Big CFM 914 Heads In U.S.A.

[wreck]

It's mainly the Spark plug angle , the guy doing my seats and valves didn't want to weld my new heads up to change the plug angle , he said fine on a race engine but not on a daily driven street engine . He knows his stuff , He was one of the top head guys back when they ran type 4's in midget speedway(oval) racing back in the seventies and eighties so I went with his advice .

[cal 67]

Wreck, I think it's behoove you to run a protruded electrode plug then.

Jorge from European Motor Works tells me he doesn't trust AA's seats. As far as the heads being complete, that must be a new thing. When I called, thry led me to believe they were only going to be bare.

[Piledriver]

Most folks are going to buy the bare heads and have EMW install new guides/seats/valves/springs (completed).
I'm curious if they have a CNC porting setup these days, one of the few things they didn't used to offer is porting.

[Piledriver]

Curious--- do they machine the plug hole, is it 12mm or 14mm?
12mm plugs are the typical "cure" for cracking around the plugs.

Would be a shame if they copied the 2L heads including the flaws.

[wreck]

I'm running NGK tri electrode plugs in my 4.04in by 71 in my Split Baja camper , I was racing my Ghia (1600 Mexican ACD) that had Kadrons , it had tri electrodes in it , I had to swap plugs because of a fouled plug and had to put basic NGK's in and lost 1/2 a second on the 1/8 mile . So sold on the BP6ET's
Once the 2,6 is up and running I'd like to go to a mega jolt ignition .

On the AMC/AA heads , the engine builder I know has had no issue with the seats or valves but changes the valve springs for heavy duty Type 1 singles . he feels the AMC springs are too heavy (never measured mind you) and may cause lifter/cam wear . these are on "camper special type" the engines in daily drivers . The last couple he has had the seat's throated out and fitted 1800 size valves .

!2mm plugs would be a good thing , but if you keep the head temps under control cracking shouldn't be an issue .

[Piledriver]

The Bosch/NGK triples are an extreme projected tip design and work/last very well in either std T4 or 914 2L heads.
Putting them in feels like adding ~4 degrees of timing, effectively it is, since its closer to the center of the chamber, and "open"(flamefront free to propagate) in that direction.
There are 12mm versions.
Unfortunately there is no iridium version, but they still last longer than most plugs.

[trapnm]

Im not sure on the spark plug size. I also don't think the new ones are amc heads but i will inquire reference both. Additionally i may have mixed up info reference complete heads and these bare castings. I'll clarify that as well. Still awaiting an update on landing date.

[trapnm]

Im not sure on the spark plug size. I also don't think the new ones are amc heads but i will inquire reference both. Additionally i may have mixed up info reference complete heads and these bare castings. I'll clarify that as well. Still awaiting an update on landing date.

[cal 67]

Piledriver, still no CNC. The only person in the U.S. that does CNC is Jake. I thought DRD did, but Darren hand-ports his.

[Piledriver]

Would be worth sending to HAM or Headflow Masters for proper port job.

[raygreenwood]

My question on these new AA heads.....is whether they are complete "new" 914 2.0 spec castings.....or whether they are AMC 1.8/2.0 heads that have been welded, plug relocated....and machined. From their site.....that was not clear as of last week.

As for the extended triple electrode plugs......nothing works better on a type 4 that I have found. Especially with higher compression....and a hot coil.
I have been hoarding them. I have about 16 spark plug changes worth of W7DTC and about 4 sets of BP6ET....
Ray

[cal 67]

Ray, as I mentioned on The Samba, they're not AMC castings. They have no markings on them. They're completely new AA-made castings, NOT of AMC origin. They're bare, without any parts intalled.

[Piledriver]

Actually a better plug existed, but they don't make them anymore.
There is nothing special in the electrode design...

I can still find stocks of Iridium Pulstars every now and then, the inconel "replacements" don't work as well or last as long as $3 Bosch Supers or Autolites for that matter... IIIRC they changed the capacitor design to make them harder to break when installing. Made the new ones ~worthless, or at least not worth the price..

All else being the same, I can pull 23:1 AFR smooth as glass with BE1i (iridium) pulstars, with any other plug ~18:1 is into lean surge/misfires. (tried most types/brands) the DTCs work better than anything other than the old iridium pulstars.

I had to richen up my cruise AFR targets when it cooled down under ~80F or it overcooled.

Probably not worth one extra HP at WOT, but for cool CHT and economy they rocked pretty well.
The electrodes were worn back into the insulators ~1/4" at ~50K miles, it still ran just fine but it started getting lean misfires... LS2 coils rock.

I wish they made an iridium/pulse discharge version of the Bosch triples though... even if it was just cladding or a long life alloy.

[cal 67]

23:1!!! I gotta hang around with you! Your mileage must've been through the roof!

Update, purchased the heads. AA's still aren't in, but I paid for a bare set from the last batch. Will be getting the intake fins welded for porting, and bored for 103mm.

Also recieved the CB Chevy 5.325" rods and conversion F/W.

I hear Kennedy's flywheel bolts are a little too long? They bottom out on conversion flywheels?

[Piledriver]

Surprisingly it doesn't help the fuel economy much on gasoline, (moreso on E85), but it gives CHT a headshot, almost 100F lower on 100++F days at cruise vs stoich.. Needs a lot of timing and throttle opening, the latter is what improves the fuel economy, running ~85 KPA at cruise vs 60 directly improves efficiency a few%..

I'm hoping with the new motor with dual plugs and much higher static compression and squish, and maybe...maybe GDI I'll be able to pull true lean burn modes, but that will require shenanigans with the MS as anything over ~25.5:1 is not calculatable in the current firmware, and anything over free air isn't readable even by a Bosch 4.9 sensor AFAIK, it has to run open loop with calculated fuel.

Most widebands only respond to 20:1, it requires a 14point7.com JAW or one of Alan Tos higher end units for really lean operation. There are other high end WBO2s that will read lean of 20:1, but the old JAW was $25 plus a sensor and cable, and supposedly reads accurately to free air.

(the GDi injectors and stand alone HV GDi injector driver box are courtesy of a Mazdaspeed 6)

Theoretically, around 17.5:1 is best fuel efficiency on gasoline, but I personally haven't seen evidence of that, my best results are ~22:1.
May be unique to my (otherwise pretty conventional) setup.
Injector aim and timing matter running like this.