Gems motor with less than 10k on rebuild. Excellent runner. Still in truck so yes you can come hear it run. Nice power.
2k plus ride or 2k picked up
2k plus ride or 2k picked up
4.6 Gems with 4.0 pistons
- Thread starter WILL.TILLERY
- Start date
Be careful of what you wish for!
You could probably build one with the engines you have now. I want to do that. Nothing like more compression.
So... do the 4.0 pistons have a higher deck? Or are the rods different? How much squish do you get with this combo? :-D
To DiscoClay - You use the 4.0 pistons with the 4.6 rods and crankshaft.
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Got it. Thanks for the detail!
This is good to know, and a no-brainer when going with a beefier cam along with a little cam retard.
It seems this combo would benefit from full sequential injection [below ~3500rpm ballpark] and detonation~pre-ignition detection. And and MSD... cap discharge works well at low rpm.
There's no need to retard entry-level or mild cams with stock valves, at least the Crower iterations. These engines need all the effort they can get and the heads are the biggest bottleneck in my experience.
The RPI-built 4.6 in my RRC was their highest output offering from decades ago, and does have valve reliefs in the high compression pistons. It has a Piper camshaft. The ports in RPI's heads are heavily modified, but I didn't measure the valves when I had the heads off.
All that is to say the Piper cam or larger valves may have neccessitated the valve reliefs, but Crower 229 and 230 cams should not.
Yes, this is what i meant with "beefy cams"
Stock cams are pretty tame. I am still interested in a hydraulic roller for my TBD 4.6 build. I'm seriously considering building my own intake with very long runners (~40")
Does the 4 year/50k mile warranty on this include trip interruption reimbursement or is it just parts, labor, and emotional damages?
Crower doesn't make stock cams. I've heard from people in SA that a 3.5 is a dog down low with either of Crower's sticks, and the 229 in my go to in 4.6s.Yes, this is what i meant with "beefy cams"
I am still interested in a hydraulic roller for my TBD 4.6 build. I'm seriously considering building my own intake with very long runners (~40")
I'd be afraid anything more aggressive than the 230 without a stall would lose on the bottom end. Of course, I haven't used anything more radical in my builds because I'm repowering trucks that need grunt.
I am not looking to repower with anything other than either a build 3.9 or a 4.6 with as much punchout as possible (apparently 200 over is doable with the darton top-hats). I am looking or daily torque.. so somewhere off (high) idle to around ~3500 rpm. Displacement is the only thing that will really deliver in that range, with really long runners giving a helping hand down there. So, I am looking at building a 4.6 with 0.200 over top-hat liners, a custom intake with really long runners and an M90/112/122 eaton blower. It's an R380 so..no stall.
Do the 4.0 and 4.6 crankshafts have different journal sizes? I could be wrong but I thought I read that somewhere. I think the main difference is the stroke on the crank.
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3.5.=89.5mm bore Std 3.5 crank
3.9.=94mm bore Std 3.5 stroke crank
4.2.=94mm (3.9 bore ) plus and 4.2 longer stroke crank
4.0 is the same capacity as 3.9 but uses later big journal crank and is cross bolted
4.6. + 94mm bore ( As per - 3.9 & 4.0) but uses later big journal (long stroke) crank and is also cross bolted as is the 4.0
re: http://www.v8engines.com/engine-4.htm