Time for a new intake?

I would make sure your timing is set right, and your carb is set up & operating correctly before pulling the engine apart - just my $.02.

Congrats on the new ride.

Rocky

quote:

I would make sure your timing is set right, and your carb is set up & operating correctly before pulling the engine apart - just my $.02.

Congrats on the new ride.

I second that. And of course I suggest you buy my book to help you do that...

Thanks guys. Yes I will definitely be checking the tune of the carb and the timing first. It's not that car runs real poor, but I thought I would check if people thought with my current combination that the F351 was a bottle neck since I have read mixed reviews about its performance. I was told by one person that they thought my cam and carb were too wild to be benefiting much from the F351 intake. It seems many prefer the Blue Thunder and Scott Cook, but maybe my application does not warrant those.
Any thoughts or advice on that?

Thanks

What you have isn't bad. It depends on what you want out of the engine though.

That intake was on my car when I got it along with a Holley 3310. The 3310 is a 780cfm with a vacuum secondary.

I have also run the Shelby version of the Blue Thunder (the original manifold the Blue Thunder is copied from) an Edelbrock Torker and the Ford Motorsport A341 version of the Torker.

I know that you could go with more cam than this for one thing. That one will go to 7000 with the right valve springs and anti-pump up lifters but in reality is pretty much done by 6,000 rpm.

The F351 claim to fame, is the old Edelbrock offering of "a light weight aluminum intake vs. the factory iron intake" and another 10hp over that.

Does that mean it is a "bottle neck"? Yes if you are looking for more than basically a 300hp '70 4v 351c + 10hp?


There are a bunch of intakes available for you to choose from now as well as camshafts that will give you considerably more than that. This engine is quite capable of around 500 and very easy to bring into the 400 to 450 range with just a few changes.

A much simpler solution though at the moment for you would be to simply change the carb to a Holley 4776, 600cfm double pumper.

That right there will crispen up what you have without seriously tearing into the engine, especially considering that in a Pantera you have to go through this entire consideration of intake manifold heights and what will fit under the screen cover. That for many becomes an academic evaluation that they don't want to have to think about.

All that information is available though, but many other choices are going to involve some internal engine work and some money.

The limitations of the 4776 matches better those of the F351 and your existing camshaft and it will be crisp and responsive.

There is no reason that you have to run without a choke on the carb. Holley sells an automatic conversion kit for it that works very well.


Sometimes lack of a choke will kill a lot of the low end until the engine gets hot. Certainly on a 4779 it will.

My impression of the Shelby intake was that it runs a lot like the F351 Edelbrock. It has a little more upper rpm potential above 6000 rpm though. In fact the Edelbrock might be noticibly crisper under 3000?

I think the Shelby/Blue Thunder is a combination manifold built in the late 60s to accommodate cars with both automatic transmissions and manual and as a result the manual trans cars suffer for it.

Dan Jones did dyno test the Blue Thunder and found that it has four good runners and four "bad ones" (his quote, not mine). With internal porting of it, it can be made to work like you expected it to, but internal porting of a 180 manifold is not for a novice of amateur at all.


I personally found that the Edelbrock Torker with a 4779 ran best for me.

I can't argue that it was a little flat up to about 3,000 rpm but then again I never had to drive this combination as an everyday car in traffic so my perspective may be tainted in that sense.

I was running more camshaft than you so without a dyno it is hard to determine if it was the manifold or cam or the combination?

quote:

Originally posted by Otis:

... Hi guys I just purchased #6243 and have been enjoying the car for just over a week now. It has been a blast, however I was expecting a little more considering what I was told of the engine ... Anyways let me know what you think, if the intake is fine or if its time to upgrade ...

Congrats on the purchase, welcome to the forums.

What do you mean you were expecting a little more? In what way is the engines performance disappointing?

I am in agreement with those who have advised making sure the carburetor and ignition are tuned properly before going any further. If the carburetor isn't calibrated properly for that engine, and you install a new manifold but reinstall the same carburetor, it still won't be right. For now the manifold is fine, it is not an obvious problem.

quote:

Originally posted by PanteraDoug:

... the Shelby intake ...

There is a dual plane 351C manifold that was sold by Shelby beginning 1970 through about 1974, and has been manufactured by Blue Thunder (AT Francis) since the early 1980s. It was actually designed by Ford engineers (Ford owned Shelby back then). That's the manifold Doug refers to.

My experience with this manifold includes manually shifted cars and spans 4 decades. I think its a great manifold. Its a bit of an anachronism these days (like me), its been around since 1970, technology has marched forward in the last 44 years. You look at the big ol' runners and its hard to imagine it doesn't impact low rpm performance ... but it doesn't. Compared to the factory manifold the transitions are smoother, and the pinch points are opened up. The newest dual plane manifold for the 351C is the Edelbrock RPM Air Gap manifold, which is a high rise manifold with a cut-down plenum divider. Block-off the exhaust heat passages of the Blue Thunder manifold and it will run shoulder to shoulder with the Edelbrock RPM Air Gap manifold (which has no exhaust heat capability).

I'm sure "porting" the Blue Thunder manifold can improve that performance a bit, in other words pick up a few extra horsepower; but the manifold performs very well right out of the box. It doesn't affect the lower rpm power or drivability, it gives a harder hit in the mid-range, and it makes the engine more willing to rev at high rpm. I think its absolutely wrong to give the impression the manifold is a "dog" out of the box, performing well only after it has been ported. Every batch of those manifolds sell out quickly at more than $400 each, and I hear an abundance of positive feedback from the buyers. It has been a well liked and well respected manifold for decades.

After reading all of the comments. I am going to try and spend more time with the car and its tuning. As for expecting more I guess I was just going by seat of the pants feel and thinking of an 06 Mustang I had that was dynoing 310hp and 300ftlbs at the rear wheels at 6200rpm and was thinking that my Pantera would feel noticeably more powerful than that car. However that was a while ago and the Pantera does have a unique feel. It could also be that the car is fairly loud so I may think it should be moving more when in reality I doubt that I have had it over 5000 rpm yet.

And don't worry guys, I am not someone that is going to come on here and think I can get 500hp with out spending some money. I am more looking into getting a combination (my current one for the time being) working as efficiently as possible.
I am now finding that one of the best parts of owning my Pantera is that ability to come on here and learn from guys that have actual real situation experience.

Thanks,
Otis

quote:

Originally posted by Otis:
After reading all of the comments. I am going to try and spend more time with the car and its tuning. As for expecting more I guess I was just going by seat of the pants feel and thinking of an 06 Mustang I had that was dynoing 310hp and 300ftlbs at the rear wheels at 6200rpm and was thinking that my Pantera would feel noticeably more powerful than that car. However that was a while ago and the Pantera does have a unique feel. It could also be that the car is fairly loud so I may think it should be moving more when in reality I doubt that I have had it over 5000 rpm yet.

And don't worry guys, I am not someone that is going to come on here and think I can get 500hp with out spending some money. I am more looking into getting a combination (my current one for the time being) working as efficiently as possible.
I am now finding that one of the best parts of owning my Pantera is that ability to come on here and learn from guys that have actual real situation experience.

Thanks,
Otis

I'm not worried.

It would be best to work with what you have now. Then determine if there are better matches that will help. You need a basis to make solid judgments on.