4.6 Bosch cam, search anxiety

discostew

Well-known member
Sep 14, 2010
7,745
1,026
Northern Illinois
So tell me if you port a head and make it flow better but don't add fuel for all that new massive super air flow coming into the engine or enhance the valve timing what are you really gaining?

It is also true that slapping a really heavily worked set of heads on a small engine with a small cam that you're not changing the tune on will make it run like shit.

You guys act like you know so much, yet can't understand a comment that deals with something that is actually very basic...

Whats so hard to understand about that?


I don't think its gonnna starve for fuel . I think a GEMS engine management system fires the injectors twice per engine revolution . I think they run way to rich.
 

robertf

Well-known member
Jan 22, 2006
4,801
366
-
I don't think its gonnna starve for fuel . I think a GEMS engine management system fires the injectors twice per engine revolution . I think they run way to rich.

it won't starve, if the engine draws in more air the MAF reports more air. Its not a MAP/speed density system like he's been describing.
it could use some tuning in the transients/accel enrich, but the real reason to bother with tuning it would be to optimize the ignition map. Since you are effectively increasing cylinder with the 229 compared to a stock cam its already an aggressive ignition map for that setup. I'm sure NOx would increase if anyone bothered to measure.


GEMS is sequential, if it wasn't it wouldn't need that cam gear that is getting everyone worked up.
 

rovercanus

Well-known member
Apr 24, 2004
9,651
246
I think our newbie talks like he knows more than he really does.
Engine block, front cover, oil pan, crank and pistons were dropped off at machine shop yesterday.
They are going to remove oil plugs, clean, replace oil plugs with thread plugs, pin the liners and measure. He gave me an estimate of 2 to 3 weeks and a price of $275 for all this work. When I get the block back I'll place an order with D&D and Will.
I also plan on adding the oil cooler to this engine. I have the cooler, just need to hoses.
 
Last edited:

discostew

Well-known member
Sep 14, 2010
7,745
1,026
Northern Illinois
it won't starve, if the engine draws in more air the MAF reports more air. Its not a MAP/speed density system like he's been describing.
it could use some tuning in the transients/accel enrich, but the real reason to bother with tuning it would be to optimize the ignition map. Since you are effectively increasing cylinder with the 229 compared to a stock cam its already an aggressive ignition map for that setup. I'm sure NOx would increase if anyone bothered to measure.


GEMS is sequential, if it wasn't it wouldn't need that cam gear that is getting everyone worked up.


Maybe its cux that sprays the injector twice . I think your right about the system figuring it out .