Replacing LDT LDX Cylinder, Nozzle and piston head

Hi Everyone,

I’m looking to tune my blaster a bit more. I’m running a 100% cylinder in my LDX Basic gearbox with a 350mm steel inner. From what I can see (looking at the forum) and using the calculator, I should be running an 80% ported.

When I change this over, I heard that a regular cylinder you get at the shops is ‘slightly’ bigger in diameter than the one in the LDX, so the Cylinder head and nozzle can be a bit loosey-goosey.

Given this, I thought I’d throw to the group for recommendations for piston heads, cylinder heads and nozzle combos that will work with an LDT T-Piece and (if possible) run a little more quietly than the standard lot.

Looking online at primarily M4A1 and xforce, there are heaps of options, but it’s hard to tell what will and won’t work (e.g. one kit I saw looked great, but the reviewer said it wouldn’t work in his LDT box…)

Floor is open :slight_smile:

There is soooo much information already covered in a number of LDX post. Search is your friend!


Call in the memes!

But what jtraus said

Then you will have more queations that are allot more specific and those often get allot of help

I normally buy the alloy nozzle & cylinder head from m4a1 and the mst cylinders from where ever I can find them as they are a tighter fit then the shitty rainbow cylinders from m4a1 which seem to be larger in diameter and for my latest build I’ve brought a double o ring high flow shs piston head and piston.

Thanks @JtrAus and @zeHamish - Hopefully I don’t need too much corrective guidance :wink:

For context: Search is my friend: I had been reading those threads, though I think I got a bit confused moving through them earlier. I’ll try and be a bit more specific below:


  1. I didn’t really see this in the posts (though it could just me my ignorance) - are the LDT nozzles the only ones that work with the LDT T-Pieces, or will any V2-Compatible nozzle work? Reason I’m asking is related to cylinder-heads below:

Piston Heads:
Thanks for this recommendation for piston o-rings: I have Greens, but if these work better, then I’ll go down this road:

Are there any particular recommendations for piston heads? I think I’ll leave the current piston in situ, though might go to a SHS Lee, but I’m looking at whether there are recommendations for quiet piston heads?

I ordered this fella: Paintball Ultimate CNC Advanced Stainless Steel Ribbed Heat Dissipation Cylinder For Airsoft AEG M4/AK Gearbox 100%/80%/70%/60%|Paintball Accessories| - AliExpress - it’s an 80% stainless (not the coloured versions). The specifications don’t give specific measures, so could be a bit of pot luck as to whether it’s a good fit or not. I might have to go down the road you took @arc, just in case the sizing messes with things.

Cylinder Heads:
I did read the forum post about the LDT Cylinder head (and thanks also @arc for your reply). I’m likely going down this road, but are there alternatives? I noticed a lot of stores advertise their piston heads as J8/J9 Compatible, but rarely mention V2: Is this simply because they will all work, or are there some important differences?

I’m probably being more confusing, but thanks for bearing with me (or just pew pew dem memes if I require a pile on) :wink:

Update: Whelp… I suck.

Put an 80% ported and a new cylinder head in and… Went from about 240-260 down to about 170ish. Getting a weird bubbly sound like “blub blub” every now and then (no screech screech thank goodness) and seems to miss a gel every now and then. Seems to be a bit more accurate, but definitely missing the Oomph it used to have.

Optimus Pew has become Optimus “meh” :frowning:

I’ll pull it down again in the next week or so if I can get a few hours distraction free to experiment.

The saga continues.

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I found when I swapped to a shs double o ring hi flow piston from the standard I lost roughly 70 fps was averaging 240. I put the standard piston head and piston back in and back to 310. Not sure why.

What cylinder head did you go with? Did you check you had good seal between cylinder, head and nozzle?

The standard nozzle and setup works better than when you start trying to upgrade.

I’ve learnt that with the Apache haha

From a purely performance perspective regarding LDX I have found the following -

Best nozzle - standard nozzle with the tip reglued with super glue

Best cylinder head - SHS red LDT cylinder head. This is the tightest seal with the LDT nozzle

Best piston - standard

Best piston head - standard with green o-ring

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@jas I can say the Titan Areo from Monkee Mods is also awesome. I found its a touch better FPS than the standard.

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I’ve always found the brass cylinder head/nozzle combo to have the best fit and offer the best performance

My ldx setup is kublai cnc 1piece cylinder/head and the standard nozzle from the ldx

Xforce sells a ldt nozzle, which has a better air seal than the stock nozzle. Its tight, needs lub, and mine needed the tip glued on, but over the stock nozzle on the stock head, way better seal.

Also fits the kublai full cnc

Im running the m4a1 head assembly and a 70% cylinder from a cyma.

Also running an xforce metal rack piston and their poms head.

Havent chrono’d yet, but that’s a plan for the weekend

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… just realised that above is a little out of context …

I have an expert and an advanced box.

The expert is in an ldt hk416 build, and runs the above

The advanced which is kind ofva test bed, runs/will run the head from the expert and that xforce nozzle, an mst 50%, (so will need to be sealed, either glue os ptfe tape), a warwolf piston and will end up in my arp9

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Sooo. The 416. Ldx expert box, stock expert spring (m100 I believe?), head from m4a1, light weight piston and poms head from xforce, and the chihai gold high torque m150 motor, and a wat stainless barrel (7.45mm in diam.)


Oh, and gels at xforce. No idea how old. Accuracy at their range wasnt bad. Will have to grow some fresh one this weekend to dial in hopup. Its been so long, it might not even have one in it

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But if variance there in fps

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Yeah. Im hoping its the gels. Probably weeks old

Was the gels, didnt take pic, but fresh gels, 310-315, with a 290ish low and a 321 high. and it is hopped

I dont remember glueing in the barrel either, so it wont be.