Author	[Modern View]
Farmall m 421 12-16-2012 08:06:44 68.171.231.85 Report to Moderator	Looking at building a 421 m. Gonna have 12:1 compression. 450 lp head. 1920 high idle. Cammed for max torque about 1500. Typical 421 type build. What type/octane fuel will I need for this type of engine? What do you guys recomend? VP110? Q16? Something else? Thanks [Reply]   [No Email]
Superih 12-17-2012 05:19:18 12.68.14.211 Report to Moderator	Re: fuel needed? in reply to Farmall m 421, 12-16-2012 08:06:44   Quoting Removed, click Modern View to see Any 110 will run fine. You do not have to worry about quench or cold clearance as the pistons must sit below the deck at top dead center to set static compression at 12:1. [Reply]  [No Email]
buickanddeere 12-17-2012 13:15:49 184.151.61.212 Report to Moderator	Re: fuel needed? in reply to Superih, 12-17-2012 05:19:18   What do you mean quench doesn't matter? If you take a little extra time and care instead of just slapping an engine together. Keeping the quench at 25-35 thou will reduce the engines tendency to suffer detonation. The engine will also make more power due to the improved combustion chamber turbulence and mixing. [Reply]  [No Email]
buickanddeere 12-16-2012 11:19:16 184.151.63.216 Report to Moderator	Re: fuel needed? in reply to Farmall m 421, 12-16-2012 08:06:44   What if any quench in that engine combustion chamber? Are you planning on 25-35 thou of cold clearance between the piston and head? That will increase power and reduce detonation . The cam duration can vary the compression pressure from requiring fuel from 87 to 115 octane . Tell you cam grinder what you have as a combo and they will grind to match. [Reply]  [No Email]
Farmall m 421 12-16-2012 17:52:40 68.171.231.86 Report to Moderator	Re: fuel needed? in reply to buickanddeere, 12-16-2012 11:19:16   A cam that would allow me to run 87 octane fuel would have overlap to the point that it would barely even run at 1500 rpm. If I want max torque at 1500 then I am going to have short duration and very high cylinder pressure. I want to know if I can run something in the 100-105 octane range, 110, or do I need something better like Q16? 87 aint gonna do for this. [Reply]  [No Email]
ss409 12-16-2012 19:32:48 72.53.194.237 Report to Moderator	Re: fuel needed? in reply to Farmall m 421, 12-16-2012 17:52:40   110 did just fine at 300psi cranking psi, under full load, at 180 degree temp for 3 minutes on dyno. [Reply]  [No Email]
Farmall m 421 12-17-2012 02:48:20 68.171.231.80 Report to Moderator	Re: fuel needed? in reply to ss409, 12-16-2012 19:32:48   Thanks. What brand? VP110 or something else? [Reply]  [No Email]
ss409 12-17-2012 07:36:12 72.53.194.237 Report to Moderator	Re: fuel needed? in reply to Farmall m 421, 12-17-2012 02:48:20   vp works fine. you was talking about cams there,,,, i dare ya to start with a 450 cam grind. if ur turning 1500 n under rpm, in my experiences, the 450 cam grind did very good in my engine. itll lug clear down to under 1000rpm n still chug out triple digit power. try it as a baseline n work ur way up. [Reply]  [No Email]
Farmall m 421 12-17-2012 09:09:27 68.171.231.85 Report to Moderator	Re: fuel needed? in reply to ss409, 12-17-2012 07:36:12   Do you have the stock 450 cam specs? [Reply]  [No Email]