Am I ready to install my headers?

[MuRCieLaGo]

Ok, from now on I got:

-Exhaust manifolds gaskets
-Paul's dipstick bracket
-OBX headers
-Patience

Haven't received the headers yet though, will I need to have them surfaced?

I will also need to order a chip from Marc Haibeck.

Do I need something else? Bolts? o2 harness extension? Permatex?

Thanks!

[Paul Workman]

Yes. You'll need that too!

[MuRCieLaGo]

Paul, I'm not sure what you mean by "that". :neutral:

[-=Jeff=-]

Bolts - YES
O2 Extension - YES
Permatex - Always good to keep on hand

[Demps]

Dipstick grommet from Jerry (unless you're very careful & lucky)

Ted

[secondchance]

My 94 did not need O2 sensor extension. I believe OBX headers, due to fake cats, O2 sensor bungs are 3-4 inches forward compared to Stainlessworks headers.
Any other OBX header users remember different?

Also, I used Permatex high temp copper sealant per Phil's recommendation. Seems to help the seal and keep the bolts from vibrating loose. Although I used Stage 8 bolts with locking tabs, Phil's suggestion was not to use the locking tabs since header gasket tends to shrink at times necessitating re-torquing of header bolts - impossible once locking tabs are used. However, there are two bolts impossible to get to once dip stick bracket is installed. For those bolts I used the locking tabs knowing I won't be able to re-torque.

[Paul Workman]

Paul, I'm not sure what you mean by "that". :neutral:

Sorry...:p. I wuz just havin fun wid ya!

=Jeff= filled in the blanks.:)

[MuRCieLaGo]

Sorry...:p. I wuz just havin fun wid ya!

=Jeff= filled in the blanks.:)

Hahaha! Jeff made it very clear.

BUT,

Will I need to surface the headers flanges? It hasn't been answered yet.

And thanks Demps for the grommet tip!

[efnfast]

My 90 needed O2 extension.
My stage 8 fasteners, the locking clips would not fit in the groove, so not locking. In my case they served no purpose making for some expensive header bolts.
I also ended up shimming the engine at the motor mounts to clear the steering shaft, the ceramic coated headers rubbed the steering shaft.

[-=Jeff=-]

Hahaha! Jeff made it very clear.

BUT,

Will I need to surface the headers flanges? It hasn't been answered yet.

And thanks Demps for the grommet tip!

I cannot answer that as I had purchased used Watson Headers and just bolted them on..

[RussMcB]

I think I read surfacing flanges wasn't needed.

My OBX headers (without fake cats) did not need O2 extensions, but that may have been because I used O2 sensors that were recommended because they came with longer leads. Sorry, I don't remember the brand/part #, but I think I got it from zr1.net/forum.

I didn't bother to coat my headers. That would probably lead to longer life but I figured I'd give the original coating a chance first to see how it held up.

I also needed a dimple and engine mount shim to clear the steering shaft.

One thing I liked about the Stage 8 bolts is you also have the option to screw them in with an allen wrench, useful to get bolts started in some of the tight places.

[Vette73]

I didn't coat my OBX headers either....I did wrap them though with titanium exhaust wrap...The wrap does not need to be wet first...It goes on well and you can pick it up on eBay or Summit...

Coating can get expensive from what I hear...My ZR1 is just basically a pleasure car so it really doesn't get a lot of miles or is in bumper to bumper traffic each day where underhood temps. could be an issue...

[MuRCieLaGo]

Thanks for all the answers guys! I got pretty much everything now, except for o2 extension harness. Some say I'll need one, some say I won't.

These are the OBX I'm ordering:

http://www.cafr.ebay.ca/itm/171855255003?euid=b2017122652c4e839f0f9c683c13f2c8&cp=1

And if I need an extension harness, I don't know where to buy it.

And by the way, the reason why I want to make sure I got everything is because I will have everything shipped in Maine and I'll travel 2 hours each way (+ customs) to grab my stuff (I live in Canada).

[secondchance]

If you are somewhat handy you can fabricate an extension using this kit and some wires.

http://www.ebay.com/itm/WeatherProof-3-Wire-Connector-Kit-weatherpack-weatherpak-wiring-harness-install-/271827034826?hash=item3f4a2762ca:g:YsYAAOSwpDdVHZs r&vxp=mtr

I still don't think you will need one but to be sure...

[MuRCieLaGo]

If you are somewhat handy you can fabricate an extension using this kit and some wires.

http://www.ebay.com/itm/WeatherProof-3-Wire-Connector-Kit-weatherpack-weatherpak-wiring-harness-install-/271827034826?hash=item3f4a2762ca:g:YsYAAOSwpDdVHZs r&vxp=mtr

I still don't think you will need one but to be sure...

Alright or I can go to a local scrapyard and build something from there! Thanks a lot! I think I got everything now! :)

[RussMcB]

I just searched for 10 minutes looking for the O2 sensor part number with longer lead, but couldn't find it. Maybe I saw it in another forum.

Not sure if it has been mentioned here, but you'll probably need to buy two packages of the Stage 8 bolts because our cars need 32 (or close to it - you can get by with fewer). I bought two packages and may have a few left over laying around. Maybe you could get me and others to ship our left over bolts to Maine for you. :-)

[MuRCieLaGo]

I just searched for 10 minutes looking for the O2 sensor part number with longer lead, but couldn't find it. Maybe I saw it in another forum.

Not sure if it has been mentioned here, but you'll probably need to buy two packages of the Stage 8 bolts because our cars need 32 (or close to it - you can get by with fewer). I bought two packages and may have a few left over laying around. Maybe you could get me and others to ship our left over bolts to Maine for you. :-)

2 packages? Oh my god, will it ever end?

Hahaha that'd be funny, 8 packages of 4 bolts each?

[MuRCieLaGo]

Is it where the air injection system goes? What if I remove it?

https://scontent-yyz1-1.xx.fbcdn.net/hphotos-xpa1/t31.0-8/12045610_10156982857850221_5097154245324236304_o.j pg

[Demps]

EGR pull off.

Only only 93-95 & I'd remove it then.
Ted

[MuRCieLaGo]

Alright then I'll go to a local welding shop to remove that port.

Thanks!

[MuRCieLaGo]

Did you have to heat the exhaust manifold bolts to remove them?

[Demps]

Did you have to heat the exhaust manifold bolts to remove them?

No.

This may be redundant but:

Here's a suggestion: remove them with the heat shields attached. It takes removing the middle & back fenderwells, front wheels plus jacking the engine (2x motor mount bolts, air duct, & MAP bracket) up & down. You have to get at the bolts from both under & side. Requires/easiest-with a SHORT, ratcheting, flex-head 10mm open/box end wrench (use leverage to break bolt free initially if needed) plus a 10mm socket with assorted extensions & u-jt. Oh, and patience.

With both manifolds off: I would double nut each header stud (one at a time), remove it, coat it with thread sealer, & replace it prior to header install.

Ted

[MuRCieLaGo]

Thanks a lot I'm taking notes right now!

[MuRCieLaGo]

Alright.

Driver side is all done. I managed to put 15 out of 16 bolts. Should I do my best to screw the last one? It is doable, but pretty hard.

I did not need an o2 sensor harness extension. I had to (barely) use the hammer on #1 pipe.

Also, I did not put the locking washers of the Stage 8 bolts. Somebody somewhere said it is better that way. Was he right?

Is it me or passenger side seems to be trickier? It seems to be a pain just to unplug that o2 sensor.

Is it safe to unscrew some of the oil pan bolts (2), will I need to put some kind of seal afterwards?

Is the dipstick bracket only holding with one bolt?

Is it a big deal if the asbestos sheets touch the headers?

I did read somewhere that I will need to cut a heat shield... I did not cut any heat shield. Should it be a concern?

Thanks for your help guys!

[secondchance]

Also, I did not put the locking washers of the Stage 8 bolts. Somebody somewhere said it is better that way. Was he right?



Header gaskets will shrink a bit after a few heat/cool cycles requiring bolts to be retorqued - reason for avoiding locking tabs. Except for one bolt behind the dip stick tube. One bolt will be inaccessible after the dip stick is installed. Use a locking tab on that bolt.

[Scrrem]

Hahaha! Jeff made it very clear.

BUT,

Will I need to surface the headers flanges? It hasn't been answered yet.

And thanks Demps for the grommet tip!

I just had to pull my header back off last week and seal with the high temp sealer that Secondchance mentioned due to leaks at the flange on both sides. When I ran a file across the flange, didn't get much contact where the tube came through the flange. So may not be a bad thing to surface the flange if you have the capability, or just use the sealer.
Rich

[Paul Workman]

Driver side is all done. I managed to put 15 out of 16 bolts. Should I do my best to screw the last one? It is doable, but pretty hard.

If they give out a prize for the most bolts installed, you'd surely be in the top 10!=D> Mine are SW headers, if that makes a difference, and I was unable to get that many in. I'd have to look, but I'm pretty sure I got at least 3/tube if not all 4 in some cases. No leaks w/ Jerry's gaskets and a smear of RED RTV...(just because).

7Is it me or passenger side seems to be trickier? It seems to be a pain just to unplug that o2 sensor.

Well...neither is a piece of cake. As I suggested, relocating them to the side is well worth the effort, IMO. (A couple bungs and plugs from Summit Racing, a drill and just a few minutes of welding, and the sensors can be mounted so they extend out toward the frame rail. (Mine are positioned so they angle slightly up; i.e., say positioned something like 85º from the top of the collector; almost as handy as C-beam plates, and you tuner will love you!)

Is it safe to unscrew some of the oil pan bolts (2), will I need to put some kind of seal afterwards?

Say, WHAT??? :icon_scra Well...for whatever reason, if you remove only a couple bolts and do nothing to disturb the seal, chances are you'll get away with it. RTV on the bolts before reinserting them has done wonders on other motors where pan bolts or timing chain cover bolts had to be removed/reinstalled. (Like I said...I have SW headers, and that never came up!)

Is the dipstick bracket only holding with one bolt?

NO. It's held with TWO.

The reason for using the 'stove bolt' provided with (my) bracket is that square ~ 5mm long shank under the bolt head slides neatly between the prongs of the dipstick anchor tab.

When the nut is drawn up tight, the tab, with the help of the stove bolt shank, becomes quite rigid; securing the tube to prevent up/down movement as the dipstick is removed and reinserted. For that reason, I suggest the bolts at each end be installed loosely (at first) to align everything, and then snug up the nut on the dipstick end of the bracket first as the header bolt will index the bracket angle as you tighten the other end. (Trrrrust me! Twaz all thought out long time ago!)

Is it a big deal if the asbestos sheets touch the headers?

I did read somewhere that I will need to cut a heat shield... I did not cut any heat shield. Should it be a concern?

Thanks for your help guys!

Hmmm..... I never had an issue with asbestos sheets on my 90. Something different, perhaps. But, just as a rule of thumb, and especially if the headers are NOT coated, it is best they don't come in contact: asbestos sheets were not intended for direct contact. If you have (ceramic) coated headers, there would be less of an issue (if any), for certain. Just my 2 cents!


:cheers::cheers:

[MuRCieLaGo]

Paul, thanks for all your answers. My only concern now is the dipstick bracket. Didn't see the 2nd bolt yesterday. Hmmm...

[MuRCieLaGo]

Thanks secondchance and Scrrem, I did not see your posts this morning. Too late for the seal though, (I've already done driver side). I will (try to) put locking tabs only on bolts behind the dipstick bracket.

Paul, there wasn't any 2nd bolt that holds the dipstick bracket. Should I put your homemade bracket before or after installing the headers?

The grommet was worn, but still there. Could have reused it.

How about the heat shields guys? I did not cut any heat shield yet. Did you?

[MuRCieLaGo]

Alright,

Headers and chip are now installed.

I did a 40 miles ride and 90% of the Stage 8 headers bolts became loose. One of them felt in the street. I just tightened them back.

I hope it won't become loose again...

[MuRCieLaGo]

It's just starting to get loose again. Did you guys put the locking tabs? I don't want to remove the fender liners and tighten the bolts after every ride.

[efnfast]

My stage 8's were manufactured poorly. The clips that hold the locking tabs would not fit in the groove. I should probably check them all for tighness (not sure if that's a word, but you get the point).

[RussMcB]

This is interesting. I've heard of retightening them once after a bit of time, but not loosening every ride.

Did you assemble with thread locker?

I installed mine last summer (Stage 8 bolts without using the locks) and haven't thought about them since. I guess I'd better check them. I think I used blue Loctite.

[MuRCieLaGo]

I did not install the locking tabs. It was a pain to clip in my hands, I can't imagine removing them when they are installed.

Local people told me to put Loctite. However, I followed Dynomite's advices and I put Permatex Anti-Seize. For me, Dynomite = God.

Should I put Loctite?

[Dynomite]

I did not install the locking tabs. It was a pain to clip in my hands, I can't imagine removing them when they are installed.

Local people told me to put Loctite. However, I followed Dynomite's advices and I put Permatex Anti-Seize. For me, Dynomite = God.

Should I put Loctite?

I use Locking Tabs, Stage 8 bolts and Anti Seize on Exhaust Manifold Bolts :p

Exhaust Headers Locking Bolt Tricks (http://forums.corvetteforum.com/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-3.html#post1581564063)

On the Injector Housing Gasket, Water Pump Gasket, Injector Coolant Manifold gaskets and Coolant Hoses as well as Thermostat Housing Halves (Anything where Coolant is Involved) I use a bit of Permatex 300 Form A Gasket (Not Too Much but on both sides of the gasket). I also use a bit of Permatex 300 Form A Gasket (Not Too Much but on both sides of the gasket) on the Oil Pan Gasket, Front Cover Gasket, Oil Filter Adapter Gasket (Anything where Oil is Involved).

Use of thread Lubricants, Loctite and Sealants (http://forums.corvetteforum.com/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp.html#post1580070553)

No Permatex 300 Form A Gasket on the Plenum Gasket (I have TB Coolant Blocked) and nothing on the Header Gaskets.

[RussMcB]

I'm a big believer of anti-seize, especially when there are different materials and heat cycles involved, but I'd still choose Loc-tite over anti-seize in this case.

Anti-seize is to help remove bolts that may be stubborn later, but you're having the opposite problem.

[Dynomite]

I'm a big believer of anti-seize, especially when there are different materials and heat cycles involved, but I'd still choose Loc-tite over anti-seize in this case.

Anti-seize is to help remove bolts that may be stubborn later, but you're having the opposite problem.

Without the use of Stage 8 Locking Tabs.....YES :p
Actually without the use of Locking Tabs I would probably not use anything ;)

[efnfast]

Why use Stage 8 if you're not gonna use the locking tabs?

[RussMcB]

Why use Stage 8 if you're not gonna use the locking tabs?One small advantage is the Stage 8 bolts can be tightened with an allen wrench. That's kind of handy since some are not easy to get a wrench or socket on. It's nice using a ball-point allen wrench to spin 'em in.

[Dynomite]

One small advantage is the Stage 8 bolts can be tightened with an allen wrench. That's kind of handy since some are not easy to get a wrench or socket on. It's nice using a ball-point allen wrench to spin 'em in.

Excellent point......some things I just do not pick up right away :p

[Johnny5]

Excellent point......some things I just do not pick up right away :p

So i am on the phone with Summit Racing to order the Stage 8 Header bolts and I tell them I need part number 8905 which is 8mm x 1.25mm and 25mm long.

The rep tells me LT5 needs part # 8908 which is 8mm x 1.25mm and 30mm long (underhead length). It comes with exactly 32 bolts.

So should i cancel the order and get the 8905 or will these work?

[Dynomite]

So i am on the phone with Summit Racing to order the Stage 8 Header bolts and I tell them I need part number 8905 which is 8mm x 1.25mm and 25mm long.

The rep tells me LT5 needs part # 8908 which is 8mm x 1.25mm and 30mm long (underhead length). It comes with exactly 32 bolts.

So should i cancel the order and get the 8905 or will these work?

Checked the threaded hole depths on two 1991 Heads. ALL Exhaust Manifold bolt holes are exactly 1 inch deep. You can figure from there after considering Header Flange Thickness + the Exhaust Gasket Thickness ;)

[MuRCieLaGo]

I need to make some additional comments regarding the headers installation.

1: You just CAN'T install the locking tabs if you're installing the headers without removing the engine. So, it makes the Stage 8 expensive bolts pretty useless. I'm sure there's a better bolts option.

2: If you're not gonna use the locking tabs, don't put anti-seize.

I just had to remove every single bolts one by one this morning, clean the threads from the anti-seize I put previously, and then put BLUE LOCTITE. Got to wait 24 hours now.