This is my first post and Im new to the BBF world. im building my first right now. Its a 429 from a 70' Thunderbird. I've heard this was a strong motor but i dont know much about it. I've used mostly Edelbrock Performer RPM parts to build power at 1500-5500 RPM range. Does any one know what kind of poweri can expect from this? Im hoping its a bit better than the 400 i just blew up.

 

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give us more specs on what you used in the internals of the engine.

 

Could be 11:1 compression if I recall correctly. Them T-bird guys weren't afraid of premium gas....

 

If it was a stock 4bbl than yes, its 11:1 compression, although Ive never figured out why they list the CR's differently just because of a carb/intake difference.....

 

Its punched 30 over. the cam is Comp cams 226/234 The carb is edelbrock performer eps800. It has stock heads with edelbrock performer RPM intake. Hooker Super comp headers

 

It is 11.1 Compression

 

Factory rated @ 360 HP (SAE gross) with a 4V carb A.K.A. 429 "ThunderJet". It was offered with a 2V carb rated @ 320 HP. I don't think the 2V got the ThunderJet moniker. They came in Thunderbirds and also were offered in the larger Galaxies & XL models in 70. Small, closed chamber heads pushed the comp. ratio up to 11:1 which made them a bit finicky as far as fuel went. It's tough to get them to run well on today's fuels and the rocker system was poorly designed which led to a tendency to drop valves in high mileage engines.

Like a lot of FoMoCo heads the exhaust port in poorly designed and had miserable flow characteristics which is basically the limiting factor on these engines. The 429 is a relatively high revving engine for as big as it is due to the shorter stroke but serious exhaust port work and a dual pattern cam with longer exhaust duration & lift can really wake it up.

Even with the short stroke the 429 produces a lot of bottom end torque. They were mostly used in big, heavy vehicles with high (numerically low) rear end ratios and still moved 5000# vehicles off the line quite briskly. 429 equipped vehicles with 2.95 rear gears will bury the speedo on a long stretch of highway and just keep going. Put in a set of 3.50 gears and you're going to be buying a lot of rear tires.

The key to running high compression engines on todays pump gas is keeping the engine from getting too hot. A low temp thermostat and heavy duty cooling system are "must haves". Replacing the old points ignition with an efficient spark delivery system will help as well. Longer duration cams help lower the dynamic compression ratio and polishing the chambers will reduce hot spots which preignite the A/F mixture. Taking it a step further, the new high temp ceramic coatings available for pistons & valves will also reduce comb. chamber temps and preignition.