72 LS5 Posted May 24, 2011 Share Posted May 24, 2011 Now that I have the exhaust on the 502, I can hear all the noises I couldn't hear before. I'm getting a ticking, which I was 99% sure was an exhaust leak. But the sound goes away just off idle, like the once the lifters pump up a little and it does not get louder with more throttle like an exhaust leak would. I have the lash set at the factory recommendation of 1/8 after 0 lash (per zz502 documentation from GM Performance). That may sound like too little, but its also the recommended for the ZZ454 per Chevy documentation (small blocks use a different lifter part number and they get up to 1/2 turn). I just rechecked each and every rocker, turning the engine over 90 degrees at a time and there none that were "loose" - even spot checked suspect rockers and they were 1/8 from 0. Is anybody running Big Block Chevy hydraulic rollers with ticking sounds? Are you 502 guys running the recommended lash or going 1/4 turn? I'm mostly interested in the BB Chevy roller lifter lash, not comp cams or others since they have their own recommendations. Thanks! Mike Quote Link to comment Share on other sites More sharing options...
cny first gen 71 Posted May 24, 2011 Share Posted May 24, 2011 Cant help ya with the bb lifter info but you may want to check for the exhaust leak first. Take a vacuum hose and put one end up to your ear and the other end go around the header or manafold where they bolt to the head that will pinpoint if there is a leak that way you can rule that out easily. You can also tape it to a peice of wire (stiff coathanger or something like that) and bend the end to get to the bottoms easily too. Quote Link to comment Share on other sites More sharing options...
72 LS5 Posted May 24, 2011 Author Share Posted May 24, 2011 Good tip - thanks! Quote Link to comment Share on other sites More sharing options...
LS5 Posted May 24, 2011 Share Posted May 24, 2011 Hey Mike, What type of oil are you using??? Is it thick enough for the viscosity needed and does it have any Zink in it.??? I am running a 70 LS-5 in the chevelle and the Lucas Zink additive has made it so all I can hear is the engine with no rattle or ping or exhaust leak...And I know Vaughn is running a 502 in his 70 Monte and is using a higher Viscosity oil and a Zink additive and the same thing, just engine noise and thats it.... Just an idea thats all.....Darren. Quote Link to comment Share on other sites More sharing options...
CrazyDavey Posted May 24, 2011 Share Posted May 24, 2011 Mike standard weight oil should be fine as long as your pressure is good, 20/25 lbs at idle (you don't need zinc with a roller). When mine was stock the factory settings never made any noise. I think it is probably exhaust, with a small leak bringing the idle up will make it go away as the exhaust pressure will blow the gases past the leak point....I always use hi temp silicone on the header gaskets for a good seal....Dave Quote Link to comment Share on other sites More sharing options...
72 LS5 Posted May 24, 2011 Author Share Posted May 24, 2011 Even though its roller, I'm still using the Joe Gibbs break in oil, and its loaded with zinc. I believe its 20/50. I'm getting about 25lbs pressure at idle, then its 45lbs. It may be an exhaust leak after all....I want that 2 hours of my life back going through all the valves, lol! Davey - so with your 502, you never set the lash more than 1/8 turn from 0? I've never tried silicone on the exhaust gaskets. Which gaskets do you recommend? Thanks. Quote Link to comment Share on other sites More sharing options...
CrazyDavey Posted May 24, 2011 Share Posted May 24, 2011 Mike I never touched the lash out of the box....I use Felpro gaskets....which ever ones you use just make sure the gaskets cover the header flange completely, trim them if needed... 45 lbs sounds a little low, at wot mine is 80 (stock ZZ stuff)....do you know what kind of clearances the bottom end has? I'm going to try the Gibbs oil in the Chevelle...they say on the dyno the Gibbs syn will increase hp even over other syn's....we'll see.... Quote Link to comment Share on other sites More sharing options...
72 LS5 Posted May 24, 2011 Author Share Posted May 24, 2011 Dave - I just used a stock BB pump, no high volume as everything I've read says the stocker is more than sufficient. I don't recall all the clearances, but the crank is standard size and within the clearance range. I haven't taken the engine over 3500ish yet - only driven a few miles so far. The oil pressure is about what the 454 ran at. I got the data below from http://www.gmperformanceparts.com/Extras/engine-installation-guides/ and the ZZ502 Long Block PDF. I think you can add 14.7 to the numbers below for regular psi. Oil Pressure (Normal): ....................................... 6 psig @ 1000 RPM ........................................................................ 18 psig @ 2000 RPM ........................................................................ 24 psig @ 4000 RPM Quote Link to comment Share on other sites More sharing options...
CrazyDavey Posted May 24, 2011 Share Posted May 24, 2011 yeah Mike those GM oil pressure numbers have been argued a lot. I don't think any engine builder would be very happy with 6 psi at idle, don't know where they got those numbers. Not saying there is anythng wrong with 45 lbs, just the ZZ stuff is higher. If the builder set it up a little on the loose side then the pressure would be a bit lower than a box ZZ. I would follow the break-in instructions for the ZZ, you need to get the rings seated properly, that's a problem area for them. I didn't get home until late Sunday night so I didn't call..you still need to talk? Dave Quote Link to comment Share on other sites More sharing options...
72 LS5 Posted May 25, 2011 Author Share Posted May 25, 2011 Those oil pressure numbers are psig not psi. I believe you have to add 14.7 to the numbers and then they will seem more normal. I think I have my lash issue sorted out, thanks. One last question regarding the break-in. You mentioned to follow the instructions from the documentation. Step 9 seems a little harsh as I always break in gradually. This is mandatory for proper ring seating? I believe I put Perfect Circle rings in there if that matters at all (it was so long ago!). 7. The engine should be driven at varying loads and conditions for the first 30 miles or one hour without wide open throttle (WOT) or sustained high RPM accelerations. 8. Run five or six medium throttle (50%) accelerations to about 4000 RPM and back to idle (0% throttle) in gear. 9. Run two or three hard throttle (WOT 100%) accelerations to about 4000 RPM and back to idle (0% throttle) in gear. 10. Change the oil and filter. Replace with 5W30 motor oil (not synthetic) and a PF454 AC Delco oil filter. Inspect the oil and the oil filter for any foreign particles to ensure that the engine is functioning properly. 11. Drive the next 500 miles under normal conditions or 12 to 15 engine hours. Do not run the engine at its maxi- mum rated engine speed. Also, do not expose the engine to extended periods of high load. 12. Change the oil and filter. Again, inspect the oil and oil filter for any foreign particles to ensure that the engine is functioning properly. Quote Link to comment Share on other sites More sharing options...
CrazyDavey Posted May 25, 2011 Share Posted May 25, 2011 sorry Mike, my mistake, I read that wrong. There still has been a lot of opinions on the oil pressure for these motors, I think yours is fine, just lower than a box ZZ. As far as the break-in, I just know there have been issues with the rings not seating resulting in high oil consumption. Most of the guys I know who had this issue said they did baby the motor. I think they want the motor to go though some quick heat cycles and pressures to get that done. When you start to hit that thing you'll find that 4000 comes up pretty fast, it's a big bore, short stroke motor. I know you built yours so maybe you should see what the ring manufacturer says. Dave Quote Link to comment Share on other sites More sharing options...
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