Mycarispurty Posted December 16, 2009 Author Share Posted December 16, 2009 Man, I remember when I started this thread. I was just curious what kinda power people made and personal stories of about them being fun to drive...now all the big players in the Z community with degrees in rocket science engineering are in here talking about stuff that's way above my head lol Quote Link to comment Share on other sites More sharing options...
KillerBjt Posted December 16, 2009 Share Posted December 16, 2009 Man, I remember when I started this thread. I was just curious what kinda power people made and personal stories of about them being fun to drive...now all the big players in the Z community with degrees in rocket science engineering are in here talking about stuff that's way above my head lol And thats why i love Hybridz!!!!!!!! Quote Link to comment Share on other sites More sharing options...
htownz Posted December 17, 2009 Share Posted December 17, 2009 Man, I remember when I started this thread. I was just curious what kinda power people made and personal stories of about them being fun to drive...now all the big players in the Z community with degrees in rocket science engineering are in here talking about stuff that's way above my head lol The simple answer: you will make good, fun power with any of the combinations you asked about. An N42 will have a less compression and may be more managable. The E31 or small chamber E88 are a lot of fun but timing can be an issue which can result in other problems. A larger E88 would have less compression but has smaller valves than the N42. My friends show car 280ZX 2+2 has an N42 on an F54 and it moves pretty good. So an N42 is probably a good option for a driver. Quote Link to comment Share on other sites More sharing options...
ozconnection Posted December 18, 2009 Share Posted December 18, 2009 Well, I changed over to a 190 degree F. (88 deg. celcius) thermostat today. The 160 degree F. unit was removed. I was actually going to test the block/head water pressure but did the thermostat instead! (In retrospect, I should have done this first, to get a baseline pressure reading. Still it can be done, just a bit of extra work that I could've saved myself. ) How does it run? Pretty bloody good, actually. Tip in response could be a little hesitant at times with the cooler thermostat, with the warmer one, I didn't notice any at all. (vaporising the fuel better perhaps?) I can't really test it with the G-tech because there are heaps of radar traps and patrol vehicles around ATM. Christmas time I guess. Double demerit points too. The disconcerning thing about having such a hot thermostat is the position of the needle on the guage, it's 3/4 hot!! But it's stable. The cabin heater works brilliantly. Tomorrow I'll work on testing the block pressure to see where it is. After that, I'll start with advancing the timing to see what happens. Todays setup was 15 degrees static, 35 degrees total @ wot and above 3500rpm and with the vacuum advance connected to manifold vacuum so idle becomes 31 degrees @ 850rpm. Todays efforts didn't cause any rough idling or any pinging. So far, so good! Quote Link to comment Share on other sites More sharing options...
woldson Posted December 18, 2009 Share Posted December 18, 2009 Without reading this whole thread agian, do you know that you temp gauge is correct? Quote Link to comment Share on other sites More sharing options...
ozconnection Posted December 18, 2009 Share Posted December 18, 2009 I'm pretty sure my guage is working ok, I've never had reason not to trust it. It's a Nissan don't forget Why do you ask? Quote Link to comment Share on other sites More sharing options...
johnc Posted December 18, 2009 Share Posted December 18, 2009 When I had Sunbelt build my racing NA 3L L6 the dyno testing showed the engine made the most horsepower and torque with the coolant temps at 200 to 205 degrees and the oil temps at 220 to 230 degrees. YMMV but what they saw on my engine was similar to what they saw on the racing BMW M50 engines they built for World Challenge Touring. I ran a 190 degree thermostat, a 32 psi radiator cap, and a oil/coolant heat exchanger to keep both liquids near the temps lsited above. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted December 18, 2009 Share Posted December 18, 2009 I'm pretty sure my guage is working ok, I've never had reason not to trust it. It's a Nissan don't forget Why do you ask? 70's Nissan gauges give only a general idea of what is going on. When I put an aftermarket gauge in my car it went from warming up to the middle and then never moving to my being able to watch the thermostat open and close. I ran a 195 as well, based on Honsowetz's book IIRC. Quote Link to comment Share on other sites More sharing options...
Mack Posted December 18, 2009 Share Posted December 18, 2009 back on topic. My 280ZX was running an F54 flat top block and a maxima N47 head. the 39cc one. calculated compression ratio was around 11.25:1 and man, did that thing feel strong. I dyno'd it ONCE. and it had a faulty ZX ignition module that limited it to about 4500RPMs. I ran the stock maxima cam and had 2.5in where-the-cat-should-have-been-back exhaust, simple cone style filter, stock ZX EFI, 60MM TB, cleaned and match ported intake and thats about it really. It made 141rwhp at 4100rpms. I have since gone and megasquirted the thing and it feels MUCH stronger. I dont know what it runs, but I had a freind with MANY 1/4 mile passes drive it and he inticated to me that it was easily a low low low 15 sec car, maybe high 14s. and its in a 280ZX 2+2, so its no lightweight. I have some issues with ping, not horrible, but its not exactly non existant either. I dont know why people are blowing headgaskets on these motors, as I am running a fel-pro (fail-pro? not from my experience) and I lived in Phoenix when I used the car as a daily driver delivering pizzas. I was not gentle with it. never had a headgasket failure, not autoXing it, racing it at MSA or beating the snot out of it on the street. I probably have 40,000+ miles on it as it sits. Quote Link to comment Share on other sites More sharing options...
ozconnection Posted December 18, 2009 Share Posted December 18, 2009 back on topic. I have some issues with ping, not horrible, but its not exactly non existant either. If I've come on board and taken this thread in a different direction, I apologise to Mycarispurty. The issue of pinging seems to be very common among those people who are trying non factory head and block combinations. Hell, even my stock N42/N42 combo sees it at anything more than 35 degrees total advance at WOT. According to Braap, this is costing me/us some power at the top end. To help out, I decided to test a theory that I read about in one of my reference books about coolant temperature and pressure. Here are todays results: Cold start 8 psi @ idle Cold engine 20 psi @ 5000rpm (I hate doing this to a cold engine! aarrgghh) Operating temp before thermostat opens 14 psi @ idle Operating temp before thermostat opens 28 psi @ 5000rpm After thermostat opens 18 psi @ idle After thermostat opens 28-30 psi @ 5000rpm. The thing I noticed was that the guage was slow to respond. I used an unused Autometer fuel pressure guage for EFI. 0-100 psi range. The fluids are a little different but I'm sure the guage won't mind . Now, if I wanted to build the block pressure up to say 35 psi, I would need a restrictor. Ideas on how to do this? An electric water pump comes to mind again! Remove the water pump/engine speed dependancy and run a constant (when warmed up) 30 or more psi coolant pressure. Expensive fix with mods to the alternator belts etc but....... Hmmmmmm! http://cgi.ebay.com/ebaymotors/CSR-NISSAN-BILLET-ELECTRIC-WATER-PUMP-FITS-L-SERIES-ENG_W0QQcmdZViewItemQQhashZitem587dd5f47dQQitemZ380068295805QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories Quote Link to comment Share on other sites More sharing options...
JMortensen Posted December 19, 2009 Share Posted December 19, 2009 Now, if I wanted to build the block pressure up to say 35 psi, I would need a restrictor. Ideas on how to do this? Common way to get a restrictor in the system (common enough to be shown in Honsowetz's book anyway) is to put a large flat washer in the rad hose where it connects to the thermostat housing. I think the idea is to prevent cavitation in the water pump usually, not really an attempt at reducing preignition so far as I've heard it discussed. Higher pressure coolant I don't believe is really the answer for preignition. I think the answer is a bigger cam, higher octane, or lower compression. I think John's engine at 12:1 with a large cam and race gas would have run just fine with a lower pressure cap and no restrictor. That in mind, what did you do to raise the pressure and why did you think it was worthwhile to do it, John? Quote Link to comment Share on other sites More sharing options...
Administrators BRAAP Posted December 19, 2009 Administrators Share Posted December 19, 2009 If I've come on board and taken this thread in a different direction, I apologise to Mycarispurty. The issue of pinging seems to be very common among those people who are trying non factory head and block combinations. Hell, even my stock N42/N42 combo sees it at anything more than 35 degrees total advance at WOT. According to Braap, this is costing me/us some power at the top end. To help out, I decided to test a theory that I read about in one of my reference books about coolant temperature and pressure. Here are todays results: Cold start 8 psi @ idle Cold engine 20 psi @ 5000rpm (I hate doing this to a cold engine! aarrgghh) Operating temp before thermostat opens 14 psi @ idle Operating temp before thermostat opens 28 psi @ 5000rpm After thermostat opens 18 psi @ idle After thermostat opens 28-30 psi @ 5000rpm. The thing I noticed was that the guage was slow to respond. I used an unused Autometer fuel pressure guage for EFI. 0-100 psi range. The fluids are a little different but I'm sure the guage won't mind . Now, if I wanted to build the block pressure up to say 35 psi, I would need a restrictor. Ideas on how to do this? An electric water pump comes to mind again! Remove the water pump/engine speed dependancy and run a constant (when warmed up) 30 or more psi coolant pressure. Expensive fix with mods to the alternator belts etc but....... Hmmmmmm! http://cgi.ebay.com/ebaymotors/CSR-NISSAN-BILLET-ELECTRIC-WATER-PUMP-FITS-L-SERIES-ENG_W0QQcmdZViewItemQQhashZitem587dd5f47dQQitemZ380068295805QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories Good info. Where are you taking your pressure reading from, head, under the thermostat in the housing, block, ??? In looking at the typical head gaskets, the coolant ports are small in diameter, and the ones that line up with the transfer ports in the block AND the head narrow down how many of those coolant passages are transferring coolant for the block into the head. Is that enough to pose a restriction to flow at the gasket vs how much coolant the pump is capable of moving? It would be interesting to see if there is much of a pressure drop across the head gasket itself, i.e. take readings from just below the head gasket and just above it at various location front to back and driver side to passenger side. If the head gasket is restrictive, strategically opening up some of the transfer ports in the gasket would allow more overall flow through the engine and depending on how restrictive the thermostat is, would allow more pressure in the head... Quote Link to comment Share on other sites More sharing options...
ozconnection Posted December 19, 2009 Share Posted December 19, 2009 Good info. Where are you taking your pressure reading from, head, under the thermostat in the housing, block, ??? In looking at the typical head gaskets, the coolant ports are small in diameter, and the ones that line up with the transfer ports in the block AND the head narrow down how many of those coolant passages are transferring coolant for the block into the head. Is that enough to pose a restriction to flow at the gasket vs how much coolant the pump is capable of moving? It would be interesting to see if there is much of a pressure drop across the head gasket itself, i.e. take readings from just below the head gasket and just above it at various location front to back and driver side to passenger side. If the head gasket is restrictive, strategically opening up some of the transfer ports in the gasket would allow more overall flow through the engine and depending on how restrictive the thermostat is, would allow more pressure in the head... The pressure readings were taken from under the thermostat, in the thermostat housing. I chose here because it would be the head by which all others feed. Your idea of taking pressures elsewhere is an interesting one. It could be done with a little juggling and the results might be worth it to see how much pressure variance there is from top to bottom,front to back. My gut is telling me though that there may be little pressure difference, there already being enough coolant passageways open to equalise the pressures. The problem exists not so much with pressure variance in this case but with temperature variance from top to bottom and front to back!! I think the biggest problem with the setup of the cooling system on the L engine is that the pump puts all of the coolant after the radiator straight back into the block. By the time the coolant has travelled to the rear of the engine, the coolant is already hot and those poor cylinders down there suffer the worst.(not to mention that percentage of coolant that moves straight back up to the thermostat housing, collecting buggar all heat and simply reducing the volume and rate of flow to the rear cylinders!!) This we already know. If we could only tap into this and send some of the coolant directly to the back of the head like that coolant line that runs under the sparkplugs to the rear of the head, then progress will be made. (From what I can tell, some hot coolant leaves the head @ No 6 and travells BACK to the pump along this 'under sparkplug' coolant line. That's a shame that it runs this way, but it could be reversed with a small inline water pump http://www.daviescraig.com.au/Electric_Water_Pumps-ELECTRIC_BOOSTER_PUMP_12V_SHORT___PART_No__9002-details.aspx to draw from the radiator return line and pump water into the back of the head! The cylinders require little flow as its the head that needs it most. The large surface areas of the cylinders work nicely to shed the heat, but by comparison there is much less surface area in the head, even though the head material has better heat transfer (conduction) properties. Again, we all know this. The head gasket ports need only to be large enough so that steam pockets don't form under the tops of the cylinders. Their size can be as small as 60 thou!(and they probably should be...lots of little buggars just big enough but not too big as to allow coolant short cuts back to the thermostat housing) The big ones at the end are supposed to encourage bulk coolant flow from the block into the head, trying to get the coolant there quickly before too much heat has been collected along the way. If only there were a situation where the cool coolant flowed into the head and dropped down into the block rather than flow into the block and rise into the head, then we'd be streets ahead. I guess that's what that sticky on head cooling is all about. If we can't equalize the temperature variance easily, then pressure will have to do! Quote Link to comment Share on other sites More sharing options...
Daeron Posted December 19, 2009 Share Posted December 19, 2009 I dyno'd it ONCE..... ...It made 141rwhp at 4100rpms. I went and did the math. Thats about 180 ft-lb of torque at 4100 RPM, and if it held onto 165 ft-lbs all the way to 6500 RPM that would be just over 200 wheel horsepower at 6500. Even 165 at 6K flat is about 190whp. Sounds like enough vroom for a bolt-together Z-car for me!!! Quote Link to comment Share on other sites More sharing options...
Mack Posted December 19, 2009 Share Posted December 19, 2009 well, using a hp 1/4 mile calculator, running a 15.0 flat in a 3000lbs vehicle,. comes to about 175rwhp. My only theories on this are all that compression, all that squish, a decent exhaust system and a bit of a freed up intake should make for some fun times. If you look at Tony Ds completely stock (save for the 2.5" crush bent) and well tuned 280Z 2+2, he claims a 15.2 1/4 mile. now, add almost 3 points of compression and some port matching, bigger TB and better mandrel bent exhaust as well as removing the restrictive stock air box, I dont see where a motor making that kind of power would be that far out of line. Quote Link to comment Share on other sites More sharing options...
skib Posted December 19, 2009 Share Posted December 19, 2009 Theres a guy here in Portland running low 13's on an N/A L28 with triples, I should find up what his exact set up is Quote Link to comment Share on other sites More sharing options...
Mycarispurty Posted December 20, 2009 Author Share Posted December 20, 2009 Found some local places that sell C16 VP fuel, and some that sell 110 at the pump. Which would you guys recommend for the E31/F54 combo to keep the timing at a reasonable figure w/o backing it off and killing all the hp I'd make from the compression boost? Quote Link to comment Share on other sites More sharing options...
JMortensen Posted December 20, 2009 Share Posted December 20, 2009 Mine required about 95 octane. So you can figure one gallon of 110 and 5 gallons of 93 would give you 95.8 octane. 110 + 93 + 93 + 93 + 93 + 93 = 575 / 6 = 95.8 gallons of fuel. I'd start there and work it down to see if you could use less. I think my motor was a little higher compression than a bone stock L28/E31 would have been. Quote Link to comment Share on other sites More sharing options...
FricFrac Posted December 23, 2009 Share Posted December 23, 2009 Same as what I read. Talking with the Electromotive guys, they said they overbuilt the cooling system, and paid a penalty for it (more weight for exchangers, etc) but they NEVER had a DNF that was cooling related. Their statement was 'you can always cover a cooler, but if you get hot during a race, you're screwed!' Note the S20 head, LY head, and even the FIA L-Series heads had a totally different cooling passageway setup with a street driven setup. These were engines designed for high specific output and racing from the factory. The LY24 was over 300HP, the S20 in racing form was 340+, and the FIA heads... well the LY was quoted as around 5% more power, so I can only figure the FIA head was a response to that same level of power (300HP). Cooling is a bear, and always overlooked. Nissan recognized the requirement for a different setup to keep these aluminum heads cool under continuous racing environments. There are improvements to the head that will allow considerable flow increases for cooling, they just need to be implemented, and in most cases people aren't willing to put that much into a head for a street car. For a LeMons car, all that cam is likely overkill. A stock low compression L28 was eating the field for 8 hours in Reno, and was competitive at Thunderhill the year before. As for rate of heating, look around many pit areas and see if you find oil heating blankets on the oil sumps (or on wet sump pans)---hot oil is what you want, the rest of it will handle itself pretty quickly on the warmup lap. But that oil needs to be hot NOW when you start the engine! But we digress... Why do you want hot oil? Is it just for start up wear? If so isn't viscosity different now with synthetics (eg 0W30, etc)? I noticed in my VQ37 the oil is used a lot more in cooling the engine compared to older engines like the L28 and an oil cooler is a necesity for very agressive driving. Just curious as I would have thought an oil cooler would help as well with the L series... Quote Link to comment Share on other sites More sharing options...
ozconnection Posted December 23, 2009 Share Posted December 23, 2009 Why do you want hot oil? Is it just for start up wear? If so isn't viscosity different now with synthetics (eg 0W30, etc)? I noticed in my VQ37 the oil is used a lot more in cooling the engine compared to older engines like the L28 and an oil cooler is a necesity for very agressive driving. Just curious as I would have thought an oil cooler would help as well with the L series... Not just cold start wear. Best power is made when the oil is between 95 to 115 degrees celcius. Too cold costs power in the form of drag. Too hot and the oil will break down and sludge will form, components will overheat and lubrication will fail. Like Tony said, "too hot and you're screwed" but too cold isn't good either! Quote Link to comment Share on other sites More sharing options...
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