Update on the FE Power Cylinder Head Testing

[My427stang]

I actually overkilled the valve spring pressure on purpose, to try to find any weak spots in the valvetrain.  I succeeded LOL 

That’s pretty funny. What is the advertised duration on that one?

[jayb]

Advertised is 319/334.

[Joey120373]

Wow, I know you were hoping for more power, but, 820 at 6500 on the first set of pulls is pretty darned impressive I think. I notice the power past that seems to be a bit of a sine wave.

I’m guessing once you get the manifold vacuum down to a reasonable level, that will clean up.

[C6AE]

Investment cast rockers will allow a redesign on a lot of the shapes, paring off some weight where not not needed.
I like it!

[My427stang]

Jay, in the end, you likely asked too much of the rockers.  Once you get that sorted you can get some clean pulls

Some other thoughts, the additional spring pressure, certainly reasonable thought for future use (or misuse), certainly added to deflection and may not have even helped.  So you may find a more "normal" ....funny saying that with this engine....spring pressure could be not only easier on parts but also make more power

I also think there is more to be gained in cam choice, but son of a gun, that's a successful run, take pride in what you did.  I would think that OEM heads aren't that successful first time at bat

[70tp]

Awesome Jay!!   The bright side of this is now you can , with the head off, see what the burn pattern is in the chamber and top of pistons.   Also any clean, washed areas.  Maybe some rocker problems could be an unfriendly lobe shape that is putting some harmonics into the valve train?  Not necessarily valve float but something happening below valve float rpm?     

[machoneman]

Definitely steel.  Aluminum may work for a drag engine but for any longevity, I think your decision for a steel rocker is the correct solution.

[Hemi Joel]

Dear Jay,

It is amazing what you have accomplished. Even though you are not finished with your R&D yet, I consider your project a smashing success. Congratulations!

Very truly yours,

One of the Others

[ntheogen]

Congratulations Mr. Brown, stellar work. I'm impressed that it's gone relatively smoothly given its an all new design from scratch.

Jack

[bsprowl]

Thank you for sharing the details.  Something always pops up in testing.  That's why its called testing.   Power is more than meets my expectations for the small amount of tuning you were able to do.  The final results should be great.

Thanks again

Bob

[WerbyFord]

Definitely steel.  Aluminum may work for a drag engine but for any longevity, I think your decision for a steel rocker is the correct solution.

x2 on steel.
IIRC, steel has a flat fatigue limit when loaded properly (under half its static strength).
Loaded below that, it will cycle forever, it just doesn't care.

Aluminum (and austenitic stainless, copper, etc) has NO fatigue limit - if loaded substantially, it will keep fatiguing until it breaks, as Boeing found out when those 737s became convertibles on the way to Hawaii.

SUCH an awesome engine.
Did I miss the head flows somewhere, and the header dimensions?
Open headers I assume?
There aren't enough mufflers in the USA to let that thing flow.

Will be interested to see JDC flow those intakes, the Gonkulator will want that info.

I do not envy Bill Conley doing that FEA. Complicated geometry. I started doing FEA in 1982 but something that complex, and dynamic fatigue failure - complicated.

[WConley]

Werby - The tools have gotten really good.  The problem is that you have to know how to load / constrain the model and interpret the results.  That's where the experience comes in...



It's a powerful thing, but like a 427 Cobra you can drive it wrong and end up in the weeds   

[cjshaker]

2" of vacuum at RPM, with a huge carb, certainly seems to indicate that the heads are wanting more! Me thinks a tunnel ram is in your future!  You didn't mention intake vacuum with the 8 barrel intake. Was it high also? I would assume it dropped some with the 8 barrel. If not much, then it seems like the heads want more than the intakes can produce. Certainly on that 4 barrel, at least. Were the 8 barrel carbs a known variable? In other words, had they been used successfully on another 8 barrel engine? If so, there has to be a reason they were so pig rich. Vacuum alone shouldn't do that, unless, combined with airflow, it started pulling fuel from places it shouldn't have.

It looks like you have temp probes in each exhaust tube. How were the exhaust temps? That could indicate any issues with intake flow problems (reversion issues with such a big cam, or just a bottleneck?), or any coil/ignition issues, if there are any.

At the risk of sounding like a doofus for missing something obvious, how does that center shaft bolt work? Is the bottom of the intake rocker slotted so that the bolt travels through the rocker, and the rocker pivots over the top of the bolt?

On the intake rocker adjuster; Is there not enough room to move the adjuster over slightly, for additional strength, and modify/machine the intake adapter for some additional pushrod clearance? Maybe there's not enough room around the port to do that?

Okay, sorry for all the questions. Thanks for the great write-up, and it seems like you're only scratching the surface with power production. This is going to get really interesting, as I think you have some real intake development in your future.

[428kidd]

Very kool to hear Jay and congrats, looking forward to some full pulls!

[jayb]

Did I miss the head flows somewhere, and the header dimensions?
Open headers I assume?
There aren't enough mufflers in the USA to let that thing flow.

Will be interested to see JDC flow those intakes, the Gonkulator will want that info.

I do not envy Bill Conley doing that FEA. Complicated geometry. I started doing FEA in 1982 but something that complex, and dynamic fatigue failure - complicated.

Head flows are in this post:

http://fepower.net/simplemachinesforum/index.php?topic=7336.0

Headers are 2" to 2-1/8" to 2-1/4", most of them with a 6" bend radius, into merge collectors, going into the dyno's exhaust system, which has four 3" inlet and outlet turbo mufflers.