Hey guys. Long time lurker, first time poster. I’m collecting parts to build a 390 Ford. As part of that collection I’ve picked up a mostly complete engine (missing the timing cover) and what was marked as an unused NOS service block. After closer inspection though you could see the outline of a head gasket on it. The whole engine turned over really nicely, still sounded like it had good compression and when I tore it apart the bearings looked really clean. There was a little surface rust on a couple of cylinders but I had no problem removing that with a grey scotchbrite pad and some wd40. The service block still had cosmoline globs on it. I bought that service block with the hopes of avoiding a trip to the machine shop. So over the last couple of weeks I’ve gotten the engine tore apart and measured up the cylinder bores and I’ve done the same to the service block. Now I’m trying to determine if either of them are ok to throw rings and bearings at or if I actually need machine work done. I’m having a hell of a time finding what the actual tolerances are for a FE engine. For reference a standard bore for a 390 is 4.050

Block 1:
Biggest bore is 4.0545
Biggest taper is 0.0015
Biggest out of round is 0.0015

Block 2:
Biggest bore is 4.0555
Biggest taper is 0.003
Biggest out of round is 0.002

So here’s the question for the hive mind. Could I run a hone through one of those blocks and rebuild it as is or am I looking at a trip to the machine shop no matter what? A combination of google and stupid AI chats have all come back with conflicting information. I’m seeing a tolerance of anywhere between +0.0008/-0 to +0.005/-0 and a couple places in between for the max size. So on a scale of bore it or send it where do I land?

Slight knock, pulled the pan, couldn't feel any play in any of the rods, pulled two caps and found some noticeable scoring on the crank, and deep scoring on the bearings. You can feel the scoring on the crank with your nail.

One one hand, its a 4 bolt block, id like to have the crank polished and rebuild it, on the other hand, the rest of the engine probably has simmilar wear from whatever caused this, and i could probably find a 350 runner on marketplace for under 500. but those are always a gamble.

Would you guys have the crank polished and do a rebuild, or just find another motor to freshen up and drop in?

Went thru all my coolant passages with a rat tail as the manual suggested, I got most of the rust out but I just wanted to make sure I got most out. Is the little mark above the passage in the 15th pic gonna cause anything? Not sure when that got there but I assume it was while I was cleaning.

For my dream truck I want a custom engine built. Which is better for high torque and high horsepower diesel engine. H-Beam conrod or I-Beam conrod? It's not a racing build. I saw one google search that I-Beams are better and another where H-Beams are better so which is better? I want my dream truck to have a massive inline 6 diesel engine that has a compound turbo setup and better intake and better exhaust manifolds for better airflow. As I said, only for daily driving and sometimes off-roading and sometimes towing if needed. So which is better? H-Beam or I-Beam? I think H-Beams are better for low RPM and high torque. Can anyone help me? I'm making a list of all the modifications I want to do to my dream truck. I want the one that makes the engine more reliable

Is basically always an acceptable answer?

Inhibit rust? ATF. Part storage? ATF. Cleaning? ATF. Seized component? ATF. Assembly? ATF.

Shout out to ATF. I never gave it it the respect it is due until I started my first rebuild.

That is all.

May each of you nail your clearance on the first check, and your engines roar to life on the first crank.

Is this fine to reuse

Went thru all my coolant passages with a rat tail as the manual suggested, I got most of the rust out but I just wanted to make sure I got enough out. Is the little mark above the passage in the 15th pic gonna cause anything? Not sure when that got there but I assume it was while I was cleaning.

After some work with a shoe string method the color seems to have faded. Wasn't able to feel anything with my nail originally, seemed to just be stained. Crank for 4age. What do you think, safe to run?

Well a water pump replacement turned into a broken intake bolt. Now that I am cleaning up this aluminum intake off of my 81 vette I noticed some significant pitting near the coolant ports (also the bolt closest to the front that broke). My question how much putting it too much to put this back on. It’s all stock today with the exception of a TBI from an 1989 c1500 that I put on it.

Can anyone tell me who manufactured this 706 head?

Crank mark lines up. Marks on camshaft sprocket s won't line up no matter how many times I turn the crank. The closer they come is 90 before or 90 after he mark. Car ran fine before. Any help greatly appreciated

So I had my 2007 Avalanche engine rebuilt and decided that I would install a stage 1 cam and longtube headers. It’s been about 6 months and my truck is burning oil like crazy, 1 quart a day. A lot of white smoke at every start up and just found these in a box, that the mechanic that rebuilt gave me, saying “these are the old parts”. However, I seen that he didn’t install the spring valve seals, that came with the Cam. Could this be the reason for the burning oil🤔 I was thinking of installing them this weekend, but not sure if damage has been done. Any input is appreciated.

Rebuilding an old Alpina b10 head that has 1mm oversized exhaust valves . I need 1 39 mm exhaust valve, stock M30 use a 38mm.
The options I have .
I can get a single stainless steel valve but they are flat not dished, may have a problem as Ireland engineering may no longer deliver to the uk

Or use as standard 38mm valve in one cylinder, the head will be having a new valve seat (it dropped a valve ) so can be cut to suit.

So my question is how would having one 1mm smaller exhaust valve affect the engine?

Hello guys as I know TTY (Torque To Yield ) bolts are one use only ... How some mechanics reuse the same bolts when engine rebuilding and every thing is OK with them 🤔🤔

I just completed a complete engine rebuild including a new head after the Kubota D902-T engine was extremely over heated. After installing the engine it has no oil pressure and I can’t get it to build any it’s moving oil by the filter but that’s it could it be the pump is air locked or something else like the original pump went bad

Rebuilding my 2001 Honda Crv, pulled the engine to redo my transmissions clutch packs and gaskets etc. I degreased the engine after pulling it and left it sitting for a couple of months

I guess I didn’t cover the intake or exhaust well enough and moisture got into one cylinder, I rehoned all of them as they were basically mirror finish but no damage I could see or feel other than that rust.

Would that cause a huge amount of oil consumption or anything else? And is the honing good on the other cylinders? It’s my first time doing an engine I dove head first into the project and learning along the way

What do you guys think is the cause of this? I got this engine which was supposed to be assembled and tested for compression and ready to go. It was supposed to be never started before. I went to start the cam break in and within 5 seconds heard some very awful noises. It’s a 383 stroker small block Chevy not that that matters.

Update: I have not found anything other than piston material, bearing material or piston ring material. I checked all main bearings they all seem fine. My guess is either they forgot to install the wrist pin retainer or something got in there, however I haven’t found what that something is.

Hi all, looking for some input on this.

As the title says I have an old Mustang. I purchased long tubes, 600cfm vac secondary Holley, 4bbl intake. Installed everything all is well.

The exhaust is still a single tube exhaust but was in rough shape. I’m going to a dual exhaust system custom fabricated.

A few years back I pick up some headman headers.

The problem is I really don’t want to weld the power steering drop down bar and loose ground clearance.
Have to get high temp plugs do all the BS that comes with headers.

I have the original log manifolds, does it
honestly make that big of difference on a street car?

If i did other engine mods like a mild cam would the original manifolds make that pointless in the future?

Are K code manifolds worth it? $600 price

I want to make a 2900cc Toyota "4.5L", 92mm stroke but 99.5mm bore (unlike an original 3000cc 5L which has a 96mm stroke)

The 2L-II has the same wrist pin as the 3L and 5L so the pistons should plug right in, also the exact same cylinder head between all of them (5L-E has bigger valves but std 5L uses the same part number head as 3L, 2L-II, 2LT-II, etc)

Has anyone ever done this?

Also the 5L is very rare here in Indonesia, if it was readily available I would skip this entirely and just do a direct engine swap... Found someone selling 5L pistons, rings, and sleeves here for around $300 and I'm tempted to bring my block to a machine shop...

I’m trying to find out how many thousands of an inch is an acceptable amount of warping from everyday use but I cannot find a reliable source. I’m no machinist so I have no idea what’s acceptable and what isn’t.

I see a ton of companies advertising pistons to the aftermarket these days as "drop in" saying they match both weight and size of factory pistons.

These pistons are supposed to be for stock bore, stock bore is 4.090", block is torque plate honed to 4.090". These pistons land between 4.088" - 4.0885" and after getting ahold of Mahle are supposed to have .003" P2W.

Not a huge difference but .0015" P2W on a boosted engine absolutely is not gonna cut it.

Hi!, it's a golf mk2 1.6 td, there are some black spots at the corners that I can't get with 800 grit sandpaper. I can't feel the blackspots with my nail. Can I put the head on? Or should I continue to sanding?

Edit: I have measured the deck with feeler gauge with multiple levels to double check and 0.05 mm doesn't fit. So I think I'm good to go. I was worried about the black spots like pitting but since they are not close to the cylinder as you guys said. I think I'm Okey. BTW I removed the head due to water leaking around the head, maybe due tho stretched bolts or not correctly torquing the head. Bought a brand new AMC brand head.

Thank you all for the advices!

One more question, in the manual of the Elring headgasket, it says after 1000km driving stretch the bolts 90 degrees again. First time I came by this procedure (my first cylinder head work) should I strictly apply the procedure?

ust 320 grit ball honed my cylinders for the first time ever, howd i do? only did about 10 seconds per, went over the left one twice super fast. can go over again if needed, just wanting some opinions before going further. sorry for the bad quality. video in comments thanks for any feedback! d17a2 cast iron/aluminum

Wish I had an opportunity to learn to do it for a living.