Hello to everybody on the forum. This is a great forum with a broad range of experiences. I do not post very often but do visit frequently.
I have a question that only this forum can answer.
Tim Meyer built a 434 stroker Ford motor for me and is currently minding it until I ship it back to Australia. You could say Tim has developed a truly international business! And all the best to Tim for his efforts.
The 434 stroker will go into a 3500 pound Ford sedan and the intention is to have a weekend warrior that will see mostly street, but also the occasional drag race. The 434 will have CHI 3V heads (225cc), single plane CHI manifold for the 400, Crane Gold roller rockers, 4V 4 into 1 headers (size not sure yet), MSD ignition, Holley Dominator carby (size not yet decided), rear 9" diff 3.89. Will use 98 octane gasoline (or even 100 octane). Will run a C6 tranny built by Broader Performance able to cope with 500 HP and wide ratio gears.
My problem is I would like to use roller cam (either hydraulic or mechanical) but do not know the most appropriate cam to use for the 434 given my intended use? In addition, what would be the most appropriate stall converter to use on the advised cam?
I look forward to your views.
Thank you
Craig

 

Hi Craig,

I am building a 434 as well to go into my 77 F250 4x4. My build is just a little different though. I am using CHI 2V heads for the low end torque. I was very curious as to what cam to use as well and then I ran a few different types in a friends dyno sim program and decided to go with the same cam Gary Walker used in the first 434 Tim Meyer built. Here are the specs:

Duration @ .050 216 Intake 224 Exhaust
Lobe separation 108.0
Gross valve lift .579 Intake .591 Exhaust

I am using a Weiand intake and plan on using a Holley 770 CFM truck avenger carb.

With my set up, the dyno sim program showed an estimated 591 ft lbs of torque @ 2000 RPM and 520 HP @ 5500 RPM. I tried a lot of different type cam options and I like this one best for the torque. Good luck on finding one as I am sure whatever you choose, the 434 will run great!!

Craig

 

I'm not to certain on the cam, but I would avoid the Truck Avenger carb... I've only used two carbs in all the motors I've built, the Street Avenger and the King Demon.

 

Thanks for information Craig. This is the dilemma: not to lose all that torque lower down while gain some top end. I was going to use Crane mechanical roller (grind number R-246/3236-2-8) Duration @ 0.050 I 246, E 256, lobe separation 108, GVL I 560, E 585. Suggested stall 3000+ rpm.
Jay from Broader Performance suggests this cam may be too much as I will miss the rev range where torque is best for this motor.
I am bringing a F100 1977 back to life. Putting in my old 400 complete with CHI 2V heads and a mild hydraulic flat tappet for bottom end. Will run on dedicated propane. Using Tim's KB 2347 with 14cc dish (CR 10.2:1). Make a good daily driver. The 434 will run CR 12.1:1.
Thanks again
Craig

 

I am running 224/244 @0.050 with 0.600 lift and Lobe Separation Angle of 114 degrees. You could probably use something like 234/250@0.050.

I'll run some sims later.

 

Danlee...with your cam you can run 92 pump right? What would the dynamic be with that big of cam.

 

I run on 93 pump fuel. The DCR is about 8.55:1. I have no detonation problems, but I have fast burn aluminum heads and my maximum advance is 24 degrees BTDC at WOT.

 

Lucky you aren't in MT.... we get lower Octane fuels than the flatlanders...

 

With Crane Roller Dyno Sim says: Torque = 378@2000 RPM and 536@4500 RPM. Peak HP = 570@6500. This is with a 770 CFM carb, and that should be about right for a 434 street motor.

I really need the seat-to-seat spec. I think the simulator works better with seat-to-seat numbers.

If I change the Lobe Separation Angle to 114 degrees then Dyno Sim says: Torque = 404@2000 RPM and 548@4500 RPM. Peak HP = 559@6000.

This produces a flatter torque curve, with less overlap for a better idle.

If I change the Lobe Separation Angle to 114 degrees then Dyno Sim says: Torque = 434@2000 RPM and 558@4500 RPM. Peak HP = 560@6000.
This will produce a lot more low end torque, and a stock stall converter should be OK, but the DCR is 9.0:1 and even with fast burn heads a limiting the maximum advance, you could have detonation problems. I have no information to tell me how much DCR you can run with CHI heads. All I know is at 8.5:1, I haven't reached the limit.

If you will give me the seat-to-seat specs for the Crane cam, I'll do some more simulations.

 

If I buy my gas in Maryland, I can get it without Corn Juice.

 

BTW, you said that you will run this motor on 98 Octane. Is that Research Octane or Motor Octane. In the states the Octane rating is Mean Octane, which is (Research + Motor)/2.

 

he's in australia... subtract 5 octane to get the real number.

they only run ethanol in midgrade here... I use it in my street motors though... I'm kind of a tree hugger...

 

Thanks for all the suggestions. Our octane figures are based on RON. How that translates into your figures I do not know? Why do I need to subtract 5 to get the 'real number'?
In terms of seat specs could you tell me exactly what you need and I will give you the details.
The LSA is quoted as 114 twice in your estimates for the Crane roller cam Danlee. Is the second estimate meant to be 110 or 108?
Thanks again
Craig

 

RON Octane is Research Octane. We need to subtract 5 to get Mean Octane, so we can relate it to the US Octane rating. 98 RON - 5 = 93 Mean Octane.

I cut and pasted that line and shouldn't have, but it was getting late. The third set of numbers is for a cam with 234/250. I/E duration @0.050 on 114 LSA. As I mentioned before your DCR will be high at 9.0:1. That is much too high for Iron heads, but I can't say for certain that you will be OK with CHI heads. I am running 8.55:1 with no problem on 93 Mean Octane fuel.

The Cam spec should give the duration at seat-to-seat, and the duration @0.050, the lift, the LSA and the Intake Center Angle.

 

Thanks again for your reply Danlee. Well, the new Octane rating changes everything. I can get 95 Mean Octane fuel here in Oz at certain Shell service stations.
The following link should give you all the details you need Danlee.
http://www.cranecams.com/?show=brows...tType=camshaft
Look forward to reply
Craig