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.

A friend was having the water pump leaking slowly. I offered to help as I have done this twice with success. As he was driving to my home, he had engine failure. The left secondary chain is off. Examining the head, I see a crack in two of the sparkplug tubes.

Has anyone replaced the head with success? If so, did you get a head from a yard, refurbished, or buy new? Is it worth it? It doesn't look as if the pistons are damaged, using a camera.

Thanks.

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?

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’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 .

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.

This is a lengthy post so I appreciate y'all taking the time to read it and any serious advice that is given.

My friend brought his G8 to a performance shop to have both his engine and transmission built with performance parts. The quote in the pictures is the original estimate he was given and he has, as of now, already put down $8k before any work had begun. It's been at the shop for several months, which isn't a big deal as it's not a daily driver or anything.

As of last month he was texted and informed that something went wrong when they went to drive the vehicle out to park as the needed the bay. The shop stated it suddenly had a dead cylinder and was making a knocking noise. They inspected said cylinder with a camera and found a bolt had fallen into the cylinder and gotten smashed around, damaging the head, piston, sleeve, and cracking the cylinder. I also worry about how a supercharger bolt could fall out without damaging the supercharger or getting caught in a valve first.

Their action plan is to replace the block, source a new piston, and somehow a machine shop is going to be able to fix the head. But they are also asking for some additional cash at this point. Claiming it's needed to get the fuel system components and install them.

As of now I told him to let them know he will get back to them about the additional cash, but I really don't think he should give anymore money until they fix what they fucked up and get back to the point it was at before it got fucked.

I am well experienced in the auto repair industry as its been my career/source of income for a couple decades, so I am able to understand the severity of the fuck up. My friend has no experience with auto repair.

I was thinking it might be best to talk to a lawyer first to make sure he doesn't make anymore missteps that could result in him not being able to defend himself if this turns into a civil suit sort of thing.

Otherwise I think the shop needs to get him back to whole as far as having a working, rotating engine before he gives anymore money. I think at the very least they need to replace the block, piston and rod, cylinder head and valves along with a thorough inspection of everything else for damage caused by said fuck up. I worry he's in over his head and will get taken for a ride.

He's a veteran and loves his G8 and I don't want him to get played by sleazy techs just because he doesn't know better.

Any advice (serious advice please) is helpful, so thank you.

EDIT FOR CLARIFICATION: Friend has already paid $8k up front towards the total owed of ~$24k. Shop has acknowledged their fuck up and says they will fix it, but want my friend to pay even more cash towards the total owed. Shop has not fixed any of the fuck up which happened last month at this point in time.

SIDE NOTE: Friend provided all needed parts and purchased them himself before the shop started work. They are all good quality brands and the correct parts, and the only thing he needed parts wise from the shop was the fuel system.

Parts list provided by friend to shop: Stage 4 circle d trans rebuild kit and boost district 2650 supercharger kit

TLDR: shop fucked friends engine up, say they will fix it but want more money first. Friend has already paid $8k, still owes ~$12k.

I noticed tonight what looks to be flash rust on my cam lobes (you can see my finger rub on the lobe) I plan to finish Sunday , first time doing a timing chain and I'm slow :( 2 kids and all and as I come across things I clean them like "valve covers / engine covers" and plenum etc.

Overnight I put the covers back on but I took the spark plug seals and vvt/oil sensor seals out and am freezing them overnight to pop them in tomorrow morning so that overnight seal is a little better at least . Same with valve cover gaskets, I'll put that on against tomorrow at until Sunday.

Should I do anything for this, go back out immediately and pour some oil over it and rub it with my finger gently or what?

I know, close it asap probably is the answer . I'm doing what I can to save like 8k.

2013 Mazda cx9 3.7L awd (for bot)

Thank you.

Hey Guys,

I recently built my LS3 (Camaro) and took it for a final tune before getting it back on the road. The tune shop completed the tune and when I picked up the car they mentioned that once the car got to temp, they noticed what sounded like a lifter tap but it cleared up. They test drove next morning and nothing. After I picked it up, I drove it home about 6 miles. Car came up to temp and ran fine - I didn’t hear much of anything outside of what I would consider normal.

Here is the current parts list:
BTR Stage 2 LS3 V2 camshaft
BTR .660 dual valve springs / retainers / seals / locators
BTR trunnion upgrade / stock rockers
BTR 5/16 chromoly pushrods (mixed sizing 7.55 & 7.57)
Johnson 2116LSR link-bar lifters
3-bolt cam conversion
Katech timing chain
Melling 10295 oil pump
Chevy Performance 4 pole cam gear
Chevy Performance timing dampener
BTR Lower Timing Gear
Chevy Performance cam retainer and bolts
Kooks 1-7/8" long-tube headers
Kooks high-flow catalytic converters (Performance Cats)
Borla ATAK cat-back 
K&N cold-air intake
MSD Spark Plug Wires
J&L Oil Catch Can
ARP Head Bolts
ARP Crank Bolt
ARP Cam Bolts

It’s hard to tell, between the injectors, link bars and head work, if there’s anything knocking beyond normal tolerance. Video for reference of motor running while warm - cuts a bit early but each side is nearly identical in sound.

About a month ago my girlfriend bough this '97 2.0 Probe for very cheap. It had a running issue (when engine warmed up rpm started fluctuating between 1500-2500rpm). Also when we were buying it I noticed the distributor was turned to retard the timing, I gave it little thought and she bought it anyway cause it was almost rust free.

After a few days a lot of white smoke appeared when I started the car and I noticed the coolant resevoir was empty and there was only air in the coolant tubes. Temp was normal.

We thought the throttle body mechanical sensor that detects if engine is warm enough to lean down fuel mixture was not working due to combustion gasses in throttle body (highest point of coolant system), causing high and uneven rpm at idle.

Then we measured the compression of the engine with my friend. It was bad and uneven - fluctuated from 60 to 90. My friend took the engine apart because we thought we needed to change the head gasket because that seemed obvious. We deducted that the distributor gear connecting to the camshaft was probably incorrectly assembled at some point causing premature detonation and therefore ruining the head gasket. Then they noticed it and retarded the timing because it was correct when we checked it with a stroboscope.

After he lifted the cylinder head he noticed the gasket wasnt very damaged at all, infact everything seemed quite well preserved (low milage engine). The block was not crooked or cracked and there were only some slight pitting and scratches (fingernail got caught). Basically no evidence the engine or gasket contributed to the coolant burning.

The only thing he noticed was that the cylinder head guide sleeve was not protruding from the block (too low).

Could this be the cause for coolant burning? Perhaps cylinder head misaligned because of premature detonation?

What would be our next step?
Pictures from engine, etc:
https://imgur.com/a/RQAaJXR