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C6 Corvette ZR1 & Z06General info about GM’s Corvette Supercar, LS9 Corvette Technical Info, Performance Upgrades, Suspension Setup for Street or Track
I thought I read a thread on this a while ago but can't seem to find it now. How many heat cycles are you guys going through before the intake is staying tight? Mine is coming loose after just about every drive, I am getting a solid 1/4 turn on every bolt @95 in/lbs. (Mamo said right around 100 and the instructions said 89 so I just split it.) Last night would be my 5th time.
Do I need to pull it off and check the clamshell bolts after a while as well? Or just continue to check the mani to head bolts?
Bro, I feel your pain. I've only put about 500 miles on my car since getting my Mamo MSD and I've tightened the bolts at least 4 times now. I can usually get at least a full turn at 90 in/lbs. I did put some blue loctite on the bolts too, so I don't know what the deal is. I guess I'll just keep doing it until they settle down.
I haven't posted on this subject, primarily because I didn't want to get into it with Outhouse - seeing as he is apparently banned, I will do so now.
I have yet to re-torque a single time on my MSD install - now, let me preface my process with the comment that I am not very trustworthy of any design I deem to have any potential for failure.
We know this is not a factory manifold - we've all heard and seen the various issues (flashing not cleaned up, interface around the injectors not being flat, ports not matching, TB to manifold interface not matching, etc.) - this gave me plenty of ammunition to justify my approach.
Here is what I did - after smoothing out the casting flash, leveling the injector bosses, cleaning up the port exits and sealing the gap on the bottom of the intake runners (I chose to use RTV, in case it ever came loose and was ingested), I applied a bead of RTV around the entire clam shell halves on both sides, injector boss area, etc. I also put RTV on the pass-through intake mounting bolts / o-ring area, not relying solely on the o-ring to seal the top of the manifold. This of course also sealed the top of the bolt / washer combo to the manifold, preventing the bolts from backing out (not saying they would, but they won't with this method).
Note that blue loctite has a relatively low temperature threshold - I would not expect it to be useful to lock the pass-through bolts in the the cylinder head - the clam shell bolts, yes (and I used blue on mine as well).
Anyway, this is ONE way to deal with gasket shrinking / bolt loosening issue, there are others.
I am going to call MSD and ask for a replacement clam shell (black) gasket - I do not anticipate to find any indication of a leak, my idle has never changed nor any variation in any scans.
Last edited by Dan_the_C5_Man; 04-27-2017 at 03:01 PM.
That is a good idea with the RTV! Do I need to remove it and check the clamshell bolts? If so that would give me a chance to get some RTV in there, but I'd rather not take it off again unless I have to lol.
Truth be told I dont mind having to re torque them, annoying yes, but its not hard. I just wondered if its normal to have to do it all the time or not.
Tony Mamo discussed this at length in one of the numerous MSD threads. He basically suggested to not use the recommended torque values, and to follow the pattern several times, until the bolts were tight. I just used a T handle wrench and did as Tony suggested. I have not installed the intake yet, as I'm fighting with clearance issues I created by using AN fittings for the valley vent and cylinder head vents, but will next week after I figure out my clearance issues. I'll monitor mine over the next few weeks and put together a findings thread.
I know how to torque a bolt and know the proper ordering procedure of these bolts. Torqued them properly and correctly during installation, and used blue loctite. I track (road course) my car, and since installation have been on the track 4 times. After each and every event, I have checked my bolts and almost all of them will take a half-turn at 90 in-lbs. I have also tried 100 in-lbs and still after a day on the track they will take another half-turn after an over-night cooldown.
Either this will become a permanent part of my after-track procedure/inspection (empty catch-can, inspect brakes, check oil, re-torque MSD, inspect tires, check battery connection etc etc) - which is fine by me, or maybe at some point they will hold. So far it is just another quick procedure for me to follow. I really hate the ones in the back though.
I re-torqued the bolts I could get to with the manifold on after every ride, about 5-6 times.
Then i pulled the manifold off to see the ones on the back by the firewall. I noticed the one bolt was rubbing the firewall a little, so i dremeled it a bit. Then one by one, i removed the clam shell bolts, re-locktited and torqued down. Then re-installed the mani and re locktited the manifold bolts. I have checked them the last 2 times since then, and I was able to get about a 1/4 turn on the manifold bolts....clamshell stayed tight.
I'm going to chock it up as another maintenance thing.. i mean it only takes 10 minutes so no big deal right?!?!
Yep, will be a somewhat routine thing for me. Could be a random thing like how some need more cleaning up than others, some rub the firewall or some dont.
Yep, will be a somewhat routine thing for me. Could be a random thing like how some need more cleaning up than others, some rub the firewall or some dont.
I actually have a special torque wrench that I use for my job. I can get to all the bolts with out any issues. So far using 100 inch pounds I have done this four times so far.
Tony Mamo discussed this at length in one of the numerous MSD threads. He basically suggested to not use the recommended torque values, and to follow the pattern several times, until the bolts were tight. I just used a T handle wrench and did as Tony suggested. I have not installed the intake yet, as I'm fighting with clearance issues I created by using AN fittings for the valley vent and cylinder head vents, but will next week after I figure out my clearance issues. I'll monitor mine over the next few weeks and put together a findings thread.
X2 on following the pattern several times. I just installed mine and maybe my torque wrench is absolute junk, but after the first 90 inch lb pass I was still getting half a rotation on the bolts when checking them. Felt stupid but I did another 3 passes at 90 until everything seemed acceptable. Must have been alot of flex in it is my assumption.
Probably not for everyone... But for me, this makes it all worth it! I trimmed my own covers and if you didn't know any better it looks like it came from the factory this way!
04-27-2017, 11:55 AM
MSD Re-Torque Procedure
Works great with a 1/4 ratchet for the rears.
Ridiculous quite honestly...