327_TPI_77_Maro

iTrader: (8)

Hi guys, here is the current timing map for my Stealth Rammed 327. I have 2 degrees PE spark at pretty much all RPMS, so my total timing ends up being a little under 37 degrees at high rpms. The engine ended up being 8.5:1 after the guy who built it years ago used 487x heads on it, which 2.02/1.6 valves and flow excellent, but are open chamber. I have no knock counts or retard, (occasionally a degree here or there but no more) but am I necessarily "giving the engine what it wants" ? With a low compression engine like this, will I be making max power if I keep pushing the timing until I get detonation and then back off? I ran as much as 40 degrees total timing on this engine back when it was carbed, with no problems.

JPrevost

MAF, eh... looks okay to me but I don't know what cam you're using or how it's been installed. Static compression is meaningless, dynamic is more important. The fact that you can run that much timing is actually interesting with those heads. I'd think if anything you'd be right around 32 degrees with open chamber iron heads. Also, that table isn't the end all timing table. Gotta make certain the initial SA matchs and the CTS timing SA table isn't doing anything to the timing at normal operating temps.

327_TPI_77_Maro

iTrader: (8)

Reference angle is matched correctly, and the coolant temp table is zeroed out in the normal operating ranges. I see 155 psi static cranking compression across all 8 with less than 5 psi variance. The cam is installed straight up and has lots of overlap (I have no idea what the specs are but the idle is very aggressive)

RednGold86Z

iTrader: (1)

And by zeroed you mean with reference to the bias, I'll assume.

I'd say you're in the right ballpark on timing. At really high RPMs you could probably go even higher AND make more power, but I would only do that on an engine dyno, and with accurate A/F readings. For a street car, you're probably just fine where it's at.

dimented24x7

iTrader: (2)

Thats about what Im running with my vortecs, less the 2 extra degrees of SA during PE. JPs right about one thing, though. Those old heads seem to be more prone to detonation.

Its hard to say what works for you but it looks reasonable enough.

As far as the timing goes, detonation is pretty much meaningless. You could go right past the point of peak power before encountering detonation.

funstick

aqll my experiences with 487x heads has been lots of advance 37-39 with low compression. for some reason the particular chamber is knock resistant. i think they have beter coolant flow.

327_TPI_77_Maro

iTrader: (8)

Funstick. YESSSS YOU ARE THE MAN! Thank G.od somebody has experience with these particular heads, I wasn't counting on that. Yeah I have 37 degrees total timing under WOT with these heads and I got ONE knock count in a half hour of driving 0 to 110 mph full pulls, it is very hard to push this engine into detonation. I could probably run 87 octane in it (I run 93 exclusively, which with 8.5:1 compression is probably why I see no detonation ever). Awesome, up with the timing.

Grumpy

Lots of guys have run alot of timing, only later to find out they've knocked the corners off the piston dome.
You need to remember the K/S is an acoustic devise and can be easily fooled. Often it's blind to preignition, and that can kill an engine as fast, if not faster then detonation.

It is possible to *mask* detonation, with too much fuel, and then run alot of timing. Which will work right up til, you knock the corners of the piston off, due to preignition.

funstick

ya know. not every engine knocks,preignites etc with 37-39 total advance. these are old school open chamber heads with poor squish. they have excelent ports however considering the time fram in which thye were built. in fact i had a carberated version of a 350 some time ago with 9.0 flattops that liked 42total advance on premium. but it had a fairly radical camshaft. again not everything likes less timming espceially old inefficient chambers like the 487 heads are. also 426 chrysler hemi heads prefer alot of ignition advance. ive seen a few street hemi guys running 46total advance on premium for very long mileage periods with no ill effects or knock or preignition.

im not gonna debate this but if hes getting the desired result and the engine isnt being harmed then obviously its what the engine wants.

funstick

givne the difference in fuels between now and 1994 when i had my 487x headed 350 i would say use a bit of caution. im just conferring with you that youve got a crappy chamber with excelent collant flow. also if the motor repsonds to more timming and its getting into knock check out evans NPG collant. ive seen nice gians in knock resistance and lower operating temps with it along with increased power in turbo cars due to its superior cooling propertys.

last turbo car i did we were able to run 3 more degrees of spark lean her up a tad and pick up 15hp measured on a mustang 1750de dyno. repeatably.

heres the link.

im not a dealer resaler etc. ive just had good sucess with there product.

http://www.evanscooling.com/

JPrevost

That's really odd considering Chrysler's own "max power dyno test" on the 426 Hemi was averaged at 35 degrees till redline. Might want to tell your friends that they're running about 10 degrees too much timing, again, dumb idea and sometimes timing is covering up a bigger problem like low speed carb tuning (too rich).
Also, most, no correction, all older open chamber heads I've tuned/helped tune (8.8-10cr) were fastest with 32 degrees, 34 and I had to richen things up by nearly a whole AFR to get the same acceleration. I just went back down to where I was running the leanest WOT AFR and the least amount of timing. The lower compression motor also liked 32, seemed to be the sweet spot. I've heard of really small cammed motors requiring even less timing (I think because of the higher dynamic compression).
To sum it up, I've never seen a sbc iron head (aluminum for that matter too) want more than 40 degrees at WOT. I'd like to know more about that 42 degree engine... I could care less about some Chrysler .

Grumpy

Look at the chamber design of a Hemi, and the answer is apparent.

Huge amount of cylinder head surface area, pulling lots of heat out of the reaction. Not to mention the piston dome did an excellent job of dividing the chamber into two areas.

Long mileage periods with how much time at WOT?. Lots of Hemis spend very little time at WOT.

JPrevost

I think I figured it out. Those Hemi's running 46 degrees WOT timing must have REALLY dirty air filters .
I did some more digging and you're right, some of the race hemi's are running timing in the mid 40's. That's pretty insane and I guess 170cc chambers with good cooling really does work .

edit: just to clearify, can't find any pump gas car/truck engine running in the 40's... only a few motorcycles run that much timing, most are in the high 30's.

funstick

the 42 degree motor was an all out effort to try to be cheap when i was just out of high school. i debureed everything. polished every edge. i knew with the cam timming i was running and the crappy chambers and low compression i was gonna have to run loads of advance to get it to not only luanch but make good power.it was an issue of a sledge hammer approach to making power. i admit it wast the best way but thatmotor went 50k before it spun a rod bearng and that was a bolt failure from an overev 7400rpm had a trans failure on the 1-2 shift i broke the intermediate roller clutch on a th350.. the rest of the engine was pristine on teardown.

the combo

holley single plane street dominator 1206 port
chevy 74cc chamber 487x cast iron head s ported as close to 1206 as i could get. rewored bowls short side turns 2.02 valve radical 7 angle
valve job. fully worked exhuast port
1 3/4 primary headers 3 1/2 collectors to dual 3 1/2 exhuast
2800 stall converter
th350 trans
355 rear gear
27 inch slick
cam specs were roughly 292 @ 50 with 570 lift with 1.6 rockers intake 1.5 exhuast on a 106 lda cam was advanced 6 degrees.

lghtly dished trw pistons at zero deck 4 valve reliefes exstensively deburred and radioused same with the chamber in the head.

in a 4100lb impala 1971 for that matter it went a best of 12.45 downt he 1/4 not bad for a brute force combo hovering on valve float with mostly old junk parts. and it ran its best et's at 41-42 total advance no race fuel just pump gas. cant say the timming was perefect to one little chain slop was in pay. i built that when i was 17 or so.

327_TPI_77_Maro

iTrader: (8)

I redid my timing map to the following:



I still have no detonation, and the car pulls even faster up to crazy high rpms now. I also added in another 10-15% PE fueling above 6000 rpms because I shift in the 6300-6500 range and have just barely maxed out the MAF at that point. The car runs awesome. I'm going to have to take the bottom end apart and put bigger rods in this thing, it seems to have unlimited top end power with this short stroke, big valves combo, and I'm afraid I'm going to break something.

funstick

got a difference in humidity between yesterday and today ? can swing the timming values up and down a bit. if your not maxing the MAf chance are you displacing the additional air volume you had before with fuel and creating a higher compression ratio with the additional fuel. again ive seen it work. i can think of a little 3.1 v6 i played with over 2yrs ago that just kept making power the richer it got until we bottomed the wb02. that not sayng for sure the pre chamber afr was really 10.0:1 but it should have been fiarly close. we did plug cuts and she was really rich. but it made power. i belive we wound up 33 btdc with a afr as indicated by the wb02 of 10.2:1 and it picked up significant tq everywhere. i also thik this low compression motor liked the boost in cylinder pressure. its been tunned this way for 2 yrs now and that was 38k ago and it gets run at WOT at ton.we like to race it stop light to stop light because civics are easy pickins. and 38btdc is still some heavily advanced timming but if its working good for you. my advice would be rent some dyno time burn a few chip in advance and go run some a/b/c tests to determine which tune performs better.

funstick

there out there. start hanging around the drag strip. the guys with the low dolar junk parts combos are always chasing 1-2 tenths with cheap fuel low compression huge cams etc out of more advance then youd expect. also dont forget nice heavy spring int eh ditributor can bring the timming on slowly towards the upper rpm band where its most useful.

funstick

really the surface area of the chamber is pulling heat ? hmm thats intresting. sure it doesnt have anything to do with the lack of quench for a contianed burn zone ? and the piston dome diving the chamber thats another great thoery i like it. problem with this one is the fact that the plug is located in the center of the dome.i think it has tons more to do with the general surface topgraphy of the chamber itself. it actually creates so much mixture turbulence that a stable burn takes a long time to get going. but then you could always call ray barton enterprise's and see what they say about it.

Grumpy

Yep. Look at the newer head designs, and how compact they make the chamber. While there obviously are other considerations (such as material), surface area does matter.

funstick

can tell you for fact newer chamber design are they way they are to do sevral things.if they were worried about heat rejection theyd all be running iron heads

optimze tumbel in the mixture process
minimize unburnt volumes for emission reasons.

hence why the ls1 variants the hemi and the newer ford engineas all have ring lands located very close to the piston crown.

Grumpy

You're now going way off topic, trying to *be right*.

Got a link to where I said chamber surface area, is the ONLY consideration?. If you can't find that then your *point* is nonsensical.

Going from design to production involves a host of factors, other then the 2 you listed.

funstick

im not sure where your gathering your info but when i ask the guys designing the engine the question you attempted to answer they give me the response i gave you. and if youd stop being lazy and check the physics of the model im proposing youd find it to be accurate. they are worried about topography of the chamber hence why every manufacturer now runs a flattop pistons and the chambers are more heart shapped with optimum squish. squish helps with mixture homoginization.if you have a piston with a raised dome or like the old hemi pistons you get 2 penaltys. excessive mixture tumble that creates and area so turbulent that the mxiture takes forever to burn becuase the fuel spins out to the side of the cylinder walls and you get an extremly heavy piston with a high unswept volume leaving excessive amounts of end gass's laying around. that drives up HC in the end exhuast content.

Grumpy

Lazy, what a laugh.
You ought to be glad, some other guys, and I were so lazy, or you'd still be looking crumbs about EFI works.

You want to argue, rather then read what's been put before you, it's sad seeing you turn into a poser.

I'm wondering if your poor spelling is masking a much larger problem on your part. You seem to also have even bigger issues with reading, or comprehending the written word.

BTW, reread what you just said here, and what I did earlier
(Not to mention the piston dome did an excellent job of dividing the chamber into two areas.)
about the Hemi timing, sad that it took YOU so long to figure things out.

Read, think, then reply. One really needs to do things in that order.

Grumpy

You've only demonstrated you know some of the words of the science with that posting. Try cut and pasting it, then take it to one of your friends and see what he says.

You need to understand cause and effect.
*****
area so turbulent that the mxiture takes forever to burn becuase the fuel spins out to the side of the cylinder walls
*****
Turbulence doesn't mandate that the fuel will be *spun* to the outside of the chamber.

funstick

no sense in explaining the real basic physics of the issue. go look at the cylinder washdown issue on fords 4.6 sohc 96-98 motors and get back with me once your done knowng it all.

funstick

your laughable at this point. the dome is not the issue. its not a divider type of boundry in the combustion process. the issue is the fuel acumulate on the cylinder wall from basically a cyclonic action being directed outwards. the heavy fuel spins out of the airstream colects on the cylinder wal and the air moves in. leans out around the plug. this is why you need so much burn time on and old hemi.

I last got tested in 1996 for reading comprehension for a college entrance exam and scored above 85% of the college professors out there. I agree my typing and spelling skils arent the greatest but im usually to busy working to sit around the house working on it.

again you still had't figure out the hemi issue becuase had you, you would never have made the rude reply you did. for some reason youve decided to argue with every post ive made in the last few months thats your choice. dont forget however your bread crumbs lead in circles.

i could go on to point out the numerous instances in which i've not only debunked what you've said on MAF systems but on other things as well and so have other members. your view on spark advance is archiac. every motor likes different spark advance. some more some less.

Ls1 chambers seem to like between 26-29 depending ont he chamber if you stick around 10-11:1 compression ratios

typicall closed chamber sbc chambers like 34-36 depending on compression typical 9.0:1-10.25:1

typical open chamber sbc likes 36-40 qwith low compression and 34-36 with moderately high compression. with race gas and a pop up 36-40 seems to be the norm.

big block chryslers like 34-36 with the open or closed chamber head. ive seen the new edelbrock heads respon well to 30-32

the new 5.7 hemi likes 34-36 dependinh on camshaft

the old 426 hemi like 36-46 depending on a myriad of things

the old 392 hemis the few ive played with like 36-38

the new ecotech engine 2.2 variety like 24-26 go figure pentaroof.

3valve honda heads work best a 30-32

16v honda heads vary greatly but seem to work between 32-34

now granted not all of these hold true but using reasonable compression ratios in a non forced induction setups these are the trends I've noticed for given engine familys.

I think the obvious truth is that your another internet guru. A guy spouting advice with no practical application knowledge. and while it seems you posess some thoery above and beyond most hotrodders , your far from what professionals deal with everyday.
again if you'd just listen to people instead of condeming the observations and opinions theyve formed and consider what are some obvious trends in internal combustion engine design and thoery maybe you'd learn something. Just like your water injection cooling the intake manifold. The real benefit or lack there of is that you totally missed the benefit and drawback of water injection, and while your using a G-tech( a cheap acelerometer with the accuracy of a bouncing ball) myself and others are working with top of the line equipment to diagnose,test, and develope calibrations so when we gain somthing its not only well documeneted it reaptably proven to work.

your missing the point. Ive seen this behavior before with the exact same cylinder head. I made mention of it and you start rambling about knock. You ever built a sbc with this head or that compression ratio ?? if you haven't then please just shut up.

should we go on about Genns gas mileage, Traxions 60ft time,etc etc etc and all the other things youve not only been wrong abot but been proven wrong and still you presist and offer not apology but more of your babling ridcule. when will it end. Im glad you have alot of dated SAE paper from way back. most of them dont apply for numerous reasons, and I'm not gona lay it out here. its a wasted effort.

and by they way to be honset none of your work has helped me in anyway. If i have anyone to thank for my EFI knowledge its tunercat and the host of factory engineers both EE's and ME's that i have as friends who have tuahgt me invualable lessons about contolr logic and algorythms. Never mind the fact that I've worked for sevral of the biggest names in fuel injection over the last 5 yrs. this ends now. Ill ignore you your ignore me but basically im sick of this BS.

guess it doesnt hurt ive been a driviability specialist since 1997 with a Master ASe certificate to go with it living in a State up until 2002 with IM240 emissions tesing. I was a state certified emissions repair technician working at a top notch emissions repair facility. so no i understodd efi long before i actually started working inside the box. thats why your dazzle people with bull**** never worked on me.

Grumpy

So now you're going to dictate to me what I should do?. Excuse me if I don't follow your order. Owww, since 97, wow, now I'm impressed.

Be sick all you want, it doesn't bother me at all, neither does your whining.

Vent all the moderators will allow, but it doesn't change a thing.

You're ridicule of SAE papers, just shows how arrogant you are.

Oh, don't forget this is DIY, not free advertising for someone doing chip work.

327_TPI_77_Maro

iTrader: (8)

Um guys, can we please keep the bashing out of my post? I appreciate the information I have obtained but don't want to look like I'm harboring a flame war here.

funstick

exscuse me ?? when have i been advertising chipping services ?

My ridicule of SAE papers isnt the pappers themselves but the dated nature with which you study them. try the more current stuff where alot of the phenomenon observed have been explianed and documented and fished out.

Venting all the moderators allow. what a joke. Stop acting like an *** all the time and maybe you'd learn something.

Grumpy

Your words.
*others are working with top of the line equipment to diagnose,test, and develope calibrations so when we gain somthing its not only well documeneted it reaptably proven to work.*
*aqll my experiences with 487x heads has been lots of advance 37-39 with low compression. for some reason the particular chamber is knock resistant. i think they have beter coolant flow.*
*i can think of a little 3.1 v6 i played with over 2yrs ago that just kept making power the richer it got until we bottomed the wb02.*
*A guy spouting advice with no practical application knowledge.*
While not a chip, related advertising:
*its gonna be around $200 and it'll hit shelves sometime in the next 3 weeks. It's been designed by myself and a EE from a tier one supplier.*
What might be called trade name infringement:
* i got a translator i need beta tested. hit me up via email if your interested. it fits an ls1 lt1 whatever maf you can find onto your car. so if your up for it drop me a line. its not a true beta anymore but we would like some durability testing done.*

Grumpy

Your words.
*others are working with top of the line equipment to diagnose,test, and develope calibrations so when we gain somthing its not only well documeneted it reaptably proven to work.*
*aqll my experiences with 487x heads has been lots of advance 37-39 with low compression. for some reason the particular chamber is knock resistant. i think they have beter coolant flow.*
*i can think of a little 3.1 v6 i played with over 2yrs ago that just kept making power the richer it got until we bottomed the wb02.*
*A guy spouting advice with no practical application knowledge.*
While not a chip, related advertising:
*its gonna be around $200 and it'll hit shelves sometime in the next 3 weeks. It's been designed by myself and a EE from a tier one supplier.*
What might be called trade name infringement:
* i got a translator i need beta tested. hit me up via email if your interested. it fits an ls1 lt1 whatever maf you can find onto your car. so if your up for it drop me a line. its not a true beta anymore but we would like some durability testing done.*
*a screened meter with the engineered and vlidated ducting system including filters is acurate to within 2-2.5%. if everything is in top notch condition. i know all about MAF calibration and the effect ducting has on it. spent some time working for pro-m racing a few years back doing development work on the gm meters. and a few others.

***how many customers you got ?***

***
My ridicule of SAE papers isnt the pappers themselves but the dated nature with which you study them. try the more current stuff where alot of the phenomenon observed have been explianed and documented and fished out.
***

So while the original data is good, the why *I stufy them is wrong*?. Take a deep breathe, and try that, again. You might even try rereading the *new stuff* to see what the truth is, try a gander at Corky Bell's book, and see how his mistates things, for a clear example of *new* just being *hype*.

All I started with is a reminder about too much timing, and fuel masking a problem, and you've go on all sorts of tangents about nothing even pertaining to the original subject.

Yes, your venting

funstick

to advertise n this board would require

1. a formal sponsorship
2. a willingness to due mail order chips. i have or never will do that
3.a location that i disclose as well as pertinant contact info.

im telling you that i have verifiable euipqment to validate work and you go ranting about fuel masking an issue. which by the way you never came out and said. in fact theres a good blurb about spark advance in this months hot rod magazine (pick up a book)big block chevy buildups refering to spark advance and stroke lenght vs bore size and its affect on spark advance

i have asked people to demo a new product i am working on and have not offered it for sale. agian if i wished to advertise here id contact dirk ( i have his email) and i pay the fee and put such posts in the apropriate area.

your issue is still the same. as soon as somebody with experience with a combo etc speaks up you start telling them there wrong. check yourself stop checking me.

as for corky bell i have publicly stated on numerous occasions on tgo and other places on the net that hes wrong on a few things but thats a matter of perspective and application.

explain to me why an ecotech that in development that ive been checking out for a while now lost power with a long tube 4-1 header over a shorty. its not a cam timming issue either. if you can do that without observable data then you can tell people how much spark advance is to much. and i personally think you think anything over 30 degrees is to much.