Running open manifolds

[1971ford]

How bad is it? I Know there is a lot of controversy over how bad it is. But I should be firing the 360 up in the '69 in a couple days and i don't have any exhaust. Would it be OK to fire it up for a while? How about driving it around the block? They are nice uncracked manifolds and i would like to keep it that way, but i've heard its bad for the valves because of the rapid cold - hot -cold temperature change..

[fomocoguy]

I wouldn't make a habit of it, but I don't think it will cause any immediate damage. Just don't take it out and run the snot out of it. I've ran open manifolds from home to the exhaust shop 10 miles away a bunch of times and it never hurt anything. Keep in mind though that if there are any funky noises going on you won't be able to hear them. I ran a newly rebuilt 351 windsor like that and after the exhaust was installed I found that it was spark knocking like crazy. It had a problem with the vacuum advance and it was advancing waay too much.

That being said, if you have a way of getting it to an exhaust shop without too much trouble I would try to get it piped first.

[1971ford]

That's the other thing, taking it to the exhaust shop. It will have to be driven there with open manifolds i guess, i forgot about that. I'll probably get the exhaust work all done for free as long as i bring the mufflers because my dad used to work with one of the head guys like 20 years ago . It's not too far, maybe 2 miles. Now off to my 390 build thread to figure an exhaust system out..

[papabug71]

If its a new rebuild I would go easy on it. Has the motor been broken in yet?

[ToughOldFord]

I think it's beyond broken in, those bearings look like about 300K give or take a 100K

J/K Ryan, a bit anyway.

[hazelnut]

Ryan i think youll be fine to run for a little while without exhaust but be careful of when your going down the road and let off the gas ( decelorate) as thats when youll burn a valve. If you think about it when your driving to get the exhaust put on and need to slow down just slip it into N and coast. plus you wont have to listen to poping and cracking of the exhaust when you let off the gas.

[1971ford]

If its a new rebuild I would go easy on it. Has the motor been broken in yet?

I think it's beyond broken in, those bearings look like about 300K give or take a 100K

J/K Ryan, a bit anyway.

i'll hear bearing jokes until i finally swap the 390 in won't i, but that's ok because they never get old
But yes it has been broken in a fair amount THis is the 360 temporary engine I'm throwing in, i wouldn't risk anything with the built 390 in the future...

Ryan i think youll be fine to run for a little while without exhaust but be careful of when your going down the road and let off the gas ( decelorate) as thats when youll burn a valve. If you think about it when your driving to get the exhaust put on and need to slow down just slip it into N and coast. plus you wont have to listen to poping and cracking of the exhaust when you let off the gas.

I'll remember that, thanks

[hazelnut]

Ryan you have to admit that some of the bearing jokes are funny even if your on the reciveing end of them. But if anything ever happins to your motor you know your going to hear about it forever and a day. BTW how big are your feet.

[1971ford]

Ryan you have to admit that some of the bearing jokes are funny even if your on the reciveing end of them. But if anything ever happins to your motor you know your going to hear about it forever and a day. BTW how big are your feet.

So true... however i think i am better off keeping it top secret confidential information if something happens to this 300k 360