller IFRs, larger low speed bleeds, etc, dropped jets down 3 primary, 2 seconday, add notched float, jet extensions, put a big old honkin' squirter on the primary side. The mixture is finally adjustable and the engine is now running better than any carb'd car I've had, idles great, razor sharp at all rpms. You'd swear it was FI. I'm running the same secondary jet I was in the 750, with a dead flat 12.4 at WOT. I know I have a better signal and velocity with the smaller carb, but seeing how far down I jetted the 750, would a 650 be losing any hp specifically mph in 1/4? A simpler question would be how much hp can a 650 carb support? Thanks!

[grumpyvette]

but this may help you

 

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

 

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

 

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

 

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

 

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

 

http://www.moparmusclemagazine.com/techarticles/mopp_0902_port_injected_cross_ram_manifold/index.html

 

http://www.engr.colostate.edu/~allan...a/effarea.html

 

http://www.newcovenant.com/speedcraf...runnerarea.htm

 

http://www.newcovenant.com/speedcrafter/toc.htm

 

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

 

http://www.geocities.com/MotorCity/T...92/vizard.html

 

http://www.bob2000.com/carb.htm

 

http://www.mortec.com/carbtip1.htm

 

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

 

http://www.centuryperformance.com/vacuum.asp

 

the question usually goes " what size carb do I need," or something similar,

4v carbs are rated at a flow rate determined with a vacume or pressure drop of 1.5" of mercury, your best power AT WIDE OPEN THROTTLE AT MAX RPMS will generally be found with a carb that lowers the presure drop or vacume to between 0.5" and 1.0" of vacume, not 1.5" at full throttle,more vacume at full throttle indicates a slight restriction to flow, now on a street car thats not going to be much if and problem, but on a race cars engine its a sign that your potentially giving away some potential power.

lets look at your comon 600cfm carb some of you guys use, a 0.5 inches of vacume it flows only about 350cfm, at 1.0" it flows about 500cfm, at 1.5" it flows about 600 cfm , rated like a two barrel at 3.0" of vacume it flows close to 780cfm, and if you stuck it on a 600 cubic inch big block spinning 6000rpm youll pull about 6" of vacume and it would flow about 1000cfm plus!

now remember youll try to stay in the .5" to 1.5" range at full throttle, to make good power.

now some of you might notice that the flow dropped NOTICABLY once the vacume dropped and dropping the vacume at wide open throttle tends to help power, provided the a/f ratio is kept near 12.7-13.0:1,AND the engine is set up to USE the flow available to it.

VOLUMETRIC EFFICIENCY

in theory a cylinder fills to 100% full, but the limited time the valves are open and the ports restrictive flow will only allow that to happen at a narrow rpm range

your engines torque curve on an rpm scale closely mirrors the engines efficincy at filling the cylinders, on that same scale, once the cam timing and port flow become a restriction power falls off because theres less fuel /air mix burnt per power stroke, the power tends to keep going up for alittle further in the rpm band simply because theres MORE ,thou slightly less effective power strokes per minute.

at 1000rpm theres 500 intake strokes per minute thats 8 per second times the intake valve opens and closes, at 6500rpm thats 54 times a second, not much time when you think about what needs to flow thru that port in the limited time....especially if you remember that of that 720 degrees in the cycle only about 240 degrees have any useful flow potential, so you just cut even that time by 2/3rds

 

some of you may have figgured out that to get the lower vacume or restriction, youll want a larger carb or perhaps two carbs, remember were trying to get that .5"-1.0" of vacume at full throttle, and that 600cfm carb is not going to flow 600cfm, at that vacume reading but between about 350-500cfm, so if you have an engine that can take full advantage of the flow it may, and usually does require a larger carb to make max power,that 383 might require an 800-850cfm carb or two 600 cfm carbs (since you double the venturie cross sectional area with two carbs the vacume reading is generally cut to about 1/2 what it was and the two 600 cfm carbs now flow about 350cfm each or 700cfm per pair) yet the carb size is just NOT all that critical,to making fairly decent (NOT MAXIMUM POWER) simply because as the vacume signal goes up, so does the carbs flow rate, and as the vacume signal strength goes down so does the flow

RESPONCE!

up till now we are talking only FULL THROTTLE POWER, but you operate under a wide range of rpms and loads, put that larger carb on a small engine and it makes good power at wide open throttle, but it also tends to have a weak vacume signal at off idle rpm ranges and it may run like crap! so a ballance must be accepted. smaller carbs are generally more responsive, but slightly more restrictive with thier smaller venturies.

 

http://www.carcraft.com/techarticles/0304_intake_manifolds_contrast/index.html

 

http://www.superchevy.com/technical/engines_drivetrain/induction_poweradders/sucp_0612_big_block_tunnel_ram_intake/index.html

Edited May 15, 2009 by grumpyvette