I was just curious what the redline was on a stock 390 (no mods) from 1976. I thought I saw somewhere the max power was at 4200 rpm but I can't seem to find the actual redline. Thanks a lot. btw it is a 2 bbl, not that it makes much of a difference.

 

I usually run my 390 out to around 4000, but I don't believe 5000 would hurt it. It is fairly fresh though(around 15k miles). Mine is a 68 Mach 1 Hi-po 4bbl with a little more cam and some rods and pistons, so 4000 is usually all I need.
I want some headers next!

 

I bone stock 390 will run out of gumpf by 4500.

Severe valve float will occurr around then, so it's pretty hard to get it over 5000.

Josh

 

Yea I got a touch of anger the other day and jumped on it hard, it broke the rear end loose with a detroit locker and 33's which surprised me and by the time I looked down at the tach and shut it down it was about 5200 rpm, which also surprised me lol. Oh well, if the damn thing blows up I guess it wasn't worth trusting in the first place and it gives me a reason to make it hotter for the next time haha.

 

the ol' girls gotta little get up doesnt she??!!!

 

I call BS on that, but oh well.

A stock 2 BBL 390 takes a lifetime to get to 5000, even sitting still spinning tires, let alone revving it in neutral.

Josh

 

Well it isn't stock anymore, I have put a new intake and a 4 bbl, and an rv cam and did some minor work on the heads, I just posed the question as a stock 390 due to the fact I have not done anything to increase redline on the motor.

 

I have basically the same engine setup with the RV cam 4bbl and edelbrock intake with 10:1 pistons and long tube headers. The one problem I've noticed is bending pushrods at high rpms. Is this common with the FE engines and what can be done to help alleviate this? Not trying to steel this thread but I thought the information might be relevent to the question originally.

 

Bending pushrods in an FE is extremely bad.

You need to check your lash with the lifters collapsed. I'll bet the clearance is too tight or you are trying to wind the engine too high.

Even with an "RV" cam you'll only see max power possibly at 4800 or less. So turning those motors any higher is just asking for trouble.


Especially you Saleen065, if you do indeed have 10:1 compression with an RV cam, you'll need to be running 105 octane fuel and have the timing so far retarded to avoid detonation to run that combo. I bet your DCR is nearly 9:1, way way too high, should be around 7.5.

Josh

 

I would call it quits at about 5k

 

Mine isn't stock, but my '73 f100 has a mildly built 390 and it doesn't like to rev much past ~4500 im neutral. But under hard acceleration (Its a four speed) i haven't shifted till ~4900 and the valves floated. Also, not very relevent, but I got a friend with a medium built 400 in his bronco and he claims to go to ~7200!

 

when i ordered my cam from comp, they said the thing will pull hard to 5500 with the setup im running. i guess hardened pushrods would be a good idea. i got a whole kit from them. cam, springs, timing chain, lifters, and i believe thats it. its not together yet, but this is what their cam tech hotline guy said.

 

Oh I love this thread !! LOL... A stock Truck 390 even with a 4BBL wont pull much past 4700 to 4800 and really doesnt do any good, Power just falls off...and the guy with the car 428 in his truck..that motor will run up to 6K and lull all the way there !

And the other guy that said his Buds 400 runs up to 7200 ? I call that BS...unless he's done one hell of a build to it and it running some killer cam and induction system !! JMO Take it for what its worth..

~Russ

 

I wasn't trying to brag I was just worried I had really screwed the pooch as they say, but everything is still running like its supposed to and no spun bearing as of yet so apparently the ol girl is alright. Apparently they do rev to 5200 fairly easily though haha

 

I missed this one?? Did his post get deleted?