1 tuff z Posted June 27, 2011 Share Posted June 27, 2011 bad dog is looking great pete-now, when do we get some video-audio?! Quote Link to comment Share on other sites More sharing options...
z-ya Posted July 2, 2011 Author Share Posted July 2, 2011 bad dog is looking great pete-now, when do we get some video-audio?! David, maybe we'll get some good clips at the convention. The clutch is slipping when the power comes on, so we got some work to do this week. Stay tuned... Quote Link to comment Share on other sites More sharing options...
DefectiveRadio Posted July 11, 2011 Share Posted July 11, 2011 Thtats one amazing piece of Z you got there! If you don't mind my asking, what's the story on the ignition system? Quote Link to comment Share on other sites More sharing options...
z-ya Posted July 14, 2011 Author Share Posted July 14, 2011 Thtats one amazing piece of Z you got there! If you don't mind my asking, what's the story on the ignition system? I'm using an 82'-83' 280ZXT distributor to trigger an MSDAL2 programmable unit. http://forums.hybridz.org/index.php/topic/97010-280zxt-distributor-with-progammable-msd/page__p__911073__fromsearch__1#entry911073 Quote Link to comment Share on other sites More sharing options...
z-ya Posted October 12, 2011 Author Share Posted October 12, 2011 Been chasing head gasket sealing issues. Finally think we have them resolved with a MLS gasket. Made 223HP on DynoJet with leaking head gasket. Now that it appears that the gasket leak is fixed, here is the latest dyno plot: I figure it's making close to 300HP at the crank. Doing a track event in a couple weeks. I'll post the results. Pete Quote Link to comment Share on other sites More sharing options...
kj280z Posted October 12, 2011 Share Posted October 12, 2011 Been chasing head gasket sealing issues. Finally think we have them resolved with a MLS gasket. Made 223HP on DynoJet with leaking head gasket. Now that it appears that the gasket leak is fixed, here is the latest dyno plot: I figure it's making close to 300HP at the crank. Doing a track event in a couple weeks. I'll post the results. Pete SWEET! Quote Link to comment Share on other sites More sharing options...
inline6 Posted October 12, 2011 Share Posted October 12, 2011 What MLS did you use Pete? Also, don't forget about putting up a sound clip. I'd like to hear it! Quote Link to comment Share on other sites More sharing options...
Noddle Posted October 12, 2011 Share Posted October 12, 2011 It looks like you go super rich at 4K, and every thing drops off, did you look at leaning it out at 4K to get rid of the dips ?? Ngel Quote Link to comment Share on other sites More sharing options...
z-ya Posted October 12, 2011 Author Share Posted October 12, 2011 What MLS did you use Pete? Also, don't forget about putting up a sound clip. I'd like to hear it! I used the 2mm Kameari one. It's really the only 2mm MLS gasket you can buy. It's loud with the dual megaphones. Earplugs needed when driving it and on the dyno for sure. I'll get try to get an audio clip at the track. Quote Link to comment Share on other sites More sharing options...
z-ya Posted October 12, 2011 Author Share Posted October 12, 2011 It looks like you go super rich at 4K, and every thing drops off, did you look at leaning it out at 4K to get rid of the dips ?? Ngel It has Mikuni 44phh carbs with the chokes removed (~50mm). With such large venturis and with the emulsion tubes they have, it is difficult to tune a that lower crossover point where the low speed fuels jets meet the high speed ones. I can try smaller low speed jets, but it may just move that crossover point to where it has a negative effect on the top end. If I run richer high speed jets it will richen it up on the top end, but it will also make that 4k droop even deeper. Would I love them to change the vintage rules to allow EFI? YES! Until then, I'm stuck with not a lot of tunability in that area. Pete Quote Link to comment Share on other sites More sharing options...
olie05 Posted October 12, 2011 Share Posted October 12, 2011 Been chasing head gasket sealing issues. Finally think we have them resolved with a MLS gasket. Made 223HP on DynoJet with leaking head gasket. Now that it appears that the gasket leak is fixed, here is the latest dyno plot: I figure it's making close to 300HP at the crank. Doing a track event in a couple weeks. I'll post the results. Pete I'm curious, what did you find out to be the issue with the solid copper gasket? Quote Link to comment Share on other sites More sharing options...
JMortensen Posted October 12, 2011 Share Posted October 12, 2011 Would I love them to change the vintage rules to allow EFI? YES! Until then, I'm stuck with not a lot of tunability in that area. Is there some reason why you MUST run without the venturis? I think I was making about the same power through 37mm venturis, I think zredbaron is making more power than either of us through 40's, I can't recall what size choke tubes he is running. Quote Link to comment Share on other sites More sharing options...
z-ya Posted October 12, 2011 Author Share Posted October 12, 2011 I'm curious, what did you find out to be the issue with the solid copper gasket? For the compression ratio I'm running (13:1), I really needed to cut grooves for copper wire into the block to get the gasket to seal correctly. Basically it was blowing compression into the water jacket once a good load was put on it. When you have a water shooting out of the overflow tank, and after a few dyno pulls there is mostly air in the cooling system, you can pretty much figure out where the air is coming from. The MLS gasket was the quickest fix. So far it is holding up. Quote Link to comment Share on other sites More sharing options...
z-ya Posted October 12, 2011 Author Share Posted October 12, 2011 Is there some reason why you MUST run without the venturis? I think I was making about the same power through 37mm venturis, I think zredbaron is making more power than either of us through 40's, I can't recall what size choke tubes he is running. Jon, these are the old style Mikunis that were modified by the guys at BSR back in the day. The mods cannot be undone. The engine specialist I've been working with can explain in extreme detail this mod and what the limitations are. He is one of the old school guys that did these mods back then. Basically it has to do with the flow through the emulsion tubes. When the flow through the carb is increased beyond a certain point, the emulsion tubes become less effective in controlling that crossover point. He says that the Weber DCO 55mm carbs can be tuned a lot better because of a better emulsion tube design, and the fact that they are designed to flow that much air. He actually thinks that my motor needs more air. He is probably right. If I didn't have these Mikunis, I probably would have run Webers because you can still buy them new and also get parts. You are correct, for a street engine, the venturis should never be removed, but for a race engine with a limited power band, the extra air flow is worth it. Quote Link to comment Share on other sites More sharing options...
duragg Posted October 13, 2011 Share Posted October 13, 2011 Been chasing head gasket sealing issues. Finally think we have them resolved with a MLS gasket. Made 223HP on DynoJet with leaking head gasket. Now that it appears that the gasket leak is fixed, here is the latest dyno plot: I figure it's making close to 300HP at the crank. Doing a track event in a couple weeks. I'll post the results. Pete Is it a tad lean in the upper area? I know every engine is different and location of the sniffer and such. Just curious. Are you happy with that 14 AFR or is that something you are working on? Reason I ask is my mildly hopped up L28 is loving AFRs in the low 12s. Quote Link to comment Share on other sites More sharing options...
z-ya Posted October 14, 2011 Author Share Posted October 14, 2011 Is it a tad lean in the upper area? I know every engine is different and location of the sniffer and such. Just curious. Are you happy with that 14 AFR or is that something you are working on? Reason I ask is my mildly hopped up L28 is loving AFRs in the low 12s. If you look at the final pull from the engine dyno, you will see high 12s to low 13s. This is where it should be. Before making any changes to the engine, I did some pull on the dynojet and got AFR reading like what you see in the plot above. I have a feeling that the lambda on the dynojet was reading a few points higher than the very accurate lambda sensor on the superflow dyno (engine dyno). I am putting a new sensor in the dash lambda gauge and will watch it closely at the track. I am fairly sure that I will see high 12s to low 13s with this sensor. I'm running 110 Cam2 race fuel in this engine. Quote Link to comment Share on other sites More sharing options...
z-ya Posted October 23, 2011 Author Share Posted October 23, 2011 The track event was successful as far as the engine is concerned. Engine ran good. Pulls hard between 4000 and 7500RPM (rev limited). Now its a completely different beat to drive, and I have completely change my shift points. AFR didn't budge above 13:1, but was really rich in areas below 4000RPM. Plenty of winter projects to do Quote Link to comment Share on other sites More sharing options...
Bob_H Posted October 24, 2011 Share Posted October 24, 2011 You are going to be banned if you don't post a video clip! You've had since July with lots of requests! Quote Link to comment Share on other sites More sharing options...
ap72 Posted October 24, 2011 Share Posted October 24, 2011 Basically it has to do with the flow through the emulsion tubes. Why not change the emulsion tubes? Quote Link to comment Share on other sites More sharing options...
JMortensen Posted October 24, 2011 Share Posted October 24, 2011 Because Mikunis only have 3 different tubes, and only one is supposed to be good for race cars. Webers have many different options. Quote Link to comment Share on other sites More sharing options...
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