I hate you guys for making me want to take on a bushmaster/promaster project
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I made the new ram yesterday and most of the ram housing, though I realized I don't have a small internal threading tool and don't want to grind one, so I'm waiting on a tap for that.
I also made some SS screw studs for the grip frame to both repair and increase the strength of the grip screws going through the thin aluminum frame.
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Hammers done. I'll have these out in the next day or so. Super excited to see how these work in Bushmasters.
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Ram housing is 99% done. It needs a little more fiddling with a file to sit level in the gun body, but the dimensions look good. This was a huge PITA to machine on a lathe so hopefully it works. The oring seals feel right, so that's a good first sign.
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I started working on my spare B2k Ram in anticipation of the Laz Valves. Unfortunately my LPR tester appears to be shot, but I was able to get started on modding the ram to remove the spring "Eric the Great" style https://www.pbnation.com/showthread.php?t=1291758.
Got a nylon plug whipped up. One "o" ring is a little crooked, but it works perfectly.
Update: Added additional porting to the ram housing. It's mentioned in that thread that "Eric the Great's" ram had 16 ports instead of the only 8 stock ports. That was stressful since I only have a dremel and a hand drill, but I was able to pull it off! I would absolutely not recommend this unless you have the proper tools, I got very lucky honestly. Cleaned everything thoroughly, Polished up the inside of the ram housing with a cloth 410 shotgun cleaner, some Flitz, and a drill.
Hacked the spring guide off the ram shaft, polished it out to 2500 grit then more Flitz. Replaced the #010 "o" ring in the ram sleeve and #011 "o" ring on the ram shaft with quad "o" rings. Replaced all other "o" rings and added a #011 bumper behind the ram.
It's smooth as shit, and holds air, and cycles beautifully.
Going to try and get my hands on a new LPR tester this weekend. I'll be using this ram for testing with the Laz valve and new hammer.
Last edited by Myrkul; 10-17-2024, 02:18 AM.Comment
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Bolt pin finished and that should be the last part machined. Now I'm just waiting on a couple 6-32 plugs to finish the ram housing.
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I spoke too soon. The plugs were in my mailbox. Routing the hoses was also a PITA but I think I got it. Someone suggested moving the QEV to the front of the ram to vent that volume faster and I thought it made sense, but there's just not enough space right next to the solenoid.
I'd bet money that this leaks from at least one spot, but I'm also overly optimistic and will hope it works on the first try. I'm not sure when that'll be, unfortunately, as I'm prepping for a cross-country move.Comment
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Bushmaster Lazarus valve results.
Results: Please note that I was using an OTP reg adapter/vert ASA, which is on the small/restrictive side as far as volume goes, I do plan to test this with a higher flow vert ASA, because I suspect that my HPR pressure was high enough to skew my results to favor weight over everything else. 345 is NOT a normal HPR pressure for a B2k to hit velocity, my other bushmasters all have zero issues hitting velocity in the sub 300 range.
First Place:
Stock valve
Polished Stock Ram Assembly
285 FPS
HPR: 345 PSI
LPR: 70 PSI
Last Place:
Stock Valve
Eric The "great" Modded Ram
285 FPS
HPR: 345 PSI
LPR: 120 PSI (on every other B2k I own this would cause the noid to leak, but for some reason this one was fine with it?)
Third Place:
Lazarus Valve
Polished stock ram assembly
285 FPS
HPR: 345
LPR: 90
Second Place:
Lazarus Valve
Eric the "great" modded ram
285 FPS
HPR: 345
LPR: 90
So essentially, the Lazarus valve deleted the massive performance drop off from using the Eric the "Great" modded ram. The fact that my HPR pressure was constant and way high for a Bushmaster across each configuration makes me suspect that the OTP vertical reg adapter/ASA was massively choking the flow off, as a result the gun just didn't want to work well with the light aluminum hammers.
Current plan is to get more air later this week and then swap out to a higher flowing Vert ASA and re-run everything to see if the Lazarus valve does better in the lower pressure ranges.
But YES it is possible to cram a Lazarus valve into a Bushmaster and have it work in the most basic sense.
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Bushmasters seem to REALLY love weight. I have a lightened steel bushmaster hammer and a handful of chopped down bushmaster bolts that all just rot in my parts bin because I could never hit velocity with them. I've honestly never been this methodical about actually throwing gauges on things before though, always just set pressures via a chronograph. I'm pretty optimistic for round two once I have more air over the weekend. Also this does have a chaos board in it, so I might need to just actually adjust the dwell for the first time in my life. -
Set your pressure to 190 and LPR to 65. With the light hammer what is your fps? -
latches109 I preset the reg to 200 PSI when I first installed it, shots were barely rolling out the barrel, it was too low for the chronograph to read.
I'm going to be re-doing everything with a higher flowing VA this weekend, should get way better results with the extra volume.
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So when inspecting things closer, the OTP VA has a 3/16" hole drilled in it for airflow.Originally posted by scottieb View Post
This is the same size hole as is in the screw for ICD's 2k3/4 vert ASA/reg adapters, but the official ICD adapters are also a LOT longer, and have a pretty sizable chamber right below the valve and above the regulator top. With the OTP adapter, there is zero space, and I could actually see where the top of the reg made contact with the bottom of the VA. The only volume it adds is the 3/16 screw hole and whatever volume the reg itself has on the top.
When I compared it to the MacDev VA I had laying around, I discovered that the airflow hole in the screw was actually 1/4", so noticeably WAY bigger. I Can confirm that Zenitram Vert ASA's also use a 1/4" hole for the air passage.
I've been able to get stock rams and valves to function flawlessly @ 200 psi with a Zenitram vert adapter before, but that gun might just be a lucky fluke.
Obviously I just busted my drill out and went at it on the screw for the ICD adapter, so they are both 1/4" holes now. I figured the steel screw should hold up just fine. I'd be concerned about drilling the OTB out though because it's just one solid piece of aluminum and the walls might get too thin....might also just chop the threaded portion off and adapt it to take a screw. The OTB adapters might also work better when used with a reg with a ton of volume up top like an AKA sidewinder, I just checked my eclipse VA and that also has a 3/16 hole, but since it has a side winder on that it's at 275 PSI on the HPR, which is still on the high side but no where near 345.
At any rate, I've ordered a handful of 3/8-24 vented socket head screws to drill out based on this. Gotta make sure the whole collection keeps up.
Last edited by Myrkul; 10-24-2024, 01:57 PM.Comment
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I got an opportunity to dig into this more this evening.
Turns out, the solenoid was starting to fail, which is why the pressures needed to be so damn high to get it it function.
I swapped out the solenoid and threw my drilled out VA on it and tested everything using the stock ram (I didn't bother with the Eric the Great ram this time.)
Stock Valve and hammer
285 FPS
HPR: 245 PSI
LPR: 65 PSI
Lazarus Valve and aluminum hammer
285 FPS
HPR: 300
LPR: 80
So it's still definitely missing the weight, but the pressure ranges are A LOT more acceptable.Last edited by Myrkul; 10-30-2024, 12:35 AM.Comment
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tyronejk
It depends on the year and model. The older bushmasters (like this one) the Manuel states 225-270. By the time they got to 04 there had been enough design tweaks that the Manuel's were stating 180-220.
Bone stock the Promaster Manuel states 250-300, but I'd honestly be shocked if the Lasoya didn't add a bit of volume to theirs.
Dwell was at 8 ms. I do think that bumping the dwell up will help the Laz valve a lot.
I did run it at 200 PSI per your comment earlier, and it was about 200 FPS.
To clarify, remove the ram spring or remove the valve spring from the Lazarus valve? Removing the valve spring from the Lazarus valve could definitely help provided it still seals afterwards.
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dang just found this thread and way to go on all the mods, cool stuff. long live ICDFeedback: https://www.mcarterbrown.com/forum/b...ova-s-feedback
WTB: ICD stuff, single trigger electro framesComment
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so did this new housing/ram work.Originally posted by tyronejk View PostRam housing is 99% done. It needs a little more fiddling with a file to sit level in the gun body, but the dimensions look good. This was a huge PITA to machine on a lathe so hopefully it works. The oring seals feel right, so that's a good first sign.
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