Vibration Problems?

It seems that after a pass or two, screws are loosing up on my gear drive cover even after using lock-tight; is this common? I was thinking of wire-tying them together. Do I need too check the balance on the crank pulley?
Thanks, Joe

 

Stud it

We had same, used studs and loc nuts, gone away

 

We had a similar problem on a SBC, didn't run that particular combo that long, but we used bolts with holes through the heads and safety wired them on.

 

It's definitely a harmonic thing going on. I run into it on the Chebbies all the time.
I balanced the cam on my own engine this last freshen. I will be interested to see if it changes anything.

Anyone know if the 4-7 swap helps, hurts, or does nothing to improve this issue?

 

We had a motor like that once, BBC, loctite, lock washers and 12 secs later some of the timing cover bolts were literally gone. Eventually the oil pump broke off from the vibration and the rods exiting the pan. The block was cracked in the main web. We assume the crank was cracked first from detonating which started the snowball effect of catastrophy.

 

Detonation????? It can do crazy things!

 

Had that happen to on a BBC. Pretty sure it was detonating as the intake bolts would back out too. The engine was balanced, the crank was not cracked.

 

That's for all the input guys. I'm going to go with Relentless and stud it. I don't think its detonation because I'm only running 10.5:1 comp. at 34* on alky and hitting it with a 44 mag.

Oh by the way Dave I have the 4-7 swap.

Thanks, Joe

 

junk the loctite..after you put it together put a dab of silicon on the nut and thread or bolt and part..when i worked for a t/f team that was the only thing that would work.Dave

 

thats what someon told me one time at a national event one time when they seen me tightening up the intake bolts and and a couple of other things he ask what i was doing i said after the pass the bolts were loose and he said you better take the heads off and look at the pistons i thought wtf are you talking about and who is this guy so not know much at that time about the alky funny car sure enough 8 sunkin pistons and 6 bent rods i still thought wtf how did that happen all that stufff is brand fukin new DETONATION IS SOME CRAZY SHIT

 

My vote is detonation too, 34* could be a lot on a BBC there is more things to consider other than just static compression and timing, like combination chamber cam profile is it lean....... I have run a lot of different BBC combos bolts studs and never had anything come loose unless it was detonating

 

Iv'e ran 36 deg bbc 13:1 38 psi but, it wasn't a 44 mag. 34 deg on a 44 may be like 40 deg with a hopped up Mallory mag.I vote detonation. Iv'e had pan,valve cover and intake bots back off. Got the tune up and the problems went away. www.fuelinjectionenterprises.com Thats what fixed my troubles. Pay now or later. 1 small payment now will save a big one down the road . Hope it helps. Craig

 

Now I am confused, why would a 44 mag set at 34* look like 40* to the motor? Only the top gear drive socket head bolts are backing out not any of the manifold bolts. I'm only running 20 psi boost with Pro-1 heads and the highest egt temperature is 1113* on #1 with NGK-9 plugs.

I am not saying its not detonation I will definitely take a closer look at the plugs tomorrow. Thanks, Joe

 

Ok I will throw my loose bolt story in here, we have problems with the rear pan bolts comming loose every pass, have not tried loctite or silicon.

I have been blaming it on our heavy ass converter and powerglide, dont think its detonation, we run 15psi boost with 11.6:1 static and only 26* of lead.

The rear main bearing itself never looks any different than the rest, I thought that was a little strange.

 

I don't see how it matters if you run a low amount of boost or a high amount, if the timing is too high and/or there is not enough fuel, it will detonate. Trust me, we've been there. Like I've said before, we make way more power now at much higher RPM's and don't wreck near the parts becuase our detonation is under control.

 

Which NGK plugs are you running?

 

I am running NGK-R5671A-9 plugs.

I check the plugs this morning and they all looked good to me. No black specks on the porcelain that would indicate detonation.

Thanks for the help. Joe

 

if your motor is apart take a look at the rings I use a eye loop to see if the rings have seen detonation,,Dave

 

Pull the hub off and check the seal end for contact with the idler gear. If it shows signs of contact, have a notch machined in it to clear the gear. Make sure you don't cut into the seal area. You can also check for a small amount of backlash in the idler gear after the cover is tight and ready to run. If it doesn't have any backlash, you will need to remove the dowel pins from the block, reposition the cover for the proper clearance and redrill the pins to a bigger size.

 

Check your crank. I had the same issues last year with my Chevy. Ended up pushing the crank out of the pan. It tried to tell me, I did not listen.

Steve