Jeff G 78

Intake system is the stock '72 orange airbox. On the cam timing, keep in mind that this engine ran this way before and after a rebuild and with two different cams. I have rebuilt plenty of L6 engines, so I'm sure that it is correct. I matched both the bright links on the chain and verified everything physically before and after assembly. I agree that not having a temp gauge isn't good madkaw and I should have know better. For those who haven't followed my journey, this car was purchased as a complete basket case for $350 and was built from the ground up with virtually no money in 9 weeks. Every mechanical system on the car was either shot or screwed with by previous owners. The 9 week build included the car being gone for 2 weeks getting a cage installed. LeMons and ChumpCar World Series isn't like any other form of racing. It's all about racing real $500 cars, not who can spend the most money. Rather than stiff springs, race shocks and adjustable suspension, the stock springs were cut, the 25(?) year old dampers were kept, and suspension tuning was done with tall spring aid jounce bumpers and LCA pivot point relocations. Rather than rebuilding the engine, we tore it down to inspect and clean it and reassembled it with new gaskets only. The body was painted with Rustoleum applied with rollers and so on. Almost all of the parts that we did replace before the first race came from my vast stash of used parts. Gutting the thermostat is a common LeMons practice that *normally* works fine. The car has run well at times when it gets enough fuel, so low engine water temp was never considered as a cause for any of the running issues we've experienced. After the first few races and lots of track days, we have replaced a few things and recently rebuilt the engine, but for the most part, it's still nothing more that a $500 race car. Take a look at the build photos in this link http://www.facebook.com/media/set/?set=a.105973052763868.11825.105972559430584 to see what we started with. Click on the first pic and scroll through them so you get the captions as well.

Correct on the pressure reading. I was thinking the same thing on the A/F without a thermostat. It really surprised me that the temp stayed so cold last year on the track. We ran a 14.5 hour race at 80F ambient and the gauge barely moved off 120F. The thermostat was in place with the valve itself removed. I would have sworn that it would have enough restriction to allow the engine to get up to temp. I guess I learned a tough lesson... I'll let everybody know how today goes. Thanks to all who have helped!!!

In for the night. It was a long day, but we made some progress, I think. Per my last note, the 4 - 7 psi pump is in place and working. According to my crappy little gauge, it is putting out about 3.5 psi with no load. I need to find a real gauge and a long hose to see what I'm getting on the track. I found the issue with the temp and oil pressure gauge. My teammate was cleaning up wiring and cut a power wire that fed them. Interestingly, the temp gauge does work. That means that for the past two years the temp has never gotten above 130F even when it was 80F ambient. With the thermostat in place, the temp gauge came up to just below the mid point just running it in the garage. I bought a 180F fail safe gauge BTW made by motorad. I think that's the same brand that MSA sold me when I bought one for my 280 a few years back. I still need to tune the carbs with the floats adjusted and the thermostat in place. I took the front fuel filter out to install the regulator and I then put it back in when I had to remove the regulator. It was the easiest way to make the hoses that I had work out. Prior to using the electric pump, the filter was always about 1/2 full, but now it's completely full of fuel. I guess that's a good sign that I have more flow. The mechanical pump is gone and we installed a block off plate. I still have the return line in use right now, but I will keep an eye on the pressure and block it if needed. I am still using the OE 260 fuel rail that is similar to a 280 rail with a return loop. If I quit using the return, I will need to come up with a safe way of blocking the hose. I guess I could install the regulator in it that won't flow anything. Tomorrow I will tune the carbs and check timing, compression, leakdown, vacuum, etc. At least I don't have any more leaks from the water neck. The helicoil did the trick. It's always good to have a M8x1.25 kit handy.

Quick update... No, the race isn't until NEXT weekend. This weekend is all about getting everything diagnosed and the pump installed. Facet pump is installed as WAS the Spectre regulator. Pump works fine, but the regulator appears to not work. With the regulator in place, no fuel flows past it. With it gone, the pump flows properly. The regulator has a In and Out marked which were checked. The carb inlets were clean and the float heights were fine per the FSM. I haven't tuned it yet due to yet another several issues. We installed a thermostat and one of the bolts felt soft upon tightening. Sure enough, it leaked and when removed, the housing was partially stripped. A Helicoil solved that problem and the leak is gone. Next, we readjusted the valves. Most were fine, but a few needed some minor adjusting after the track day and a fresh valve job. The next issue is that we started it up and it ran great, except we have no oil pressure or temp showing on the gauges. Before, the temp would climb to 120 and the oil pressure worked just a few days ago. They are both completely dead now. I can't see anything wrong, so now I'm off to check the archives for how to check the gauges. The cam lobes have fresh oil, so I know it's just the gauges. Everything is hooked up as it was a few days ago when they worked. We haven't made near the progress I had hoped today, but we still have time to get it done.

Wish me luck tomorrow. I will go through the list and see what I can do to fix the issue. I was able to find a Spectre regulator just like the one beermanpete showed earlier in this thread. I wasn't able to find a gauge yet, but I do have the little tiny 0-10 psi gauge that I can use until I find a bigger one. I will have lots of things to check and swap tomorrow and hopefully I find SOMETHING that gives me hope that the problem is fixed. Since I found a regulator, I will use the 4-7 psi pump and I have a new Bosch FI canister fuel filter from my '78 that I can use before the pump. It should provide good flow and have lots of filter media. Should I try to keep the return to start with and run the regulator in the return line? What about the mechanical pump - should I remove it right away, or keep it in series to start with?

Bruce suggested I talk to Steve in the shop, but nobody has been answering the shop number when I call. I'll try again tomorrow.

The two Facet pump numbers are 610-1077 and 610-1078. They are Facet pumps, but also have Napa branding on them.

I never heard back from Black Gold Man on the RX7 pump, so I stopped today at Napa and bought both Facet pumps. I am still confused about which one is the better choice. From what I understand, the SU's want 3 - 4 psi right? The Facet pumps are 1.5 - 4 psi and 4 - 7 psi. The higher pressure pump flows about 10% more as well. So what exactly does a pump's range mean? Is the 1.5 - 4 pump going to be too low of pressure? I tried but failed to find a regulator locally, but I got a lead from the guy at Napa of a race shop in town that might have them. I'll check tomorrow. If I find a regulator, the higher pressure Facet pump should be better and then I can adjust the pressure down, but if I don't find anything, which should I use?

Steve, My plan is to return the needles to the correct heights first since that's the way we ran it Sunday prior to my experimenting. I will then CHECK the fuel height in the nozzles. If they are WAY off, I might have found a cause, but I doubt they will be off by much. I made myself a float height gauge block last year and that's how I set the levels. My SU's are from a '72 so they have different float heights front to back. Here is the block I made per the FSM. It makes setting and checking the floats WAY easier. Captain, Unfortunately, it will be fire drill time at the track, but with the right planning, I will have a pile of parts to try and a specific order in which to try them. If NOTHING fixes the problem, then we simply become a rolling chicane for 25.5 hours and I will be very bummed. BTW, we have also tried different wires, cap/rotor, and plugs. The spark we have is very strong. When we did a compression check and I pulled the coil wire, the spark was jumping well over an inch from the coil wire to the body.

Hey Blue, Is all that work being done on your 280, or a different Z? We need pics!

We ran a 4 panel wink. It might have been about 30" long.

I do have a block off plate on a spare 280 head, so I'm good there. I might leave the mechanical pump in place for now though until I get an idea of what's going on. As for the temp gauge, I'll have to diagnose it if it still doesn't work. The sensor and gauge came from a '75 that I parted out. The gauge worked 20 years ago when I quit driving it. :-) Oh yeah, we always have an extinguisher in the car and ready to use.

How have you been Ron? I hope you've had so time to work on the Z. I'd love to borrow your module. My dizzy is working great and hopefully the module is as well, but it would be nice to rule them out just in case.

I'll add it to the list Zed Head. Maybe Geezer will loan me his module so I can try it if needed.

Thanks all for the continued ideas. I got the car back late last night and I'll start trying all of the great suggestions you have given me. My plan is to do all of the most likely fixes. From there, I'll prepare to do others at the track in case the not-so-likely becomes the likely once I hit the track. I have one week to get the parts needed and installed before I leave for my race. Here's my game plan: Remove the mechanical pump and install an electric pump near the tank with a single quality filter. Install a fuel pressure gauge and position it to be in view from the driver's seat for testing. Check all fuel lines and hoses for possible leak paths. Check carb hoses for signs of kinking. Recheck carb inlet screens and float valves for debris Install a new quality thermostat. Recheck the valve clearances. Perform vacuum, compression, and leakdown tests on engine. Install an additional ground strap between the engine and body. Check fuel pressure w/return. Block fuel return system. Recheck fuel pressure w/o return. Set the SM needles back to the properl height. Retune/synchronize carbs. Adjust the fuel level in the bowls per Bruce's method. (set fuel level to 1/16" below top of nozzles) Check timing at high RPM. If nothing jumps out as a smoking gun, I will *try* to get to a dyno this weekend. More than likely, I will not have the time, so we will leave a day early and pay for the Friday track day at Nelson Ledges to test the changes. Assuming it runs well without hitting the 5,000 RPM wall, I will remove the excess fuel line and reposition the fuel pressure gauge to underhood. If it still falls on its face and none of the other ideas help, I will swear and pout for a bit and then have a really crappy weekend playing rolling chicane for 25.5 hours. Am I missing any of the ideas? Hey BGM, did you locate the RX7 pump? If not, I'll buy the facet pump tonight.

Ray, this is the one we use. I mis-spoke before, we got the 14" mirror, not the 17" one. From the driver's seat, I can clearly see directly behind me and all the way around to about 10' straight out from the RH door. The wink didn't have near the range and it was very distracting. http://www.ioportracing.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=L22534-37&Category_Code=MIR

We had a wink in the race car for a few years and we just switched to a 17" panoramic mirror. HUGE improvement! The viewing angle is far superior and now we can actually see everything behind us on the track.

madkaw, I will look closely at the hoses, thanks. beermanpete, I thought about the dual filters, but have never tried to run just one. I haven't looked at the timing at high rpm, but it's dead stable at 2500 where I checked the total advance. I'll check at higher rpm too. I ran a holley red and a regulator just like that on a '72 with triple Webers. I called around and can't find anything local. I do like the idea of higher pressure and flow with a regulator adjusting it back down to the exact pressure needed. pizzaman, this tank hasn't been treated. The first tank was and yes, the inlet was clogged with POR. That was one of the reasons for the tank swap. This tank is clean and free flowing.

OK, thanks all. I will add a (quality) thermostat back in and see if the temp gauge actually does work. Bill, YES, please try to find the pump and let me know if you find it. I will be buying a pump tomorrow after work if you don't find it. Randalla, no, the tank is good and we ran it with 4, 12 and 16 gallons of gas in that order with no change. Steve, I agree that a wide band work be the best way, but we just don't have time to add one in time. We are thinking about going to a dyno this weekend (if we can get in) though to check and tune. I might also try the OE needles, but we did have the problem with and without the SM needles. No other carbs available and no old hoses to try. I think the old hoses cracked when I removed them. Gotta run and go pick up the Z from a race shop an hour away, but thanks all!

The T stat is gutted simply to avoid a stuck thermostat and an overheating condition in race conditions. I can certainly put one back in. That was on my radar as a possible problem, but I figured it wouldn't be an instantaneous cutout, but rather a general running problem. As for the plugs, I didn't have a chance to shut the car off during a stumble to check them at that moment, but after a session and cool down lap, the plugs are a perfect light tan color. I can't say if it bogged prior to hitting the wall, but I don't believe so. I think it's fine and then terrible. I am running new hoses from Bruce. When I installed them, I made sure they were straight and they show no signs of kinking, but how can I tell? Is there any evidence to look for of them collapsing? Mitchell, thanks for the pump suggestion, but I need to find something local due to time constraints and the only thing I have found is a Facet 1.5 - 4 psi cube pump from Napa. I just talked to Bruce and he thinks that will work fine. The low end of the pressure range scared me a bit, but ??? They also have a 4 - 7 psi Facet cube pump, but Bruce is worried that the pressure will puke fuel out the vents. Thanks all for the help and keep the suggestions coming. IF I ever fix the problem, I'll be sure to report my findings.

Bruce, the needle adjustment was a trackside test just to see what it would do. I didn't really expect it to fix anything, but I wanted to see what direction it took us. As for electrical vs. fuel, I certainly agree, but I have tried three different distributors and three different coils. In every combination, the symptoms didn't change at all. I will add another ground strap, but I don't think that is a problem either. Randalla, I have read about fuel lines sucking air elsewhere as well. All of the hoses are new and the hard lines are in good condition, but I will verify once I get a big gauge connected that I can watch. You must be talking about Guernsey Farms Dairy. I live within walking distance of it and go there often in the summer for ice cream. What electric pump does everybody recommend? And don't say get an RX7 pump from a JY because I haven't seen a JY RX7 in these parts for decades. I'll probably look for a 3 -4 psi Facet cube pump, but I want to find something local if possible to save time.

Update: I got feedback from another driver and she said that when she drove the car (prior to my needle test), the car ran fine for the first few laps and then wouldn't rev past 5k. After her session, I raised the needles and re-balanced the carbs and it was the next driver who reported the issue occurring right away and at 4k rather than 5k.

Bruce, I have a quick question. What is the ID of the fuel hoses between the bowls and chokes? I need to buy some clear hose at lunch today to double check the fuel height in the bowls.

Hey Bruce, I just asked my teammate (I never drove the car on Sunday) if the car accelerated OK when he first pulled onto the track and he said no. His run in the car was after I raised the needles a bit to see if that made any difference. The car wouldn't rev above 4k for him even right out of the pits after it idled for a bit. I should get more feedback from the other two who drove the car prior to me adjusting the needles. I did not check the bowls on Sunday, so I guess it's possible there could be some debris in the valves, but there never has been anything there in the past. We run a filter near the tank and another before the mechanical pump. Both filters are 3/4 full of fuel when we check them in the pits, but I don't know what they look like on the track at speed.

Thanks Bruce, I'll call you after work today before you leave.