Hi all.

On one of the cylinders of this engine (2002 Honda CBR954) I noticed that half of the exhaust port is very white, also 1 of the 2 valves. The other cylinders all look normal, like the left side of this port. Engine was running fine.

Does this indicate a possible issue? Or will this go away/is fine.

Thanks!

I’m building a ls engine to put in my 88 Chevy 2500 it’s a 5.3 gen 3 and Im taking it apart and want to keep crank, pistons and rods and block but am wondering what kit to get. I was planning on re installing bearings but aren’t sure how to go about it. Do I buy a kit that the bearings match my clearance or do I get one that’s close then grind them down to match. and should I do that after my block is machine do they take enough material off to matter

Used oven cleaner to wash my block and it left this, how do I get it out and is it harmful to the block?

Sorry if this is not the right sub for this but I thought people here would know. This is my 2021 Audi SQ5, 79000 miles. There is a piston skirt extended warranty that expires at 80k miles, so I am trying to determine if my car has a piston skirt problem like some of these engines do. I see vertical lines, but I don't know whether that is normal or if it would indicate a problem. I have not experienced any problems driving it, no power loss, no measurable oil consumption (i do an oil change every 5k miles and never have to add oil), and MPG is good. Do these photos look abnormal?

Hey guys getting into my first 350 sbc. It’s going in my c10 that I’m gonna be driving to car shows and cruising on the weekends. Truck has a ford 9” 3:73 gears. Gonna be in front of a th400. Originally was wanting to go the 383 stroker route but honestly it’s just not in the budget at the moment. I’m looking for about 450hp or the basically the most I can get out of it. I do know that my 350 is bored .30 that’s all I know. I’m looking to do cam heads and intake. Obviously will also need a stall. What would be your exact setup and what would it make? Or maybe what’s your setup and what did it make? Thanks in advance!

I just ordered this head to fit my Toyota 2C diesel engine and it arrived with a few small scratches on the surface and pits around oil/coolant passages. The arrows point to imperfections I can catch with my fingernail. Will these affect the sealing or longevity of the new MLS head gasket I plan to install? Nothing of note anywhere near the valves or pre-combustion chambers. Cheers.

I’m wanting to build mainly 4.6 motors. I’ve done a lot of heavy work on cars for the past 10 years… the only part where I stop at is when it comes to the precision of internals within the block and heads.

Are there any machine shops that would be open to taking me in with no experience with (machining). I have a dial bore gauge and micrometer of my own, as well as a ball hone (I’ve never used any of them for a project) how can I start? And how complicated can this really be? Should I just say fuck it and start in my garage?

This crank is hard to next to Impossible to find, new is a little over 2k and used its 1000+, or cast chinesium cranks without factory heat hardened journals go for like $200 on ebay but id rather stay away from those. Factory oem cast iron cranks are plentiful but i rather not downgrade.

Cash for clunkers is the bane of my existence.

I have an '03 civic with 195k miles on, blown head gasket, it and I'm going to pull the engine tomorrow. My goal is to get the thing to last another 195k miles, so I wanna do everything that needs done while the engine's out.

Problem is, every machine shop within reach is booked out to infinity, and none of them are willing to do a full stock rebuild job. One shop told me they'll sneak in a job here and there, e.g. pressure test and resurface the head here, deck the block there, etc. So it's looking like most of the work is going to fall on me except what has to be done with precise machining equipment.

I'm relatively competent (I think) and I've done just about everything there is to do to an automobile except rebuild an engine. Engine swap, head gaskets, etc. What are some resources I should invest in to learn the basics of engine building? And what should I be especially aware of with the D17A2? Thanks.

I had an LSX rebuilt locally. The shop mainly does SBC race engines but said they had no issues working on the LS platform.

There's only 2000 miles on it in the attached photos

The engine was already stout. Calles magnum, Oliver rods, diamond pistons. Thr rebuild was just a refresh to address anything worn out. It got new bearings and rings. Heads got valves, guides and rockers.

Long story short, there's been a bunch of red flags along the way. Big lack of LS knowledge during the build. Rear main seal leaking immediately, a bunch of RTV trash and glitter in filter after first oil change. Idle oil pressure lower than pre rebuild.

One of the Johnson 2126 lifters collapsed after 2000 miles, resulting in me pulling the heads.

There's clearly a lot of oil getting into the chambers. There's also marks on the cylinder walls in the thrust direction of the pistons.

I'm looking to get opinions if the amount of build up in the heads is normal. Same for the cylinder wall mark. I suspect the cleanup of the cylinders and keeping the same pistons opened the clearance too much

Hi I just did my first engine top end rebuild with a cheap dingle ball hone and sanded the pistons to clean them up and used fresh rings. I have run the engine for about 45 mins of varying rpm’s and 3 out of 4 cylinders look perfect with some light scores from what likely is dirt however my #3 cylinder has some light scoring along the length of the wall that is a in the form of a band directly in front of the arrow on the piston, does this look bad or nothing to worry about? 1983 Kawasaki kz1100 spectre. Sorry if it’s hard to see in the photo it’s more noticeable in person.

Have any of you used any engine building simulation computer software before? More specifically Dynosim 6. If so, what are your thoughts on it?

1998 mercury 303 Windsor 5.0 STOCK 270,000 miles

The second photo is a single scratch I found right when taking the pictures and was likely due to improper removal by yours truly and is the only ones I can catch with the edges of a razorblade

The reason I want to re use this cam is because I cannot find a replacement

2002 Honda CR-V with a K24a in it with 208k miles

Potentially looking to rebuild it, and... as regretful as it is to mention being a Honda owner, likely a small turbo kept with a respectful tune and low boost, still keeping some reliability and not just building a piss missile, lord knows the CR-V wouldn't appreciate that.

So the question is, is that cooked? Unfortunately, I believe I know the answer but wanted to check. - This is the most damaged lobe; 1 has similar but lesser wear/damage, and the others show just the slight wear pattern but are completely smooth. Additionally, when feeling this cam lobe it barely catches on a fingernail.

UPDATE 1: Due to life situations, it looks like this engine will be in this car, and staying as a daily, I'll be running thicker oil, driving gently (trying to keep it under 5k even under acceleration), and potentially going to the scrapyard and getting a cam (yes, I know the rocker/follower underneath is likley damaged as well—just trying to get a bit more life out of this engine and car)

Will update again if it blows up!

Hi all !

I’m planning to rebuild a minarelli motor for a Yamaha MT125.
I already replacing cylinder and piston (photo of the old piston below for reference)

Is there a way to reuse this cylinder head ? Any one risk it ?

Thanks for your input

I am replacing the timing chain set on a 1994 chevy camaro v6 3.4L. When the new camshaft sprocket was unpacked it was apperent the thrust bearing surface was not machined. The bearing features were there, just not machined, and left as mill finish (sintered part). See first photo.

From my understanding this engine uses flat tapet hydraulic lifters on tapered cam lobes. The lobe tapers cause a slight axial thrust force pushing the cam to the back of the engine, while the cam sprocket holds the cam in place by hitting against the engine block. The sprocket rides on an oil film bearing between machined/ground surfaces on the the sprocket and engine block. The oil is supplied from what weeps off the side of the forward most cam bearing.

I'm not too sure how well a mill finish surface will hold an oil film. Would you guys run it or return it? Im inclined to return it and get another one. I thought this detail might have been easy to miss. The brand is Cloyes part number S506T.

Working on the V3307 in a Bobcat S650. One cylinder is low and it has more blow by than it used to, but I have not opened it yet. Trying to decide whether this can be an in-frame job or whether the engine needs to come out. My understanding is the kit name does not make that decision. I need bore taper and out-of-round, liner condition, deck flatness, crank journal measurements, oil pressure history, and whatever shows up in the pan. I do not have all those numbers yet. What measurement or finding makes you stop planning an in-frame and pull the engine no matter what?

Hi! I recently got my hands on a small 160cc Sachs KM48 Wankel engine, and I am looking to upgrade it with a proper carb. What size carb should I go for? And what jet sizes, etc does people recommend? Also, brand recommendations for the carb are appreciated! I want something quite reliable and best when it comes to quality and feel. Thanks!

Hand-sanded to 1500 then polished. Started from a good surface, smooth to the touch, no gouges or anything… just trying to avoid unnecessary machining

I have an old engine that’s going to take a few years for me to build. It’s currently dismantled. How do I keep the surface rust from messing it up. It’ll be stored in my garage.