JaysZ Posted January 28, 2005 Share Posted January 28, 2005 i just ordered a header and weber triples with marking (Tipo 40DC0e18 No 9J ) to replace my worn round top SU's. can someone walk me through the installation process? i don't have a heat shield, should i wrap the headers? also, there is a big hole (refer to pics please) in the header, can someone tell me its function? i'm a noob to carbs, so i apologize. thanks, jason pics here: http://www.hpphoto.com/servlet/com.hp.HPGuestLogin?username=jkoh1&password=29945336 Quote Link to comment Share on other sites More sharing options...
JMortensen Posted January 28, 2005 Share Posted January 28, 2005 It looks like your header is coated... if it is coated then don't worry about the heat. Actually, you don't really need to worry about the heat anyway if you have insulators between the manifold and the carbs. If you really want to worry about it, I'd suggest you make a heat shield rather than wrap the headers. Wrapping headers makes them rust very quickly, and I had a problem with overheating after I wrapped mine (although that seems to have been an isolated incident). The big hole looks like one of those heat riser tubes should plug onto it. I don't recall any SU's using a heat riser tube, so why it's there I don't know. So you can pretty much just bolt it on and go. I don't see any linkage to connect from the firewall to the carbs in your pics, but I'm assuming you have the linkage... Now would be a perfect time to add an O2 sensor to the collector in your header. That really helps with tuning. Just get a one wire O2 and measure the voltage with a voltmeter, or you can get a whole gauge and install it permanently in the car somewhere. Quote Link to comment Share on other sites More sharing options...
mark Posted January 28, 2005 Share Posted January 28, 2005 Installation is pretty easy. Unbolt the old stuff and bolt on the new stuff. Make sure the mating surfaces are clean and use new gaskets. I usually use a little high temp RTV on the header mating surfaces as most I have seen don't seal great. The large hole on the header looks like a place to put a cold start hose, directs warm air to stock carbs, you won't/can't use it with that set up. also looks like an O2 bung is welded to one of the pipes or could be a place for the EGR to attach to. Hard to tell in the pics. If O2 bung, great for a wide band O2 and some help getting the jetting right. If EGR, plug it and your good to go. Mark Quote Link to comment Share on other sites More sharing options...
JaysZ Posted January 29, 2005 Author Share Posted January 29, 2005 thanks for the tips, i'm actually glad that i dont have to worry about getting it wrapped or what not. the linkages come with the carbs but just weren't pictured in the photographs. i can't wait to put them on, hopefully they'll come in soon! Quote Link to comment Share on other sites More sharing options...
olie05 Posted February 3, 2005 Share Posted February 3, 2005 dude, nice find! hope it wasnt too much $$$... I'd be down to help you if you want with the install. I'm also curious to see what the body shop did with the car! -Oliver Quote Link to comment Share on other sites More sharing options...
JaysZ Posted February 4, 2005 Author Share Posted February 4, 2005 i'll definately be posting pics, but unfortunately i cant find the recharger to my digital cam so i'm missing out on some of the steps. i wish i could get all the cool shots from when they do the floor. they've already cut out a lot of rusted areas in the "dog legs" (under the door and near the rear tire well) and welded in new patches. also, since i removed the rear bumper, they filled those holes with sheet metal as well and then bondo'd over it. they also frenched the mirrors, but i'll be installing some chrome bullet mirrors after they paint. i've gutted the entire interior and they will be painting the interior as well. i want to leave it bare.. it would give it a nice vintage race car look imo. i think a viper gas cap would compliment it very well, too bad they cost so much though. anyway, should be done soon! thanks olie, i'll be giving you a call! you free this saturday? Quote Link to comment Share on other sites More sharing options...
Nismo280zEd Posted February 16, 2005 Share Posted February 16, 2005 Please... Please Please.... use a heat shield and header wrap!!!! This is how my car caught fire with my EFI motor!!! Take my advice and make a heatshield. And bare min wrap the header. -Ed btw...Welcome to tiple hell -current member Quote Link to comment Share on other sites More sharing options...
briann510 Posted February 16, 2005 Share Posted February 16, 2005 our header is ceramic coated and it still puts off intenese heat enough to fry the fuel in the carb bowls and lines, the intake runners and carbs themselves, especially after turned off and heat soak sets in. i use a header blanket sandwiched in between the header and intake/carbs. it isnt wrapped around the header, only laying between so it can still have air underneath to exit under the car and it keeps everything cool when running and when shut off. my fuel lines are also wrapped. im gonna use the left over heat blanket and wrap it around my intake runners also. if we restart the car after a heat soak we flip the fuel pump on a couple seconds before firing to purge any hot fuel through the lines and back into the tank. Quote Link to comment Share on other sites More sharing options...
JaysZ Posted February 16, 2005 Author Share Posted February 16, 2005 yeah i need to get a heat shield for it.. i was told by several people to avoid wrapping the headers because it will rust the headers eventually right? how do i just lay a blanket w/o it coming loose? what other options are there for heat management? i havent had the time to put them on yet, will most likely do it when the car is complete and painted (few more weeks arghh).. Quote Link to comment Share on other sites More sharing options...
briann510 Posted February 24, 2005 Share Posted February 24, 2005 the header blanket just kinda laid over the header and tucked over the end tubes. i didnt tie it down. it more or less molded to the way i wanted it to sit then once it heated up a couple times it held the position. it hasnt moved at all on me in 500 miles. i also cut some extra blanket and laid more between the intake runners and header and also a section in front that blocks the radiator heat on the front of the intake. it keeps a tonf of heat off everything, including the clutch/brake lines. it smelled kinda weird while it was baking but we got used to it. this way the herader isnt wrapped and the heat goes out under the car. the blanket cost $70 from summit racing. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted February 24, 2005 Share Posted February 24, 2005 our header is ceramic coated and it still puts off intenese heat enough to fry the fuel in the carb bowls and lines, the intake runners and carbs themselves, especially after turned off and heat soak sets in. i use a header blanket sandwiched in between the header and intake/carbs. it isnt wrapped around the header, only laying between so it can still have air underneath to exit under the car and it keeps everything cool when running and when shut off. my fuel lines are also wrapped. im gonna use the left over heat blanket and wrap it around my intake runners also. if we restart the car after a heat soak we flip the fuel pump on a couple seconds before firing to purge any hot fuel through the lines and back into the tank. This is something that you've mentioned in a couple posts, and I can't help but think that there is something wrong with youre setup, and I'm thinking it's probably that you don't have insulators on your carbs so the heat from the head is transferring through the manifold into the carbs. I've run my car with triple 44's and a non coated header with no heat shield in 114º and not had the fuel boil in the carbs. I did get rid of the mechanical pump and the steel fuel rail (I think this is a MAJOR heat source) and ran a rubber line across the radiator support then back to the carbs, so my fuel wasn't picking up any heat from the head, and I have the original asbestos insulators. If you don't have insulators you really NEED to have them IMO, and if you have a steel fuel rail bolted to the head get rid of it. As to the original question, header wrap will soak up moisture and hold it right next to the header, causing rust. Coating the header is a much better idea, blankets are usually attached with hose clamps. The blanket should have the same basic effect as the wrap, holding moisture against the header tubes. One interesting shield that a friend of mine made was two layers of aluminum with a layer of header blanket to insulate between the inner and outer heat shield. Quote Link to comment Share on other sites More sharing options...
preith Posted February 24, 2005 Share Posted February 24, 2005 I've run my car with triple 44's and a non coated header with no heat shield in 114º and not had the fuel boil in the carbs. Amen, there's a local guy who vintage races a 240 in 90 + degree weather without anything (heat sheild, blanket, or coated headers) and has no issues. I went the safe route and fabbed up a stainless sheild as well as insulators, but cannot compare since the car was never run without. I guess I could have searched it, and it may been talked about before, but we could talk at length just about different insulators. IMO the Nissan Motorsports ones are the best, but the most expensive too, I think about $40 each x6. My TWM manifold came with the o-ring setup, it was never used. Quote Link to comment Share on other sites More sharing options...
gramercyjam Posted February 24, 2005 Share Posted February 24, 2005 I get the fuel boiling/vaporization problem without a heat shield on my Weber 45's. Thats with 2 sets of manifold insulators installed. It's not heating up from the head or the fuel lines. The problem shows up as a no idle, stalling/flooding/hard start condition after a hard 60 sec. run that really heats things up. The problem cannot be reproduced in the garage or tooling around on the street. The installation of a thin aluminum sheet between the headers and the carbs cured the problem immediately. There might be some differences in the way our carbs/engines are setup as to why some people get the problem, and some don't. Quote Link to comment Share on other sites More sharing options...
Nismo280zEd Posted March 7, 2005 Share Posted March 7, 2005 That what my heat shield is... header wrap rivited to sheet metal with some AL bracing screwed on... works great! I also changed my fuel rail, it comes up the back side along the firewall, runs through a SS pipe i made, then into rubber to the carbs, no return line. you said asbestos insulators... are you refering to the rubber vibrations dampeners used mounting the carbs to the manifold? -Ed Quote Link to comment Share on other sites More sharing options...
JMortensen Posted March 10, 2005 Share Posted March 10, 2005 Mikunis used to come with asbestos. Almost a clear white, sealed to carbs and manifold by o-rings. Nissan Comp sells (sold?) the rubber type which are preferred, they sound like what you have. I don't know if that is the standard Weber insulator or not. I thought the Webers came with a solid insulator, not the rubber ones. Not a Weber guy, though... Quote Link to comment Share on other sites More sharing options...
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