stroker 429

[keane]

Hi again Dave in UK wanting to pick a few brains!! I have a 71 T/bird motor which I am putting in my dax cobra, I have a Hawks racing stroker crank(4.140) which I am hoping to use with 6.7 H beam rods and Keith black pistons, giving me about 9.7-1 cr. Is anyone out there running a similar setup? I need the lowish cr for uk streetability, I am thinking about the balance aspect, the original was internally balanced, will the same apply? I have now shelved the plans to use manual and am having a heavy duty c6 being built as we speak, the flexplate I fit will also be governed by the balance question? I have got quotes for rods about $359ish and summit do the pistons for $311, unless anyone knows better, on the question of torque converters,what are the views on this? as always any feedback is greatly appreciated, happy new year to all. Dave Keane

[Tom Wells]

Hmmm....

Lotta variables here - almost not practical to try to answer all the questions without a bit more info, so here's my setup and a few recommendations and a question or three:

MY SETUP

Ford 521 crate motor with lotsa mods. It has its original 9:8 compression. Low (?) compression seems to suit this engine - it made 600hp before I changed it for street use! It has a 4.30" stroke crankshaft and a .030" overbore.

I got rid of the high rise Dominator flange intake and used an Edelbrock Performer dual plane. I wanted a Stealth intake but the hood scoop would have been sky high. I used a Demon 850 vacuum secondary - not recommended - use a Holley instead (voice of experience)! The whole thing is now in the process of being replaced with EFI based on the Holley MPFI kit and a Torker II manifold. If I'd known then - I'd at least have used a Torker II for the hood clearance; it's the lowest height available intake for the 460.

I used stock length Eagle rods (6.605" ?) with the Ford 460-sized 2.5" big end. You can also find rods to fit the big block Chev (2.2" big end???)

It now has a Crane hydraulic roller cam with the 1.73 ratio rockers.

It has a 2200 stall 12" Edge converter click here and a C6 automatic with a 2.88 Powrlok Jag rear.

It is a nice street engine with a wonderful idle quality - noone ever mistakes it for anything else other than a really big block car It will also spin the tires at 100mph (315-35/17 Michelin Pilots) if you whack the throttle.

ANSWERS (or at least, opinions)

Balance - talk to the source for your crank - they should tell you what you need. Don't guess!

Torque converter - I started with a TCI. Don't do it It died and took the trans with it. I've got 4000+ miles on the Edge in the last three months including a 35 minute track session at 100-115 mph with no problems so far. Be sure the trans and converter stay cool. And change the oil and filter pretty often.

As far as other recommendations, the primary question is "what is your intended usage for the car?". If it is more for racing you might want a different camshaft, converter and axle ratio. If it for street use, the above items work nicely. If you don't mind adjusting valves regularly (I DO mind ) you can go with solid lifters and get a bit more hp, or flat hydraulics and save some pounds ($ over here) either way. I did change the valve springs too since high lift capable springs may only last 3-5000 miles.

It is most important that you select the pieces that make sense to you - don't use someone else's choices unless you are convinced they will suit your idea of the right stuff for the car!

Have more fun,

Tom

[HighPlainsDrifter]

Dave;
Big motor for you high $ gasoline[petrol]. I would think you have a externally balanced 429. My 460 is a internally balanced motor,but the earier 385 series engines were external balanced. Anyway with new stroker crank/rods/pistons you MUST rebalance the whole rotating assembly with flexplate and harmonic balancer included so the engine will survive. Don't go wild on the cam, less duration is good on the street plus easier at the gas pump. I run a pro street/strip C-6 with 2,800 converter from Precision Industries [GER] in Pennsylvania. I have 16,000 miles on it[ over 120 drag strip runs] with no trouble.
Good Luck,
Perry.

[keane]

Tom/Perry, Thanks for the reply, yeh I know I did ask a lot of q's,the feedback whatever it is matters because most people over here don't want to "go outside the box" by using something different, it will be expensive to put gas in but so what you only live once!!there are lots of variables, I have an edelbrock perf intake, almost stock cam, and probably will go for a 780-850 holley(vac sec) I intend to have 9.7-1 cr approx,I can't see me having any strip/track action so it needs to be very streetable. I will need to confirm the int/ext balance issue as the flexplate fitted originally had no weights, is this right for a 71 T/bird 429? the question of the converter is interesting, I have seen a "big ford" converter advertised on ebay that is supposedly up to the job and giving 2800-3000 stall speed, and priced at $159,I do not want to purchase an item that will fall apart on me, I will have a look at the edge type as mentioned, anyway as I said the info is great and appreciated. DAVE KEANE

[Jack21]

L 0.02

For mostly street use, you don't have to get particularly wild on aftermarket parts. A stock displacement 429 is plenty. A stock torque converter, even an aftermarket one, is plenty. Stall speed should be 1400 - 1800 RPM. You want a stock passenger car to RV (recreational vehicle or SUV) stall speed on this. Go with a 2500 - 3000 RPM stall speed will get you excessive heat, excessive wheelspin, a slower car, and horrible fuel ecomomy.

Remember, you have an extremely light car with a large engine. Making torque isn't a problem. Propelling the car with the available torque is the problem. You want the fattest rubber on the rear wheels as you can get, and a rear suspension that will let you "Hook it up" to the extent possible.

In the U.S., the faster cars are running 302's, or stroker 302's (331 - 347) with superchargers.

Consider a retrofit hydraulic roller cam and roller rocker arms before going with strokers to optimize what you already have. Keep the duration conservative for street use. 218 - 224I, 224 - 234E for a mostly street use cam will give you a rumpeta-rumpeta idle, and 15" vacuum at idle. 6200 RPM will be the max RPM for this engine, with this cam. No exotica is needed on the bottom end to achieve this.

A Holley, or Demon 750 is the right size carb for this engine. With automatic trans, vacuum secondaries will work fine. For street use go undersize (750cfm) rather than oversize (850) on the carb. Snappier throttle response.

Where you are, U.K., your only competition is another Cobra. Granted, you'll ocasionally run into a turbo Porsche which with your roller 429 you'll easily eat for breakfast (up to around 130 MPH); you don't have Vipers or Vettes to deal with. So count your blessings, build your ultimate muscle car, and rest assured that damn few (if any) will kick (or attempt to kick) sand in your face.

[keane]

Jack, thanks for your input,I feel better already! as I said earlier any info is appreciated and you people over there are a valuable source of knowledge,I feel I will be able to achieve everything from the motor by being sensible with what I want to achieve, besides being a policeman I suppose i'd better behave myself anyway!!! Dave

[wilf leek]

Dave- you betcha we will be watching to make sure you behave!!

Mind you, if you are anything like my own police neighbours, the right foot will get plenty of flexing.

luck with the build