Delta 202 cam no good?

[JiFaire]

Good posts, BJ - there is significant difference in having a cam ground for asymmetry on an NA and a FA engine, but I'm also skeptical about the amount of difference. Still, it is a fine line to walk, as BJ points out.

Guys, It's important to remember a few things; Fuel/Air is forced INTO a turbo cylinder, but it has to push to get out. That would be fine if you weren't overlap limited, but on a 6.5, that push can give you a reverse float near the end of the cycle, which is why the duration is different on exhaust.

Cam geometry that ran fine in my NA 400 Firebird engine would make a 6.5 crap out... completely different things.

A number of years back, only Crane ground a cam for the 6.5, and nobody I talked to (including John Kennedy, Bill Heath, and Lyndon Wester) thought a cam did a damn thing for the 6.5.

Because none of the symmetrical grinds tried did. A few guys tried them, and gave up.

Now that Bill has an asymmetrical grind that is working.. sort of ... he likes them. Go figure.

On a related topic, just a friendly reminder:

You can slag the guy for charging too much, but in my book, that's chickenshit ... It is the same kind of stuff that made this place go all strange before, with people attacking Dennis (Slim Shady), Bill, even Leroy.

Bill is an easy target because he's expensive. Let's try a different example:

Somebody got on my case once because they thought Leroy charges too much for a boost bolt. After all, it's just a manifold bolt that he drilled and tapped, is what they said. I agreed, and told them to go and drill their own. Turns out they didn't have the tools or the skill, but they still wanted Leroy's product and thought he was greedy for charging so much. I finally told them to grow up, at which point they got mad and left the site. I waved goodbye.

Here's another: Some guys (like Lyndon Wester or KOJO) shared the details of their chip burning, then had people copy and use what they shared to make and sell chips of their own, which cost the original guys business.

Bottom line:
- If you think a vendor charges too much, don't buy from him.
- If you're mad that a vendor won't give you his specs, don't buy from them.

But don't complain about a vendor being expensive or secretive... they're just trying to make a living. Remember that all of them have also cut people deals, and saved our members lots of money, in different situations.

They're just protecting their business, and that should be entirely understandable.

 

[turbovanman]

There is no vacuum in our engines.

My new engine build is using GEP van heads with the stock van intake manifolds and a custom crossover piece so I can retain my current turbo pipe setup.

 

[turbovanman]

On a related topic, just a friendly reminder:

You can slag the guy for charging too much, but in my book, that's chickenshit ... It is the same kind of stuff that made this place go all strange before, with people attacking Dennis (Slim Shady), Bill, even Leroy.

Bill is an easy target because he's expensive. Let's try a different example:

Somebody got on my case once because they thought Leroy charges too much for a boost bolt. After all, it's just a manifold bolt that he drilled and tapped, is what they said. I agreed, and told them to go and drill their own. Turns out they didn't have the tools or the skill, but they still wanted Leroy's product and thought he was greedy for charging so much. I finally told them to grow up, at which point they got mad and left the site. I waved goodbye.

Here's another: Some guys (like Lyndon Wester or KOJO) shared the details of their chip burning, then had people copy and use what they shared to make and sell chips of their own, which cost the original guys business.

Bottom line:
- If you think a vendor charges too much, don't buy from him.
- If you're mad that a vendor won't give you his specs, don't buy from them.

But don't complain about a vendor being expensive or secretive... they're just trying to make a living. Remember that all of them have also cut people deals, and saved our members lots of money, in different situations.

They're just protecting their business, and that should be entirely understandable.

Totally agreed and the same as what I said earlier.

This type of stuff happens all the time on my Turbo Mopar forums, I've had designs blatantly ripped off.

 

[Paveltolz]

I'm no Cam grinding expert either but I've got the HT-4 and I've no regrets other than the OP has stated, 'there were other changes made at the same time so as to make pinpointing the source of improvements impossible.'
Same with my motor...too many changes made at once to make a definitive statement as to what actual improvements the cam has made. Still, others here have ridden and driven the truck and while it is no off the line screaming meany, it holds its own, even with a self destructing center cartridge! With the lighter rims and tires, its a lot better, quicker, livelier...just I was told it would by, um, Bill.

As for Bill, my 2 cents.

He'll talk to you on the phone for a while playing the "I'm not there but please try to help [him] understand what you mean by 'rattles like a coffin full of bones in cement mixer' " type descriptions he sometimes gets. Just don't ask for his advice after you've bought parts from someone else and expect him to give you customer support.

Folks that want a tune for an ATT or a Holset or whatever can get them from him and can work with him to get it better if there's an issue. I did with my ATT and had what Waking J said was one of the best tunes he'd seen and at the time he was marketing KoJo.

He'll talk you out of buying stuff you don't need until other options at lesser cost have been exhausted. That's rare.

 

[Will L.]

Great White, Thanks as always for your knowledge in the 6.5 world, light years beyond mine in many aspects.
Paveltolz, I did like the ride of your truck. Something in there is working nicely.

Just ponder: If the 4 grind helps at all on a side mount turbo being fed thru different length runners, than how would it not hurt that same percentage on the center mount turbo design using the intake manifold in vans and hummers. Then there is still the n/a question.
Yeah, the equal length design on some 6.5s,- Every turbo van and turbo hummer/hmmwv.

n8in8or, you already have the 202 cam, right? I would not hit the panic button. I am not trying to use your thread as a beat up bill page, but your questions only arose from them trying to sell you a part. I have experienced this from him before- on more than just the cam. I don't think continuing in front of the general public is appropriate because if one is knowledgeable he can be of good service to future customers. Anyone wishing to start a conversation in group, I will answer an questions. Trying to squash this in a respectable way, while not relinquishing issues.

If the 202 is junk, can anyone post old reports of people having problems with them. I know they built the 206, which was identical except more lift, and have not heard a lot of complaints on that one. Ease your mind and use what you have already paid for.

 

[FellowTraveler]

There is no vacuum in our engines.

My new engine build is using GEP van heads with the stock van intake manifolds and a custom crossover piece so I can retain my current turbo pipe setup.

It would be interesting to use and equal length log type intake on the center mount setup.

 

[FellowTraveler]

Let me take a shot at trying to give some understanding of cam choice in a forced induction engine in as short and simple a way as possible.

Lift is less important than lobe separation angles (LSA) on a FIE. Lobe duration has a more salient effect than lift, but it also starts interacting with LSA to change overlap when it gets bigger (which can be a negative thing as we will see further on).

The other problem you are facing in a 6.5 is inherent to the design, but I’m getting a little ahead of myself.

Lift is limited in a 6.5 by a couple things, but mainly the geometry (IE: valve clearance). Lift is also not as important because you’re dealing with more than 1 atmosphere trying to rush into the cylinder. It’s not irrelevant, but not as big of a gain. Lobe duration is more effective than lift to get more of that 1+ atmosphere in that chamber.

LSA is directly related to the amount of pressure in the exhaust. Basically, more pressure at the exhaust port means more overlap means more reversion in the exhaust flow.

Yeah, that’s really nice but what the heck does that mean?

If you have too much overlap (say somewhere around 108-109 degrees LSA, keeping in mind overlap is a function of both LSA and lobe duration) in a turbo engine (normally in the 112+ degree range), you end up with exhaust trying to cram it’s way back into the combustion chamber while the exhaust valve is open too long. You can think of it as the opposite of scavenging effects in a NA engine.

The 6.5 itself and its exhaust system are another big issue here. The turbo is naturally a restriction, but it has to be there or we wouldn't be having this discussion. The exhaust is another restriction, both in it's design and just by the nature of friction in the pipes. You can free it up with a more modern turbo (increased efficiency) and a free flowing exhaust. Then, in theory, you could tighten up the LSA in an old 6.5

But there’s another gotcha in the 6.5 to re-jigged LSA: High compression and head design. Tightening up the LSA means opening the exhaust valve sooner. The danger of this is possible bent pushrods.

Say what? How can LSA bend pushrods if it clears the piston?!?

Well, the valve face surface pushing against high combustion pressures (remember we’re starting at 21:1 here) is quite large relative to the rest of the valve train components. This means increased pressure in the valve train. Everything in the valve train is relatively robust and supported in guides and bores, except…..the pushrods. When push comes to shove, the rods loose and deflect. Believe it or not, I've seen it before. We all thought there was something binding somewhere bu there were no obvious rubs or binding when turned over by hand. Had us all bedeviled. Swapped in an OEM cam (not a 6.5). Bingo, pushrod problems went away and the engine made darned near the same output. Well, as much as we could run the engine on the dyno before it roached a pushrod that is...

It’s all kind of moot anyways. The 6.5 heads are a pretty poor design by modern standards. heck, they're even a pretty poor design for 1982. Easy and cheap to produce, but low expectations in the power dept. Keep in mind GM built these to be “penny pinchers” in both running and production costs (and it shows).

And even if you do manage to overcome all those tidbits and end up with a cam with tons of overlap that works, the prechamber design is going to throttle you right back to crap gains at best. Open ‘em up and you lose efficiency which starts to cost you power as well.

It’s just innate to the design…runs great on crap fuel, low injection pressures and met noise and emissions in it's day, but makes low power. Only way to get around the basic design is to yank it and drop in something better from the start, which is what GM did with the LB7.

Now, assuming all this didn’t deter you and you still wanted to design a cam that worked better, you’re going to get in pretty deep. You would have to redesign the combustion chamber, exhaust manifolds, turbo and exhaust to match it. I would suspect this is why people selling “cams” for a 6.5 TD are reluctant to public specs: those that know would read them and know they aren’t that much different than OEM. They can’t be unless you redesign the whole system. Releasing specs and them being close to OEM would be “letting the cat out of the bag” as it were and any chance at profit would be gone like a fart in the wind.

Unlike a NA engine, it’s not as simple on a forced induction engine as swapping cams and enjoying more HP at the range you want…..a cam is just knocking over the first domino in a very expensive run.

And we still haven't even touched on how cam selection is effected by vehicle weight, gearing, torque converter, etc.....toss in how it effects prechamber behaviors and the characteristics of the diesel cycle (ie: ignition delay, fixed burn times, etc) and it gets really murky really fast. This is a lot of why DI is easier to build more power, you can literally just cram in more air and fuel to make more power (until it pops, then just build it stronger).



I kind of went back and forth there a little bit, I pulled that off the top of my head and I haven’t messed with cam geometry or abstract combustion theory in a while. Please excuse any errors.

Excellent!

 

[great white]

There is no vacuum in our engines.

My new engine build is using GEP van heads with the stock van intake manifolds and a custom crossover piece so I can retain my current turbo pipe setup.

Actually, there is a vacuum source. It's between the turbo and the air cleaner. It's used to "scavenge" the crankcase and is limited via the CDR valve.....

 

[great white]

It would be interesting to use and equal length log type intake on the center mount setup.

build it.....all it takes is assorted aluminum, a lathe, a mill, a TIG and various cutting tools....

 

[JiFaire]

n8in8or, you already have the 202 cam, right? I would not hit the panic button. I am not trying to use your thread as a beat up bill page, but your questions only arose from them trying to sell you a part.

If the 202 is junk, can anyone post old reports of people having problems with them. I know they built the 206, which was identical except more lift, and have not heard a lot of complaints on that one. Ease your mind and use what you have already paid for.

I completely agree. From what I know, your cam won't hurt anything; it may not provide the performance jump you are looking for, is all. Most times, performance gains in a 6.5 come as the sum of a bunch of other things, rather than from one upgrade.

As for my comments, I want to apologize... I'm not looking to pick on anyone, nor protect any vendor, I just know how destructive that public conversation gets, and would rather not live through it again. Thanks for humouring me, guys.

 

[hookedup50]

IMO, no apology necessary. I may have inadvertantly helped steer the thread in that direction, which was not my intent, I was only stating Bill's business stance. Bill, along with many on this forum, were invaluable on the repower of my truck. Leroy and Bil, for example, still answer the phone when called. That is getting rare in this day. I still plan on taking my truck to visit Bills establishment. Coincedentally, All my best vendors for my Jeep and Datsun are all located in a 50 mile radius of Bill. Instead of a pub crawl, it would be a parts crawl with a 300o mile drive.

 

[n8in8or]

Holy cow....I guess I wasn't getting notifications that there were updates to the thread!

Lots and LOTS of good information guys thanks! I would quote the relevant posts here, but it would be WAY too long a post. Between what I have read here and the similar post I did over at the place plus a couple emails and PMs, I have learned a lot and it helped guide me on a reasonable path.

This wasn't a thread intended to discredit Bill's business. If you have a product or service that nobody else has, then you get to charge what the market can bear....if he's still in business with what he charges, then good for him...sounds like a successful business model to me!

What I realized later was that I was emailing with JOE Heath, not Bill, and apparently he was taking more of a hard sell approach with me. I PMd with Mike from Missouri who had worked with Bill to get a tune he was happy with on his HX40 setup and he had no concerns that Bill would work with me to get me what I wanted.

I didn't want something that was going to have drivability problems and with all the information I've seen I don't think I will. Now it sounds like the powerband may be a little weak on the bottom, but healthy on the top...I can probably live with that, we'll see. What I'm going to end up with is a well documented group of parts and we'll see how it runs together. I will do what I can to dyno it (though this is only marginally relevant since every dyno is different and I won't have any "before" dyno runs to compare to) and I live half an hour from a drag strip so I may take it up there just to see. I know it's not going to be a hot rod, but for a 6.5, I think it will be fun...and it can tow a travel trailer for my family, so that will make me a happy camper...as they say (it's ok to groan ).

So I just got off the phone with Bill himself and he was GREAT to talk to! He didn't try to sell me anything else and didn't seem concerned that he could figure something out that I'd be happy with. He said he's going to give me all the pump can do (which is probably the limit that Great White referred to). At this moment I'm very pleased and can't wait to get my combo together. Once it's together I will answer the question I asked - is the 202 junk and does it give more drivability (with my combo)....we shall see.

Thanks for everything guys, I appreciate all the feedback!

 

[great white]

There seems to be a bit of misconception on what "dyno runs" are good for. Perhaps I can clear some up.

Chassis dyno runs aren't much use if you're looking for bragging rights, or even comparing one vehicle to another.

What the dyno does is allow you to make changes and confirm the results in a rapid manner. Ie: add some timing, run, add some more timing, run, back the timing off cause it was a bit to far, run, settle on the sweet spot for timing, adjust fuelling, run, adjust fueling, run, too much smokeor egt, back it off, find the sweet spot for fuel, run, adjust the timing, run, OK it can use more now, run, back it off a bit, run, sweet spot for fuel and timing, mess with boost tables, run, etc.....

Now, take it out and see how that translates into real world performance. Ie: driveability, mpg, acceleration, etc.

That's the purpose of a dyno. Rapid prototyping and confirmation if you will.

Doing a one or two hit run to see how big the numbers can be is......well, pretty much pointless. Doing runs days or weeks apart is useless. I didn't start making decent gains in a reasonable time frame until I found a shop (3.5 hrs away, but we make a weekend thing out of it) that was willing to trade for dyno time for tuning experience. We did all this while the shop was closed and for mutual gains. When I say gains, I mean experience, not the truck. Knowledge is the pursuit, not et's.

Throwing big numbers up on a runs can be fun, but its the runs that get you there that matter. That's where a dyno fills its purpose in life.

"Dyno days" are great for the guy who owns the dyno though, it gets kids to help pay for his shop tools (ie: dyno),

 

[n8in8or]

There seems to be a bit of misconception on what "dyno runs" are good for. Perhaps I can clear some up.

Chassis dyno runs aren't much use if you're looking for bragging rights, or even comparing one vehicle to another.

What the dyno does is allow you to make changes and confirm the results in a rapid manner. Ie: add some timing, run, add some more timing, run, back the timing off cause it was a bit to far, run, settle on the sweet spot for timing, adjust fuelling, run, adjust fueling, run, too much smokeor egt, back it off, find the sweet spot for fuel, run, adjust the timing, run, OK it can use more now, run, back it off a bit, run, sweet spot for fuel and timing, mess with boost tables, run, etc.....

Now, take it out and see how that translates into real world performance. Ie: driveability, mpg, acceleration, etc.

That's the purpose of a dyno. Rapid prototyping and confirmation if you will.

Doing a one or two hit run to see how big the numbers can be is......well, pretty much pointless. Doing runs days or weeks apart is useless. I didn't start making decent gains in a reasonable time frame until I found a shop (3.5 hrs away, but we make a weekend thing out of it) that was willing to trade for dyno time for tuning experience. We did all this while the shop was closed and for mutual gains. When I say gains, I mean experience, not the truck. Knowledge is the pursuit, not et's.

Throwing big numbers up on a runs can be fun, but its the runs that get you there that matter. That's where a dyno fills its purpose in life.

"Dyno days" are great for the guy who owns the dyno though, it gets kids to help pay for his shop tools (ie: dyno),

That is what I was referring to when I said that if I did put it on a dyno it wouldn't be very relevant. The main reason I'm thinking I would take it is so I would finely have a baseline for myself. Many times I've meant to take it to the dyno so I could compare after I made my next upgrade/modification, but unfortunately the timing of everything hasn't worked out that way. Once the thing is together I should hopefully finally have a consistent and reliable combination of parts. Then if/when I do further changes like tubular headers, WMI, intercooler, change the cam, etc, I'll know what difference they made, if any. The only thing I won't have is dyno runs that are really close together in time....unless I do one just before I do the mod, do the mod and then run it again as soon as I can. We'll see how life shakes out. Thank you for explaining that fully though, I appreciate that.

The dyno time swap that you're referring to, was that for 6.5 diesel tuning experience or was this for a different vehicle? Just curious because if it is for the 6.5 I bet it's hard to find a shop that would be interested enough in the 6.5 to do that. I'd be lucky to find one just 3.5 hours away I bet.

 

[great white]

The dyno time swap that you're referring to, was that for 6.5 diesel tuning experience or was this for a different vehicle? Just curious because if it is for the 6.5 I bet it's hard to find a shop that would be interested enough in the 6.5 to do that. I'd be lucky to find one just 3.5 hours away I bet.

Both. Additionaly, wanted to try out Tunercats II (which is what I use) and see how it compared to things like efiLive ( which is one of the tools they use). They also wanted to see what i knew and if it was something they didnt.

From there it just evolved into fun weekends of therorizing, tuning, cutting, welding, thrashing and some mutual learning. Little beer and some good fishing thrown in the mix too.....

 

[n8in8or]

Both. Additionaly, wanted to try out Tunercats II (which is what I use) and see how it compared to things like efiLive ( which is one of the tools they use). They also wanted to see what i knew and if it was something they didnt. It just evolved into fun weekends of therorizing, tuning, cutting, welding, thrashing and some mutual learning from there.

Sounds like a lot of fun! I appreciate you sharing your experiences with a 6.5 novice such as myself.

 

[uniquediesel]

Honestly, the specs on a DS4 are pretty much irrelevant anyways. Without some VERY involved programming work in the ECM, it's hard coded to max out at 79.7 mm3:

I only know 3 people who have the ability to break that limit in the coding and 2 of them don't sell anything, it's all private/personal work. The third can't be bothered anymore as there's not enough money in it. Pop pressures, plungers or whatever: all pointless with the software limit in place.And even then, just because you are commanding it over 79.7 mm3 that doesn't mean you are actually getting it.....

So, just an FYI for the bust on this post. The one little guy that says he knows how to overcome this limit is...

He calls himself the Great White Liar.

Yes, Great White says he has the secret recipe to overcome the 79mm fuel rate limitation.

But wait, none of us are worthy of this information. I talked to him via PM about it, and guess what no information!

All I ask is either back your stuff up old man, or quit posting about things you haven't done and cannot do.

You'd think that people like Kennedy, Heath, and others would be interested in overcome this limit. And if it was doable they'd make it happen. But this lowely Great White guy has the recipe. I doubt it very seriously.

He says he won't prove it, we all know what that means.

Just calling a spade a spade is all..

 

[Paveltolz]

I'm thinking I'll stick with Great White, but thanks...no really!

 

[hookedup50]

X2 with Paveltolz.

 

[great white]

Well, this is outside the thread topic and I try to ignore insulting "callouts" (to say nothing of the insulting PM's I received) but I will indulge this time and try to confront the insults with knowledge. Apologies to the forum members and admins if I get a touch "catty" here or there. I'll try to keep a lid on it as best I can. Once this is done, there will be no further comment on the matter from me as I have nothing to gain but further insults.

First, you need to be able to write a VDF. It has to be your own. If you take Lyndon's and alter it, you are breaking the agreement when you purchased it to not alter or reverse engineer his work. Besides that, it's just plain low, unethical and dishonest. God help you if you redistribute it. His 6.5 stuff is proprietary, but somehow I don't think you're going to worry/care about that.

If you do decide to "crack" it, don't let him find out you did.....he's pretty protective of his stuff. It's beyond most peoples ability anyways, so Lyndon is pretty safe there. Lyndon and I are definitely not what you would call "close" (most of his emails are quick and curt, he's a busy guy), but he knows that I have never (and will never) release his or my work into the wild without the nod. I even keep it all on a toughbook without internet access, since I had someone who thought he was good "hacker" decide he would outright try to break in and steal it when I refused to give it to him. He got a nasty surprise when he thought he was "in"....el wipeo esse's hard driveo.....too bad you had all that work on there.....HA!

I did get the OEM calibration that I alter from Lyndon (it was part of my purchase), but that's not proprietary to Westers. That's GM's stuff and the jury is still out on whether or not altering it falls under actionable breach of use. That's what you are altering with your GMT program in the switches, constants and tables. GM doesn't seem to care anyways. The number of guys diddling around in their cupboards is pretty small potatoes.

Next; Learn hex, you're going to need it. That's going to take you a while...it ain't like learning a couple HTML codes....

Once all that's figured out (be ready to spend a few years there, unless you steal Lyndon's work), you're not even halfway there. You need to go after the "hard coded" limit on the board. You need to build a BDM hardware interface (your 20 watt soldering iron isn't going to cut it here either). Once you're done that you need to program a software interface in order to use your BDM hardware.

You can't do it through the ALDL ports, they don't have "access". Same reason you can't download the calibration file from an OBDII PCM. It's not like an OBDI board where it's all (essentially) on one chip. On an OBDII PCM it is kept on several chips. This is why you can upload to an OBDII, but not download. Winflash can't access, compile and download the calibration from several chips. That's why you get an error when you try. Guys will try to tell you it's disabled in winflash so you can't "steal another guys tune" and all manner of reasons why you can't down load, but it's a simple hardware limitation when dealing with the ALDL. No way around it.

Once you've downloaded the "firmware" via the BDM points, you have to decompile it into something you can work with. Now you have to try and UNDERSTAND it. You're pretty much back to square one like when you had to build a vdf now. Then you have to find where the limit is hardcoded. Once you alter that, you have to recompile it, blow it back into the board and hope it doesn't brick on you with your non oem hardware/software interface. It bricks more often than it doesn't so have a good stock of PCM's on the bench, unless you have/know how to use a surface mount workstation to lift and replace PLCC32 chips.

Now you blow your modified calibration into the PCM via winflash and your modified VDF and hope the calibration file doesn't conflict with the "firmware" you just blew in through the BDM points. If it does: brick.

You also have to hope you didn't modify anything else by mistake in the code or there wasn't an error in recompiling something. If you did: brick...or your transmission explodes inside when you try to drive it.....or some other weird/destructive behavior happens.

Now, if you get all this done and you think it worked you go to confirm it. You command more than the OEM limit.

Do you get it?

You'll never know. You'd have to run it on a DS4 capable calibration bench to know. Those aren't exactly on every street corner. Luckily, I know of one in my home town and I have a few "ins" there. Guys right about this "old man's" age by some strange coincidence.....

Even if you do get it to eek out more fuel, there's timing and all sorts of other variables that will need to be worked out because you don't know if your injection event is where it should be in the cycle, if the ms pulse is correct, etc. Those are not accessible in the program like they are in, say, a DB7 program and efiLive. Black smoke doesn't just mean you're overfueling, there's lots of other things it could be in this scenario.

It's also going to probably start tossing weird error codes (yes, it will code, it's outside of spec, I know). Now you're chasing all this crap down just too get it to run right and/or keep it out of backup fueling. Welcome to the computer age.

Like I said, very few people have done it. Very few people WANT to do it. There's no money in it and in today's litigious society no one WANTS to market it. At least, that was the last word I had and that was a fairly long while ago.

I don't sell anything, market anything nor make any money off anything. My day job pays the bills quite nicely thank you. What I do I do for my own entertainment and maybe a few close friends I can help along from time to time. I'm hurting nobody, so nobody selling this stuff bothers with me. I do occasionally come up with something that I share with a close group on the net and they sometimes use it to make money. I could care less, means nothing to me. If they need to use it to make a living, more power to them. Glad I could help.


Now leave me alone. Both in PM's and in the forum. That's the last I have to say on it.