Cheapo ebay turbos

Figure this will be fairly controversial!


I was at a hotrod show this weekend, Lonestar Round-up in Austin, TX... It was more of a 'rat rod' kinda show, lots of questionable mechanik'n on display, but one thing that i couldn't help but notice was the prevalence of these cheapo ebay turbos. Saw lots of twin turbo V8's... a couple of them were actually really well built (out of junkyard parts) one in particular had pretty clearly been driven on the road quite a bit, it was covered in road grime, bugs and the plumbing had obviously been run hot.

I should have brought a camera, but you can tell these things pretty easy by the weird names on them like 'master power' etc. and the crappy finish quality.

but it did pique my interest.. obviously these guys are having some success with them? Also the user 'first fox' seems to be having good results with his.

I had more or less completely discounted them, and put them in the category with cordless tools from harbor freight, but now i'm seriously considering it for my 240 'stage 2' build this summer.

The advantages are:
1) The t3/t4 style turbos are better suited to a wide RPM range, and several A/R ratios are available so i could choose something sized better than a junkyard turbo, the TD04E-16T that i had previously picked is starting to look like a bad choice the more research i do.

2) brand new, for what its worth, no rebuild needed (a junkyard turbo @$70 + rebuild at $60 = total cost of new china turbo)

3) easier to adapt and connect than the 'oem' turbos that use different flanges... bolt on changeability between various turbos if it blows up or turns out to be sized wrong.

4) available from various online sources for $120 or less... completely bonkers!


The disadvantages are:

1) china, china china... could get sent a box of complete scrap metal

2) probably less efficient, possibly leaky or completely wrong trim/AR compared to what is advertised

3) could explode and send shards of compressor into my engine

4) external wastegate needed

5) probably going to be noisy and un-balanced


Seems like most people that have bought these turbos are idiots with no experience, probably many of the claims of problems (leaky seals, bad bearings, etc) come from folks that didn't set them up correctly to begin with. I haven't heard anyone that specifically has run one, knew what they were doing, and put some serious miles on it, except for First Fox.

Just curious if my points are valid, or if there are any major holes in it, and if any of you guys have more experience with these, specific brands/sellers or identifying characteristics that you can look at a listing and say 'that one is definitely one of the better ones' or 'that one is total junk'


I'm trying to put together this 240 without opening it up, more or less just to experiment with the concept, see how the big six handles boost and make the mistakes before i start into a full-longblock build of a 300. I've already learned quite a bit just from daily driving my 'stage 1' build with the converted 2100... stuff like realizing that the Big 6 likes to rev a lot more than i thought, so this 'stage 2' engine will hopefully inform whether or not i need to go with bigger valves, cam, lower comp pistons, etc. to deliver the 'factory stock turbo' level of performance that i'm looking for.

ach i've wrote a tome:

tl;dr: anyone used the cheapo china turbos on ebay? will they work for a mild build or are they complete junk? if some are good/some bad how do i tell them apart?

I can't say for sure yet. BUt I ordered an el cheapo special at 130$ shipped. It has minimal shaft play, shows signs of being balanced. And while the casting is rough, seems to be in good running order. I ripped the whole thing apart and there was no "sand" or "machining debris" like many people will say is left behind.

I then emailed the seller and said it had shaft play. He said to just send him the tracking number for it coming back and he'd send a new one. So at the very least, decent customer service.

I genuinely don't beliebe it will POP on first startup like lots say they will, that being said I designed my whole system around being able to drive home after the turbo pops, then replacing it easily with a garret.

If something goes awry I simply discconnet the oil fee and return, use a fitting I had made to connect them together. Pop the cone filter off the turbo, and put it on the carb hat and voila. Drive home. Granted with very little ignition timing and probably running rich enough to need a plug change. but I can change that at the road side too if its a long drive

TO replace it is an 11 bolt affair. :mrgreen:

tl;dr, if you dont expect it to last, you wont be dissapointed when it pops. COnsider the 120$ an investement to see how the big six can handle boost. But don't use it on your long-term build.

yeah, the more i think about it and break down the risk factors, the more i am convincing myself this is a good idea.

i'm almost to the point that i can't move any further with the project (although other projects like paint, weatherstripping and trans swap are keeping me busy) without picking a turbo.

at least picking and assuming i'll be using a 't3' style turbo will get me what i need to carry on with fabrication, etc.

If it helps I need to either find second hand forged pistons or try and find a company that'll make them cheaper than classic inlines. There's no ebay replacement for that

AngryEyes":1iqk0er2 said:

If it helps I need to either find second hand forged pistons or try and find a company that'll make them cheaper than classic inlines. There's no ebay replacement for that

Click to expand...

Racetec.

I used them for my build. They make a 2618 alloy forged, and a cheaper, higher silicone offering.(like a 4110 alloy?) I had them build me a 2618 piston, dished to fit my compression needs. The price quoted was 690.00 for 6, including pistons, pins, and locks. The cheaper piston will be sufficient for boost less than 10 lbs, but I couldn't tell you how much they cost. I'm gonna shoot for 16-18 lbs, so the better piston material was what I chose.

the piston thing doesn't trouble me much, i've worked on a couple turbo builds with hypereutectic cast pistons and they seem to survive just fine if you don't detonate them in the more conservative setups. Plus the whole point of this is really just overcoming the poor flow characteristics of the stock head and not trying to create a balls out, pushed to the limit, turbo monster.

pmuller has mentioned he has a source for custom forgings with the short deck for 240 rods, if i were to spend $500+ on new pistons, i'd go that route, otherwise whatever the cheapest hypereutectic with a dish in them or machine my own dish on something with enough meat.

i've also been kicking around the idea of starting with the EFI head and having the chambers completely re-cut on a CNC for lower compression. It would probably put me ahead of starting with the pre-EFI head and having to mod the rocker studs, hardened valve seats, add the bold holes for EFI manifolds, etc.

Not sure how the AIR would affect things but that is a topic for another thread

at this point, the 'stage 2' is looking like a prototype that can be used for some basic testing... what level of boost pressure will cause knocking, what needs to be done to pull timing, how does the carb respond, get things like exhaust, plumbing, etc laid out.

motzingg":38svyac1 said:

pmuller has mentioned he has a source for custom forgings with the short deck for 240 rods, if i were to spend $500+ on new pistons, i'd go that route, otherwise whatever the cheapest hypereutectic with a dish in them or machine my own dish on something with enough meat.

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The company I got my pistons from is AutoTec. It is the same company as RaceTec where mike1157 got his pistons from.
AutoTec is the division that makes forged pistons from a 4032 alloy and cost less than the RaceTec forged pistons using a 2618 alloy.

motzingg":38svyac1 said:

I've also been kicking around the idea of starting with the EFI head and having the chambers completely re-cut on a CNC for lower compression. It would probably put me ahead of starting with the pre-EFI head and having to mod the rocker studs, hardened valve seats, add the bold holes for EFI manifolds, etc.

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Arnie at C-Tech mentioned this as a possibilty.
I would sonic check the chamber walls around the spark plug area to see if there is enough material to pull the chamber out to the cylinder bore circle.
If you can get the EFI chamber out to 76cc then the piston dish will be 3.00" diameter and .275" deep for 32 cc.

OP, I have a "China-Charger", T3/T40E internal watergate, shipped for $140. Can't beat it! It maybe inefficient, but it has served me well. It is not a daily driver. And....yes I had low expectations!
If this turbo were to die I would purchase another one, without any hesitation.
I bought it from ebay seller cxmotorsports and I think its the same as www.cxracing.com

Awesome, exactly the kind of response i was hoping for. I'd do 140 from a known seller rather than some rando for 110 or 120...


PMuller, I do remember FTFlyer talking about his sectioned head for porting, i know there is a very thin spot somewhere in that head, but i think he was saying it was in a port, not in the chamber itself.

I've got lots of folks that i work with who have CNC machines, but they aren't auto machine shops, they are more on the industrial/prototype end of the spectrum. I could get someone to come in after hours and run a program that i modeled/wrote, but to them it would be the same as just cutting any other hunk of metal.

The volume thing (30 cc pistons are commonly available, read: cheap, so that would be rad) isn't as big of a concern for me as the geometric characteristics, i would mostly be trying to remove the 'high swirl' ridge and create a smooth bowl that wont detonate, and might improve quench as much as possible. I've read all that you've been posting about dynamic CR and learned a good deal from your cam selection info, but from my limited personal experience and what i've read in Bell, and Blair, i'm pretty well convinced that the best approach is to optimize the geometry first, and let the volumes fall where they may. A good geometry should produce power with lower pressure and reduce detonation to the point that the DCR won't be too touchy. Anything else should be tuneable with pressure and timing adjustments, and fuel to a lesser extent.

The last time I read through Bell's 4 stroke tuning book i skimmed the U-flow head section because i wasn't working on that at the time, but I will have to dig it out after I move, I remember specifically he had a lot of good anecdotal information from Coventry/Lotus some of the other inline 4's and 6's being raced in the late 50's and early 60's in europe.

Given that I have access to the CNC and the modeling software, and my CNC shop has 5-axis license of MasterCam, the actual machining part would probably be cheaper and easier than paying a auto shop to do the hardend valve seats, rocker studs, and valve cutting on an older head, plus i could get whatever geometry i want (within reason) and maybe even get by with stock pistons.



Most importantly, getting the 240 built up as a test bed, seeing what kind of mods i need for the 'seat of the pants' driveability factor. If i end up blown away with 5 lbs on a tired old 240, i might just freshen up my motor, throw on a 300 head, and run it. If its good but still lacking, i'll plan on a mild 300 build and start collecting parts, if its a total dog and minimally improved (worse than expectations) i'll see how far i can push the boost and what breaks, and how, and start planning a more comprehensive project.

At this point, just going off books and forums, its hard to get a feel for where the various stages of complexity will actually benefit the operation of the truck, and where the point of diminishing return is, for reliability as power increases.

I'll chime in as well and say that my China charger has served me well. As much as I would love to buy a quality part, the fact is that there is a HUGE price difference and a cheapo from eBay allowed me to actually turbocharge my car instead if talking about it while saving the additional cash required for a garret/precision/turbonetics etc.

My concern was also not sizing the turbo properly and ending up with an expensive turbo that was laggy or too small that I would be stuck with. I figured if I made a bad choice on a China charger and wanted to try a different size, I wouldn't be out that much cash.

motzingg":1z7n74ew said:

PMuller, I do remember FTFlyer talking about his sectioned head for porting, i know there is a very thin spot somewhere in that head, but i think he was saying it was in a port, not in the chamber itself.

Click to expand...

There is very little material around the exhaust ports and if there is any core shift it makes exhaust porting a problem.
I lost one head to CNC porting because of that.

Anyway on this head you can see where I scribed the cylinder bore circle and brought the chamber out to the scribe line.
This was a carb head so I didn't have to remove much.



I don't have an EFI head to look at but just looking at pictures it looks like it wouldn't take much there either.
As you said the most attention is going to be at the 'high swirl' ridge.

Ideal quench would be a piston with a "D" dish that mirrored the combustion chamber.
The "D" would be rotated slightly to match the chamber position.

The piston is the one area where I would not go "Cheap". At least go with a custom forged 4032 alloy piston.
IMO it is not worth the money savings to have less than desired results and/or lose the engine due to piston failure.

We use 2618 alloy pistons in our forced induction engines.
We have bent rods, bent piston pins, concaved the head on an intake valve, detonated bad enough to weld the top rings to the piston but never had a piston break.

Just to double check, Is your head and piston combination for a 300 not the 240?

Yeah, despite my minor setback (see 'big six' forum), i was planning on doing a conservative build on the 240 to see where problem areas might arise, while i build the 300 the 'right way'.

Given recent events, i might have to get the 300 sorted and installed sooner than i planned, building a turbo-able motor and holding off on the actual turbo buildup until my budget recovers. In fact this may be a blessing in disguise as it forces me to get my horse figured out first before slapping a cart to it.

I hear you on the pistons, but this being a pretty conservative project I think i can keep some run of the mill hypereutectic slugs alive. In the other turbo projects i've helped friends on, we've had good success with modern high-si castings as long as you don't detonate them.

Its like i tell folks when i build high performance 2 strokes, just because it has the power doesn't mean you have to use it all the time. That's where I think the cast/forged thing comes into play, the ultimate tensile is probably pretty close, but the high-stress fatigue life is dramatically shorter for cast hypereutectic than forged. A high performance engine that runs at 50-60% of max capacity all the time can live for a long time, two or three seasons of easy riding, the same engine might not make it through a weekend of racing WFO all the time.



That chamber is great, i can see what you mean about the offset D dish... is that something available in the off-the-shelf cast pistons for 351?

The other thing i was wondering about, is it common for a piston to come cast with enough room to mill out the dish, or do they not have enough meat behind the piston face? I guess thats kind-of a stupid question, just tough to know without being able to handle and measure a lot of pistons.

motzingg":4rkc20e5 said:

That chamber is great, i can see what you mean about the offset D dish... is that something available in the off-the-shelf cast pistons for 351?

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If you want to use the wide selection of 351W pistons you will need to use the 1965 - 1968, 300 six "No Hole" connecting rod.
It has the .912" pin small end. Forging number C5TE.

Miles at B and P rods will supply a reconditioned set resized with ARP bolts or you can ask him to sell you a core set and do the recon yourself.
FTF also had a core set at one time.

There are several "D" dish 351W pistons with a 22cc dish and a compression height just over 1.70".
Of course you need more dish volume and the "D" dish would have to be modified but there are a few shapes that look interesting.
Like you, I don't know how much material is under the head to modify the piston to get what you need.

motzingg, pm sent.

well, i'm a bit discombobulated now posting on this thread and posting on the other thread in 'big six' performance...

i got the engine back to the house on wednesday, started going through the boxes and looking at everything...

I've got (at my disposal)
- the entire 240 '68... assuming its the same as the truck it is in. which isn't for sure
- a complete '91 4.9 with 120k in very good condition, along with a re-ring kit for it, i.e. bearings, rings, gaskets
- a bonus '84 head that has been reconditioned with the valve guides cut in a ribbed pattern (apparently some old school trick), and all the valves and seats ground. surfaced, the whole shootin' match.

the short term plan is to get the truck running. right now i've been driving around on 5/6 cylinders. I'm going to re-assemble the 4.9 motor with new rings, bearings, and no machining aside from hand-honing the bores. I'm going to put the 240 head, intake, exhaust on the 4.9 block (as little work as possible) and get the truck running.

Since i have the bonus '84 head anyway, i'll probably re-assemble and junkyard a second carb'd exhaust manifold... my 240 manifold has a cracked of mount flange... for welding the turbo flange on to. I'll re-use my converted 2 barrel manifold with the same carb. I thought that '84 should be hardened valve seats, but the machinist told the guy i bought it from they weren't... either way i'm not too concerned with smoking them. That head can probably go together by the end of the summer


the EFI pistons already have a really nice D dish in them, i haven't looked at the EFI chamber yet but i'm guessing they are almost a perfect match. Its probably going to be a really good setup naturally aspirated with the 240 head, chances are they will be really close. If i was smart i'd probably just throw the chevy lifters in it, weld up a nice exhaust and run the EFI exhaust manifolds and be happy... but i'm not.

The 'kitchen sink' build... if i decide i like where the turbo is taking me.. means taking the 240 block and having it bored, blueprinted and magnafluxed. Finding a 300 crank or a HD if i'm exceptionally lucky, and having it shot-peened and ground, maybe even balanced.

Using the 240 rods i already have, buying the autotec pistons, and doing the chamber porting on the EFI head, along with o-rings and a proper turbo cam.

then that head has either the efi manifolds with two small turbos, or a log-style with one large turbo.

either way, its a long ways off, just helps me to start thinking it through now so when various pieces of the puzzle turn up i can grab them

The main thing to watch out for on the Chinese turbos is the sizing, most are meant for higher revving 4 bangers. Even the $1500+ turbos from Turbonetics and others can come apart if they are subjected to over-revving. Many guys over on Inliners have used the cheapos with no issues, and you should be able to also.