Engine failure after 20000 km.

[c9zx]

" however, my Mustang would then lose its registration as a classic car. " That sounds crazy to me, however I know the TUV can be a serious pain. Do they know how to tell a FMX from an AOD? I do know Daniel D. and Michael have T-5 transmissions in their muscle cars. Maybe ask them how they got them approved. Chuck

 

[Vicus]

" however, my Mustang would then lose its registration as a classic car. " That sounds crazy to me, however I know the TUV can be a serious pain. Do they know how to tell a FMX from an AOD? I do know Daniel D. and Michael have T-5 transmissions in their muscle cars. Maybe ask them how they got them approved. Chuck

Registration as a classic car becomes more difficult every year and is not granted for eternity, but is generally checked every two years during the regular TÜV inspection. Many owners of modified classic cars simply take the risk and hope that they will get away with it. As long as there is no accident with personal injury, they may be right.

 

[Vicus]

Frank, As bad as it is, it could have been MUCH worse. At least you don't have a window in the block. Oliver P. may know someone willing to replace the seats. Also Abudi in Wien may know someone. The CHI heads are indeed great. However they seem to be overkill for how you use the car. If you want to use original heads, 2V or 4V, I can find a set and have them rebuilt to suit the cam you want to use. New thick wall pushrods, in custom lengths, are available from Trend, Manton, and Smith Brothers. I've used all of them with no problems but Smith Brothers ar easier to deal with in my experience.
I would disassemble the short block to clean and check for collateral damage. Hopefully you won't find any. Let me know if I can help. Chuck

Chuck, thank you very much for your offer to help.
I have already discussed the subject of CHI cylinder heads with Abudi. At the moment, I'm leaning towards the CHI 2V heads. These seem to be designed in the style of the Australian 2V closed chamber heads and fit my intake manifold as well as my 351-2V Hedman headers. Even though it might be a bit overkill, I should have peace of mind for years and in combination with the 2.75:1 rear axle everything should fit again.

 

[cv_72mustang]

You said the push rods are original?. Depending on the years and miles on them it would not surprise me they failed due to heat/age fatigue. I had the same issue years ago. Just my opinion.

 

[Spike Morelli]

These are the original cylinder heads and I had already asked several engine builders in the past about fitting hardened seat rings. Unfortunately, no one here in Germany wants to do the work. They argue that the valve seats of the two valves are too close together due to the angled design and that a permanently tight fit of the hardened seat ring can therefore not be guaranteed.

"Therefore not be guaranteed" , well, interlocking valve seats are done all the time, and any competent machinist has been doing so for years. A person never knows these things until one seeks out machinists, but you should likely seek another cylinder head shop and have your exhaust seats machined for hardened. As a reference, you can find that many, if not most, performance cylinder heads will have larger valves, close to one another, that require interlocking valve seats. Many aluminum cylinder blocks will have sleeved large bores close enough to each other that they require a "flat" on the upper edge of the sleeve to mate with the "flat" on it's neighboring sleeve. It's entirely possible that your local machine shop there in South West Germany hesitated doing the seats because they aren't accustomed to doing it, but it's common really. Should the pushrods be too weak for whatever spring tension you run, you can specify , as I have, thicker walled, case hardened 5/16" in your order , as I did. I run Smith Bros, pushrods in 5/16" diameter, to run with factory 5/16" guide plates.

 

[Vicus]

You said the push rods are original?. Depending on the years and miles on them it would not surprise me they failed due to heat/age fatigue. I had the same issue years ago. Just my opinion.

Thank you, that's a valid point. I will definitely replace the pushrods and hydraulic tappets.

 

[giantpune]

I've also thought about a transmission with overdrive. In most cases, however, my Mustang would then lose its registration as a classic car. I think that installing the original 2.75:1 differential on the rear axle will help considerably.

What are you allowed to change without losing your classic car status?

These cars were made back when 55mph seemed like a good idea for a national speed limit. They were not setup to cruise at 120km/h and pass people at 150km/h on long road trips. They can certainly get that fast if you need them to. They weren't meant to just sit at 3600rpm for a 100 mile trip, no matter what all the other cars on the road currently think about it.

I would look at running taller tires and swapping back in the 2.75:1 at a bare minimum if you expect that sort of road tripping. I'm unclear on what the regulations allow you to do there. If you can not swap the transmission, can you at least install an aftermarket overdrive like a gearvendors?

Registration as a classic car becomes more difficult every year and is not granted for eternity, but is generally checked every two years during the regular TÜV inspection. Many owners of modified classic cars simply take the risk and hope that they will get away with it. As long as there is no accident with personal injury, they may be right.

Every 2 years? Thats a long enough period, i would be inclined to swap the transmission long enough for whatever inspection, then get home and swap back in the overdrive one. But I do agree with the sentiment that how would they know what's original and what's not? Most likely, they will trust any writing, tag, or stamp thats on the body. Drop in an overdrive transmission and put a tag on it that says "this is definitely the original FMX". Smear it with dirt and grease. Then its up to them to prove its not.

 

[Vicus]

"Therefore not be guaranteed" , well, interlocking valve seats are done all the time, and any competent machinist has been doing so for years. A person never knows these things until one seeks out machinists, but you should likely seek another cylinder head shop and have your exhaust seats machined for hardened. As a reference, you can find that many, if not most, performance cylinder heads will have larger valves, close to one another, that require interlocking valve seats. Many aluminum cylinder blocks will have sleeved large bores close enough to each other that they require a "flat" on the upper edge of the sleeve to mate with the "flat" on it's neighboring sleeve. It's entirely possible that your local machine shop there in South West Germany hesitated doing the seats because they aren't accustomed to doing it, but it's common really. Should the pushrods be too weak for whatever spring tension you run, you can specify , as I have, thicker walled, case hardened 5/16" in your order , as I did. I run Smith Bros, pushrods in 5/16" diameter, to run with factory 5/16" guide plates.

Spike, yes I can very well imagine that this is common practice in every engine shop in North America. Unfortunately, this is not common practice at engine shops here in Germany. Perhaps they also refuse to do it because they can simply make more money repairing a classic Mercedes or Porsche engine.
The more I think about it, the more I lean towards aluminum cylinder heads.

 

[Spike Morelli]

Thank you, that's a valid point. I will definitely replace the pushrods and hydraulic tappets.

Your lifters have already mated-in to their respective cam lobes, if you have hydraulic or solid flat-tappet lifters, replacing them after break-in is not done and will most likely preclude another valvetrain failure. Camshafts and lifters are replaced as a team. Your camshaft has a high percent chance now of NOT breaking- in a second time to another new set of lifters. Leave them alone. just attend to the pushrod and valve seat issue.

 

[Spike Morelli]

Believe it or not, most all european engines have aluminum cylinder heads with seat inserts, and any competent shop has been doing hardened, and bronze seats for years. I strongly urge you to find another shop comfortable with doing the job................unless buying different heads appeals to you for performance reasons. I totally get that. ( Notice that those aftermarket cyl heads will come with interlocking valve seats too ), but will now have guide plates requiring case hardened pushods , your 5/16" bolt-down rockers will not work because most all aftermarket heads will come with 3/8" screw-in rocker studs, so new rockers, and nuts will be needed. The oil deflectors will not work with aftermarket heads, so they're gone as well. You will need to check pushrod lengths as things will change with a cylinder head swap. When using soft aluminum heads, head bolts should use washers under the bolt heads, you may think about a new set of ARP head bolts. MLS gaskets may be required as aluminum heads and iron blocks expand at different rates, MLS gaskets were designed for such a combination. On top of these items, your current valve covers may not fit over the new adjustable valve train, so be aware of purchasing those new covers in all probability. If your spark plug wires were loomed over the factory valve covers as came stock, there is always the chance that they may now be too short to go up and over new taller valve covers, so will the bolts holding down the stamped steel valve covers be possibly too short for aluminum covers, if that's what you end up doing. I'm not trying to deter you from the cyl head swap, it's only to direct your thoughts to other issues which occur when going aftermarket, it starts adding up $$$$.

 

[Vicus]

What are you allowed to change without losing your classic car status?

These cars were made back when 55mph seemed like a good idea for a national speed limit. They were not setup to cruise at 120km/h and pass people at 150km/h on long road trips. They can certainly get that fast if you need them to. They weren't meant to just sit at 3600rpm for a 100 mile trip, no matter what all the other cars on the road currently think about it.

I would look at running taller tires and swapping back in the 2.75:1 at a bare minimum if you expect that sort of road tripping. I'm unclear on what the regulations allow you to do there. If you can not swap the transmission, can you at least install an aftermarket overdrive like a gearvendors?


Every 2 years? Thats a long enough period, i would be inclined to swap the transmission long enough for whatever inspection, then get home and swap back in the overdrive one. But I do agree with the sentiment that how would they know what's original and what's not? Most likely, they will trust any writing, tag, or stamp thats on the body. Drop in an overdrive transmission and put a tag on it that says "this is definitely the original FMX". Smear it with dirt and grease. Then its up to them to prove its not.

I was always of the opinion that the general top speed of 55 mph was only introduced in the USA in 1974. Therefore, all older vehicles should have been designed for higher speeds. Whether the roads and traffic allowed higher speeds remains to be seen.
Generally speaking, if a car is to be registered as a classic car in Germany, it should look as it did when it left the factory. It must be well-maintained and have at least vehicle condition 2. This includes a paint job in a color that was common at the time, in my case a maximum of 15" wheels (diameter, not width), etc. The installation of an AOD gearbox would be possible in principle, as it was launched in 1978 and therefore within 10 years of the date of manufacture of my Mustang. A T5 manual gearbox, first used by Ford in 1983, would be outside this time window.
I am well aware that I am having a rather academic discussion when I consider the installation of aluminum cylinder heads. I need to see that I have a reliable engine in my Mustang again soon.

 

[giantpune]

I was always of the opinion that the general top speed of 55 mph was only introduced in the USA in 1974. Therefore, all older vehicles should have been designed for higher speeds. Whether the roads and traffic allowed higher speeds remains to be seen.
Generally speaking, if a car is to be registered as a classic car in Germany, it should look as it did when it left the factory. It must be well-maintained and have at least vehicle condition 2. This includes a paint job in a color that was common at the time, in my case a maximum of 15" wheels (diameter, not width), etc. The installation of an AOD gearbox would be possible in principle, as it was launched in 1978 and therefore within 10 years of the date of manufacture of my Mustang. A T5 manual gearbox, first used by Ford in 1983, would be outside this time window.
I am well aware that I am having a rather academic discussion when I consider the installation of aluminum cylinder heads. I need to see that I have a reliable engine in my Mustang again soon.

The 55mph speed limit did go into effect in 1974. That means it would have been discussed and voted on for several years prior. If 55 did not seem like a generally sensible speed limit, it would not have made it through to become law. At the time it was enacted in 1974, 12 of our states already had their own 55mph max speed limit and 9 states had lower ones.

For the tire size, you can stick with 15" wheels and there is a world of different sizes that fit. More sidewall will give you a taller tire, which will let your car go faster at a given driveshaft speed. Our cars had about a 26" tall tire. On my 1982 truck with 15" wheels, the stock tires are 28" tall. All this may not be worth the trouble though since you are allowed that 10 year window of parts.

Are you allowed aftermarket parts from within that 10 yr period? Gearvendors overdrive came about in 1979. You can stick a gearvendors behind any of our stock automatic or manual transmissions.

 

[Vicus]

The 55mph speed limit did go into effect in 1974. That means it would have been discussed and voted on for several years prior. If 55 did not seem like a generally sensible speed limit, it would not have made it through to become law. At the time it was enacted in 1974, 12 of our states already had their own 55mph max speed limit and 9 states had lower ones.

For the tire size, you can stick with 15" wheels and there is a world of different sizes that fit. More sidewall will give you a taller tire, which will let your car go faster at a given driveshaft speed. Our cars had about a 26" tall tire. On my 1982 truck with 15" wheels, the stock tires are 28" tall. All this may not be worth the trouble though since you are allowed that 10 year window of parts.

Are you allowed aftermarket parts from within that 10 yr period? Gearvendors overdrive came about in 1979. You can stick a gearvendors behind any of our stock automatic or manual transmissions.

I should really think about an OD gearbox, whether AOD transmission or Gearvendors OD. However, the 2.75:1 rear axle reduces the revs by ~15% compared to the currently installed 3.25:1. That is immense.

 

[Spike Morelli]

Generally speaking, if a car is to be registered as a classic car in Germany, it should look as it did when it left the factory. It must be well-maintained and have at least vehicle condition 2. This includes a paint job in a color that was common at the time, in my case a maximum of 15" wheels (diameter, not width), etc.

This, to me, is not altogether a horrible idea. Lest anyone reading this think I am not a "Hot-Rodder", almost all of all of the cars I've owned since my first car in High School have been modified, so I'm in agreement as to the enjoyment of customizing your own car to one's own taste, but I concur that "Classic Cars", of any make, by definition, or shown in competition, should adhere closely to the visual and mechanical configuration it left the factory in. Otherwise, any changes might be better defined as a "modified version of a "classic". Splitting hairs, I realize, but for insurance reasons, concourse judging, and such, the two are sometimes worlds apart. I attend as many car shows as I have time for, and I see owners taking liberties with what they propose to display. Take the much cherished "55 to "57 Chevy Bel-Air. I'll bet you most that you see today restored were originally six-cylinder cars with a three-on-the-tree. Today, people swap in a 283 to 572, 5 speeds , add nauseum. Cool, but not , as a car, a "classic". Fibreglass Cobras with 351ws engines, 1969 Z-28 Camaros with LS power, '40 Willys coupes with blown early Hemis..............these are Hot rods and Customs not of factory manufacture, and must, should, be represented and viewed as such. They're still cool, but not a "classic" to me, if only in year of body style originally. As long as I'm here on my soap box, don't even get me started on where "Rat Rods" are, in the universe of the car hobby.

 

[giantpune]

I should really think about an OD gearbox, whether AOD transmission or Gearvendors OD. However, the 2.75:1 rear axle reduces the revs by ~15% compared to the currently installed 3.25:1. That is immense.

I have a couple of these cars still with the 2.75:1. They'll spin the tires (or just the 1 tire if its an open diff). I think the only time you see a benefit from having a numerically higher gear in these cars is when you stomp on the gas from 0 to however fast you want to go. The rest of the time, its nicer having the lower ratio.

That is especially true now. Like you describe, being on the highway with everybody flying past you. Modern cars coming with dual overdrive gears and from the factory designed to cruise at 70-90mph. Soccer moms in their SUVs sipping on starbucks are driving circles around a 50yr old car. If you expect to keep up with that traffic for extended periods of time in your old car, something will need to be replaced.

 

[Cleveland Crush]

I have a couple of these cars still with the 2.75:1. They'll spin the tires (or just the 1 tire if its an open diff). I think the only time you see a benefit from having a numerically higher gear in these cars is when you stomp on the gas from 0 to however fast you want to go. The rest of the time, its nicer having the lower ratio.

That is especially true now. Like you describe, being on the highway with everybody flying past you. Modern cars coming with dual overdrive gears and from the factory designed to cruise at 70-90mph. Soccer moms in their SUVs sipping on starbucks are driving circles around a 50yr old car. If you expect to keep up with that traffic for extended periods of time in your old car, something will need to be replaced.

Oh Spike! What a stomach churning visual you just painted:

"Soccer moms in their SUVs sipping on starbucks are driving circles around a 50yr old car (Mustang)"

 

[Cleveland Crush]

Oh Spike! What a stomach churning visual you just painted:

"Soccer moms in their SUVs sipping on starbucks are driving circles around a 50yr old car (Mustang)"

Ment to reply to giantpune not Spike!

 

[giantpune]

Oh Spike! What a stomach churning visual you just painted:

"Soccer moms in their SUVs sipping on starbucks are driving circles around a 50yr old car (Mustang)"

 

[Don C]

These are the original cylinder heads and I had already asked several engine builders in the past about fitting hardened seat rings. Unfortunately, no one here in Germany wants to do the work. They argue that the valve seats of the two valves are too close together due to the angled design and that a permanently tight fit of the hardened seat ring can therefore not be guaranteed.

I had them installed on M code heads in 2000 and they're still functional, and have a set of Q code heads at the machine shop now having them installed, along with valve guides and adjustable rocker studs. Neither machine shop had any concerns about the spacing or orientation.

 

[Stanglover]

So I guess you have ditched the 4 speed top loader idea then.