Ceramic Coating a new Exhaust Manifold?

[RuzzTMan]

Anybody ever do this on your Mk1 before? I had the cracked (sheared) 4th pipe and was tired of carbon monoxide in the cabin making be think I was flying. So, I got a new one from Lithia Toyota.

I was going to paint it with VHT (with ceramic) or Rust-Oleum inside and out but then decided to price having it done professionally. Jet-hot is $150 and Performance Coatings is $115. Now, I know that is almost doubling the price of the part, but is it worth the cost to never have the new part crack or break again or will a spray heat insulation coating do just as well for this engine? I don't know how much heat is generated by the exhaust manifold but it can't hurt to cut heat out as much as possible. It's a 1.6L 4AGE by the way.

[Jackstand Queen]

The stock exhaust is heavy and not particularly efficient horsepower wise.

Everyone that reads this post is wondering why you replaced the exhaust manifold with an oem part.

Which leads me to ask why did you go with an new oem part?

You asked for opinions on a ceramic coating. Spending more money on a stock exahaust would be compounding the error.

[RuzzTMan]

Thanks for the reply.

I was placing an order for TRD springs from Lithia Toyota, and figured I should order a new manifold at the same time. I didn't know there were other options aside from what I had found in the way of aftermarket parts that were pretty expensive.

It would be nice to have a TRD version, but as far as I could find there weren't any anywhere to be found. And TRD, OEM or other, I don't want to buy used parts that could produce the same problem (which appears to be heat related) in the future. That's why I want to ceramic coat it; to prolong or prevent the problem happening again. I figure if it lasts me 10 or more years, then it will be worth the investment.

I do remember reading somewhere that the OEM and TRD are not very different in horsepower. So, in the same situation Jackstand Queen, what would you do?

[Medusa]

Custom-fab a new set of headers.

Cheaper than a pre-fab set, and suits your needs exactly.

[Jackstand Queen]

Jumpin Jeehoseffat! Ruzztman is right!

I thought I'd just pop on Google shopping and Shopwiki locate a large number of relatively low priced headers and post the links.

In one minute's search, I couldn't find a single lead on a MkI header.

All I can say is that 5 years ago, there were a lot more aftermarket parts available for MkI's. I've been living in the past.

And RuzzTman has brought me up to date.

Reality sucks . . . . Argggghhh.

[RuzzTMan]

Thanks, I appreciate the input!

Medusa, I see you're in Reno. Do you know any place that does custom fab parts in the Pacific Northwest? I used to live in LA and there were plenty of shops, but I'm in Montana now and don't know of any in my area. Also, never did that type of thing before, but I'd be willing to check it out.

The only other thing I found out was that the '87+ version (which still fits my '85) moved the EGR pipe connection elsewhere (the side I think) which might have been Toyota's answer to the problem. They never explained why they did that. That part was $100 more than what I paid for my part and it also meant that I'd have to get a new EGR pipe, etc, etc and I just didn't want to deal with unknowns.

Oh well, when the new pipe cracks I'll post an update for the archives so we can see just how long these things actually last.

[Medusa]

I used to live in Washington, about a half hour north of Everett. I just moved away about 2 months ago.

I can't think of any well-known custom fab shops, sorry. I'd just weld it myself or befriend an experienced welder and have him help you.

[mr2_jake]

Beware of cheap aftermarket headers. All they will do for you is lose a couple pounds and add a few decibels. Stock manifold is relatively efficient as is, just heavy. I replaced my stock manifold with a very nice (and very pricey!!!) GReddy header, and only noticed a slight power increase in high RPMs. However, it came with there "signature" Jet blue coating, which I noticed drastically reduces engine bay temp. If your not concerned with making more power, I would say ceramic coating the stock manifold is an awesome idea! The more heat you keep out of the engine bay the better. If you DO want more power I would suggest going with a quality header, such as a TRD piece. FWD corolla headers work as well, which are available from many reputable companies. Check out MR2 Owners Club Message Board&#8482 out, there are usually good used headers selling on there all the time!

If you want real performance, cheazy eBay headers are not the way to go!

Check out:

::: Welcome to TED's Compnents :::

[mr2_jake]

BTW, where you at in Montana!!??!? I'm in Billings, and know of a couple good shops!

[q-authority]

I wouldn't pay too much attention to those claiming the oem exhaust manifold is no good, or that significant gains can be made from TRD or other after market manifolds. If you go back and search through this or other forums regarding this issue, you will find that no one has ever published data to support those types of claims. All of the old timers acknowledged that the TRD headers look great, and can save you some weight, but you will be lucky to get more than 1 or 2 hp gain out of it unless you do massive internal modifications, and even then you're maybe only looking at a couple more. I had one on my original '85, and it did absolutely nothing except melt the fiberglass firewall material, and save me a few pounds in the rear. I then put heat wrap on it, and it collapsed in about another 6 months due to the trapped heat, since they were only made out of mild steel.

Ceramic coating a new oem exhaust manifold could have the following advantages:
a) prevents manifold from rusting, and will look like new for a very long time;
b) will keep the manifold cooler and will likely prevent it from cracking on the #4 runner;
c) will supposedly improve exhaust flow due to keeping the exhaust temp up (I don't know the math on this one, and I doubt it really does much, but it is claimed on all ceramic coating sites); &
d) the smoother interior finish will also likely minimize carbon build-up, and therefore help provide a slightly smoother/more free exhaust flow over time;

I coated a new SC oem manifold and collector pipe a year ago and they still look like brand new. They also both run significantly cooler (exterior wise that is) than without the coating. I also had them coat the outside of the original catalytic converter, which looked like it had been left on the bottom of the ocean for decades, and afterwards it came out looking brand new. It should also keep the cat inside temps up and provide for a cleaner exhaust come smog time. I used a Titanium (very dark grey) coating which I am very happy with.

But if you really want a nifty looking set of headers check out the following link. They make TRD knock-off headers, but with better steel, and they will make them in SS if you want. And hey, they are just south of Seattle.
Headers for Toyota, Suzuki, Honda, VW, exhaust parts for home built do it yourself automotive, marine headers.

[YellowJacket]

Originally Posted by RuzzTMan

I don't want to buy used parts that could produce the same problem (which appears to be heat related) in the future. ...I figure if it lasts me 10 or more years, then it will be worth the investment.

The only other thing I found out was that the '87+ version (which still fits my '85) moved the EGR pipe connection elsewhere (the side I think) which might have been Toyota's answer to the problem. They never explained why they did that. That part was $100 more than what I paid for my part and it also meant that I'd have to get a new EGR pipe, etc, etc and I just didn't want to deal with unknowns.

Oh well, when the new pipe cracks I'll post an update for the archives so we can see just how long these things actually last.

I just ordered the exact same thing from Aaron yesterday - for the exact same reasons. This thread couldnt have been more relevant to me.

Ceramic coating on the outside of the mani wouldnt that trap more heat in and make the internal temps hotter?

[q-authority]

Originally Posted by YellowJacket

I just ordered the exact same thing from Aaron yesterday - for the exact same reasons. This thread couldnt have been more relevant to me.

Ceramic coating on the outside of the mani wouldnt that trap more heat in and make the internal temps hotter?

That's why it was mentioned that the internal bores should be done as well, and that is standard procedure for a proper ceramic coating shop. DIY projects probably won't have the ability to properly coat these areas, however.
Someone please clarify for me if they have actually managed to switch to the later model exhaust manifold on their early MKIa's. That is, did they manage to switch to the manifold with the egr outlet on the side of the #4 outlet, instead of on top, and get it to hook up to the original egr valve by just installing the later egr connecting pipe. I wasn't sure this could be done, as I haven't had a chance to look at any late MKI's except for my SC, and I had assumed that its EGR valve might have been repostiioned enough as to make the changes on an earlier MKI unfeasible, and I didn't know if the late MKI's had the egr valve in the same location or not.

[Medusa]

Simple fix: EGR delete.

[mr2tim]

Damn, I love this discussion.

First off, recent research indicates exhaust gases move faster thru hotter exhaust tubing as there is less drag..(so like chics the hotter the better?)

Problem: this means insulating exhaust tubing and not creating more heat in mid-engined engine compartments.

Safety Note: As a SCCA corner marshall I have personally seen fires in MR2's without aftermarket header "wrappings".

I concure that the 4 into 2 into 1 OEM exhaust header is efficient, but yes, you may gain1-3 HP with aftermarket "tuned" unit-but is it cost effective?

Coatings that add to the heat retention may be valid.
Preventing rust on a 1/4" thick steel casting is a joke, maybe perpetuated by the same folks who paint their valve covers yellow?

Just maybe it all boils down to personal preferences?

[RuzzTMan]

Geez, I need to set this forum to email me when people post. Here I am thinking there was no more input and haven't looked at it in a month now. But, in the mean time I have been replacing the exhaust manifold and I'll attach some pics of how the old one looked, the OEM replacement (pic in the first post) and finally the ceramic coated one that got installed.

So far, after some minor issues with installation, I am very pleased with the results!

Here's what I have noticed since installation:
1) Very little gassy exhaust smell in the cabin. (Although there is still some..gonna have to track that down at some point.)
2) With no exhaust leak the engine is quieter and I can respond to how it sounds and feels better.
3) Definitely better acceleration and less bogging down.
4) The exhaust note is a ton better. The muffler sounds great.
5) The idle seems to waver less.
6) It looks so damn good!

With installation, the biggest problem I had, had nothing to do with parts or fit, but instead "user error". Believe it or not, I have never used a torque wrench before, managed to set it incorrectly and sheared two of the three studs off the bottom connection to the exhaust pipe. After a quick call to Aaron (that guy is great!) I figured out how the wrench was supposed to work and got everything torqued down to specifications after salvaging two studs from the old part.

The only other thing I had a problem doing was keeping the ceramic coat from getting scratched when I installed the manifold from underneath. I was on a dolly with the manifold on my chest and the bottom of the engine about two inches above that. Luckily I had a friend grab it from up top and hold it while I seated the nuts to the studs to hold it in place. No scratches!

If you look at the pics, the coated manifold has been blasted and coated inside and out. I used Performance Coatings in Auburn, WA. They charged me about $140 including shipping which I thought was a decent price. It was gone no longer than a week from my door and back again. I picked the Satin Gray Ice type of coating which is a very nice medium gray in color. Their warranty is pretty reasonable too.
Performance Coatings


The #4 crack that prompted the replacement. It goes all the way around! The wet stuff is penetrant I used to get the bolts off.


That is some nasty carbon build-up.


Back from Performance Coatings.


24 year old manifold next to a brand new factory OEM part with ceramic coating.


Got hasty and bolted the O2 sensor on before the heat shield. D'oh!


Not much to see after the heat shield is on. I sprayed the heat shield with VHT manifold paint. Does anybody know if there is a lower (inside) heat shield for this? I have seen one on a 4AGZE.

Next up:
- replace fuel injector o-rings
- switch out OEM springs for TRD springs I picked up from Aaron.
- replace old engine mounts

[RuzzTMan]

Originally Posted by YellowJacket

I just ordered the exact same thing from Aaron yesterday - for the exact same reasons. This thread couldnt have been more relevant to me.

Ceramic coating on the outside of the mani wouldnt that trap more heat in and make the internal temps hotter?

Originally Posted by q-authority

That's why it was mentioned that the internal bores should be done as well, and that is standard procedure for a proper ceramic coating shop. DIY projects probably won't have the ability to properly coat these areas, however.

This is why I opted for a professional job. I went out and bought the rattle cans of high temp manifold paint and everything. But the more I thought about it the more I wanted it done in the best way possible that I could afford.

[q-authority]

Originally Posted by RuzzTMan

Geez, I need to set this forum to email me when people post. Here I am thinking there was no more input and haven't looked at it in a month now. But, in the mean time I have been replacing the exhaust manifold and I'll attach some pics of how the old one looked, the OEM replacement (pic in the first post) and finally the ceramic coated one that got installed.

So far, after some minor issues with installation, I am very pleased with the results!

If you look at the pics, the coated manifold has been blasted and coated inside and out. I used Performance Coatings in Auburn, WA. They charged me about $140 including shipping which I thought was a decent price. It was gone no longer than a week from my door and back again. I picked the Satin Gray Ice type of coating which is a very nice medium gray in color. Their warranty is pretty reasonable too.

Nice to see yours came out nicely. I chose the Titanium Blast, which is a little darker than yours. If your old one had not been cracked they could have ceramic coated it to look exactly like how the new one came out. They did my old cat, which probably looked worse than your old manifold, and it now looks brand new.
Unfortunately, during a current round of work they are doing for me, they screwed up my pistons and had to buy me a new set, which has caused further problems because my block had already been set up around the original pistons, and my new rods had already been reamed to match the original wrist pins. The new wrist pins are smaller, and I will now have to have new bushings installed and reamed (on brand new rods).

[RuzzTMan]

That's a good idea about the cat, I might just do that. Maybe spray it instead since you wouldn't ceramic the inside of it?

Sorry about the pistons and rods. What a pain!

[q-authority]

Originally Posted by RuzzTMan

That's a good idea about the cat, I might just do that. Maybe spray it instead since you wouldn't ceramic the inside of it?

Sorry about the pistons and rods. What a pain!

Concerning the cat, yes, they plugged the internals to avoid getting anything on them. Plus they managed to remove some permanent type gasket material, the previous owner had applied, which I could not begin to remove.

[efx]

Thanks for posting that. Man I thought about doing that and just didn't know how that would look. That looks great though. I guess that's applied just like a regular power coating. I was just reading a magazine with an article about power coating and other things like that. Well, that was about two weeks ago I think. Interesting. And is this the site for those of us that didn't know?
performance

I've been looking at the lighter options with the headers, but like others said, you can't find the darn things anyway, and if you do they want an arm and a leg. Maybe Toyota just needs a non breakable exhaust manifold for this car. Well at least for the early years I guess since I haven't seen any later years with that problem, but I'm new so what do I know. Not to mention they won't do that for an old car any more. Either way, a very helpful post. I may end up just welding the sucker though. I want to see how well that will hold since I really don't do much spirited driving myself.

Oh yeah, I miss the stronger feel of the car when all the exhaust is nice and tight. No leaks on the exhaust = a very HUGE smile on my face.