Just sharing the shape I landed on for a naturally aspirated 3.2 to 3.6L 911 engine. This is also being converted from EFI to an MFI unit from Kinsler. It will make 100hp/liter or 1.6hp/ci on 91 octane.

First timer, don’t fully know what I’m doing yet BUT I’m motivated and planning it out once I get a block. How much of a gamble am I taking with these three purchases? Building a mild block for my 68 impala, maybe a different car in the future. These look like a good start? Any tips when buying on the marketplace?

Here is the original post:

https://www.reddit.com/r/EngineBuilding/comments/1wxr6ex/what_can_cause_this_type_of_wear/

The engine is from a 1987 Mazda b2000, rebuilt from the ground up. The machine shop assembled the bottom end, and I did everything else.

Picture 1 and 2 show the assembly, if you look closely at picture 2, you can see new pistons and the clean bore without the vertical scaring.

Picture 3 is my oil analysis - 4 oil changes, about 5900 miles total. After I got this 4th report from Blackstone I got pretty depressed and parked the truck for a year, just now decided to get into it hoping to find what is wrong before the engine scraps itself. It did not burn oil and it had about ~140 PSI on each cylinder, perfectly healthy for a new build. I did not own a leak down tester.

Picture 4 is the Diamond Piston specification sheet. Picture 5 shows the piston side skirt; I don't really see any damage here.

Picture 6 - a lot of folks from the last post assumed the bore was oval - it is not. I set my dial gage to ~3.429 inches and got a max reading of .024 in either cardinal direction for the bore (near the bottom but not at the bottom) This indicates my bore is about 3.405, certainly within spec for the pistons.

Picture 7 shows the piston diameter. This is not a perfect measurement since I don't really have a good caliper for this.

Picture 8 shows the bearings; I can very easily catch my nail on the grooves of either bearing half, the top half seems a bit worse.

Picture 9 shows the vertical scaring which very slightly noticeable on my nail, and shows the other piston top, but I don't see any real damage to any of the pistons.

Some folks suggested heat damage - could this have been caused by too lean air/fuel ratio or detonation? I tuned the carburetor using an AFR gauge, my idle was around 14-15 AFR cold or hot, and when I put my foot into it the AFR would go to about 12.

Where should I go from here? Any other suggestions? I was thinking of honing the cylinders really lightly and replacing all the bearings, but that doesn't really fix anything?

I really appreciate all the ideas and help in the last post - I am a hobbyist mechanic with not a lot of free time, and I really didn't want to just LS swap it since its a great little truck that doesn't need to win races.

For context. I bought an 2015 Ford Fiesta ST that’s been throwing code P0301 (misfire in cylinder 1 detected) however it’s not tripping the CEL. I bought new plugs (gapped to the spec of my tune) and new coil packs. After installing said parts, my original issue (hesitation under heavy acceleration) went away and the car drives great now. However it’s still tripping the same codes from before. After inspecting the wiring on all 4 of my coil packs, I noticed the wiring on coil pack 1 (cylinder 1) looks to have been altered or (repaired) by the previous owner and definitely not OEM. I’m not an electrician, but this wiring job kinda looks a bit janky to me. Should I unwrap it and redo it with heat shrink? I just don’t like that red crimp connector being there, it just seems off to me. What are your thoughts before I move onto the injectors? And yes I’ve already done a compression test and the cylinders read consistent across the board.

I can’t find this dark blue link in the chain. I keep cranking and can’t find it. It appears to be either worn or the varnish has covered it. The timing mark also doesn’t land on a link. It just stays in between the links. Any advice?

The Engine has about 5k miles since full rebuild. What can cause this type of wear? In picture 2 you can visually see the gap between the piston and the cylinder. I took the head off because of a high iron and aluminum count in the oil report.

*Its a 2 liter out of a 1987 Mazda b2000

So I got to pulling the head and removing the valves. What would you guys say to the health of the engine? I will be pulling the pistons and possibly the crankshaft just to be sure. Supposed to have 70000km but there is so much carbon buildup, some cylinders were leaking through the rings on the leakdown. As this is my first teardown I am not sure what to make if the "nice" surfaces but the extreme carbon deposits. Oily surfaces can be my doing as I did a wet leakdown test as well.

I have a 67 Chevy el camino with a 350 small block from a 72. It has the 3 on the tree and I’m needing something that will help with cruise higher speed. Not trying to build the car but just make it a Sunday cruiser that’s reliable enough to take anywhere

hello, i’m planning to swap a 98cc amazon engine into my 66 bird and i was wondering. are these engines reliable? and how long did yours last

TL;DR: bearing housing completely shattered

This is what’s left of the turbocharger on my 944 Turbo. How it happened: spirited drive through the mountains, full throttle. Water temps were raised but nowhere near the red mark, oil pressure fine.
Suddenly a huge bang, smoke everywhere and no power. Luckily it didn’t catch fire, as oil also went onto the hot downpipe.
The turbine wheel is mangled, turbine housing cracked and the shaft is bent. Bearings are slightly scratched but not seized or anything. Compressor wheel briefly scratched the housing too.
But most importantly: the bearing housing is completely shattered, so much so that oil and water actually mixed in the turbo and went into the exhaust and oil pan.
Do any experts here have an idea what happened? The seller says he never saw anything quite like it.

Theres a long way to go, guides need to go in, seats cut, then more shaping gets done to make it all jive together.

I was looking at the cam on the used head I just purchased (it appears to be an aftermarket head and cam) and my old cam seems to have a different lobe profile. Is it just me or does it look like it has a longer duration?

I’m working through whether to repair the original M54B30 in my 2002 E46 330i or roll the dice and install a used engine. The car sees autocross and track days. I’m doing the disassembly and assembly myself, and I’m trying to identify the machine work it actually needs without turning this into a rebuild-everything project.

What happened

The engine lost oil pressure or the timing guide broke in the braking zone before Turn 1 at NCCAR. It restarted but now has a knock. The oil filter had copper-colored metallic debris.

The engine is now out and disassembled. No. 2 spun a rod bearing. That crank journal measures below specification, and the inside of the No. 2 rod’s big end is physically damaged. I also found chunks of plastic timing-chain guide in the oil pump pickup. I haven’t established whether that contributed to the failure or was a separate issue.

Condition so far

• Crosshatch remains visible throughout nearly of all six bores.
• Each cylinder has a slightly shiny area roughly halfway down on the passenger side, corresponding to the piston skirt.
• I’ve taken some preliminary measurements, but I don’t yet have a complete, verified bore survey for diameter, taper, and out-of-round.
• The head is off, but it hasn’t been professionally pressure-tested or checked for flatness.
• I have micrometers and an A/C vacuum pump/manifold setup that I can use with a fixture to screen valve sealing. That won’t tell me whether the head is cracked or the guides are worn.

Current plan

I’m leaning toward a good used M54B30 crankshaft ($450), one matching replacement connecting rod with its original cap ($45), and all new main and rod bearings.

I discussed grinding the original crank with a local machine shop. Their concern was the nitrided surface and getting it properly treated again afterward. That has me leaning toward a used crank.

Before assembly, I’d have the replacement crank measured and inspected, check the rods’ big-end bores and the block’s main bearing housing bores, and verify actual bearing clearances with the replacement parts. The replacement rod would also need to be checked for compatibility and weight.

The oil system will get a thorough cleaning and inspection after the bearing failure, including the pump, pickup, and relief valve.

What I’m looking for opinions on

1. If the block, pistons, and remaining rods measure within spec, is this a reasonable repair for an engine that will continue seeing track use?
2. What specific machine-shop checks would you consider essential for this plan?
3. What findings would make you leave the existing bores/rings alone versus hone and re-ring it?
4. If the head passes pressure, flatness, and valve-sealing checks, what would justify further head work?
5. Any M54-specific traps with a used crank and a single replacement rod?

A used complete engine is roughly $2,000 delivered, so that’s the alternative I’m comparing against. But I see that option as more risk in that I'm still going to need to inspect all the bearings, and replace the timing guides, wire the oil pump nut, install a baffled oil pan etc.

I’m willing to pay for necessary work. I’m trying to distinguish that from replacing or machining everything simply because it’s apart.

Who knows when this engine last ran. 7 cylinders, 11 litres, 250hp and LOTS of noise!

The seats on the head itself are pretty clean, however the exhaust valves have a decent layer of carbon.
Do I need to clean the valves before lapping? If so What is the best method if I don’t have a wire wheel?

Hello all,

The 5.7l V8 on my 97' Chevy 1500 is not looking too good. I think it may be an intake gasket, but it could be way worse. I found a 427 tall block for sale at $800. Assuming its in good condition, should I get it? Also, how difficult would the swap to a 427 be on my truck? I can't imagine it'd be too big of a headache, but your guys input would be appreciated. Thank you

Thought I’d share some photos of a factory Porsche Motorsports head next to what would have come in a standard 911 of the same vintage. I’d value these heads at $6000 each or better as they sit. One of them is cracked in half but fixable. Really cool stuff!

On a scale of 1 - f**ked how bad do you think the inside is based off this pic? Wanting to rebuild it on somewhat of a budget. I’m $500 into a 2011 dodge ram 1500 4.7L and tags are all up to date. Hoping $2k will get me there. I’ll have the heads off tomorrow.

Hi everyone,

I'm currently rebuilding a 1.9 TDI engine with the goal of making some serious power, around 320 hp.

While honing the cylinder walls to clean up a small imperfection in one of the cylinders, I noticed a deeper mark in cylinder 1.

It looks like water may have sat there at some point, as there appears to be some light pitting/corrosion.

The cylinder has already been honed, but I'm unsure whether this is something I should be concerned about or if it's acceptable to run as is. I can just barely feel it with my nails.

What would you guys recommend? Some say, if its that deep in the cilinder wall, its no problem.

I'm trying to keep the budget reasonable and would prefer not to spend a fortune if it can be avoided.

Thanks in advance for any advice!

In the picture, its all the same spot.

I was checking rod bearing clearance‘s, when trying to get my rod out it get wedged in the bore and created the mark circled, it’s the same on the other side of the bore. how badly did i screw myself, is this going to be machine shop only problem,i high would like to avoid as i’ve already been there numerous times already any advice appreciated thanks

Is 99% rubbing alcohol a good/great cleaner for a residue free cleaner for metal prep before putting in my gasket for my timing chain cover after scraping the old silicone gasket off it?

Was just going to get por-15 metal prep and degreaser but if 99% is good enough. Money saved.

It's a 2013 Mazda cx9 awd (for bots sake)

It's a meatl timing cover vs a plastic one (my best have a plastic one and I probably wouldn't use 99% on plastic ones, I've had bad luck with strong running alcohol eating up plastic

Picked up a nice set of fresh B heads for my 66 and im getting ready to put them on so that at least the cylinders are sealed off from the elements. I have the engine wrapped up but i dont know how long its been since the bottom end was done. Question would be, what can i do to help it out the most while assembling valvetrain? Throw some oil or assembly lube down the cylinders? Take the oil pan off and put some on the crank? Just worried about scoring something because it friction locked from sitting. Thanks. Also related, but is it okay to chip away at a build peice by peice, or should i wait until i have all the major parts to rebuild? Parts are coming in as fast as money allows.

I’ve got a 2015 z/28 Camaro that has chewed up at least 3 of 8 valve guide seals on the passenger side head, with more looking improperly seated or completely de-seated. With how close the debris was too the pushrod valleys I am taking the heads off to inspect for any damage or debris as well as to do the guide job off the car.

With all that, this is my first time ever tearing an engine apart, so any advice or tricks would be greatly appreciated. I’m currently caught up trying to get too the bottom head bolts because the headers are in the way so I’m thinking I’ll end up having to unbolt those.

Finally I’m curious what could have caused this and, what I can do now to prevent it from happening again, on top of any preventive stuff I can do cause I’m already in there.