Tony D

That header flange is NOT the same thickness as the stock intake flange! If it were, you wouldn't have to grind a step in the washer!!! The EFI and the Carb flanges are THE SAME thickness. You can swap EFI onto a head with a carburetted exhaust manifold withotu changing the washers... because of this! Cannon may not be casing proper thickness, but Nissan Flanges are damned consistent on their height installed. The stock flange is close to 12-15mm thick (REGARDLESS OF EFI OR CARB!), what you have there is maybe 8-10mm thick at tops. Hence the need to grind the washers. Look at the proximity of the weld to the edge where it clamps as well---if the washer is on the weld bead it will be hard to clamp, or fit the nut on it. Pacesetter does NOT (as far as I know) use the proper thickness flange on their headers---never has. Typical American Produced header flange, used the same thickness as they did on the SBC. Some of them would have tabs of scrap welded on top from punch press operations which made the flange 1/2 thick, but placement was iffy... Clamp with flanged bolts to keep decent press on the bottom of the intake manifold. Using stock nuts and lockwashers you will run the risk of bending the cut down items. Regardless of how long you have been doing it, it's a result of someone manufacturing the header flange too thin---a correctly manufactured flange (such as on a Trust, Greddy, or now MSA) will the identical in thickness to the stock cast iron manifold, and will not need alterations to the washer to 'make it fit'... IMHO, this is a step you should not have to do. For what they charge for the headers, they can put the proper flange on it! Others do, and have done so for over 35 years now!

Well 1650 for T.I.T. isn't really out there, if you have the valves to handle it, and the turbine wheel is of proper metalurgy. I know our stationary engines which were 'lean burn' natural gas ran 22:1 AFR,s and a consistent 1100F T.I.T., which was identical to the EGT found on the exhaust elbow. T.O.T. would vary, but was usually consistent being it was a stationary, fixed speed, variable load engine. Turbine Delta T was a derivative of the load being applied to the engine. The more load we had, the higher boost we would run, to it's wastegated point, at which point the Turbine Delta would start increasing to it's normal point near full load of 2100KW (which was around 15% overloaded...) When I started looking at Gasoline-Fueled rich burn engines, the difference in EGT was something I had to get used to... the Rich Burn Models of our same engine would be around 800F EGT!!!

See the EBP unused never installed for $8, or new in box for $89, not bad at all... My recollection of the results are fuzzy at this point...who knows what happened.

You can borrow mine, it's certified duct tape! I'd sell you some... Oh, I see donating members are the only ones allowed to post classifieds now... Cool. i'm going to donate so I can sell my certified duct tape to people far and wide. Did I tell you of the time I wore an onion on my belt? 'Twas the fashion at the time, and we called Turkey's "Walking Birds"... Hmm that magical 30 post count doesn't mean much now. Good. I digress...

"The smaller valves were deemed to be an advantage (by me) over the stock L28 valves which are heavier... With some attention to this, a very high revving valvetrain could be achieved on the E30, coulped to a bigger cam profile to take advantage of this rev-ability, which was also deemed acceptable to bleed of some of the cylinder pressures at low rpm's which could have thrown the engine into detonation." Nik the idea that 'L20A Valves are Lighter and therefore will rev higher than heavier L28 Valves' This L20A is running 'heavy' L28 sized valves, and our shiftpoints are WELL below what we have actually run the engine up to testing valvetrain stability. We have not floated or lost valvetrain stability yet on our engine... And we have stock, unlightened, un polished, generic nissan rockers on this engine as well... Don't overthink this stuff...

What are those ITB's? From a Bike? I was looking at stealing BMW ITBs since they sit out in the open and are rubber mounted, so with my Leatherman it would be easy pickens in most European Cities when I visit... But if you can give me a better thing to target (and it looks like you can) I'd like to know specifically where they came from!

"This is SPARTA"---did a quick handover to another engineer, and hopped a plane to Seoul... one day, pete, one day... The Japanese politely told me they will be doing the two weeks worth of work I planned on doing this month at the 'end of april' Yeah, MSA time? I think not, Dreamaru-San! So that means I will be home in about two weeks (huh, that's what I thought in Sparta...) So that is the plan. i may have some JeffP torture photos on the phone or on the laptop, maybe those will work. If I can find them...

It's 0115 at 'home' in SoCal. But I'm not there.... I'm in Seoul Korea... where it's 1815. And being in Denmark you're only a half a day behind me... If you have an E88 Head, I'd likely use that. It's dependent on if it's an L24 E88, or the L26 E-88. Some differentiation of the combustion chambers. Unless you are willing to spend the time to make the chambers you want by hand...the E30 will be a lot of work. For someone making a full on race head, an E30 may result in some more 'labor' time for hogging out ports, compared to an E88 or N42 head... but you won't be welding on the combustion chamber, and since you're changing to big valves in that case anyway it ends up being a net savings using that head. Plus, no welding warpage to worry about!

Putting in larger valves without the corresponding intake runner diameter increase? That seems like a lot of work to just strangle it. The combustion chambers are going to be what? Maybe 40CC's? On a 458CC bore? 11.45:1 compression... I think bigger valves cutting the chamber larger will knock that down minimally, but that's pretty high for RON gas... 95 R+M/2 might fly in the heat, but RON only may be a tad pingy...

Casting number is really a more a matter of what was available to the builder than anything else. With the work needed to make a proper head, it really won't matter much which one you start from...

Jeff forgets how obsessive he can be at some times... Trust me dude, you were obsessed with EGT's and the number of 1250 for quite a while. Remember we should have had the map done in 45 minutes (in retrospect) but we both got hoooked (obsessed) with doing something else and just kept making run after run... Afterwards we can deny our obsessions, but watching the runs from the 'outside looking in' obsessed sounds like a fair evaluation of the state of mind at the time. The key is to try to not let that happen, keep objectivity, and work using all the information available towards the ultimate goal of power to the ground, and under the curve. That Ford EBP sensor sounds like a neat little gadget, make a nice insturment loop and hook it to an open channel on the MS for a datalogging point. Thanks!

I'll have to send the link to this post to Andy Flagg. He's been running a Caddy forever in an S30. What intake is that? Andy used an adapter for a ford 460 because at the time he couldn't find a cheap aluminum 502 intake. Running the car for the first time way back when Brotherhood Raceway was open in San Pedro (91?) he went out and made a first pass at 11.72 or something. Track officials started giving him guff for no helmet, no cage, no nothing... "HEY MAN THIS WAS MY FIRST PASS EVER HOW DO I KNOW WHAT IT WOULD DO???" I put a Toranado 455 Drivetrain in the back of a VW Beetle, only because i'd seen it done in a magazine and thought "hey that looks cool!" went over well back home (Michigan)...

So now we're talking about aged suspension components and not new ones? Talk about schizophrenic... I understands Frank's Duct Tape comment more and more. Yes, use duct tape. It's superior in it's abilities to repair anything, anytime. I'm still waiting for the photo of that super secret IMSA inspired A-Arm Suspension Nissan Installed in those Turbo ZX cars with 1000 Hp. I mean, since it was so terrible, and couldn't ever do well in competition with such a terrible suspension they had to change it because in the first post 'racing is something totall red herring' because they changed everything. What was that word again? "Schizophrenic"? Yeah, that's the one! The prediction unfolds as usual.

Same as ANY L-Head. The 'clean slate' refers to the ability to simply REMOVE metal to give you a profile that you want as opposed to having to weld in metal to close combustion ports, etc... The biggest problem with an L is getting a quench head configuration, and most heads fully built will have the CC welded and the head redecked. With the L20A head, you don't need to weld the head, and you don't need to deck it and loose lifetime on it, you simply start reshaping the chamber-since it's so small, you are virtually unlimited in what configuration you can use. Everybody changes the valves anyway, so that's not even worth mentioning...

EGT is universally taken at exhaust flange or port. <CENSOR BOT DICTATED EDIT> T.I.T. and TOT are a different reading, meant to check turbine efficiency. Now some misguided people will refer to <CENSOR BOT DICTATED EDIT>T.I.T. (Turbine Inlet Temperature) as EGT, and technically it could be called that, but tuning to a temperature at turbine inlet is total folly indeed! EGT is at/in/near the exhaust port as possible by the probes being used. Anthing other is another reading. I know of one person who went from 17:1 to 10:1 puking smoke out of his car and complained he didn't see a change on his EGT Gauge (twin gauge of good reputation and fairly accurate when the thermocouple was checked!) Helps if it was someplace useful, and with an AFR gauge, this engineer didn't have the common sense to realize (like the guys in the SDS article) that the gauges were obviously wrong, and to quit using them and follow the instrument that is tracking the physical symptoms that the engine is displaying!

I forecast another pointless Rolling Parts Hatefest coming on, with no good justification other than his misguided ire... I was unaware Datsun changed to the secret double a-arm suspension for the racing ZX's. Seems to me they ran the trailing arms just fine. And like Mr. Poll polielty mentioned, the BMW's have similar (if not identical in makeup) rear suspension and do just fine in both stock and racing forms. Sadly, this obviously has been discarded as logic will have nothing to do with any post from this point onwards...

"Inspection Nazis" in Japan couldn't care less what head is on your engine. Shaken-Sho ONLY verifies block number. If you have an L20B in there, it passes, because it's an L20 (A)... Same for Celicas and Trueno's. I knew plenty of guys with "2T" or "18R" engines, which clearly were originally SOHC or PUSHROD engines that did the 2T-G conversion, or 18R-G conversion (or for the more arcane, the 2T-B or 18R-B which were dual two barrels with progressive secondaries.... or even SU's...) As long as that block said 2T, or 18R, it didn't matter that the engine was now a 145HP 18R-GR from a 1973 Corona GSS or the original 18R-C that was in there originally. Ask me how I know. Ask me which car I lost my license driving... As I have said over and over: head casting flow numbers are pretty irrelevant, you're going to rework it totally if you're racing anyway, so get the best one with the least corrosion. Case in point: the engine we have here! I would disagree with the octane selection advice given earlier. For a race car I would NOT 'run the least octane you can'... If I could get 120 octane for the class and legally run it, I would. Octane is margin. If you play games with cheaping out on your fuel, your 'economy' will soon be rewarded with a bill for new pistons, and possible a rod, or a block, etc etc etc... At Bonneville, we are restricted to running ERC fuels, as they are a 'sponsor'---guess what fuel we tune with? What we run on the dyno? Sure, we can make more HP on better VP fuels while running at El Mirage. But many who do that get sad wakeups when they get to Bonneville and have to run the ERC and then start guessing what changes they need to make to keep their engine held together for at least 10miles at top rpms....

Argh! Someone else who bought a cheap header with the el-cheapo flange. Good luck with that. See my comments on triples in the other post regarding these washers.

Couldn't everything they mention be accomplished with bushings with holes in a different orientation than the previous model? It can alter the K Member It can move the pivot (pickup) points on the trailing arms. Perhaps you need to look at the bushing part numbers compared to N/A cars. Know it alls will say 'the turbos got stiffer rubber that's why the bushings are different'---but did they notice a hole that is bored 2mm differently than a N/A bushing---especially when the arrow signifying 'front of the car' remains similar? I mean, if the bushings are concentric, there should be no orientation difference. And even if concentric, hollows in the rubber will change which way the bushing allows deflection easier than other directions... Just sayin'....

What the gist of my post was getting at was NOT the EGT. Jeff seems obsessed by EGT, as do others, but what my point was is that there is no 'magic number' for AFR. People tuning to 11:1 after torque peak likely are running rich and loosing power. The last post from the SDS link is pretty good in that they are saying the same thing I am: Power Output and AFR are what the primary items that dictate tuning of the engine. If the EGT is too high for materials at peak power output, either improve materials, decrease power output, or figure out why it's too high. We were not (at least I wasn't) correlating power to EGT, Jeff didnt like how hot the car was going, and he was trying to tune to someplace in the 1250 range as I recall... But ultimately the result of the days' experimentation was that setting AFR's at some static magic number was only good for a BASELINE TUNE. After that, pulling AFR gave us more power. That it lowered the EGT's IMO is coincidental, but can partially be explained by some of the graphs and charts already posted, all are well rich of Stoich, but running towards a leaner mix resulted in more power after torque peak so like the SDS guys said, 'that's all that matters'. Getting hung on instrumentation readouts may be good for an indepth analysis and ultimately finding out why something happened. But never loose site of the functional result of more power. The thing to take away from my post was that AFR changing after torque peak (pulling fuel) made more power than adding fuel. And that coincided with what the SDS symptoms in their '17:1' example. Regardless of the AFR, once they added fuel and it lost more power, they pulled fuel, and made more power. It's if-then and-or logic when on the dyno. If you get bogged down with what the instruments are saying when the are doing exactly opposite what the power pulls are telling you, then skip the instruments---they're wrong. Most people set or tune to get an AFR like it's a magic goal. "I'm 11:1 and heres' my pull results." The purpose of the dyno is not to tune your car to identical AFR in all the load cels, it's to get the most power under the curve---and that will require different AFRS in each load bin. And I was simply trying to say 'leaner in the upper bins past torque peak' should be something you want to try if you are at 11:1 thinking this is giving you maximum power. Likely, it is not!

DONT! Thinner washers are prone to flexing, and can cause vacuum leaks! What I did was go 'pick of the litter' from cars in the junkyard, every time I see someone who has pulled manifolds, I harvest those thick washers, and grade them into same thickness and flatness. It helps when they are uniform. Turning them on a lathe out of a piece of stainless round stock with a parting tool will make some that look nice, but not be any more functional than the OEM bits. The biggest thing I see is that american header manufacturers (until REALLY recently) simply refused to buy the proper thickness flange. There should be no big 'angle' these washers need to bridge. If you have a cheap header with tabs of scrap welded on to make it even with the intake flange thickness, drill the hole bigger in the center. It will keep the washer from binding adn stressing the stud while in operation. It will also help them clamp somewhat better, but because the cheap flange is so much different from the height of the intake manifold, they simply won't clamp effectively. Weld on more crap to the header flange---or better yet, buy a new header with the RIGHT flange thickness---they're what? Like a couple hundred bucks. I just bought one that was coated, and it wasn't that outrageous. Bought it kicking and screaming, and only because my stock manifold was trashed.... Because of the sourcing of the flange (which is now cut properly) the old problems with nut clearance and washer binding are greatly diminished. Not that I EVER had any problem with the JDM headers---they went on and off like OEM cast peices. They had a proper thickness flange, they had a proper header washer to tube clearance... Easy on and Easy Off. But those thick washers don't flex AT ALL, and that's what you want when clamping things. I don't re-use studs. When the manifolds come off, I get new studs. Now, having JUST replaced a header on my SU's let me tell you, that last set of studs was on there for 10 years, and 60,000 miles. So what was the cost per mile of a new set of studs and flanged nuts? Which brings me to flanged nuts. I use them. They have little serrations on the bottom that really bite nicely into the OEM washers, and really work to keep them flat between the flanges. I got the tip from JeffP, and singe using them, I'm sold on using them. I don't put lockwashers on there any more. Serrations hold fine, flange spreads out loading so the washers should clamp better. And yes, after 10 years, and 60K miles I replaced those as well. Do I really have to make the comment about being incredibly cheap if you are re-using exhaust hardware? Except the washers. Everybody uses those over. And since I cut mine on a lathe with a parting tool out of stainless steel some 25 years ago and haven't yet run out of my 'washer box' of junkyard examples let's forget about reusing those---that one is O.K. The nuts, lockwashers, and studs are disposable. BTW, if you don't use lockwashers, and use the flanged nuts, you have more thread engaged positively and they spin on nicely to stabilize the washer before you drop the intake down on top of them... You guys do put the washers and nuts on before you lower the intake manifold on, right?

MACHINED? Get yourself a big belt sander, steady yourself, and lay it on gently. A reference jig helps... Or on your layout table, rubber cement down some 80 grit sandpapaper, and start with the 'figure 8 lapping' motion, it will be flat soon enough. Is this a new manifold you bought, or secondhand? If new, I'd simply call Gary at TWM, but without seeing the gasket face on the manifold, I can't tell what has been done to it previously. Those manifolds are machined AFTER casting, and should be flat. I can't imagine what would do that kind of warpage short of someone taking my first suggestion with the belt sander and not being very careful...

I was forced to install headers on the daily driver turd, and was really impressed by the header blanket sold by MSA. I wrapped my old set of headers, but this time put the blanket on instead using their little clamps and safety wire. There was PLENTY left over, so I could wrap whatever else I wanted for 'double protection'---but the headers are not causing any issues that the stock manifold did on my SU's---much different than my experience with the header wrap I had on another car. This blanket was pretty heavy, and seems to do a VERY good job keeping header heat where it's supposed to be: next to the headers and not in the engine bay. It's a PITA to get on, but it seems to work superbly!

If you add a balance tube, make it REMOVABLE. You CAN NOT synch the carbs with one on there! What I noted on my turbo car was that without the balance tube, I could literally feel every cylinder hit---a bery 'bumpy' acceleration. Once I installed the balance tube (constructed out of brass T's and 1/4 and 3/8" fuel line) the acceleration was turbine-smooth. Made a REAL difference in the way the car felt on boost on throttle. In N/A mode, it seemed slightly smoother as well. WOT or not. It definately helped with the idle. While the statement that the carb in triples is "on" for one pulse, and "off" for five---the balance tube changes that, and you can literally run the car off any one of the barrels. It makes a big difference at the lowest engine speeds where every cylinder sucking slightly from an offline runner keeps air moving through the carb barrel helping transient response when the throttle is opened. As best as I can explain it now...

Sounds like you have float height or fuel delivery problems from the right turn stalling and the pinging issue. As well as possible vaccum leaks---check all that first. Those 30mm chokes are for down low driving, that puts the mains on line much earlier than power sized chokes would, pinging without knowing what region is a guess, see comments below about recurving the distributor. Your mains are one size smaller than what I used on 45's to make 280+ HP, so they are likely well in hand for total fueling...if your float bowl is maintaining the right fuel level. The stock mechanical pump should be more than enough for that setup. If you have problems with the throttles returning to match the idle stop screw, it's not vacuum doing it, did you check synch barrel-to-barrel on each carb to check for a bent throttle shaft? They should be open about 0.003-0.005" (use a tapered feeler gauge when you have them off) for initial setup, this works well for setting the linkages to the right length, and then you can move the idle speed screws to appropriate idle speed. They will NOT be 100% closed, if they are, you will not idle at all, and will run the 'chop throttle stall' almost like you describe. YOU DON'T STATE WHAT CAR YOU HAVE, but if it's not a 240Z, and you have the BIG return line like on a 260Z, without a restrictor jet in the return line you will likely dump FAR too much fuel down the return and the carbs will suck down the pump supply too quickly. Put something like a 0.050 or 0.065" jet in the return line and see what your fuel pressure at the carbs does under load using a 't' and a pressure gauge taped to the windshield. Free Revving will tell you little to nothing. Universally, I've traced new conversion with 'rough idle' to low idle speed, up your idle speed to at least 850 or 900. If you are using a lightened flywheel it will react differently than a standard flywheel. Without a dashpot to hold the carbs off idle, you simply go rich (no air compared to the fuel now suspended in the runners) and the speed drops. The idle speed raised from stock to slightly below 1000 will make this less of a concern. You didn't say it 'died' just that it dipped and then rose back up---indicative to me that your idle speed is not high enough. With a cam, an idle speed of 1100 or even higher may be dictated. It's not uncommon for large cams with no vacuum to have to idle as high as 1700 rpms to keep the engine smooth enough that it won't die. The same car, with the same cam, but with EFI on 45mm ITB's would amazingly idle as low as 450rpms---so low you could swear you could count the pulses coming out the open headers! I don't think anything is wrong other than your idle speed is set to low. It's a common mistake. Even on hot SU's this is recommended. RPM's make vacuum through a carb (as will ignition advance, which should be recurved for use with Triples---I run 15 initial with no vacuum advance on most triple setups I do), and that keeps them functioning. On the vacuum note, if your valves are not adjusted before you synched...tsk tsk tsk! Back to square one, adjust those valves and recheck synch, THEN set the idle speed and idle ignition timing. Good Luck!