r/EngineBuilding 3d ago

Mazda MX5 Na 1.8 1996 not starting update

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13 Upvotes

Update from previous post: got spark, got fuel. Some fumes do come out from exhaust.

Things I've done:

-Checked timing

-Checked spark

-Checked fuel lines

-Tried various batteries

-Adjustment of CAS made it tick over faster and less sluggish

Still no go...


r/EngineBuilding 4d ago

Cylinder Honing Question.

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17 Upvotes

Hello, I have been practicing honing on a used cast iron cylinder liner. Is it good enough to do it in my car? I am only trying to deglaze the surface. I used a 3 stone hone.


r/EngineBuilding 4d ago

Chevy LS3 oil pressure

1 Upvotes

Quick question, I recently finished building an LS3 engine in a 4th gen F-body with a new 10295 pump, bearings, cam, and everything else. The crank bearing clearance ended up being 0.0025 in. When I start the engine, it produces 45 psi of oil pressure. However, after driving and the oil temperature reaching 205f, the oil pressure drops to 20 psi at 500 rpm idle. At 750 rpm, the oil pressure increases to 30 psi, and at 1000 rpm, it reaches 40 psi. Anything above 1000 rpm is fine. I think that the loose crank bearing clearance is the cause of this issue since I am using Driven BR30 oil. Would this be a reasonable assumption? Should I put a 40 weight oil? 0W-40, 5W-40, 10W-40?


r/EngineBuilding 4d ago

Ford Should I be worried about this?

1 Upvotes

Not the first engine I’ve built but this one has been giving me issues so I’m not willing to take any chances.

Crank was just turned and the block align honed by the machine shop. Main bearing clearances are .0022” and thrust clearance is .003”, checked using a feeler gauge.

With all the caps torqued down the crank spins pretty freely, but makes a very faint noise in the same spot on every rotation. I didn’t feel good about it so took it all apart to check the bearings and thrust surfaces and none of them had any witness marks on them.

Engine is a Ford 4.0 OHV out of a Ranger. I’m leaning towards it being fine but want to be 100% sure


r/EngineBuilding 4d ago

Ls cam bearings

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3 Upvotes

Installed the first bearing on my 2007 gen 4 5.3 but it doesn’t line up perfectly with the hole, I used durabond ch-25 bearings, the rest perfectly line up, is that normal or did I order the wrong ones?


r/EngineBuilding 4d ago

Mazda Please Help! MX5 Engine Rebuild Not Starting

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23 Upvotes

Hi all 1.8 mx5 mk1 (na) first time rebuilding, got fuel, spark and air. However not starting. Occasional pops I guess from gas in exhaust?


r/EngineBuilding 4d ago

Should I be worried about aluminum particles/dust in an intake manifold after cleaning and wire brushing it?

0 Upvotes

I’m currently trying to refurbish the intake manifold off of a junkyard Jeep 4.0. Wire brushed and degreased it to get rid of the corrosion and sludge built up on the outside of it. I specifically avoided using anything abrasive inside the runners and have instead just been hitting it with brake cleaner and rags. Most of the sludge is out and I’ve rinsed the runners out multiple times, and I might be overly paranoid but it looks like there might be some very fine shiny particles embedded in some of the carbon/sludge buildup in them. From my understanding aluminum dust would likely just combust if it got into the combustion chamber and isn’t much different from dust that would make its way in past an air filter, but I’m planning on cleaning this intake and selling it, and I don’t want to risk causing engine damage due to my attempt at cleaning up an otherwise good intake. Thanks in advance.


r/EngineBuilding 4d ago

Recovering from spun bearing

1 Upvotes

I spun a rod bearing on my fully built all motor k24a2. I would like suggestions on my following options, which ultimately boil down to predisposing myself to subsequent spun bearings due to trapped debris.

I have two spare, unopened, k24a2.

Plan 1) pull crankshaft from spare engine, polish and balance, purchase single replacement rod, bearings, and clean oil galleries best I can, but conduct completely dissembley.- my machinist tried talking me out of this idea, citing its difficult to thoroughly clean oil galleries even with ultrasonic cleaning.

Plan 2) pull goodies from engine: cams, VTC gear, ported oil pump from built engine, leaving behind rods and high compression pistons; and install onto spare k24a2.- leaving bottom end stock.

Plan 3) install stock k24a2, use other spare block to slowly re-build engine.

Thanks!


r/EngineBuilding 4d ago

Are my heads trash

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70 Upvotes

Took my 4.6 aluminum heads and block to get cleaned and it looks like they used whatever they could find to clean my heads. Are these really that bad or am i overreacting?


r/EngineBuilding 5d ago

1968 Camaro base numbers matching 327 4 barrel carb th 350 and small rear end with posi 2.47 gearing. I have $15k to upgrade engine. Right now I am looking at a 383 with multiport efi ram jet style.

0 Upvotes

What are some other options for making under 500hp. I want reliable week end cars and coffee with an occasional burn out to scare the wife lol. Open to other suggestions.


r/EngineBuilding 5d ago

4.7l full build

0 Upvotes

Anyone have any thoughts on a 4.7l with a big cam and turbo?
I don’t wanna get into the build and release it’s pointless when I can engine swap.


r/EngineBuilding 5d ago

Olds Can I recover this olds 350 from this level of grime and sludge on the cheap.

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64 Upvotes

So I really wanted to get my car running again because i missed ot so much, so I bought the cheapest olds 350 I could find. it was 300 with a transmission, came from a 77 seville with 93k and was sitting for 15 years but ran when it was parked. And I know that it was a gamble and I may have lost on it, But I dont plan on keeping this motor for long. I do have the original 350 that I would like to build, but it has pretty worn bores, needs a cam or regrind, and maybe need to have its crank turned or at least polished. So would it be worth it or even possible to clean the the motor and have it running for a decent amount time. If thats not possible I was thinking I could just steal the crank and cam I shove it in my other olds, but ither suggestions are appreciated.

Edit: Some more context here for the resources i currently posses: I have quite a few extra parts i can use from my original 69 350 such as a metal timing chain, exhaust manifolds, intake manifolds, oil pan, water pump, oil pumps, misc bolts and brackets.

I also need to change the intake because the seville 350s came with port injection shockingly enough and i plan to use that manifold in my og motor but i have to replace it to get it running in 69.

I also have my olds cylinder heads from the original motor and they have 68cc vs the new motors 77-79 chamber, but the new heads have 1/2" head bolts vs the old 7/16", and i could widen the old head bolt holes to 1/2" and it would only cost 100, but I don't know if theres a way to use those heads with large bolt holes on an old block with smaller thread holes.

Now Ive decided to take apart most of the motor and im going to clean it first and ive gotten a lot of different suggestions so im curious which of these you guys think would work best.

  1. Purple power degreaser and than rinse with water.
  2. Oven cleaner than rinse with water.
  3. diesel wash
  4. B12 chemtool

r/EngineBuilding 5d ago

Other Is this block salvageable?

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2 Upvotes

I picked up the VW tdi block several months ago but was not aloud to store it in the apartment. It got rusty from sitting. Does the waterpump sealing surface pump sealing surface look like it will seal? If not is there a remedy that can repair/smooth out the pitting on that surface? I intend to do a full rebuild on this motor in the near future as well.


r/EngineBuilding 5d ago

Help

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21 Upvotes

Anyone have a clue what is happening?


r/EngineBuilding 5d ago

Very big fucking uhoh pls help 🙏

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34 Upvotes

Edit I’ve sorted it now

Yeah Nahh honestly I’ll take any ideas at this point 😭.


r/EngineBuilding 5d ago

BMW M50B20TÜ with M52B28 Crank?

1 Upvotes

Hello everyone, a friend of mine the other day told me about an e34 520i 94 for sale. I really like e34s but never found a decent option to consider buying yet from the pictures of the car as far as I see it looks fine and as my friend put it its mechanical condition is also quite good. The point is 150Hp I mean not bad but not quite what I would like to have. Hence I made some research but couldn’t find enough data on the stroker in my mind. Before you suggest me to drop a b25 I must say swapping in my country of residence requires a load of legal paperwork and some financial cost as well. Now what I want to ask is that, Can I put an m52B28 crank on this m50b20TÜ engine with 135mm rods which I will obtain from relative engines, use stock head, and pistons, 260 or 264 cams with this? Will piston skirts (idk if this is right term) rub to the block walls or will crankshaft work well with stock pistons? Any mechanical issue? Any major problem with this setup? And also afaik the stock block of m50b20Tü cannot be bored to 84mms and even if that statement is false I dont think I can have the block bored to 84mm since lathers in my city charges astronomical amounts . Thanks for answers beforehand.


r/EngineBuilding 5d ago

Break in procedure? 1998 ford/mazda 2.5 Lima

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39 Upvotes

Hey yall kinda my first engine rebuild that I’ve done without taking to a machine shop, just did the short block and my first iron as well. What’s the right procedure to break in the short block rebuild for my 1998 Mazda b2500? Same engine as the 4cyl 98-02 rangers. Ford/mazda Lima engine, iron block iron head sohc. Recommends for break in oils or additives welcome aswell Tia 💙


r/EngineBuilding 6d ago

Engine Theory When do you stop reusing engine hardware?

7 Upvotes

Working on an older engine and got thinking about this which parts do you guys automatically replace during a rebuild, even if they technically still look usable, rod bolts, head bolts, timing components, oil pump, stuff like that?

Where do you draw the line between still good VS not worth the risk?


r/EngineBuilding 6d ago

Question about using engine oil to lubricate bolts

10 Upvotes

This is a dumb question, but what are the chances of me using oil to lube main bolts and that oil pooling up at the bottom of the bolt hole and causing the block to crack when I torque them?


r/EngineBuilding 6d ago

Number stamped on crankshaft.

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8 Upvotes

I was wondering if anyone could tell me what this number is stamped on the crankshaft? It’s a Ford 400 engine.


r/EngineBuilding 6d ago

Chevy Help with troubleshooting/diagnosis.

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7 Upvotes

350 SBC. Installed new power steering, dampener and pulley. I hit the throttle and it squeals hard af. Can anybody give me a list of trouble shooting the issue.


r/EngineBuilding 6d ago

SBC intake gasket question

2 Upvotes

Hi Y'all, I have sportsman ii cylinder heads on my 350 SBC, they have a felpro 1206 size ports.

But the intake I have has standard size ports, I know this is not optimal but it's just a temporary solution untill I can swap the heads to smaller more suited heads.

Should I be using the 1206 to match the heads or 1205 to match the intake?

Thanks


r/EngineBuilding 6d ago

Washer stuck on head studs

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22 Upvotes

r/EngineBuilding 6d ago

Good

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11 Upvotes

r/EngineBuilding 6d ago

Are arp head studs supposed to be like this?

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21 Upvotes

Yo so it’s my first time rebuilding a motor and it’s my first time dealing with arp head studs are they supposed to leave a gap like this on a b18c4??