advice for rusty bolts on manifold - gasket replacement

[Keef]

Just a thought ... you're not running a leaded fuel engine without a lead replacement additive? That could explain leaky valves/low compression.

[Kjeles]

Intersting idea.

According to Haynes, the unleaded-fuel issue is solved by retarding the ignition timing from 6° to 2° BTDC. I suppose that the combination of 6° BTDC and no lead could cause burnt valves.

My Pinto 2.0 L engines run at 2-3° BTDC and no additives.

[V184]

The manifolds are crap they used to crack under the heat shield (the one in the picture isnt fitted with one) & they came from the factory with no gaskets between the head & manifold, the studs used to snap but most times you could drill/easyout them, as i mentioned earlier always replace the studs if disturbing them

[ernie b]

Intersting idea.

According to Haynes, the unleaded-fuel issue is solved by retarding the ignition timing from 6° to 2° BTDC. I suppose that the combination of 6° BTDC and no lead could cause burnt valves.

My Pinto 2.0 L engines run at 2-3° BTDC and no additives.

Timing will solve the pre ignition problem when switching to unleaded fuel.
However if your head does not have hardened exhaust valve seats they will eventually wear out. If I remember correctly Ford's did last fairly well compared to some other brands in this regard.
I can't remember off hand if an 86 should be unleaded or not, I have doubts it would be. Unfortunately all my stuff is in storage for a house renovation so I can't look up when Ford started fitting hardened seats as standard, there was also an overlap where both were produced and you had to check codes on the head to see.
Thats assuming the head is original and hasn't been changed..
I'd do a compression check and if you see problems then head off to check.
Basically, if it's not broke don't fix it. Luckily the old pinto is still fairly popular and parts are still available.

[Kjeles]

Very interesting information. I didn' t know this.

I found some info on Burton Power's web page (https://www.burtonpower.com/tuning-guid ... -fuel.html):

SOHC Pinto Engines

All engines produced after 01/89 are suitable for use with unleaded fuel. For all other engines, an identification mark (adjacent to No 4 spark plug) must be present to designate suitability for unleaded. These are:
* 1.6 - M, MM or N, NN
* 1.8 - S, SS
* 2.0 - P, PP or R, RR

I checked my 1987 Pinto 2.0 engine. And indeed, there is a 'P' stamped on the head by spark plug #4. Engine good for unleaded. Good to know!

Unleaded Fuel.jpg

[ernie b]

Very interesting information. I didn' t know this.

I found some info on Burton Power's web page (https://www.burtonpower.com/tuning-guid ... -fuel.html):

SOHC Pinto Engines

All engines produced after 01/89 are suitable for use with unleaded fuel. For all other engines, an identification mark (adjacent to No 4 spark plug) must be present to designate suitability for unleaded. These are:
* 1.6 - M, MM or N, NN
* 1.8 - S, SS
* 2.0 - P, PP or R, RR

Yep that's the info I was thinking of.
Unfortunately I'm just old enough to remember the panic about unleaded fuel damaging engines and was reading up on anything I could find at the time

[Dave_BG]

This car runs on LPG, so that's different again I guess.

Haven't been able to get it to the mechanic yet by the way, because they were full and couldn't take it. We've also had to put it in its Winter storage now, so are going to have to wait for warmer weather again (I'm in Bulgaria and we've had plenty of snow since yesterday).

[Dave_BG]

So finally it's Spring again and we took the car to the mechanic...

They managed to undo the bolts by heating them. And then they successfully replaced the gaskets. Very happy and the car runs quieter now. They did point out that the manifold had been welded (this is visible in the first picture), which I never noticed, and also that it's bent. They did their best to do a good job with it, but recommended that I look for a replacement to get the best result.

Thank you everyone again for your advice and following along. For now we have a positive result