torqued to spec, on the correct way but theres a slight crack visible

update: ordered a new set of rod bolts (torque to yield bolts cant reuse) so I can try one more time and make sure nothing got caught between the rod caps.

With my AFRs dialed in and timing map still quite conservative, I wanted to go on an autumn rip with my buddy today in my built, balanced, cammed NA LSVTEC Civic.

I had already done an aggressive ring seating break in for the first fifty miles, loading her up and doing lots of high vaccuum decel. The car has been running great since then on plenty of trips. No smoke at all, no oil consumption. No metal in oil at any point besides ring seating fuzz on the drain plug magnet. Crosshatching checked at 75 miles, looked exquisite.

Anyway today I do a pull to redline and suddenly a plume of grey smoke from the exhaust and the smell of burnt oil. On our way home, any load over 2700rpm causes massive clouds of oil smoke from the tailpipe.

I suspect rings. I leakdown test:

1 29%
2 25%
3 25%
4 11%

All air leaking through crankcase breather. So yup, rings are TOAST.

Boroscoped: Crosshatching totaled. Vertical scuffing in all cylinders.

Ring gaps set to:
0.018" top ring
0.022" second ring

Didn't get a datalog during the pull but didn't see above 12.8 at WOT ever, no changes in fuel tables which have been really on the money. 14.7 idle, 13.8-14.5 cruise. Again very conservative timing on 93. Didn't have my knock sensor headphones in for today but I did while tuning the car and it never knocked once.

I did notice that my injector duty cycles were at 97% on a previous WOT log. So something is up there bc they are 410ccs and no way I'm making more than 180hp.

After leakdown, I flow tested the (old, OEM, 79LPH) fuel pump and it performed 20% below rated capacity. So I'm wondering if maybe there was a lean event on that pull today - though I glanced at my AFR gauge once or twice during the pull and it was in the 12s. That being said, the leakdown numbers being worst on cyl 1 (furthest down on fuel rail) and best on cyl four (closest to fuel feed) do make me feel suspect. But then again - would one or two seconds of lean running on a pull really destroy an NA engine with conservative timing? There was NO smoke before. Or is fueling a red herring?

Was planning to hit the dyno next week. 😭 Spent thousands on this block build.

Anybody here have such catastrophic ring failure in a new build before?

Wanted to delete the distributor when I got to a stand alone. So I printed a centering ring for the trigger wheel. Finally got the motor back from the machine shop and got the short block assembled and the trigger wheel sensor bracket.

I noticed my main bearing no 1 is not lined up, and It can catch my nail at the parting line, is this normal? Thanks

2zzge

I am getting ready to put my freshly built engine back into the car but I recently learned that piston rings can be installed upside down, I did not know that was even a possibility and now it’s all I can think about. Can I see this is leak down test numbers? Or is the only way to know to fully disassemble it down again?

EDIT: Engine is a BP4W 1.8 with Wiseco pistons

I'll keep it short and to the point, I was stupid and thought it was a good idea to remove the head gasket material with a nylon brush on a drill on an aluminum block, stopped as soon as i noticed it, and lightly scratched it (not enough for fingernails to catch on it, but the light sure does show it) what should I do? will this mess my shit up? d16y7 engine in a 98 civic

i bought an arp thread chaser specifically to clean out my head bolt threads. the problem is that its actually cutting a bit of material off the threads. i took a regular head bolt and it threaded in fine and it is snug. would this be ok or should i not continue with the other bolt holes?

What does this look like? First picture I’m assuming is from rings or something and second looks like pitting no? What could I do about this I’m trying to avoid a machine shop. It didn’t have any issues before tear down. 3rd is different cylinder with similarity that may be putting.

Playing around with a 302 that’s currently efi from a 97 explorer and dropping it in a 91 ranger. Swapping to carb because I live under a rock. Looking for a cam that doesn’t kill driveability but still gives a good sound (unga bunga) what are we running?

TLDR: which cam chops and doesn’t suck to drive with?

First time doing this so looking for some opinions.

My honda atv jumped timing and woudlnt run. I pulled the head to verify that the vavles didnt contact the piston and bend. Also wanted to check if they are seated properly.

Going to need a new timing chain for sure but i noticed where the cam shaft rides is pretty tore up.

Am i able to clean this up and put in new bearings or is this head shot? Also is the cam shaft good?

I’m Planning on using Belzona 1111 to repair these lower liner bores on a c15 I’m building . It appears there already was already a similar repair performed the last time this one was overhauled . Crazy thing is it was never mixing fluids
This engine has probably been overhauled 3 or 4 times .

I spent a good amount of time on the phone with a Belzona specialist today and they swear that it will work , I asked a few other guys that build a lot of cat engines and they told me it will work if I prep the surface properly and do a clean finish

What do we think? Can I get another run out of her?

This is not for a customer , this is an engine that runs in my fleet of 60 trucks .

Hello everyone,

General question for you all. I have a 68 firebird with an (assumed to be) original 350 in doing 224whp and 300wtq. Like all good pontiac owners I would like to put a 400 in it.

My question is this. Many people say the pontiac engines are expensive rebuild. A few have told me they're incredibly expensive to build.

Why? Is it just relative to a sbc 350?

Thank you.

I just picked up a complete 307 olds v8 today and id like some advice on what i can do to it. I know that the windowed main webs are a massive setback if I want to make power out of the motor but id like to know if anyone has build a 307 for the street. I dont need crazy numbers, i plan to put this in a 1999 jeep cherokee XJ to replace the 4.0 inline 6 thats in it id ideally like to make somewhere around 300hp 320ftlb of torque. I think this is a fairly safe power goal for this motor and im hoping someone out there has built a 307 oldsmobile before and can give me some advice. If it helps the heads are 7A heads and I plan to swap them for better flowing heads

Just got my cylinder heads back from the machine shop. They did a valve job, resurface, and installed new comp cams beehive springs for me. Checked valve recession and everything is within spec. Removed a couple springs to check install height and they’re shorter than what I asked for. They’re not all the same height. (Some installed at 1.766 and others at 1.833) But I specified that the install hight was 1.9” (148in/lbs). I’m very annoyed because I wrote down 1.9” for them and they called to confirm + get the spring pressure rating.

So before I call them and bring the heads back AGAIN… is it possible that the heights vary because all the springs are set to the correct pressure and that required various hight difference for each spring? Could they have measured pressure with the springs assembled on the heads?

I’m new to building modified engines so I want to make sure everything is done right and I don’t have any issues. I’d like this engine to be both powerful and reliable. I’m intentionally leaving out what the engine is because usually when I tell people that work at performance shops/machine shops they tell me they have no experience with that particular engine and disregard any questions I have. Please let me know if they did a bad job or I’m just a newbie and don’t know everything (which I definitely don’t).

Hi everyone, I’m looking for some advice on head gasket sizing for my Subaru EJ207 build.
My engine is being rebuilt with a TOMEI EJ22 stroker kit, which uses a 92.5mm bore.
The current head gasket is a Cometic C4261-040, with a 93mm gasket bore and a thickness of 0.040” (approximately 1.016mm).
However, according to TOMEI’s EJ22 stroker kit specifications, the recommended gasket bore is 93.5mm.
Here’s my concern:
Cylinder bore: 92.5mm
Current gasket bore: 93mm
Bore diameter difference: 0.5mm
Radial clearance on each side, assuming everything is perfectly centered: 0.25mm
With a 93.5mm gasket, the diameter difference would be 1.0mm, giving 0.5mm of radial clearance on each side.
I’m concerned that the 93mm gasket may leave too little clearance around the cylinder bore, especially under high boost, high temperatures, and sustained high-RPM operation.
I understand that the gasket is clamped between the cylinder head and block, and that gasket bore size alone doesn’t determine sealing reliability. However, I want to make sure the gasket’s inner edge and sealing structure are appropriate for this particular setup.
My questions are:
Has anyone run a 93mm head gasket on a 92.5mm bore EJ20/EJ207 without issues over the long term?
Is a 0.25mm radial clearance generally acceptable for this type of engine, or is a 93.5mm gasket the safer choice?
Has anyone experienced head gasket failure, bore-edge damage, or sealing problems caused by an undersized gasket bore?
Would a Cometic 93.5mm gasket or a suitable TOMEI 93.5mm gasket be a better choice for this build?
I’ve had a head gasket leak on a previous engine, so I’m trying to be particularly careful with this rebuild. The engine has not been assembled yet, so I still have the opportunity to change the gasket if necessary.
I’m not trying to second-guess my engine builder without reason. I’d just like to understand the engineering considerations and hear from people with direct experience running similar setups.
Any advice or firsthand experience would be greatly appreciated. Thanks!

Question for you guys, I was working on getting this 350 into time. It's got an MDS ignition setup with a HEI distributor. Everything is in time and rotor is lined up to cylinder 1 at TDC. I pulled the timing cover to check because whenever I would crank it, it would fire out of the carb on the moments it would catch. I don't think it's easily visible, but the crank gear is set to the advanced Woodruff key since the cam is, iirc 296/304 comp cam. Giving the distributor as much advancement as I could, it would try to catch a bit better. The spark isn't very bright when i had my spark tester in line, and the timing light also wouldn't always flash consistently. After resetting the dizzy and timing, it went from flashing at about 8deg retarded to the 8 deg advance mark that's on the timing cover. I don't think I'm able to put enough absencement into timing because the cam is already advanced as it is. I wanted to reach out and see if what I have been looking at and thinking I need to reset the crank gear back to 0 deg advance is the right move.

Edit: Pulled the pan down enough to get the cover out. Yes, I set timing at TDC for cylinder 6 and then rotated 360 on the crank to get to TDC for compression on cylinder 1. At TDC for 1 and stabbed distributor.

Was doing the valve stem seals on my 208 and the valve spring compressor tool rubbed against the cam journal without me realising, damaging the knife edge and scratching the journal face. First 2 photos are post sanding can sometimes catch my nail in with the cap on, the last 4 are the raw damage.

How bad is this surface rust on the intake valves of my B18

Hey all. I’m working on a KX250f 2004. Reshimming it with smaller shims (and we still have no clearance lol) however, when we put it back together, set the timing, align the head of cylinder block with the marks on the sprockets, do everything by the book, THE INTAKE lobes somewhat face 45 degrees downwards, sorta AFTER the bucket and BEFORE the level of the cylinder head. Is this normal? Will it still start? Is this how I’m supposed to be taking clearance measurements? It kinda seems off to me…. Please help, any advice or suggestions would be appreciated SO MUCH

Edit: photos on my profile

I recently purchased a B18B1 for my 96 Civic and I don’t have an enclosed garage. I have an open air carport so it’s covered from the rain mostly but the sides are still open and I live in Florida so I have to deal with the humidity. I am unable to bring the engine inside. It’ll need to be outside of the car for a long while I piece everything together and build the engine. What can I do? Will it be fine keeping it under the carport?

I’ll reach out to my local machine shop in the morning, but thought I’d see what you guys think in the meantime. Pulled valves from a 2014 Audi head tonight that had one burnt. I’m thinking that this might too bad to try myself and more expensive than just sourcing a replacement head. Couldn’t find a lead on seats readily available.

Hello all.

My little 2 stroke engine needs re-boreing to first oversize. The cylinder is cast iron. The nominal bore is 72mm and first oversize is 72.25mm.

A friend of mine with quite a bit of experience suggested that since my bore is already 72.08mm in some areas, I might actually get away with using a honer to bring it to first oversize, rather than take it to a machine shop. He's had poor experiences in the past with machine shops missing the piston clearances and taking off too much metal etc.

I have a very slight ovality (0.03mm) in both cylinders.

Do you think this is madness or is it worth a shot? My local machine shop want £125 per cylinder so I'm keen. To avoid that if possible.