Advice on a 1.6 engine build
 

Hey, so after getting some boost creep up to 15 PSI, running way lean, blowing a head gasket, filling my cylinders with water, developing a rod knock, and then subsequently shooting a rod through the side of the block, I'm looking at building a 1.6. I just picked up a 93 long block last night that had rod knock for $100. I've mostly been trying to price things out and figure out which brand of things I want to go with. I'm shooting for a maximum of 250whp, most likely closer to around 220, as I had about 160-170 (my estimate) before and really don't think I need much more as I'm just building a drift car. I'm mostly looking to increase durability as I beat the crap out of my car and hold it at, near, and sometimes past redline for prolonged periods of time, so I also would like to be able to safely rev the engine higher than 7k. Yes, I know it doesn't make any real power after that point but a lot of times in drifting you just can't grab another gear. I'd like it to be able to handle 8k reliably, with perhaps some brief moments as high as 8500. Now, I am on a budget but I'm willing to spend a little extra in places where it'll make a difference. So far my wishlist looks like:

949 racing supertech piston/wiseco ring combo 8.8 CR
Eagle or Manley rods
ACL main and rod bearings
ARP main studs
ARP head studs (already have these actually, going to re-use them from my old engine)
ARP flywheel bolts
Cometic head gasket (do these only come in 80mm bore?)
Boundary engineering street oil pump
Supertech valve springs and retainers
Engine balanced at machine shop

I just spoke with Dave at Rebello racing and he told me they've used supertech and JE pistons and was telling me the JE are much more robust than the supertechs. Do you think it's worth the extra $100-150 for the JE at my power levels? I also don't know whether to go with eagle or Manley rods are there any pros/cons between the two? I asked Dave about machine work and after he explained their process I'm leaning towards having them do the machine work since they're local.

I'll most likely be just building the bottom end for now and building the head a little later since I have a spare I can build on the side now. Can the stock valves hold the kind of revs I'm looking at or should I be getting those too? Also, I'll just mention now that I understand that a built engine will still fail if it's not tuned right, and that a megasquirt and bigger injectors are in the works.

Sell it, buy a 1.8.

/thread

If you're doing the 1.6 for 220hp, I'd do stock pistons with rods.

But if you're buying pistons and rods, buy them for a 1.8 and build that. If you want to reduce stress, a 250 1.8 will be much less stressed than a 250hp 1.6.

If you're really struggling to find a 1.8, don't do 1.6 pistons, just rods, hot tank to clean up, and a rebuild kit just to get it running safely and quickly. Then once you find a 1.8 do a proper build on the side and sell your 1.6 for $3-400.

Agree with Curly. The stock 1.6 head won't hold the revs you want, and it would be an even greater tragedy if you actually put money into a 1.6 head.

When you're looking at $3000 of rebuilding parts, a few hundred for a 1.8 shouldn't be an issue. They both cost the same to build, but one is objectively better than the other in every way.

grr.... A 1.8 was my original plan but I figured the 1.6 can hold the power levels I'm looking at no problem. How would a STOCK 1.8 handle what I'm looking at, because naturally, after weeks of looking for an engine, a running 1.8 comes up for sale the day after I buy the 1.6. He says it was pulled for a v8 swap so it's likely "drop in and go" ready. Otherwise there's a 1.8 with a rod knock for even cheaper.

I was avoiding a 1.8 since I'll need a new turbo manifold, which means likely reworking my downpipe and intercooler piping, and the FM swap stuff. All this adds several hundred to the price, but if it's really worth it... Like I said, I'm trying to get out as cheap as possible but I'll spend a little extra where it'll count. I was under the impression that a 1.8 made more low end torque but that the 1.6 could handle more revs. If this info is incorrect then I guess I should ask could a 1.8 handle those revs and power reliably with just rods, the oil pump, a balance, and valve springs/retainers?

If I were in your shoes I'd probably stick to the 1.6 as well, I'm in the same situation with the manifold and such.

Just put rods ($250) in the 1.6, hone the block ($50), have the pan, block, and large auxiliaries hot tanked ($100)(but NOT sandblasted), maybe have the entire rotating assembly balanced ($200), and throw it together with ACL bearings and a rebuild kit ($400??). Still $1000 for a 1.6 rebuild, but it'll be better than $2-3000 for a full rebuild, which should really only go into a 1.8.

The 1.6/1.8 revs thing is a myth. They're built the same. With larger pistons maybe people think they feel more vibrations? Either way it's a myth. Both engines are happy up to 7000 rpms, very unhappy past 7000rpms, and will start complaining after sustained 6000+rpms during drifting hooning. Any engine won't be too happy with that kind of abuse, but they'll handle it for a while.

On the street, absolutely. On the track? probably, and since you talked about drifting I assume it can definitely handle that because it's a lot easier on components than grip driving.

I was going to recommend just that in fact. There are quite a few members on here starting their "rods only" 1.8 rebuilds. The stock pistons should be able to handle upwards of 300whp (you know without major det of course). If you can find a 99+ head even better as I'm not sure how the NA hydraulic lifters handle revs compared to the solid lifters of the 99+.

I wouldn't let Dave Rebello rebuild a lawn mower engine for me. You also don't need any of the FM swap parts if you're using a Megasquirt.

I don't build 1.6 engines, but if you want a 1.8, call me at the shop. I have way more experience than Rebello does building forced induction motors, and I can probably beat his price as well. I'll even put the parts you pay for in the engine at no extra charge :party:

I'm showing the Livermore-Sunnyvale drive as 40 minutes, I'd seriously take him up on this offer. Put $100 in parts into the 1.6 and sell for $300. Or just scrap it. I'll bet Savington has a 1.8 on the shelf or near by for ya.

PM sent! ;)

On a 1.6, if I replace the oil pump gear with a billet one, get the supermiata crank dampener for extra assurance, have the rotating assembly of the engine balanced, and use aftermarket valve springs/retainers (flyin miata claims on their site that they're good for 9k rpms without valve float) what would be holding the engine back from being able to reliably turn 8k rpms?

The rods won't survive past 7800 and you'll break the throttle body shaft and destroy the motor at some point.

even eagle/manley rods won't survive?

Forged rods will, you left that out of your previous post though.

Right sorry.

I just picked up that running 1.8 today. I hate you guys :fawk: Still deciding if I want to build it up a little, build it up a lot (with a credit card), or run it as is for the time being while I save up some more cash to build it a lot.

This isnt just Andrew trying to get business. Wouldn't trust Rebello either after taking apart a failed Rebello motor at the track that had some special hellaflushed valves and a few parts missing.

And boost isnt rebello's specialty. Their specialty is making nearly undetectable "stock" cheater motors.

Why not use scat / m-tuned / ebay rods?

Ballance them, weigh them, put ACL bearings in them. Good to go.

It appears the M-tuned rods are discontinued. I figured connecting rods were one place where one wouldn't want to buy ebay stuff, but after some searching it appears they're actually ok to use. I've been meaning to call up Belfab too and see what they want for some rods.

I found rebello racing on miata.net while searching camshaft options for the 1.6 a while back. Apparently they have some for cheaper than anybody else (never actually asked them about them though), and I just noticed they offer pistons and rods too which is why I called them up, and asked about machine work while I was on the phone with him. If you guys say to stay clear though I will.

So, if I were to just put rods in this thing you guys think it's ok to just polish the crank, slap the new rods and bearings in, and re-use the pistons and rings? I'm guessing if re-using the rings that the cylinders won't need to be honed either? I'm not a big fan of this option, but when my alternative is just running the engine how it is, I can't see it being worse. I tried to see how much stock pistons and rings were from mazda to see if I could save a few bucks but it's pretty much the same price as buying supertechs. I can however get some sealed power or NPR pistons and rings for dirt cheap through my work, but I don't know if they'll actually be worse than 140k mile oem ones :laugh:

One last question, this engine I got didn't come with a throttle body so since I need to get one anyway I was thinking I might just get a skunk2 off the bat. I see skunk2 lists a different one for 94-97 and 99-00. I looked up the part number for a throttle body gasket though for both and they both use the same gasket so I'm assuming the difference is not in bolt spacing but just the iac valve and TPS. But since I'm going to be using a megasquirt and will have to splice the TPS connector in anyway, I could use either one right? I'm just trying to figure out if I buy one, that if/when I upgrade to a 99-00 head down the road I won't have to get another one.

Why get a NB1 head when you can get an NB2 head?

Idk, I haven't really even looked into it too much and I don't have an endless amount of money to throw at the car. I've decided I'm going to slap all new gasket in this motor, plus a new water pump and timing belt, then use the money I was going to rebuild it with to buy the megasquirt, manifold, a coolant re-route, polyurethane motor mounts, and perhaps some other things I needed anyway. That way I can get it running now and it'll give me some time to tune it (this will be my first experience tuning with something other than an SAFC so I expect it to take me a while to figure out), then maybe 6 months or so down the road I can have Savington rebuild it and swap to a later head. I'll just try my best to keep it under 7k until then :P

I've already picked up a set of 460cc rx7 injectors from the junkyard that I'm going to have cleaned before putting in. And I'm having Abe at Artech make me a manifold that will orient the turbo in the same spot so I can re-use my downpipe and everything. I need a throttle body and fuel rail anyway, and I see that OBX makes both. The TB looks like a direct copy of the skunk2, but I searched and couldn't find any instance of anybody using one. The fuel rail I figure is just a piece of aluminum with some holes in it, pretty hard to fuck up, but I thought I'd get opinions before ordering either.

Couple quick questions on interchange stuff: I looked up Gates water pumps at work and it appears that there is a different part number listed for a 1.6 and 1.8, but 949 racing lists their water pump as fitting all 90-05. I just replaced the water pump on my 1.6 like a week before the engine blew so I'm wondering if I could just re-use it on the 1.8? Also, FM lists their motor mount brackets as fitting all 94-05 miata's, but I found a pair on ebay listed for 99-00 that look different, they don't have the threaded hole at the top that I've read is for the starter bracket. Will these work or no? Pair of 99 00 Mazda Miata Motor Mount Brackets | eBay

You are talking about the 1.8 motor you just bought correct? The order of operations of how you should get the car running is as follows.
1. Swap in 1.8 motor, leave 1.6 ecu and injectors, get the car running.
2. Swap in MS, swap in wideband, leave stock injectors, get car running.
3. Swap in larger injectors, get car running.
4. Finally put on turbo and then get the car running.

For the waterpump you want a GMB branded one. This kit off ebay will work if you have a 94-97 engine. I have used ebay kits for the past 6 years or so on dozens of miatas and never had any issues with them.


Learn to tune the car NA before putting any turbo kit on. There will be a learning curve and you might as well do that when you are not as worried about popping the motor.

Having the injectors cleaned and having Abe build you a manifold are good ideas. I may have a 94/97 TB in my garage. I will check later and let you know how much. You can get an oem fuel rail from any of the companies that part of miata's for about $20, no reason not to go that route. I typically get my parts from Panic Motorsports.

I believe those motor mounts should work, but I am not positive. I know the NB's have a slightly different sub frame, so that might be why slightly different brackets, I would yet again just check with Panic Motorsports for some.

Correct, I meant I hadn't looked into what head I would eventually put on it, I'm just worried about the here and now for now. I'm not a total noob to this stuff, I've just never actually tuned with a standalone before. I do have a fairly good understanding of how an engine runs and how fuel and timing affect how it run, so I'm sure I'll be able to figure it out after a few dozen hours of reading :rofl:

I get an awesome discount on oe replacement parts through my work, and I can probably order a GMB pump there if it's really better. I was planning to use all Fel-Pro gaskets, and a Gates timing belt and water pump.

I actually went to the local wrecking yard today and was able to get an oem fuel rail. Somebody had already grabbed the injectors though so the spacers that go between the fuel rail and manifold for the bolts were missing, so if anybody has a set of those let me know! The throttle body was also missing too unfortunately, but I did get a sweet valve cover that doesn't have the cam cover section from a 323 or something (maybe somebody can help me identify it), it was tucked behind the seat of the miata like somebody was saving it for later, but finder's keepers :giggle:


I actually made a WTB thread on a local roadster forum and someone replied to tell me he had a pair of the FM ones, brand new, and only wanted $10 for the pair, so I'm hopefully picking those up tonight :cool: