Exhaust manifold question (1 Viewer)

[bigredmachine]

So the question is whats the difference between the 93-94 and the 95-97 manifolds? I know that the 95-97 dosnt have the port for the pair valve, that's why I bought them, but I'm assuming that they should just mount right up no problem. I need some exhaust work done and figured that this would be easier and I could just give him a set of manifolds to replace the old ones and delete the pair at the same time.

I was also planning on having them ceramic coated to help keep the temps under the hood down, any reason why that would be a bad idea?

 

[Heckraiser]

Not sure on the first question, but I don't see any reason why not to ceramic coat your manifolds.

 

[baldilocks]

I assume you are also planning to delete the egr system as well? If so, and I were going about this the way you are with different manifolds, I would weld the egr gas port on the rear manifold shut instead of making a block off plate at the valve end.

 

[Malleus]

To answer the first question, look at the part numbers for the gaskets. Unless someone has direct experience doing this, that should tell you if they will fit the head.

To answer the second, the heat will still be there. If you insulate the headers, it will move downstream until it finds a way out of the exhaust system, very likely near the floorboard.

 

[bigredmachine]

I assume you are also planning to delete the egr system as well? If so, and I were going about this the way you are with different manifolds, I would weld the egr gas port on the rear manifold shut instead of making a block off plate at the valve end.

I would like to but right now its just disabled and plan on removing the egr garbage at a later time.

To answer the first question, look at the part numbers for the gaskets

good idea didn't even think of that

 

[bigredmachine]

To answer the first question, look at the part numbers for the gaskets. Unless someone has direct experience doing this, that should tell you if they will fit the head.

got the gasket numbers looked up at work and they are the same so looks like it shouldn't be an issue. I also looked at the exploded views of the head and exhaust system and they appear to be the same manifold.

I would weld the egr gas port on the rear manifold shut instead of making a block off plate at the valve end.

ill look into it but may not go that route now, it would be a lot of filling in the port with weld and then having to grind it smooth so it sits flush with the head. I would probably have to make a gasket for the rear manifold and would prefer to be able to stick with a Toyota gasket

 

[Malleus]

Post your results. I have a '94 and two '95s. I would like to know how you make out.

 

[bigredmachine]

Post your results. I have a '94 and two '95s. I would like to know how you make out.

I may not get around to it for a little while ive been busy with work and want to get the manifolds cleaned up and ready to go before going to get the exhaust repaired, but ill be sure to follow up. may be a good way for guys to delete the pair and keep it stock looking in ares that require a visual look for emissions testing.

I think that baldilocks may be onto something with deleting the egr this way but it would take a lot of work, ill get pics of the back manifold so you can see what would have to be done. my concern with filling in the egr port would be getting the manifold flat to the head and sealing without any leaks

 

[bigredmachine]

top pic is front manifold, needs a little cleaning up just has normal amount of carbon

second is the egr port on the rear manifold. so fun fact the front and rear manifold flanges to the head are mirror image so if someone was looking to weld and fill in the port you could probably use the front manifild gasket and instead of the rear and it should seal to the head. you could also use it to mark out where It needs to be filled in

third is the rear manifold, not really sure what all that white crud is. has a kinda chalky consistence and was pretty easy to start to chip out.

fourth is closer shot of the chalky crud and where the pair port would be on the 93-94 manifold. theres plenty of meat there to drill and tap for an upstream o2 sensor or if you wanted to a pyrometer

 

[jjdeneen918]

I’m curious how much heat ceramic coating insulates?

I’d do it just for rust prevention & looking awesome, but I’m curious if anyone has measured before/after temps with coating.

Not sure how scientific a laser thermometer would be since there would be so many other variables, outside temp, etc....

 

[scottryana]

It depends on what kind of ceramic coating you are talking about. If you are talking about the ceramic coating that most powder coaters do, I would say it isn't much just barely measurable. The one that you say looks awesome is probably like the Jet Hot coating which isn't much better. If you want a true ceramic coating, you would need to go with something like Swain Tech's White Lightening coating which is many times thicker then the other coatings and is actually sprayed on ceramic.

White Lightning Exhaust Coatings | Swain Tech Coatings | Industrial Coatings | High Performance Racing Coatings

I’m curious how much heat ceramic coating insulates?

I’d do it just for rust prevention & looking awesome, but I’m curious if anyone has measured before/after temps with coating.

Not sure how scientific a laser thermometer would be since there would be so many other variables, outside temp, etc....

 

[jjdeneen918]

Swain’s website:

Reduces radiant heat by 33-55%. That’s impressive!

Cost: manifold- $150-$235 (cast 6, 8, or 10 cylinder)
Down pipe- $40 a foot

Located in NY, so shipping cost back & forth too.

 

[bigredmachine]

got the studs out of the rear manifold and gave it a bath in the hot tank, looking better. still soaking the front manifold to get the studs out

 

[bigredmachine]

Studs for the front manifold are out and now their soaking in degreaser before they go off the blasting cabinet. ive wire wheeled most of the rust off and cleaned up the gasket surfaces but still need a little more prep work before it goes out to get coated. ill get pics up when their out of the degreaser bath

 

[Jgunner]

Id coat it, you can always wrap your exhaust br the floorboards or get the whole exhaust coated! Ha! We’ve done manifolds on other trucks but did them inside snd out. Was noticble by just putting your hand down near it.

 

[bigredmachine]

im going to coat them with a shop that is close to work and weve used them before. its a machine shop that does powder coating and ceramic coating as well as all machine work.

I may also wrap the down pipes as well but ive noticed some rust build up on the exhaust of my dirtbike after I took off the wrap. I'm guessing that it was holding in some moisture and not drying out as quickly as an unwarped exhaust

 

[Jgunner]

Yes, wraps will hold moisture. Get as much as you can coated if it’s reasonable.

 

[bigredmachine]

so manifolds are back from getting sand blasted and the new gaskets are in. I was hoping to use the front manifold gasket for the rear and fill in the egr port since they appeared to be a mirror image, they are not. its close but not close enough to work so I may just skip filling in the egr port and get them coated and read to go.

 

[bigredmachine]

so I did some searching and found that there is not an oem gasket for manifolds that do not have the egr port, I would have to make my own if I wanted to delete the egr by filling it in with weld. I wasn't really looking for that as the factory gaskets have lasted for the 24 years and I wanted to keep it oem with the gaskets.

manifolds have been straightened out and sent out for ceramic coating, hopefully ill be able to pick them up tomorrow. they were pretty straight and just needed a little cleaning up on the mating surfaces. ill get pics up of the coated manifolds when I have them in hand

 

[Saito]

Cool. I just got my Genie headers back from Jet-Hot. I didn’t get a new gasket set from Australia but it appears that if you flip the front gasket over and cut out one of the lower bolt holes on the gasket, that it’ll work(and block off the EGR port too). Genie headers don’t have the EGR provision. There’s only one bolt that’s not spaced the same on the front compared to the back and you should be able to cut it and make it fit. That’s my plan anyway.