Bob,<br>you sneaky devil, you know this is cam thread ;D<br><br>Don~

 

This is a cam thread, and it will stay on topic.

 

What do you get when you cross a mule and a slice of bermuda onion : ;D This is not too far off from the topic is it?

 

Gene,I have seen one break in a puller. But,I would say it's pretty uncommon.

[edited by admin - Keep it on the topic, not on the person.]

 

Did anyone see Ron Capps Skoal flopper blow up today in Dallas? After the engine blew completely up-the body of the car followed suit. I was amazed Ron was ok. The explosion was very powerful.
As I watched the blow up I knew the crank or cam had broken and caused a bad valve timing event that made the engine explode. After a closer inspection it turns out one of the valve retainers had broken dropping the intake valve. The explosion traveled straight up through the combustion chamber, through the runner and into the blower. Bad times Man! I have these visions of broken valve train components or broken camshafts in our trucks when racing, pulling, or even dynoing. Add in propane or nitrous to the mix and potential for serious disaster is real. I have seen nitrous explosions , but never propane. Lets hope this does not ever happen.
Im sure the NHRA will have some videos of the explosion on the website by tomorrow.

Oh, the valve springs in a 6000rpm V-8 engine bounce open 50 times per second. That is incredible and harmonics can destroy their ability to keep the lifter on the lobe, and break valvetrain components like plastic.

http://www.nhra.com

Don~

 

[quote author=Floor It link=board=7;threadid=5607;start=30#52456 date=1034554787]<br>What do you get when you cross a mule and a slice of bermuda onion : ;D This is not too far off from the topic is it? <br>[/quote]<br><br>You get hot eats when you cook them on a George Foreman grill! Good tasting, and good for you!<br><br>I just don't know if these miniscule changes are worth the cost and hassle of a cam, if you want to change things, go for broke, notch the pistons!<br>It seems a lot of guys are just changing them because it was always what they did with their Chevy, 20 years ago.<br>Which is fine, I mean, knock yourself out, I'm just rambling here!<br><br>BULLWAGON,<br>That is the only one I have heard of also, and that one had a good reason to let go, I would say, eh?<br>

 

Actually gene its a piece of A** that brings tears to your eyes. <br> Just trying to break the heated discusions. I'm curious as to why notch the pistons to get a bigger lift cam in? At 60lbs of boost only so much air is going to get packed in, no matter how much valve lift you have,even with more duration too. Just curious.

 

hehehehheheeh ;D

 

<br><br>[glow=red, 2, 300]That away to keep everybody on their toes![/glow]

 

JetPilot: Why does it show 0 on your boost gauge? Well now why does it only show 3-4? Just curious... ???<br><br>Tony

 

Tony,<br><br>To answer you questions.... prior to the cam change when I was running on level ground at 65 mph I had zero psi of boost indicated on my boost gauge. After the cam install with the same conditions my truck was showing 3-4 psi of boost. The increase in boost is attributed to the cam design. It allows for the turbo to spool up sooner thus decreasing egts and making for more complete combustion.<br><br>Doug

 

Yea Gene,that's the extreme!

 

<br><br>Really?? It's funny that every CART and F1 spec motor built today (for the low price of just $4 million per season for a CART motor) all run gear driven valvetrains. I guess they realize that at 15k+ rpms they need all the strength they can get. The top fuel guys don't run gears because a chain is a much quicker disassembly/assembly for them in the pits between runs. <br><br><br><br>Running nitrous oxide with nitromethane would be defeating the purpose. Nitromethane itself is an oxygen bearing fuel which lets it build power better than Charles Atlas. The one problem those guys don't have is running rich.<br><br><br><br>How is that so? If you're going to increase lift by .030, then you're going to have to take .030 out of the cam somewhere (ignoring rocker ratios). Either way, you're still taking off the same ammount of material... the marine cam doesn't magically provide the extra lift. True, the percentage of material taken will be less, and there will be more there when you're through, but the total distance ground away will be the same. Also, most cams are rehardened after they are ground to the new specs, so grinding into the case hardened area is a moot point. A standard induction hardening only penetrates ~.030 anyway, so it's mostly gone after the grinding process.<br><br>I personally don't think you're giving enough credit to rpm in the cam breaking scenario. Have they been broken? Yes. At a &quot;normal&quot; rpm range? Nowhere near it. It's a simple fact that flat tappet lifters are not the answer for high rpm use and are contributing to a large part of the problem for these guys when they start twisting these motors that hard. <br><br>John

 

Being we are an over head valve engine, how do we have solid lifters? How do we have lifters at all? I'm still new on the whole internal thing on how our engines work. I've only had the valve cover off once and looked at it. <br><br>Using nitrous and nitromethane in a top fueler? ;D Can we say sick? They run 4's now on 90% nitromethane. Imagine what they could run on nitrous. Although I know it won't ever happen (for reasons of safety, and traction) it would be pretty neat to see a 2 sec. time slip.