increasing power, tuned intake and exhaust ?

[hotater]

When I worked in the aerospace sub-contract machine shops we were constantly bombarded with blueprints that represented nothing but job securiety for the draftsman.  One of the best examples was small 440-C valve parts that it was my job to turn from stock, but the REAL work would be the grinding and lapping of them after heat-treat.  MY lathe print called for four digit tolorences BEFORE heat-treat.

......then there was an A-2 tool steel bar-- it was a slab of tool steel .500" x 2.000" x 30.000", heat-treated to Rc60-61  with twenty-four, two inch pins with a spacing that couldn't be greater than .003" cumlitive error between any of them that would be press fit in jig ground holes after heat-treat.  It had a couple of mounting holes countersunk to ground tolorences, too.  It took three tries to get the shrinkage rate and warpage figures so the initial holes could be drilled in oversized stock, then heat-treated, then ground back square and the holes ground to location and dimension for a press fit on the dowels. (no EDM at the time)
  We found out later that was a board to hang test cables on in the lab.  It *could* have been made with a strip of lumber and a handfull of finishing nails.

Good post, Kevin.  A higher power to weight ratio makes a difference if you have to move the engine with the power it makes.  We don't.   

[GuyFawkes]

4) We don't know how the "India" cam compares to the "Original" profile.
    a) The original Lister Company made more than one cam profile. Which one do WE get, or is it also different?
    b) Does anyone out there have "real" detailed drawings degree by degree and thou. by thou. to compare?

5) Cams and Valve trains are better now.
    a) Thanks for the update!
    b) Why do you suppose Listers and Roids have Dual Valve Springs?
        1) The Origonals and the Roids have two. Is that because they want to do the extra machining and make the second spring just to "Impress" Us?
        2) My "Guess" is that they at least mitigate, if not eliminate any harmonic problem.
        3) They provide a lot of "seat pressure" and a lesser "rate" which is best for steady low RPM running.
        4) One could probably apply some "modern" high tech design and materials and do it with one, but what will we GAIN?

a/ for camshafts you need to formula, a bunch of data on lift at each degree is NOT enough.

(this is one of the things a spreadsheet is actually very useful for, generating a cam profile from the formula)


b/ dual valve springs are a neat way of getting controlled valve rotation... valves should rotate a little same as tappets, but main benefit is a motion dampener, both springs are different "rates"

[GuyFawkes]

......then there was an A-2 tool steel bar-- it was a slab of tool steel .500" x 2.000" x 30.000", heat-treated to Rc60-61  with twenty-four, two inch pins with a spacing that couldn't be greater than .003" cumlitive error between any of them that would be press fit in jig ground holes after heat-treat.  It had a couple of mounting holes countersunk to ground tolorences, too.  It took three tries to get the shrinkage rate and warpage figures so the initial holes could be drilled in oversized stock, then heat-treated, then ground back square and the holes ground to location and dimension for a press fit on the dowels. (no EDM at the time)
  We found out later that was a board to hang test cables on in the lab.  It *could* have been made with a strip of lumber and a handfull of finishing nails.

I'm going to print that one out and keep it...

[kpgv]

Hi Jack,

When I worked in the aerospace sub-contract machine shops we were constantly bombarded with blueprints that represented nothing but job securiety for the draftsman.

When I was doing the "G" code thing (Precision Sheet Metal), I actually had a guy (Wet-eared Cad F***) tell me:

If I can draw it, You can make it...!!!

LOL

Kevin

[mobile_bob]

not sure if i should take offence or not, being how i am a new guy here.

never was my intension to stir feathers or blow anyones dress over their head either!


for the record i am not presuming to state that the cam profiles should be remodeled, quite the contrary i think the cam is fine just as it is.

what i am saying is the intake runner length is not optimal, just as the exhaust length is not optimal, period!

is there someone here that argues that point? if so step forward and state your case.  i don't want to hear a bunch of shit about that is just the way it is! i want some sound reasoning, some good math (and i don't give a shit whether or not you use a slide rule, computer or an
abacus).

i will take mr. ricardo's work as being exhaustive and legendary, no question about that.

but one would be sadly mistaken if they take the position that short cuts are taken routinely in order to make a nice neat package that
is economical to manufacture.

why do you think that most if not all engine manufactures have adopted sound engineering (in re: to runner design/length) on just about every known engine currently in production, be it  formulae one cars or heavy diesel engine's and everything in between.

step up and quit slinging shit and lets discuss the issue, if one is sure of one's position he should be able to relate it rationally without resorting to anger or name calling.

i guess i got thick enough skin to stick with it, do you?

 a sidebar:  btw, nascar banned the use of roller cams, to limit hp, not in an effort to increase hp.

bob g

[Halfnuts]

Bob,

Don't sweat it.  Everybody's got their preferences, their experience and their personalities (or lack thereof).  At the end of the day we're all just a bunch of guys who love these engines.  Nothing's worth taking offence.  It's just words on a computer screen.

Welcome to the board.

Halfnuts

[snail]

Bob G
       Good on ya! We need a few more posts like that when the ranting starts! Maybe if we had more experimenters  out there and less of the subjective opinions, the world would be a better place.
      I like the sound of the poster board tubes as a starting point.If the rack is moving at a constant load, doesn't that equate to a change in fuel efficiency? Sounds good to me . Surely there are  others interested in that?
     Does anyone know of a cheap and cheerfull way of measuring airflow into the engine so that we can establish a baseline? Actual CFM (or your preferred currency) would be nice, but any fairly accurate but relative figure would do. Between us we must have some pretty amazing facilities at our disposal. I'm willing to do a bit of work on this provided it doesn't send me bankrupt Anyone interested?

Cheers,

Brian

[mobile_bob]

i don't know of a cheap flow meter but perhaps this might work to get some relative data

take a mass air flow meter off of a small car (import ?)  one of the hot wire types might be about right.

provide it with a 5 volt regulated reference voltage from a pc power suppy.

then use a digital meter to measure the base air flow voltage at rated speed and load.

i realize this will not give real world numbers, but is will give you an indication of whether more air is moving into and thru the engine
with the modified intake runner length and exhause header.

my obd 2 scanner will give air flow numbers on an obd2 compliant engine, perhaps one could get the voltage reading at different measured air flows from the donor engine to graph out some good data from a lister.

i think i can get an mass air flow unit from the local pickapart for about 10 bucks from some small engine. and if i can find a like
running engine to get the obd2 data to relate air flow to voltage then i might be able to come up with an airflow meter to get real
data from a lister.

just a thought

bob g

[snail]

Bob g
       our equivalent to radio shack is selling an air speed meter for around $70 Australian (US $50?) If it looks OK and has the right range I'll buy one and lash it to some sort of telescopic inlet tube. Should prove interesting if nothing else.As if I don't have enough to do at weekends!

Cheers,

Brian

[Ironworks]

Ebay ....I have seen air flow meters go on there for $10.  I almost bought one. Wish I did now.

[mobile_bob]

also i would think that you would have to fab up a receiver/surgetank/ plenum to dampen the intake air as the pulsations (pressure waves)
would play heck with your readings

bob g

[snail]

Good point, maybe a 44 gallon ( 55 to you) drum would be enough .I've got plenty of those around. I assume the length of the intake that we're after would be from  the drum to the inlet valve . The meter would be upstream of the drum .I dont think the drum would cause any odd reflected pressure waves would it?

Cheers,

Brian

[mobile_bob]

i would suspect that the drum would be ample to dampen any pulsations.

probably overkill, but if you got it use it.

bob g