New Production F134 Headers

Dave Eilers recently updated his earlier post on eWillys about these headers by Clifford Performance. A new production run is apparently scheduled to start next month:

F-head Headers … UPDATE

 

prepare for a $300 + price tag

 

I'll be getting one.

 

How much power, we actually talking bout over stock manifold?

 

Probably best to think of this in terms of % not net lol

 

In my mind, 300$ for 7hp is kinda steep.
I've messed around with the stock cast manifold system. The original downtube was 1/4 In smaller than mine now, going into a cherry bomb style tube muffler, ending in front of rear axel.
It has noticeable power increase over stock. (For under 100$)

 

But 7HP is a ~12% gain. In most performance parts, $300 for a 12% gain is pretty good.

 

If you want a F134, this looks like the only option. I'd buy one if I had that motor.

 

The drive train in a 134L or F, T-90, D-18, 5.38 drive train requires approx 20HP in 2wd to run itself. If you hop up the engine in anyway the drive train will not increase its need for HP (at a given rpm) so if the stock drive train delivered 72HP with 52HP going to the draw bar then an additional 7HP is just a hair under a 14% increase in HP if that only cost $300 thats some dirt cheap HP improvement.

 

In my experience, virtually no power increase can be expected with just adding headers without first increasing the air flow efficiency. The problem with a 134's breathing is not on the exhaust side of things. Well, it is partly, but it's in the flathead exhaust valve chamber design, not downstream from it. More can be accomplished with some head work and a port job in coordination with a flow bench, than just a set of headers. Getting the air to flow more freely in and out of the engine does wonders without losing any bottom end. If the pistons can't get the air out of the exhaust valves fast enough before the next cycle, what style of exhaust routing that is on the other side is irrelevant.

Just my $.02

 

The FHead made 62 Net (modern rating) HP @ 4000 RPM. Net Tq was 108 ft-lb @ 2100 RPM.

 

I believe the major impediment for a F134 CJ is its aerodynamics, not the engine power. A 36 or 40 hp VW easily travels at highway speed. Wind resistance goes like the square of the velocity. Even if the power requirement for the drivetrain were a fixed 20 hp, that would leave 42 hp out of the 62 net that could be used to overcome wind resistance. If the power increased by 7 hp, that's an increase of about 17%. If you take the root of that increase sqrt(1.167), it's 8%. So your top speed after header installation (assuming an actual 7 increase in hp) might be about 8% higher than before. 55 mph increases to 59 mph, and so forth. Wind resistance is a mighty barrier.

Intuitively, it makes sense that the most restrictive part of the F134 exhaust is the valve-in-head part. I would look to the flathead Ford literature about hop-ups. There's plenty out there about improving the flow of valves in the block. You could also look closely at the intake side, and see if flow through that side could be improved.

 

I have plans for the lack of air into my Lhead.

 

I think a little boost would go a long way. I have always had oiling concerns however. If that could be somewhat remedied, then turbo is a decent option.

The Holley BBD would make that setup very clean.

 

I purchased one of these back in 1982 when they were still available.
My home made header which had been used for years and years between a couple Jeeps had given up the ghost.
The header exited inside the frame rails close to the engine. I had an F4 in my Jeep at the time.
The tubes were way smaller than my home made job.
Anyways, I never liked it. It went with the F4 when I sold it to help pay for my V6 conversion.

 

During the first body off. Had dual collector; you could "un-cork" without removing muffler.


Later, at Dumont sand dunes, painted it blue apparently.

 

In the second photo, take note of how much stuff is in the way for inside the frame header application.
As I recall, the Clifford may have hung down a lot lower than this home made wheel well job.

 

Tri-Y! Nice setup.