SKiddell

IMHO You could do alot worse than look to the Japanese tuning scene for ideas, anyone that runs big rev 340+ HP NA engines (credible dyno figures not some back yard shade tree setup)running 11 second 1/4 miles has got it right. On many of the engine pictures I have seen ATI seems to be very popular. I have used one for many years, not cheap but spares are readily available.

I can thoroughly vouch for the copper gasket route. I use a 1.4mm copper gasket machined to fit 88mm bores on a P90 head and N42 block with 12:1 comp. When I first used it I had to ease it very slightly with an air die to fit, heads been on and off so many times I have lost count, just clean the gasket up with wire wool (anneal if necessary) spray with Hylomar gasket dressing and re fit.

I have got a well skimmed E88 to run at around 11:5 to 1 static but thats on UK fuel (99 RON) I accidentally ran it on 95 RON and it took 2 pistons out in a heart beat, cut through the ring lands like a blow torch. That E88 Head was skimmed down to 106mm thickness, chambers were down to around 35cc's with an 86mm bore and a 1mm felpro gasket(can't remember exactly it was a while ago) A lot depends on what the dynamic compression ends up (static compression combined with the cam profile etc) I have seen a "theoretical" high static compression motor that has run well on pump fuel due to the cam profile EG Schneider stage IV (which has bugger all lift on overlap), conversly I ran a 320 duration cam that had over 5mm of overlap lift which was a pig. Just my £0.0123693488 worth

Not all stainless grades are non magnetic the term stainless is more a generic term used for steels that have very good corrosion resistance (usually have high chromium and nickel content) To be completely non magnetic a material requires a magnetic permeability (MP) of 1, some of the high austenitic steel grades reduce this magnetic response to a value where it is not easily detected and thus appear to be non magnetic, however this 100% austenitic steel is often not practical as some ferrous component no matter how small is often present, typical MP numbers for austenitic stainless steels are in the region of >1.05, super high grade austenitic stainless steels used in research environments, MRI scanners etc. get as low as 1.005. Martensitic stainless steels have noticeable magnetic properties but are still classified as "stainless" as they also have high corrosion resistance.

Agreed Tony however like a lot of things there is little (useful) written about it so one has to discover it all over again.

Echoing what Leon says, the overall runner design will greatly affect the characteristics of the engine and as such its difficult to work at a this level without knowing the intended purpose (Road, Race, Rally) or induction method (Carb, TB, Forced) and the exact specification of the intended engine. Just as background info From a recent rolling road session we experimented with different ram pipe lengths on an individual TB NA L6 for a whole day, the results were astonishing, long pipes gave great low to medium range cylinder fill and thus great torque (252 ft/lbs at one point which is a BMEP of over 200 and a VE of 111%) but the car ran out of steam around 6700, shortening the pipes brought the low to mid torque down a little (we settled at 242 ft/lbs ) but lifted the peak power up to 7300. The worse results were for open ram pipes and no pulse plate this absolutely killed the power curve (theory was…out of phase reflected pulses from the inner body work), we gave up on pinning it down as the results were so poor. Of course these results were a net result of changing the overall tract dimensions resulting in velocity changes, possibly enhanced venturi effects and pulse wave tuning.....this experiment no doubt would have delivered different numbers but probably the same overall "effect" on Carbs and gives a little insight into just how critical the dimensions can be, ….I guess what I am saying is that you need some idea as to the required dimensions and then they will influence the design On a side note would really like to try short body TB's in an attempt to get the overall tract length below 300mm. Now you watch TD or JC come shoot me down

Same here really I have not been able to find rhyme or reason behind the alpha numeric codes and have noticed significant differences not just at the main bearer pad but on the under side webbing (to the point of fouling on the spring retainer in the worse cases) and the offset at the lash pad end skewing the wipe pattern (on the cam lobe not the rocker pad) left or right by up to several mm. I have matched up a number of "codes" but they still seem to have these differences therefore the codes must mean someting else (batch, date, time ??) Alan (T) if your around, or any one else do you have any insight as to this coding, any info would be greatly appreciated.

When we built my steel motor last year we took the opportunity to measure the wall thickness in several areas across all bores (ultra sonic unit), my plan was to only go to 88mm on a stroked billet crank, and boring out to this left between 150 and 160 thou of wall thickness. Personally this is a minimum for me as I am running around 12:1 compression and didn’t want any barrelling of the bores. Recently it’s made close to 290 FWHP on the rolling road with 242 ft/lbs of torque (not bad from a 3 litre that has to be driven on the road to comply with club rules), with that I don’t see the value of scraping out the bores further for what would amount to small power gains and potential reliability issues (personal choice) Re sleeving (Tony D) another block we did ran into porosity issues at 88mm and we had to sleeve one cylinder (fast road engine), the company we used did a cracking job and its hard to see why its not done more often (cost sure). If I had the budget and needed to go to a big bore then I would sleeve the whole damn thing given half the chance, and leave nothing to chance, nothing to stop you using some of the more exotic materials on the liners and rings then.

Z-Ya Out of curiosity, how deep are your retainers and what thickness pads are you running I have seen a pad "skew" in a shallow retainer.

Couldnt possibly say either way:mrgreen: On the back plate we included a reversed lip that the clip "hooks" into. The clips are secured into the main box by securing plates and nylok nuts....I then use aluminium foil race tape over the top, once bitten and all that.

I run 65 mm carbon fibre stacks under the airbox, clearance is fine. The carbon fibre air box does a good job at keeping incoming air temps down (around a max of +15 degrees whilst driving but more often lower) due to being connected to a cold air feed that goes through the rad support panel to a drum type ITG foam filter. The CF backplate is cut out (6 x 50mm or 2" holesaw) to sit between the stacks and the carb bodys (ITB's in my setup) the stacks then hold the backplate in position, stainless overcentre clips then hold the airbox onto the backplate. Its been on the car for 2 years with no issues, doing around 150 drag passes, several really hard track days and umpteen thousands of miles on the road.There are a number of cars in the UK using the same solution in either glass or CF. I'll try and post some "install" pictures I sell these units at cost (materials+labour) although the high dollar to £ at the moment would propably make the whole thing impractical. Good for me buying stuff at the moment though:mrgreen: We started making these after a very VERY bad incident with a $300 aftermarket, black, non flowcoated, fibreglass unit spat a rivet into number six inlet and nearly trashed my engine:fmad: the rivet pulled trough the thin glass and trapped itself under the inlet valve, the valve stuck open (partially) and the lash pad popped off its seat, the rocker broke, the seat was mashed and the valve bent. They shouldnt have used rivets unless supported correctly and riveted the right way round The makers didnt want to know about a replacement so we set about a redesign. I won't mention who they are as thats bad form. PM me for any other details

You could get one of these I supply them (I own the molds and a collegue/friend makes them) to guys in the UK. Full carbon fibre (or glass if required) colours possible. comes with 6 x stainless over centre clips and lip seal Can be connected direct to 80mm cold air feed or cone filter.

Get out of it, turbo's are for people who think turning a dial is tuning:biggrin: (good job I'm 4000 miles away Ha).

just Newtonian Physics, (He was the English Guy with the apple yeah) I agree its not spot on ...never said it was..but hey claiming to do a 13.9 with no timing slip is hardly accurate is it bud The above formula will give you a reasonably close figure on what your setup can achieve...not what it will achieve Err Duhhh!!! A coefficient by definition is a constant not a variable. looks like you made about as much contribution to this thread as in building your engine (s) Anyway lets respect the thread owner and other interested parties and keep it on topic, I for one apologise for taking it off

Not if you don’t have a timing slip you didn’t, so far you only have a slip for a 14 second run so 14's is all you got, you can beer-talk all you want but until you can repeat it you’ve got squat. I once got a 12.7 @ 111 MPH (with a ticket) but I don’t claim it as it was a "footed" run, IE the track marshal couldn’t be bothered to stage me properly and fudged the light with his foot. I can however reliably run low 13’s (18 runs this year sub 13.5, 40 runs this year under 13.8) so I can safely claim, low 13’s nothing more. I also don’t get why people think we should all be running 300HP, to get anywhere near 100HP per litre is very tricky and costly…the pro builders on here (Braap, 1 Fast Z etc) will tell you….why no one is listening to them God only knows. And regarding I’ll treat this statement with the contempt it deserves, it clearly shows your total lack of understanding on this matter, professional and amateur drag racers have been using calculus for years. Clearly you are neither, so how can you speak with such implied expertise See http://www.crew-chief.com/ http://www.web-cars.com/math/quarterjr.html http://www.altalabinstrument.com/software.html The NHRA even do correction charts for altitude Summit Racing even have a log book available so you can log the weather conditions to use later in your calculations A good friend and mentor of mine who used to run in “Pro ET” a UK race series (regularly ran 9’s so he knows what he is talking about) first put me on to this and I use Quartermaster to plan out my entire race season mods.

12.8 with a 3.1 is way impressive indeed:eek: , a Diablo runs a 12.4....and a Murcielago runs a 12 dead but they need around 500+HP to do it You clearly have no concept at all of power to weight ratios by saying There is a quantum leap between a modest 13.9 and a 12.8, thats over a second and at those speeds that over 10 car lengths. So until you can do it, dont knock it. BTW Bubble....You can use high school physics (mass x acceleration etc) to calculate with surprising accuracy your expected ET and trap....Newtons 3rd law of motion and all that. Drag racers use programs like Quarter master etc to calculate likely 1/4 times given certain weather conditions, ratios, weights etc.. when I plug your numbers in,, (unless you are making nearly 270HP at the fly), they dont add up. Maybe your timing slip could shed some light on it? Anyway apologies for hijacking an interesting thread. I would be very interested to hear from those running individual TB's what ECU's/injectors/duty cycles/fuel pressures/headers/collectors etc people are running, has anyone experimeted with runner or trumpet lengths or tapered throats. maybe some of you have some dyno plots you would be willing to share. So many questions:ugg:

Fine but if you want to talk injection, heres one we made earlier (18 months ago:burnout: ) [/url] Proper throttle bodies

OK but I have seen plenty of "quick" runs -- we even have video of a 300ZX TT in stock tune apparently running an 8 second pass --- due to faulty timing gear:burnout:. I am more interested in the 60ft, 330ft, 1000ft data as the ET and terminal dont match typical normally aspirated times/speeds. (I have 20 years worth of drag data on Z's if anyone is interested including a genuine 8.46 1/4 done by a BBC powered 280ZX on gas in Pro ET class) For a 2700lb car to pull a 13.9 it would take around 250 - 270 at the fly and mildly tuned NA L seiries engines dont do that easily, so it would be interesting to see any dyno runs etc to understand what else Mr Guniea has done to the engine Cheers

Hey Bubbleguinea You still havent posted up the timing slip of your 13 second run that I asked you for ...... nearly a year ago (remember my PM's:wink:) No slip, no time bud:wink:

Please don’t mistake these posts of mine for anything other than inquisitive banter, I am only seeking to understand the reasons why...not seeking to prove people wrong. But in my previous post and according to the octane rating methods used in both countries, 91 octane is equivalent to the 95 or so that we get here (standard) and 10:1 compression ratios on 95 RON happens all day every day. I fully understand that, but the guy "could" have be from anywhere in the world so the advice may have been technically incorrect, as it happens he wasn’t. My point being that people all over the world read these forums and take advice from them. no "apparently" about it, its a fact but certainly no big deal. I hear what you are saying and I cannot deny that you have the advantage of living eating and breathing the American Z tuning scene so ultimately will have 100% more knowledge about what works and what doesn’t......in the US, but take for example the cylinder head you worked on recently for a fellow club member (beautiful port work), this is destined for the UK and according to your specification has a 55cc chamber volume (more or less stock size for a P90) in the UK we use the P90 and the first order of the day is to shave the snot out of it, then shim the towers (I prefer the Kameari tensioner myself ) just to get the compression up, hey you did agree that if possible, compression is a good thing I am curios as to why you retained the large CC when it will be used solely in the UK, in an environment where higher compression ratios can be achieved. Like I say I am not seeking to flame or dis anyone, maybe you have found ideal cams to suit lower ratios, producing good dynamic ratios, maybe you have found compromises in the valve size and geometry or exhaust systems that overcome some of these issues, in the UK we only have 200 240Z's so development is done by only 1 or 2 people where as you guys were fortunate enough to have 1000's of the darn things.

BRAAP Please don't take this as in any way offensive or aggressive but I am a little confused. Else where in the world, certainly in the UK, Z compression ratios of 10:1 are fairly common place and I know that in Japan where there has been more L series development than anywhere in the rest of the world put together, on serious L series engines, high compression is defacto. Personally, I run 11:1 on an 2.8 litre using standard 95 RON fuel with 34+ degrees of advance and making almost 260Hp at the fly....is it about to fall apart into a knock induced early grave? well some 60 or so 1/4 mile passes (15 of which were under 13.5) and nearly 10,000 miles of road use says no. Further more, in a classic race series in the UK (HSCC) there are 4 240's running, along with at least 2 hill climb cars in other events... all of them have 11:1 or greater ratios, one 240 has just placed 3rd in the Spa 6 hour endurance race (see http://www.zclub.net/forum/showthread.php?t=7564&highlight=spa) which was certainly running greater than 11:1 .....and significant advance. I know this to be true as either the owners or the engine builders are members of our club. Now I agree that more often than not they are running as high an octane rating as possible (97 or so) but if you work it out, this is the equivalent to your 92 AKI rating (different systems of octane ratings RON vs. Average RON+MON etc) So that goes someway towards factoring differences in octane rating out. You also mention Compression is known to be a tried and tested method of increasing power output, particularly on the L series. Once, without thinking I swapped a 1mm 89mm dia head gasket for a 91mm HKS steel, (inadvertently dropping the compression by 0.4 of a point) on the dyno the engine showed a 15hp power drop off, we tore the engine down and as matter of course replaced the gasket, using what we had left which happened to be a Felpro 1mm @ 89mm, we then re-dyno'd it and hey presto normal service was resumed.... You could write this off "shade tree" mechanics but to give UK engine development a little more credence, in January I know of at least 2 all steel 3 litre engines being built, using a custom designed 83mm stroke steel billet cranks [/url] lightweight Carrillo rods and custom forged, short skirt pistons http://www.zclub.net/forum/attachment.php?attachmentid=2430&thumb=1&d=1161459548. One will run triple side draughts and the other individual throttle bodies. Both these will be running in excess of 11:1 on 97 Ron fuel (approx 92 AKI) We even have one guy seriously looking to have aluminium L series blocks cast. Yes I agree that excessive compression can be extremely damaging but if spark and mixture are controlled, quality components and machining used, then why not run 10:1? many factory models are in excess of that.... now if we want to start talking dynamic compression well that's another thing all together.