Ricey McRicerton

Hey guys, well I'm half way through my y8 intake manifold swap, and I get the old mani off (y7 mani sucks!!!) and I go to grab my Intake Manifold Brace, but hell...I can't find it. Come to think of it, I can't even remember when the last time I saw it was (should have gotten all of my stuff together, but was excited about my new 3" AEM ITR CAI). Anyone tried to modify their Y7 mani brace to work with the y8, or would it be really stupid to run my y8 mani braceless for a couple days until Honda gets the brace in (already got it ordered)? I know the brace is there for a reason (to keep stress off the studs) but would I even be able to put the brace on the mani once it's on the car??? Thanks guys!!! I am super stressed out about this, and if I can't get my car back together tonight Ill be bumming a car off of my parents!!! Thanks!

Ricey McRicerton

bump one time before bed....somebody has to know!!! Please help!!!

Ricey McRicerton

Well, I ended up making on...Ill let you guys know how it works out!

blackANESE

iTrader: (2)

I'm not running the brace on my ITR manifold.

Doesn't stress me one bit.

Ricey McRicerton

Yeah but I was worried about snapping off the studs...so I made one out of stainless steel. Looks good and is super strong!

Evs-One

garbage

Nextelbuddy

why would you be running a 3" CAI, it does you no better than the correct size for your manifold which i beleive is about 2.25 or 2.5. 3 inch is for the b18c5 motor

Marauder

I'd round file the manifold brace. I think Honda just put it there so they would have a place to tie-up wires. Those studs should be able to hold 3000 lbs of tensile load....and with 7 of them....it'll stay up there just fine.

Maybe they put the brace there for all those people standing on their engines! Yeah, that's it!

Evs-One

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Marauder &raquo;</TD></TR><TR><TD CLASS="quote">I'd round file the manifold brace. I think Honda just put it there so they would have a place to tie-up wires. Those studs should be able to hold 3000 lbs of tensile load....and with 7 of them....it'll stay up there just fine.

Maybe they put the brace there for all those people standing on their engines! Yeah, that's it!</TD></TR></TABLE>

actually...I think that brace is there to cause a longer length of time for servicing= more money...lol.

Firstn thing I do when pulling an engine is throwing that stupid thing away. No more going under the car just to pull the intake mani. Oil change are easier, as well as reaching sensors, etc back there

Kamin

i hate those damn braces.
throw it in the garbage. they dont do ****.

Ricey McRicerton

Yes the 3 inch is for the ITR...but Im using it for my car

BigZ88

so you seriously dont need it? WHY PUT IT THERE IN THE FIRST PLACE THEN!? grrrr caused me a few problems/pains in the *** when doin my swap. (came up from under the car so rear mount was a bitch to get in...forgot to take that brace off before i came up....stupid me

btw in response to guy up there a ways, they arent normally in tensile load...they are in shear which would break them ALOT quicker

Ricey McRicerton

Allright....I was going to make another thread about this, but I guess this one will do. Ive got everything on the car and started it up. It runs fine for about 5 seconds and then there are big jumps in idle (almost 1k jumps). I know this is because of a vaccum leak and something seems to be wheezing underneath the intake manifold itself. Did anyone have the problem, because I have checked all the hoses on the intake mani, even plugged up the holes that it didnt mention in on the makuragi site (or whatever the one that everybody links to all the time is). I cannot find this, and have had 3 people check it...someone please help!! Ive got the PCV valve line running to the top nipple on the IM and the coolant line from the metal coolant line by the PCV valve running where its supossed to go on the small nipple on the passengers side of the car. The open nipples are on the bottom of the TB....and on the top of the IM...the one right by the block...would one of these be my problem ??? Somebody please help!!!

Ricey McRicerton

oh yeah...and if anybody has a pic of how they ran the 3 inch ITR CAI on thier EK then please post it up!!! Ive got mine run now, but don't really think thats how its supossed to be....thanks!

RSZero1

check the torque on your IM bolts, that would cause high idle problems, and do you have your IACV wired up properly? On your DX it's a 3 wire on the TB, on the Y8 its mounted on the IM and it's only 2 wire.

Ricey McRicerton

so incorrect torque on the im bolts will cause high idle??? Its not a high idle though, its a pulsing idle...and I left the IAC valve on the back of the y8 mani (its on a y7) and and ran a loop of hose on it to prevent vacuum leaks. I used the y7 tb on it. Do you know the torque specs on those bolts, because I torqued them down pretty good....BTW thanks for the help!

Marauder

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BigZ88 &raquo;</TD></TR><TR><TD CLASS="quote">
btw in response to guy up there a ways, they arent normally in tensile load...they are in shear which would break them ALOT quicker</TD></TR></TABLE>

Hmmm...shear.....so the bolts are preventing the manifold from sliding off the head???? When you torque the nut against the manifold it pulls on the stud in the axial direction putting the stud into a tensile preload. Now during regular operation of the engine and driving, the vibration on the stud will be a combination of tensile and bending, but for the stud to have shear loading, there must be a sideways force placed onto the stud by the manifold bolthole. I would say that the studs are not in any type of shear loading, but vibration can fatigue a stud if you look at the lifecyle of a stock Honda engine for about 300k miles.

As far as the idle problem, surging sounds like a vacuum leak, maybe have a torn hose. I forgot to look up father on the thread, is your Y7 a manual or automatic?

BigZ88

weight causes shear. Mass*gravity=force that force would generally be in a downward direction. Yes the IM is slightly angled but yea. Tighting the bolts shouldnt be a problem as long as they are torqued correctly so that force shouldnt cause much of a problem. Vibration could cause a bending moment, but that is fairly small

Marauder

There will be absolutely no shear load, even by the wieght of the manifold. Why is that?? because the hole that the stud goes through is not in contact with the stud, there is clearance! The manifold is prevented from sliding down off the head by the surface contact of the nuts.

Yes, vibration will cause bending moments, only slight forces will be transfered to the studs. Most of it will cause bending of the manifold, and could cause the manifold to crack.

Most of the load of the studs is transfered to seal the head and intake flange surface with the gasket inbetween them. It is over engineered as far as holding the manifold to the head, but it is needed to seal for leaks.

Ricey McRicerton

No, to whoever suggested that the hoses are ripped, I bought all new hose to replace the old stuff and even checked for leaks at the hoses by pinching them off (my dads suggestion, and he worked on marine helicopters for years). Anybody know anything about a wheezing sound under the mani??

EDIT: Also, the studs are at the correct torque settings....so thats not the problem..the car is a manual, and the IM is a manual....any other ideas??

BigZ88

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Marauder &raquo;</TD></TR><TR><TD CLASS="quote">There will be absolutely no shear load, even by the wieght of the manifold. Why is that?? because the hole that the stud goes through is not in contact with the stud, there is clearance! The manifold is prevented from sliding down off the head by the surface contact of the nuts.

Yes, vibration will cause bending moments, only slight forces will be transfered to the studs. Most of it will cause bending of the manifold, and could cause the manifold to crack.

Most of the load of the studs is transfered to seal the head and intake flange surface with the gasket inbetween them. It is over engineered as far as holding the manifold to the head, but it is needed to seal for leaks.</TD></TR></TABLE>

can i ask where u studied? cause i am fairly positive the bolts would break well before the manifold seeing as the weight of it is moving as a unit. Now i see where u are coming from, with the majority of the weight being in the intake end of the runners in the intake chamber, but doubt that it would cause the manifold to crack or break before the bolts. The "clearance" of the manifold is EXTREMELY minimal. In no way is the force of the nut or head of the bolt holding tight enough against the block to prevent it from sitting on the bolt or on the metal dowel things. So my firm belief is still with there being some shear load existing. That is my judgement from studying as a Mechanical Engineer. It doesnt really matter tho because there will always be people who use the brace and those who believe it is useless. Personally i am still up in the air. I'll think about it tomorrow when im finishing up my install.

Marauder

Yes, I am a mechanical engineer.....I went ot UC Santa Barbara which was in the top 40 something engineering schools in the nation at the time I was there.

This is what I think of when I think of shear stress, as far as loading of a bolt.



I don't doubt that there maybe some very slight shear loading of any intake manifold studs, but I see the load applied being so small as to never fall into any failure mode of a stud.