eugene Posted October 17, 2001 Share Posted October 17, 2001 Finally, after many months I got my 350/700r4 bolted up and it started on the first turn! Got everything wired and plumbed, just need driveshaft and exhaust and I'll be running. I've got two questions: 1: A friend told me to rev the motor at 2,000 r.p.m. for about twenty minutes to break in the new cam (stock cam, hyd. lifters, late model 350 with one piece rear seal) Should I do this? So far I've only started it three times and ran it less than 30 sec. each time. Everything is assembly lubed and the oil pump is primed. 2: Going to try to make my own exhaust a la pparaska's web page. I can't tell from the pictures if the tubes are butt welded together or if they are joined and then welded. Which would be the best way? Thanks to everyone for all your help, this forum sure made the job easy!!! Quote Link to comment Share on other sites More sharing options...
pparaska Posted October 17, 2001 Share Posted October 17, 2001 Congrats! 1. Definitely don't let it idle for the first 20 minutes. The cam needs lots of oil splashed onto it by running it in the 1500-2000 rpm range. I've also heard it's a good idea to vary the speed a bit for that time period. 2. I but welded it. I felt that was better, and easier. I think it looks better, the flow is most likely better too. Why do Mandrel bends and then put a bunch of flow interruptions in the system? Seems counterproductive. Quote Link to comment Share on other sites More sharing options...
eugene Posted October 17, 2001 Author Share Posted October 17, 2001 But welded, huh? I have a Lincoln wire feed welder with some flux core wire. It makes good welds with some cleanup but I've never tried to weld something thin like exhaust tubes. Do you think this welder might work out or do I definitely need a MIG or TIG setup? If so I'll have to decide whether to have it done or spring for the MIG conversion kit (always looking for a good excuse to buy tools!!) Quote Link to comment Share on other sites More sharing options...
ZROSSA Posted October 17, 2001 Share Posted October 17, 2001 FRANKINZED I dont think that a mig will make much of a diff. over a mig. A lot of exhuast guys still use gas. I use gas wit a henrob tourch. It works ok once you get used to it. A mig is on my x-mas list. Douglas Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted October 17, 2001 Share Posted October 17, 2001 The flux core will work just fine, in fact great. Just make sure you set it up to weld the type of metal. If it's a lincoln the setting is B (amps) and around 1.5--2 wire feed speed. It'll even fill in gaps and the bead doesn't flow inside the tube much at all(at least it didn't in a test I did with 3" aluminized tubing) jon Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted October 17, 2001 Share Posted October 17, 2001 And they were Butt welds. Quote Link to comment Share on other sites More sharing options...
eugene Posted October 17, 2001 Author Share Posted October 17, 2001 Oh yeah, I forgot to ask about ceramic coating. What should that cost for a complete exhaust system. It seems like a waste to spend so much time building it just to watch it rust away! I'm doing a budget build but a few hundred dollars seems doable. Probably more like several hundred though, right? Quote Link to comment Share on other sites More sharing options...
pparaska Posted October 17, 2001 Share Posted October 17, 2001 The bill to clean up my welds and coat 90% of the exhaust and blockhuggers (all except the mufflers and a short pipe to them) was (hold your hat) $700. I can't remember if shipping was included. I agree, after spending 60-80 hours building my exhaust, I couldn't see letting it rust. Plus I was hoping to keep heat out of the floorboards. I used Baxter Custom Engineering (thanks to a tip from Scottie-GNZ) for the coating. Stainless Ceramic (they are the only ones doing it, last I heard). Stays shiny longer and has a better shine. 1600F temp max. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted October 17, 2001 Share Posted October 17, 2001 May I offer a bit of advice? I've done two systems on my Z now, the last one, parts of it are very well tucked in, other spots, well they just have to be low because of what they must pass under. At any rate, my point and advice is, periodically step back and do a visual site line on the bottom of the car from the side and see where pipes are falling out. I found it real easy to look at it laying on my back and thinking "I'm the man, that looks great" only to lower it down, and find not only were you NOT the man, but now speedbumps are a nightmare. Just word of warning, and yeah as mentioned the flux core works fine, I did two of them that way now. (I used a lincoln weldpak with the same suggestion, range 'b' and I adjust the wirespeed by sound, if its pulsing and pushing the torch away from the weld, then you've got it to fast. Listen for a crackling bacon sound and you've got it dialed.) Also, expect to blow through, its very thin, and if you file or grind the edge of the butt joints they can easily burn through. If it does, don't panic, pulse the gun on and off around the edge of the hole slowly building up metal to bridge the hole. Good luck and have fun Regards, Lone Quote Link to comment Share on other sites More sharing options...
Guest digitalz Posted October 17, 2001 Share Posted October 17, 2001 lone got some good advice. put the car down and look under it from the side and you can really see whats hanging out. i used duplicolor hi temp paint with ceramic supposed to be good for 1200degrees i think. costs 3-4 bucks i think and because i'm cheap and there is no one that does coating on kauai i'm using that. it works and has not burned off so far. only running about 300 miles tho but i figure i can give it a shot every once in a while. also i had some mandrel bends that had some stuff inside i guess to prevent rust. anyways it was causing the mig to flame and burn through. my exhaust isn't beautiful but it works and doesn't hit often. there are parts that i have not sprayed and rusting so i guess the ceramic paint works. i also used it on my cheap pacesetter headers for my dodge neon. sorry so long. kent Quote Link to comment Share on other sites More sharing options...
RPMS Posted October 17, 2001 Share Posted October 17, 2001 Gawd, I feel like a complete idiot for having to ask this, but why don't we just beat the floorpans with a big hammer.... *ahem* I mean, why don't we clearance the floorpans to allow the exhaust to tuck up higher? With some insulative material between the piping and the floor, I can't think THAT much heat would be transferred, to the cabin, would it? Oval pipes would minimize the amount of clearancing needed even further. I would imagine that ceramic coating your entire exhaust system would be a complete waste of time and money if it hung low enough to scrape on speed bumps. As soon as you've scraped the coating off of even a small section, you've exposed metal and invited rust to come out and play. I'm speaking from COMPLETE ignorance here, since I'm still an inliner. So please, be kind and educate me! Quote Link to comment Share on other sites More sharing options...
Owen Posted October 17, 2001 Share Posted October 17, 2001 Well then, I'll speak out of complete ignorance too! I sprayed the floors with heat paing, Dynamatted them with two layers and then coated the whole interior with Dupont truck bed liner. Underside of the floors are heat paint and bed liner. The exhaust pipes are also sprayed with heat paint, inside and out. I had to hammer the tunnel for the T56 and when I did the floors, I actually did weld them up higher than stock, not on purpose though... Passenger side 3" pipe tucks up higher than the subframe connector and you can barely see it from the side. Driver's side had less clearance so I used 3" tubing CAREFULLY squeezed into an oval with my press. The lowest part of my system is where it runs under the diff. Will use oval tubing there as well. Oh, header collector and J-bends are 2.5" which then open up into the 3" pipes which merge into the single 3" muffler. Got about 1" clearance between the pipe and the slave cylinder. Not pretty and not super efficient, but it looks like it'll get the job done, hopefully... Owen Quote Link to comment Share on other sites More sharing options...
pparaska Posted October 17, 2001 Share Posted October 17, 2001 My exhaust had to run quite close to the floors that were already painted, etc. I've been in enough hot floored V8Z's that I decided that it was worth a try. Running exhaust close (within 1/2") of the floor will cause some good radiation to heat the floors. I felt stopping the heat at the source (the pipe outer surface) was the best method. Plus it keeps the stuff from rusting. My exhaust is tucked up well and higher than the subframe bottoms in all but one place. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted October 17, 2001 Share Posted October 17, 2001 Yeah, they put grease in those mandrel bends (I'm assuming to make it easier to draw out), it does cause the weld to get all weird if the grease gets in the weld so definitely wipe the inside back a ways from where the weld is going to be. If you buy them (u and J mandrels) from summit they will arrive with packing peanuts stuck to all the grease inside the pipes at no extra charge... Regards, Lone Quote Link to comment Share on other sites More sharing options...
Modern Motorsports Ltd Posted October 17, 2001 Share Posted October 17, 2001 "I would imagine that ceramic coating your entire exhaust system would be a complete waste of time and money if it hung low enough to scrape on speed bumps. As soon as you've scraped the coating off of even a small section, you've exposed metal and invited rust to come out and play." Ceramic coating with today's aluminized pipe is IMO for keeping the exhaust heat in the exhaust gases and getting it out the tailpipe. I coated my headers to keep engine bay temps down, and I'll most likely paint my Y pipe too as they all influence my starter/firewall/floors/transmission cable/tranny etc....just a good thing IMO. My Y pipe isn't coated now but next one will be. I've got a layer of proform heat shield pads from front of bucketseats to 14" up my firewall, and then proform sound pads from rear of bucket seat to up my firewall on top of that in same area. Made a big difference in cabin heat (wife really appreciated it, as do I) AND noise. I didn't think todays aluminized pipe was very prone to rust? On the few aluminized systems I've seen, they looked just fine at least 5 yrs later. Any other experience with that? Quote Link to comment Share on other sites More sharing options...
Modern Motorsports Ltd Posted October 17, 2001 Share Posted October 17, 2001 quote: Originally posted by pparaska: Dude, a bit of salt on the road and the Aluminized stuff goes to rust! Haven't seen that happen here or in Alberta, and both have lots of salt, especially here where it's borderline freezing and not deeply subzero...so salt is more effective. I'd give it a 5yr+ great lifetime before it shows any signs (as I've seen none yet)easy, just from my experience. their were changes in piping 5 yrs ago or so in case our material comparisons were different. Quote Link to comment Share on other sites More sharing options...
pparaska Posted October 18, 2001 Share Posted October 18, 2001 Dude, a bit of salt on the road and the Aluminized stuff goes to rust! Quote Link to comment Share on other sites More sharing options...
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