Did you mean Sir Harry Ricardo, and maybe "The high speed internal combustion engine"?

 

Yep.... Most street guys never see it but the torsional motions of a camshaft are a bit scary..... One of the reasons racers go to larger journals and the same reason the LS1 is that way, a larger journal cam is a stiffer cam and has more accurate timing cylinder to cylinder because it is less likely to deflect and cause inaccurate timing.

I've been touting these things for a while now.... one reason why I stick to billet cores for motors that turn over 6000rpm


That's awesome.... good comment.

Bret

 

Most of these guys have never run spring pressure in excess of 600#(like 1000#+) or the lift to go with it(1"+),so most don't have any idea what a cam goes through.
Most cams here are hyd roller and most HR cam's I have built are with a billet core,even with 350-400# on the nose.Most won't spend the extra bucks or know the advantages of a billet core.

 

since you guys are talking about valvetrain dynamics, what are your thoughts on gun-drilled camshafts? This is another thing that GM has done with the Gen3 motors that sparked my interest.

 

thats rough dude.whether its because im an aeronautical engineering major in progress[who does get laid,thank you very much]or whether its the fact its totally true any even basic level class will bend your brain in 5 different ways,and its onlt gonna get worse,i cant decide.damn you and youre truth,Mindgame! J/K.
Anyway my dad used to contract for NASA;so i got to sit in on some of the scramjet research/testing[the field i want] here at JPL just to get an idea of what it was about,and man, was i over my head but it was the most stimulating "bench racing" ive ever seen, imagine a bunch of dudes comparing and interpreting dyno results but everyone has [multiple] degrees and there are computer models with thousand of points compared to hp/rpm graphs.Im stoked about it,whether or not i can hack differential equations and the like to get there remains to be seen....

 

Keep at it, stealthblack. Thermo and diff-eq taxed my brain also so very long ago, but it was worth the fight. No, I didn't "look forward" to thermo class.

FWIW, isn't "steathblack" redundant?

A very good friend of mine has a one digit Bandit number. Unfortunately, he couldn't share much of what he knew for a long time. He didn't want to have to shoot me.

FWIW-2, the best engineers that I know are the also the best communicators. Take as many of the writing and speaking courses as you can squeeze in during your undergrad years. It will pay back big dividends.

Good luck.

 

The bridge that failed, Tacoma Narrows bridge I think.

The failure was due to harmonics, but the cause was the wind.

The wind blowing across the span caused vortexes to form on the sides of the bridge, when the vortexes detached they caused a vibration that happened to match the natural frequency of the bridge.

You would think that the bridge would fail due to live load such as trucks and cars. But the engineers designed for that. Civil engineers don't work much with air flow. So they got blind sided by the vortex vibration.

The location of the bridge was in a narrow valley that funneled the wind.

So the real problem was the aerodynamics of the bridge.

*Note: Anyone know of any good Mechanical engineering jobs that haven't been outsourced yet?


Z28

 

Figure that something like a Comp 977 Dual spring with 1.6:1 rockers puts 600-700lbs on the lobes.....

That's why I only do billet cams.... might as well give people the good stuff for the money.

Bret

 

thank you, i will.
Im lucky in that i used to be an instructor, so i have great comm skills[now to figure out how to cut the swearing] writing im working on.
It was gonna be just stealth but that was too short for the computer.black z that looks bone stock but is not=stealthblack

 

[QUOTE=1racerdude]Most of these guys have never run spring pressure in excess of 600#(like 1000#+) or the lift to go with it(1"+),so most don't have any idea what a cam goes through.
QUOTE]
are not blown fuel cams and the like ground in anticipation of torsional flex under load??I thought i heard something like that but cant remember// or even PS or TS cams with 1"+??

 

Yea,you're right.
If you tell a customer $300.00+ for a cam,he's going to say "I can get a cam for $189.00 out of so-n-so's catalog" so there you go.

 

[QUOTE=stealthblack]You are correct.

 

There might be a few other pushrod engines where that's done, like 9500 rpm endurance engines (over a million revs per race) with flat tappets.

 

I have a question for the engineers on here.

I am currently at Wyotech in automotive and chassis fab. School isnt anything like the recruiters make it sound (big surprise). Not saying its a bad school, we learn alot, but we just learn how to be Technicians and work in a dealership. Although it is a good basis for any performance application, it just isnt what I was looking for.

I have taken a class at a reputable engine builders shop who builds for a few top fuel teams I guess, and has worked as a head engine builder for (SP?) Kuwickis NAscar team in the early 90s before he died. This class was very helpful in a lot of "nitty gritty" engine building techniques and parts choice, but still not to the level I want.

What I am getting at is that if I am not able to attain a job in the field I want out of here: that being either a bigname fuel drag team, or something in the F1/Indy type racing environment. Or at a big name engine building shop, or R/D for engines, just that broad spectrum of things.

I have lately been thinking if I do not find a career like that, that I might go back to finish what I started in ME a year and ahalf ago. What Im wondering is if a ME degree is a really big help in this field, I dont want to sit behind a desk designing parts for washing machines, I want to work at least in this field, but designing connecting rods or things like that would be awesome, especially on specialized projects for GM like the LS7 or something.

I know it wouldnt be a waste, but I dont want to spend 4 years becoming an ME and not do what I want to do, I can learn anything very quickly, and would not NEED the schooling to be good at something, but I know you need a degree to get started somewhere that you can learn even more.

 

Yeah and so and so's $189 cam ain't nothing special... some guys know that and some guys don't.

Hell wearing off a lobe on a soft cast cam that's a bitch too..... billet cams have enough positives to me that it's crazy NOT to run them.

As for the ME degree...... it helps a ton. I kinda wish I had one.... it doesn't fit me due to a lot of things one of them the idea that I could design parts for a washing machine is one of them.

Getting into doing the cool stuff like motors is a lot harder. The amount of knowledge that you need to actually be a engineer in a race team is staggering..... and you need experience in the field, that's the hard part you can't get anywhere without experience. It's great stuff to work on but like anything it has it's drawbacks.... customer, problem parts etc....

I did it by having my own shop..... most guys go and work for someone like WJ or Kaase, DEI, RCR etc....

Bret