1939 Ford coupe 221cu detonation update.

[Phil Gillespie]

So after my No4 piston failure due to detonation earlier this year.Engine has been rebuilt and back on road with 475 mls on it to date. New 4 ring pistons and rings, all new brgs, mains, cam, bottom ends, new rods(nos),existing heads, Edelbrock 1125, 65cc comb. chamber. 8BA valve train all new . New Stromberg 97 carb, rebuilt Distributor, 78 model,standard cam, plugs, NGK R5671-A non-projected type plug. radiator cleaned and minor leaks attended to.Fitted 180 stats . Once some miles on it to verify nil chance of further problems due to detonation. Car went into local firm, for dyno checking and fueling check. Fuel in use 96 Octane. here our lowest being 91 Octane. Dyno was a computer controlled unit, with rear wheels off the car and adaptors fitted to fit pods either side. These dynos designed and made in NZ and exported.Prior to this driving the car it seemed to run well. Single fitted Stromberg 97 carb was fitted 45 jets and 65 PV. During checks noted a little lean at WOT so jets were changed to 46, this sorted this one.As not too many miles clocked up, max RPM was limited to 3500 rpm. Initial checks showed max torque at 2200 rpm. later timing was advanced 2 degrees and this then showed a max torque of 175 ft/lb at 1700 rpm. Part throttle cruise: 15" vaccum to 2250rpm 13/1. 2500 to 3000 13.8/1. Loading up Acceleration 10" vaccum to 2000 rpm, 14/1. 2000 to 2500 14.5/1. To 3500 14.7/1. WOT:1500 rpm 13.7/1. at 3000 rpm 12/1. Peak torque: 175 ft/lb at 1700 rpm. Peak HP: 87 at 3000 rpm onwards. This is actual readings at the rear and nil 15, 18 % added for drive train losses. The engine is 3.1455, 83 thou over. Distributor is a 78 model, initial timing in at 900 all in at 2200, max timing of 19 degrees.There was some interference from cars plug wires etc to dyno unit. But results seemed good, fueling and timing are good, response is good.No sign of any detonation . At WOT it was a little lean at the top hence the change from 45 to 46 jets. As mentioned in a previous post only problem to date, a new set of adjustable solid lifters, No5 exhaust came loose and wound inwards giving 30 to 40 thou clearance, not what you expect, but at least this has been changed and all others rechecked. I did not fit a new head gasket at only 400 plus miles and surfaces were good.
The Bob Shewman stats work well and give a good run temp at 180. This car is now begging for more trouble free miles to be clocked up on it.Trust this info is useful.
Phil NZ

[A bones]

Nice reporting, enjoy the ride. Hope the details all perform well.

[Phil Gillespie]

These deails as to torque and HP produced qith dyno checking seem to be in line with results as per JWL's book I feel.
Phil NZ

[Ggmac]

Good report and happy and safe motoring

[DocJohn]

Good news, and have fun getting some miles on the clock!

[GEOFFNZ]

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Very informative Phil.Sounds like you have put in the hard yards with the engine.Better than new. Cheers