First Generation Firebird

Engine leaking, exhaust manifold cracked

Posted By: olli

Engine leaking, exhaust manifold cracked - 06/05/19 07:06 AM

The engine of my 350cui 1968 FB leaks quite a lot and, since at least one exhaust manifold is cracked (RH) and as it turned out 2 bolts of the other exhaust manifold a broken off. Thus, it is now time to address these topics and the engine will come out.

Currently, I have got one used exhaust manifold to replace the cracked one. Since I live in Germany and parts are not as readily available as in the USA and a shop will do the work it is better to order parts in advance to keep turn around time at bay. Gaskets are no problem. Exhaust manifolds, however, are. Would you rather buy a complete set of:
https://www.ramairrestoration.com/p...-long-branch-d-port-factory-headers.html
to be hassle free compared to used ones that might crack (I would have to obtain a used LH via eBay in case the currently installed on has also cracks)?
Since the thread of the oil pan is apparently worn out something needs to be done here, too. Is there a repair kit (metal piece to be welded inside containing a new thread) available or is the Canton 15-389 oil pan the better choice despite having the plug on the side?


Oliver
Posted By: uconn86hgiv

Re: Engine leaking, exhaust manifold cracked - 06/05/19 01:23 PM

You have a lot going on here. Not sure either one requires removing the engine but you may have more going on than just these items.

You said your engine leaks? That can mean many different things? But since you list a few I'll give it a shot.

You have many exhaust manifold options. You can replace with stock log type which will not require any modifications to your existing exhaust. You can also upgrade to longbranch set as you mentioned. They are a nice upgrade but not cheap. You may need an oil filter re-locator and need to adapt to your current exhaust. You can also go with headers but they have their own set of issues and may require additional fit work. You should gain a few horses with longbranch or headers.

As for the oil pan... I can't tell if you are talking about the drain plug or the bolts holding the pan in place but either one should be a relatively easy fix for any mechanic to retap and not require a new pan unless the drain plug hole has been already repaired before now beyond repair. They even sell oil drain plug fix kits just for that occasion.
Posted By: olli

Re: Engine leaking, exhaust manifold cracked - 06/05/19 03:21 PM

Actually, I want to keep the FB as stock as possible. The link I posted regarding the ramairrestoration headers would require additional changes to the exhaust system as I’m aware of now. So I prefer to find a LH exhaust manifold to add to my replacement RH side one, which has been lying dormant for 6 years.
I meant the drain plug thread and there are time sert kits available. However, depending on previous work on the thread you may need different kits - this can’t 100% be decided before removing the pan. I know there was a flange available for C2 Corvette oil pans facing the same problem: GM #3723008 or you can make it by yourself: 1/4”- 3/8” flat steel about 2 x 2” and a thread 1/2-20 in the center, which is then welded in the pan. This is something I can prepare in advance.
Since at least one stud of the LH manifold is broken and it needs to be drilled out I was told the engine has to be removed. Most probably more will shear off while removing the manifolds.

Oliver
Posted By: uconn86hgiv

Re: Engine leaking, exhaust manifold cracked - 06/06/19 02:50 PM

You should be able to find an exhaust manifold pretty easy. Check ebay or used Pontiac parts stored online. Frank's Pontiac parts etc. come to mind. I can think of a long list of projects to tackle while the motor is out. Great chance to have access to the entire front end too.

As for the oil pan I would find it hard to imagine you can get it repaired fairly easy. Especially if the pan is removed.
Posted By: cme469

Re: Engine leaking, exhaust manifold cracked - 06/08/19 12:44 AM

Hey olli, if you can’t find a 9777755 and just want one that will work, I have a box of miscellaneous Pontiac manifolds I could look through for you.
Ron
Posted By: olli

Re: Engine leaking, exhaust manifold cracked - 06/08/19 10:53 AM

@Ron: thanks for your offer. However, I was was able to obtain one on eBay. If its condition is bad I’ll come back to you.
@uconn86hgiv: also thanks for your input.

Unfortunately, this is a project that my limited experience and tools prevent me from doing on my own. So the only thing I can do is to order used parts in advance and gather information on which companies to choose with respect to new gaskets and quality.

I’d like to know which engine sealant kits are recommendable. Summit Racing offers one. But I would choose Bop for the divided rear main seal (Viton) and one piece oil pan gasket and omit respective parts of the sealant kit. What do you think? I suppose the suitable down pipe bolts and exhaust manifold bolts can be ordered arbitrarily - or is there also a company preferable?
Thanks in advance.

Olli
Posted By: cme469

Re: Engine leaking, exhaust manifold cracked - 06/08/19 07:44 PM

You may hear different opinions on gaskets but I have always used Fel Pro. On the manifold bolts and studs, ARP is many folks favorite, but there are many good choices.
Posted By: olli

Re: Engine leaking, exhaust manifold cracked - 06/09/19 04:04 PM

And how about the rear main seal? Is a Viton one as offered by BOP the least troublesome - or is this plain marketing? I heard stories by my garage that sometimes a replaced rear main seal leaks just after 700 mls again.

Olli
Posted By: uconn86hgiv

Re: Engine leaking, exhaust manifold cracked - 06/10/19 07:19 PM

Fel Pro makes nice gaskets and ARP makes nice bolts and studs. I don't think anybody will argue those.

Rear main seals can be quite a bear but as you are pulling the engine you should be ok. The originals were made of rope but more options now. Lots of opinions on the best products and courses of action. Some have had good luck with a product only to have it sworn off by others. Lots of threads here you can look up on the topic. Viton is a popular choice.

Are you doing this repair or a mechanic?
Posted By: olli

Re: Engine leaking, exhaust manifold cracked - 06/11/19 11:36 AM

I’m undecided ... I have never done a comparable task. Some people here in the forum did it without any previous experience, too, and were successful. I’m currently looking what tools I would need: an engine stand - not too expensive. An engine crane can perhaps be borrowed. Regarding the nuts and bolts that are rusted and, thus, hard or not easily to open, I would buy an induction heater instead of using a flame. For the labour costs in the shop a lot of tools could be bought :-)

Oliver
Posted By: uconn86hgiv

Re: Engine leaking, exhaust manifold cracked - 06/20/19 12:19 PM

So here is my 2 cents on "do it yourself". Some things are worth it... and some things not. There is no doubt you can do it. Thousands before you have done it. Whatever it is. You just need to consider "What is the worst thing that happens if I screw this up?" Depending on the repair that can vary.

If you take your engine apart to replace the rear main seal my guess is that you will properly be able to put it back together. With some help and a good shop manual of course. Worse case scenario is things are not repaired and a lot of oil continues to leak. However if you are not careful in reassembly things could go very bad. The up side is you will learn a lot along the way and if you do it properly save a good deal of money. Make a big mistake and you will be looking for a new engine! What you will be missing out on is that a good mechanic might be able to tell you a good deal about that engine while they are in there!

Here is where you get into the fun of an old car. While you have that engine out and torn open there is a list of about 100 things that you should probably look into doing. It's all about time and money. It's not just about the engine... you now have wonderful access to the front end too. See what I mean!

As far as your exhaust manifolds go those rusted bolts can be a real pain in the butt! You may find that you hit them with some penetrating oil and let them soak and then some heat and they come out. You win. But you might need to drill them out or worse have the hole retapped. Better to leave that to a pro. It's worth the few dollars.
Posted By: olli

Re: Engine leaking, exhaust manifold cracked - 06/21/19 07:43 PM

Here are two pictures of the holes with the missing/broken bolts. Still nothing removed just used a tiny USB camera for a smartphone. More bolts will most probably break. These broken bolts have been my biggest concern so far because experience is the key factor. Regarding the rear main seal I would use the divided 3” Bop Viton seal so that the crank case can be left in place and only the main cap anti rotation holes require high temp silicon. For removing the old rope seal there is this sneaky pete tool.
I think i need an exit strategy, i.e. when to hand over to a pro. This can be when the holes need to be retapped and/or the crank case needs to be loosened or removed in case the Viton seal doesn’t work.

Olli

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Posted By: olli

Re: Engine leaking, exhaust manifold cracked - 08/18/19 01:20 PM

Here is my plan regarding the issues:
I’ll clean the underside of the engine and auto and put crayon powder on, drive the car and hopefully better see where the leaks originate .. or at least to better near the “leaking issue” down. Compile a parts list based thereupon.
After finding out (or wishful thinking based on some hard to come by information) that the factory only used 8 exhaust bolts despite 12 holes in the exhaust manifolds and heads the driver side should be fine - the spacer are still on the outer most bolts. The passenger side one is to be replaced due to the crack. 6bolts are present (no correct spacers used) - at least two welds from previous cracks are on it - so it was removed at least once. If all bolts can be removed- great. If the outer ones break - well, only 4 were used by the factory - justification to not remove the engine purely due to that. I have started to apply Liquid Wrench (ATF + Aceton would damage surrounding rubber and other non-metallic parts). Before trying to remove the bolts my induction heater will be used on the bolt heads and the respective spots of the engine where the bolts go in. If one or more bolts break, the engine must come out. Then the leaking issue can be addressed also. If all goes well with the bolts I will try to address the leaking issue with the engine remaining in the car only lifted so much to remove the oil pan to subsequently replace oil pan gasket and rear main seal, which I presume to be the culprits. I know it is tough to do it with engine not removed but I will give it a try using a ramp to bring the car up approx. 25” to work under it lying. According to Bop Engineering only the rear main bearing cap has to be removed to reinstall the 2 part seal. From what I have read the 350 engine is not so prone to the out-of- alignment groove issue.
If I fail I’ll see ... my mechanic has a closed trailer to pick the car up :-)


Olli
Posted By: salmon38

Re: Engine leaking, exhaust manifold cracked - 08/18/19 04:03 PM

Sounds like a good plan.
Posted By: Gus68

Re: Engine leaking, exhaust manifold cracked - 08/22/19 03:46 PM

Take the engine out. Do it right from the start and you will save time and money. And the stuff you will learn is a hell of a lot more useful than work arounds.

Have a look at this thread... https://firstgenfirebird.org/forums...s68+%2Bengine&Search=true#Post317949
Posted By: salmon38

Re: Engine leaking, exhaust manifold cracked - 08/22/19 09:26 PM

It's one of those things we take for granted living in the States. In Germany, it's pretty much illegal to do most involved DYI auto repair procedures where your activities can be seen by the public. Especially things like engine removals where you might accidentally spill ANY engine related fluid onto your driveway. Spilling such chemicals will get you a hefty fine.

I will bet you those restrictions have a big impact on Olli's plans. Unless he has a large garage (rare - most are barely bigger than the car) or acreage away from prying eyes (also rare).
Posted By: olli

Re: Engine leaking, exhaust manifold cracked - 12/01/19 01:12 PM

A couple of months have passed and .. I haven’t started to work on the car. But at least I have all required tools now. The most expensive one was the car ramp to work under the car, which arrived 3 weeks ago. A small welding shop here in Germany made it for $600 (converted from €) incl. shipping.
I revised my plan what to address. Firstly, I’m going to replace the passenger side exhaust manifold, which is cracked. I have started to spray creeping oil on the bolts. After doing this 2-3 times I’m going to use my induction heater and then try to remove them. If I’m successful the leaking issues (leaking tranny pan and most probably rear main seal) will be done next storage season.The engine oil is almost new. And I plan to do this with the engine in place from the underside, just by lifting it to remove the oil pan.
If the bolts break then ... I need to revise my plan slightly grin

Oliver

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Posted By: Gus68

Re: Engine leaking, exhaust manifold cracked - 12/13/19 04:50 AM

If your planning to take the rear seal by jacking up the engine your not going like too much. Not to mention even IF you get it changed it will probably leak.

That stand you have there...that must be the before pic. The after pic will be taken by the coroner. You push on that car and it's going to fold up like a house of cards.

Why are you that high and the car is on it's wheels. What on earth is it giving you? Ability to pump up your tires from the standing position?

Sorry man...call them as I see em.
Posted By: Firebob

Re: Engine leaking, exhaust manifold cracked - 12/13/19 05:20 PM

I don't know. It looks pretty stable to me. I might think about some sort of cross brace on the end but I kind of like it. A little more room that jack stands and a creeper. Car lots have been using these forever on the corner of their lot.

I agree with Gus about the rear main. If you do try to install it while in the car you're looking at about a 90% fail rate after all that work. Either live with the puddles of oil or pull the motor and do it right. Even then you probably looking at 50/50 that it won't leak eventually.
Posted By: wovenweb

Re: Engine leaking, exhaust manifold cracked - 12/14/19 02:01 PM

Originally Posted by Gus68
That stand you have there...that must be the before pic. The after pic will be taken by the coroner. You push on that car and it's going to fold up like a house of cards.


Puah on the car in which direction? You realize what the angled braces are for?
Posted By: Amervo

Re: Engine leaking, exhaust manifold cracked - 12/14/19 04:02 PM

"It looks pretty stable to me"
X3

"You realize what the angled braces are for?"
NO!

Common sense call: people who don't have mechanical aptitude will have a 90% failure rate on all mechanical repairs. Also, this explains why a car has sat in a box for the last 10 years, with ZERO progress, never to be completed.

"Sorry man...call them as I see em."
So don't be hating because I do as you do!
Posted By: Gus68

Re: Engine leaking, exhaust manifold cracked - 12/14/19 04:48 PM

Taking another look I see there is more than enough steel to hold the thing up in the air. Over kill on steel IMO.

What can you use it for? After you get it up there are you going to jack it up to take the tires off? Are you going to pull the engine, remove the rear end, clean the floor pan?

Now your finished using it. Where do you put it?
Posted By: Bartbird

Re: Engine leaking, exhaust manifold cracked - 12/15/19 04:28 PM

Originally Posted by Gus68
If your planning to take the rear seal by jacking up the engine your not going like too much. Not to mention even IF you get it changed it will probably leak.

That stand you have there...that must be the before pic. The after pic will be taken by the coroner. You push on that car and it's going to fold up like a house of cards.

Why are you that high and the car is on it's wheels. What on earth is it giving you? Ability to pump up your tires from the standing position?

Sorry man...call them as I see em.


agreed, not to crazy about the welds either, hopefully we're wrong but some extra safety wouldn't hurt
Posted By: ped

Re: Engine leaking, exhaust manifold cracked - 01/03/20 02:48 PM

Originally Posted by Amervo
"It looks pretty stable to me"
X3

"You realize what the angled braces are for?"
NO!

Common sense call: people who don't have mechanical aptitude will have a 90% failure rate on all mechanical repairs. Also, this explains why a car has sat in a box for the last 10 years, with ZERO progress, never to be completed.

"Sorry man...call them as I see em."
So don't be hating because I do as you do!


You are 100% correct, I'm professional welder/fabricator, with all the triangulated braces it is more than strong enough for the weight of the bird, maybe a X brace at one end would could be added but not necessary. I think you got a great deal for your $ on the fabrication.
Posted By: Bluebird428

Re: Engine leaking, exhaust manifold cracked - 01/03/20 07:00 PM

I've had more than my share of rear seal problems with my engine. Not too long ago there was a post from a member who had the rope seal replaced while the engine was in the car. But, My opinion is to pull the engine to replace the seal.

I just did an R&R of my 373 posi diff. After rolling under the car on a creeper for a few hours, I wish I had something like that ramp to give myself some more room. Still would have had to get the rear wheels in the air but could be done on the ramp somehow. Wouldn't want to have to move it though. Looks like it's in bolt together sections?
Posted By: olli

Re: Engine leaking, exhaust manifold cracked - 02/23/20 12:49 PM

Ok, I'm not dead lying buried beneath my Firebird.
Due to a hand injury and the cold garage I had to stop working. Since the car is still on the ramp I post the URL of the manufacturer here. It is ramp #6 that I have got.
The sections are bolted together.
https://pkw-rampenmann.de/Rampen-Typen-und-Preise/mobile/
I postponed the rear main seal fix ... maybe infinitely. After the exhaust manifold I'll address the leaking atm oil pan. If this significantly reduces the leaking I can live with the rear main seal drops - especially based on effort and (non)success rate.
Yesterday I opened all exhaust manifold bolts on the passenger side - result -5:1 ...
The most forward one broke. However, since the respective thread/hole was not used by the factory and I'm a big fan of originality (great excuse, isn't it) I leave it.
Attached is a picture of the broken bolt. Appears to me as if exhaust fumes reacted with the surface - maybe the reason for the sheared off bolt ( another excuse).

Regards
Oliver



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Posted By: uconn86hgiv

Re: Engine leaking, exhaust manifold cracked - 02/27/20 09:04 PM

Well if all your other manifold bolts came out and you got that much of that one out I would say you did very well! IF the engine was out of the car you would be able to drill out the rest of that bolt, or use an extractor etc. But with it in the car you got no shot. Just no room to work. You might be able to get by with putting all new bolts back in and just using a shorter bolt in that spot? Clean up the threads first. I'll bet it tightens pretty well. You got some threads to work with.

And glad the ramp held up for you! For what it's worth my rear main leaks too. Sometimes more,sometimes less. I keep trying to convince my wife we need to have the engine rebuilt so it "will stop leaking".
Posted By: Gus68

Re: Engine leaking, exhaust manifold cracked - 02/28/20 12:57 AM

Hi Oliver,

I wish you good luck. In the absence of any addition good luck, may I suggest you remove the engine from the car. You would learn how to remove and engine and fix various things on your engine you would not dream of doing from under your car. If you start fixing things under your car is only going to teach you new language skills (swear words).
Posted By: Bluebird428

Re: Engine leaking, exhaust manifold cracked - 02/28/20 07:46 PM

I don't know what 459 Euros is worth in canadian dollars, but I bet I couldn't by the steel up here for that much. Probably fix up some wheels or casters to move the sections when the time came.
Posted By: Gus68

Re: Engine leaking, exhaust manifold cracked - 02/29/20 12:15 AM

Originally Posted by Bluebird428
I don't know what 459 Euros is worth in canadian dollars, but I bet I couldn't by the steel up here for that much. Probably fix up some wheels or casters to move the sections when the time came.


$680 Cnd
Posted By: olli

Re: Engine leaking, exhaust manifold cracked - 03/28/20 05:03 PM

Today has been a nice and warm day so I have removed the manifold. I have redrilled the threads except the one that broke - flush - as it has turned out. As mentioned, I planned to install another exhaust manifold leaving the broken bolt since it hadn’t been used when the engine hab been assembled. BUT - the surface of the cylinder head looks bad ... at least to me. I’ve attached a picture ... does it have to be removed and resurfaced?

Regards
Olli

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Posted By: bigchief

Re: Engine leaking, exhaust manifold cracked - 03/28/20 05:28 PM

if you could drill and tap the bolt hole it would reduce the chance of any leaks. Use the red high temp RTV on the exhaust gasket surface and let it set up a few days to prevent any exhaust leakage around the rusted areas.
Posted By: olli

Re: Engine leaking, exhaust manifold cracked - 03/28/20 06:45 PM

The bolt broke off at the other end of the exhaust manifold (front)... and there is really not much space to drill it out - if at all. Perhaps with a Dremel.
So on this side (to firewall) with the rust I could install the bolt.
I thought about this https://www.quiksteel.com/18022ktri-exhaust-system-repair-kit/

I’ve ordered this one now ....

https://www.permatex.com/products/g...m-temperature-rtv-silicone-gasket-maker/




Olli
Posted By: uconn86hgiv

Re: Engine leaking, exhaust manifold cracked - 03/29/20 12:02 PM

If you get into doing this any way other than the correct way... which it to get all those bolts set up properly you will eventually be unhappy. Some other fix may work for a short time but will likely not work for long. Especially on exhaust manifolds where you have very high heat.

I know you have been trying to avoid taking the engine out. But it isn't really that big of a deal as long as you have someone to help you and it will make this much much easier. Then you can do it right. And you can get a good look at all kinds of other things very easily while its out. If nothing else to some good cleaning and lubing. I think you will be happy you did. You can probably rent a lift and an engine stand is not expensive. And you an sell it when your done.
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