redbird555

Installed my Mamo ported msd this past weekend, I've had fast manifolds on other cars but this is the first msd. I noticed that when jumping on the throttle or digging into it fairly decent from lower rpm say around 2k the engine has a deeper growl to it if that's the right way to put it? At first I thought it might be rubbing against something but the motor mounts are stock and clearance looks ok so I'm pretty sure it's just the engine note. TB is still the stock 90 for now. anyone else noticed anything similar? Car is also still on the stock heads/cam

MTPZ06

Have you confirmed that the back of the manifold isn't coming in contact with the cowl, or that your TB isn't touching the top of the water pump?

RedZ4me

Yup - just like mine. Search msd and hinson mounts, i think that's the thread. Anyways, most likely touching the rear firewall - mine in storage but will look at it next spring. It was my last mod i did, before the msd intake, no issues and yes i describe it the same - -a growl

outhouse

Exactly what it is.


Mine did.

outhouse

OP you need to dremel down the rear allen where its rubbing AND dremel the firewall without going through.


Exactly like mine yours is almost free and just needs a little dremel love.


The intake needs to come off anyway so you can retighten all the now loose clam shell allens. Do not torque, just use common sense and tighten all tight by hand.


My 6 top and bottom allens stayed tight, just the clamshell were loose after 2 hours running.

redbird555

Where are you all specifically talking bc the car still has stock mounts so I didn't think hitting the cowl should be an issue

redbird555

I'll pull the manifold off tOmorroe will it be noticeable on the cowl where it's contacting

redbird555

Outhouse so it was he Allen screw on yours that was hitting? Not the actual manifold itself? Could you point out which one it was in the pic here?

outhouse

Bolt #12 is probably rubbing, and yes you can see the contact plain as day bud.




When I started my car for the first time that rumble noise was constant unless I took off or slowed down. Little freaky because it sounds like something bad happened. The next morning after rubbing through somewhat, the description mirrors yours 100% perfectly.


With stock motor mounts mine also rubbed on top and I dremeled the top of the msd in the back top passenger side for clearance. Hopefully yours clears there.


Like I said it literally needs to come off anyway to retighten all of #12's brothers.

redbird555

Gotcha I'll give t a check in the morning. Mine clears the cowl there on the pass side but just barely did you actually grind the top of the manifold. Idk if I'd be too keen on doing that being how thin the lid is

outhouse

I was cautious doing such, and just dropped the top a hair in that corner. About the thickness of a penny at most. I'm guessing about a 1/3 ish if the thickness in the flattest part.


Id rather thin out the intake then screw up the firewall.

double06

One idea is to put a button head bolt on number 12. The lower profile and rounded top would probably be enough.

Mordeth

So is it just blind luck whether these always hit the cowl or not? Considering adding this along with a NW TB once I am done with my suspension and brake mods. A button head bolt sounds like a good idea.

double06

Also do button head bolts -( good steel grade 8.8 not ss - too soft) on the valley pan bolts so the bottom of the MSD does not hit them. The stock valley pan bolts you need 10 (11 actually but one does not go under manifold) are actually fairly high. The FAST intake requires you change them so if you have a FAST then it should have been done already. But the higher grade steel is much better for torqing bolt down as the SS strip easy.

outhouse

Not needed


Not an issue with this intake. The only reason John had issues was because he added a thermal blanket to the bottom of his.

outhouse

Maybe, but a little dremel work and you keep the structural integrity of the bolt without compromise.


Its just barely hitting. The washer is also hitting and needs to be ground down

double06

Actually one guy had an issue on the back valley bolt of his MSD when the engine was out of the car and he could see straight through. May vary from intake to intake. I could see using a smaller washer or dremel on it as that hangs over.

redbird555

So it was hitting the firewall a bit I filed down the intake a bit as well as the washer. I had the Button head bolt idea as well which since I don't need the car back together today I'm just going to run to lowes I the morning and pick one up. That way at least I know I have the most clearance possible

redbird555

Ok all well since I hate it when I read threads that are unfinished I figured I should post up my final results. I replaced the socket head bolt with a button head as I said and it offers much more clearance than the socket head from msd could even after you grind it quite a bit...bc I did try that. I've got ample clearance now that I can see and no more growling noise. Sorry for the bad pic as I couldn't get the lightin. To cooperate but you can se the height difference from the stock bolt to the button head one

ChevyCobb

Sounds like mine is doing the same....at least I hope that is it. Sound cant be heard well from outside, but inside is loud at idle and coming off throttle. I didnt notice it until it came up to temp though...maybe as it all expanded.
I'll take it all back out and hope this is the case.