Engine Building 101
 

I don't have the money, or trust to let someone else assemble my engine, so I will ask you all, plus, I have some local support as well.

1: Where do I get the tolerances for the 1.8 engine. I found an FSM, but it was for a 1.6. I remember this site had one for a 1.8 (99) but it dissappeared.

2: Even though I had the machine shop mic and polish my crank, I will still use plastigauge on re-assembly, because like I said, I don't trust other people with my shit. I have arp main studs and rod bolts on belfab rods. How do I find the proper stretch that the rodbolts need to go to, and if there is new torque specs for the main studs.

3: While plastigauging the rods, will I use the stretch gauge on plastigauging them too? It seems like if you stretch them to the peak of their capacity once, you wouldn't be able to do it again. Requiring new bolts. Would I just torque them down to spec, or a little less, check plastigauge, then re assemble with the proper stretch if everything is kosher?


4. Rebuild kit/ bearings. I have not purchased these yet. My short block has inadvertantly turned into a full buildish kind of thing. I have a boundary street/strip pump. 84mm supertechs, and belfab rods. What should I tell the machine shop to do for clearance on the pistons. Do I need ACL race bearings? I plan on revving probably max 7500-7700, I wasn't planning on 8k. I am gunning for mid 300's. Probably 350-375 max, but more like 325.

5. What should I tell the machine shop to do for clearance on the pistons. I read somewhere .003 is a good number. Should I get the machine shop to do the piston/rod assembly? I don't have a mic.

6. Oil squirters. I have read about people removing these. I don't think it sounds like a great idea, but I thought I would throw it out there.

Subscribed. I have all the same questions.

Take the pistons to the shop so that they can measure them and hone the cyls and match the pistons to them if need be. Also bring whatever papers came with them as well. Then sit down and talk with them and explain exactly what you plan to do with the engine so that they can better understand your build. I just got done doing the same thing. Depending on how many miles are on the head you may want to have them do a valve job. I would also say to make sure they do a good inspection on the block and head even if they are not going to be doing any head work.

Have a great day,
Jared

That is what I was planning on with the pistons. They also magnafluxed everything (block/crank). As for the head, I think I will snag a low mileage vvt head. I am just really concerned with the shortblock as of now.

Oh, So that means I will have to run an 01 hg? how will this effect the reroute? I read in a thread your not supposed to do both. Are the ebay hg's decent? I ran one on my car, and didn't blow it.

Buy this book or use what you can read online. Between searching here at mt.net, mnet and what you can read of this book online I think most of your questions are answered.

http://books.google.com/books?id=8eN...epage&q&f=true



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Your piston clearance will be determined by what you use the car for, street cars can run tighter clearances that race cars do.

I believe the consensus was that your best option is to run the 94-00 headgasket and use the reroute. The 01+ heads still have the same passages, several of them are just blocked off.

This is correct. I have a 99 gasket on my car. Don't know if they are different. I personally like to use PEKING gaskets. That's just me.

Have a great day,
Jared

agree with pdexta - there's no reason to run the 01+ HG

Rodger. I just confirmed the VVT head for less than 300 dollars. That shit looks brand new. I will be picking it up on the first. I can't wait for the VVT controller to come out with a DIY kit so I can build me one. I think I have settled on an ebay head gasket kit then, my other one held just fine, and I will just get felpro lower gasket set, and then acl race bearings. So, about my plastigauge question. I might just have to make a call to arp.

Just upgrade your MS to MS3 and very soon you can have it control VVT.

That is on the list, but not now, since I need to get the dam thing rolling first. Any Ideas on the rodbolt Idea?

Summit sells a rod bolt gauge if you can get to both ends of the bolt. Depending on the bolt, we've just torqued the ls arp rod bolts to 45 foot pound and walked away. Assuming the rods came with those bolts, the rod "shouldn't" need machine work.

For the mains, the machine shop needs to check them for out of round with the arp's. Some need line honed, others don't.

my belfab rods needed machined on the big end for out-of-round

Hmm. I used plastigauge (well it was made by sealed power) on my crank yesterday on re assembly. It ended up somewhere between .003 and .004. Not max but close. The machine shop told me the crank was in spec for use with the .010 bearings I have. Something is amiss. So, is that too much crank oil clearance? I haven't made it to the rods yet. I freaked out when it wasn't exactly at the factory standard. Also, I might try a different brand of plastigauge and re torque everything. Ideas or suggestions?

Oh, I am using ACL race bearings, .25mm/.010in undersized, and asked that my crank was cut and spec'd accordingly.

The only thing I can comment on is the squirters. Everyone here will tell you to keep them, but my motor does not have them and has been fine for 6000kms with a lot of dyno tuning, one track day and a hill climb making 230whp. .003/.004 is not that out. IIRC my motor is right around the same because the crank was pretty worn from 200,000kms of use. It's a bit looser then factory specs but given the power I'm making, what I'm using it for and spinning it to 8k, it's fine.

Being out on the "loose" end of things is common for race oriented bearings, as you don't get a 1000 mile break-in on a race engine the way you might on a street engine. All of the bottom ends I've done have used the ACL Race bearings and were near the loose end of the factory spec. I don't remember what the exact numbers were but Sav might have the spec sheet I gave him when we did his bottom end, ask him.

.003 is super loose on the mains. Factory spec is .0008-.0013, rods are .0012-.0018. The last motor I did was .0035 mains and rods, and I had crap oil pressure and the bearings didn't look so hot coming out after ~20 hours of runtime. I pushed it down to .0020 on the mains and .0025 on the rods this time, but that's for my motor, which sees nothing but track time at 400whp. For a street motor, I would set the clearances right at the top end of factory spec - we're assembling a street MSM motor right now and it's getting mains in the .0010 range and rods in the .0015 range.

ACL makes a STD bearing, a STD-X bearing which is .001" more clearance, and an .025mm undersize bearing which is .001" smaller. You should be able to get whatever clearances you want, no matter what.

You should really have a rod bolt stretch gauge if you're assembling engines. I have an old set of ARP2000 bolts that I use for assembly, and the fresh ones get saved for final torque. Their spec sheet says 60ft.lbs, I've found that the .0055-.0060" stretch comes at between 65 and 75 ft.lbs on my torque wrench.

Maybe I was thinking .00013-.00014.

Well, I am already .010/.25mm undersize. I guess the machine shop cut the crank too much. I don't know if my plastigague is shady, or what. I will buy more and try again. I plan on using a rod bolt stretch gauge. Thanks for answering my question on those. Thanks also for posting the stretch numbers on those, I didn't have those with my rods. I will give her another whirl, and I guess I might need to go .020 under with the bearings.

Ok, So I am a dick for one reason. I was following the torn up haynes manual that was soggy in the back of my trunk when I bought the car, and only torqued to 40lb/ft. I came home, and laid the green and red plastigauge down and torqued to 60 lb/ft and actually used the arp lube (I was saving it for the final assembly). The green read pretty much .002 On the red it was always a bit smaller than .002 I am no where north of .003 as I had suspected due to improper torque, I would imagine. I assume this is at or near the larger end of factory spec, but not much to worry about at this juncture. I didn't think that much torque would make a difference, but then again, this is a thousandth of an inch we are talking about here.

I looked at the FSM, enthusiast manual, and the haynes manual is the only one that shows how to stagger the piston rings is the haynes. It says to stagger the top ring 30 degrees to the left of the wrist pin, and the bottom one 30 degrees to the right, leaving 60 degrees of stagger between the two, and on the opposite side, the same with the oil control rings, with the ring spreader thingy centered between them, Is that correct?

Supertech has instructions on how to set the piston rings up on their little sheet that comes with the pistons.

Yeah, it said it was an example of a subaru or something on the front. I wasn't sure if that was legit. I guess I will use that then.

Its standard issue on most all pistons. The piston doesn't know what car its in :)

How tight are the wrist pins supposed to be in the rods. Mine are kind of tough to move, and not as easy as the ones I pulled out. They take some encouragement to move from side to side, and the wrist pin moves easier inside the piston than the rod. Is this ok? Or do I need to have the insides of the rods machined out?

They are, in my experience, tight on initial install but did you grease them with assembly lube (or at least lots of oil) first? I've had to tap them in even if they were greased first on occasion.

The ones you took out had worn a bit, assuming you're using pins that came with the pistons they should be the correct size for the pistons.

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Yeah, I had to tap it in. Not too much effort though.

For the record, they are belfab rods, and supertech pistons, wrist pins.

Wrist pins are supposed to be tight in the pistons. You want the movement in/on the rod.

Where do you guys get your engine clearance specs? I bought the Mazda workshop manual a while back but noticed it doesn't have this information. Is there a Mazda engine specific workshop manual?

I'm pretty sure there are stock engine bearing clearance specs in my 94 FSM. I can look them up if you need. On the various specs that are necessarily non-factory (piston-to-wall with forged slugs, ARP fastener specs, etc) that's where the accumulated experience of people on this forum comes in handy.

I'm trying to gather up as much info as possible. I'm planning to put 99-00 pistons in a 2002 motor with forged rods, nothing fancy. I believe I'd be looking for factory specs for the mains, rods, and piston rings. Very n00bish with this stuff, so I'll probably be asking for specs for other things as I go.

94 FSM lists clearances in metric and also lists the inch conversions, but if you do the math you'll find the inch spec they list is sometimes off by a ten-thousandth or so. These are the inch specs taken verbatim:

Piston ring end gap:
Top: .006-.011"
Second: .006-.011"
Oil rail: .008-.027"

Wrist pin fit in the piston has a negative clearance spec of 2 to 5 ten-thousandths, IOW "tight."
Wrist pin clearance in rod small end: .0004-.0010"

Main bearing oil clearance: .0008-.0014"
Rod bearing oil clearance: .0008-.0017"

What ended up causing all my problems were the stupid belfab rods. They were infact too tight up top, and out of round on the bottom, causing lots of problems. After hearing someones experiences, including mine, I would avoid belfabs at all costs.

Thanks for listing the values. I'll mark that down.

I am going to be using a set of $170 ebay rods.

I can stop by the machine shop sometime and get them. I just threw in the towel and had them spec everything. I certainly don't know them off the top of my head. All I know is when I plastigauged the rods is that the green plastigauge was smooshed on one side til it was too big for the paper to read. Like .0005

Are you referring to the big end of the Belfab rods? I'm hoping these china rods are ok. The defunct Leatherface used them and said his didn't have any clearance issues out of the box.

Are the wrist pins press fit or do they have a spring retainer? My searches result in conflicting information.

Do you guys hone the cylinders yourselves or is this something I want to pay a shop to do? $25 vs $200 question up here.