I Think I Blew Up the Engine in my 1968 Mustang... Part 9

In this episode, I think I may have ruined the inline 6 engine in my 1968 Mustang. After a troubling engine compression leak down test, I attempt to fix the top end by replacing my cylinder head and head gasket. After some pyrotechnics out of the top of the Holley Sniper, I troubleshoot the timing, fuel deliver, and compression again and things are looking worse. I'm left having to decide whether to continue fixing the original Ford I6 or instead to swap the engine for something more modern.

[@tcjmods73]

Dang man this was a rough one😅. I didn’t want you to have to break it down but I’m glad I got to see inside the motor. I support you in. Whatever you do. I’m here for the content. I think if you take your time shopping for the parts, an engine swap could be really cool to watch. to offset the cost sell some no bolts left behind merch cause I’ll snag some

[@noboltsleftbehind]

Thanks man, I appreciate it. Yeah, I'm feel like an engine swap might be the best move at this point. I'm doing some research

[@MH-rb7lp]

A couple of Options 1. - you could do what we used to call a backyard overhaul which requires you to of course remove the engine and disassemble it. You will be putting in new rings and bearings after you hone all of the cylinders. Yes it would be better to take it to a machine shop etc. however back when that car was new people were doing exactly what I am proposing every day all over the country. Do you think farmers and ranchers ran their vehicles to machine shops? No they didn't they rebuilt what they had at home in the shop (usually had a dirt floor). You will want to get something flat that you can put a sheet of emery cloth on and then block sand the top of the block and head to get a good seal. Put new gaskets in along with new valve seals (I would disassemble the head and check to make sure the valves are seating by using a magic marker or Dykem, if not use valve grinding paste and a suction cup to mate them. This is how it was done "back in the day", granted these were typically not high HP engines but neither is yours. When I was a kid I did more than one of these whether it was my rig or a buddy's. If you look on KZbin I am sure you will see people doing what I am talking about (i.e. Pole Barn Garage...) 2. Do an engine swap go look for a 5.0 Stang at your local junk yard 3. Buy a complete running car and transplant the drive train (i.e. another Mustang, Crown Vic, etc.).

[@sidney9534]

I second number 1. I did something similar with my Honda ZC engine (on my channel) - DIY hone, rings, bearings, DIY lapped valves, new seals and gaskets. Runs perfect and quiet. Cost me maybe 600 USD in parts? If he wants to get fancy he can buy new pistons, and it will run for another 50 years. (Assuming it's a weekend driver)

[@noboltsleftbehind]

Thanks for the write-up, it gives me some confidence I can pull off a refresh. I’m thinking I’ll definitely be doing one of these three options.

[@MH-rb7lp]

@@noboltsleftbehind You can definitely refresh that engine and get some more life out of it. Also if you do the refresh and then down the road decide you want more power and do a engine swap, you could sell that engine to someone as a drop in and not a worn out pile. I know it seems odd or even maybe wrong to not take everything to a machine shop and pay them a small fortune to get your engine done but trust me, people were doing their own rebuilds in their garage/yards for decades. During WWII many an engine was rebuilt on the spot to keep them going. Unless something it broken you are good, rings, bearings and gaskets are about all you need. Look though some of the old manuals and you will find instructions to do exactly this (like I said I imagine YT has many videos to help).

[@carlosdonestevez7532]

For future reference, if you want to check a head for valve seats, close the valves, turn the head upside down, and put fuel in it. If it bleads off, you have bad valve seats. You can do the same with the pistons. Pour fuel in there, and if it leaks right past the rings, you have a problem.

[@noboltsleftbehind]

That’s good advice, I’ll absolutely be using this trick in the future 👍

[@brandonloveday]

Yep, those are the breaks sometimes. These are just an outsider's opinion so take it for what it's worth: 1. You already have the car set up for an inline 6. You have an EFI (not cheap) you have a new head for it. So the top end is already in your possession. That's a positive. 2. An engine swap will be very time consuming unless you can find a donor car with all the stuff you need. I swear tracking down those little crucial parts can be maddening. 3. The car WAS running with the setup you had. From an economical stance, this is the way to proceed. Again, outsider's perspective. Find another 300 cu in inline 6 and go ahead and rebuild the bottom end. Then boost it. I'm serious. A turbo charger would be insanely cool. Everyone has v8 swapped these cars but a boosted 6....c'mon man THAT is a conversation starter and it would give you a lot of smiles. Just something to think about. Thanks again man, I like your videos.

[@NightWrencher]

I dont think its a 300. Pretty sure its a 200

[@brandonloveday]

@@NightWrencher you know, I Believe you are right. I have been looking at too many Ford truck videos.

[@andrewwasson6153]

I realize you’ve already moved forward with the engine swap but fortunately your car is a 68 and the 6 cylinder Mustang platform is structurally the same as the v8 car. Upgrade the springs, shocks and swap bars and you’re good to go (in addition to your engine, transmission and maybe rear end). I’d add a Monte Carlo Bar and bolt on frame connectors too but it’s a pretty simple upgrade, all things considered. I broke my in-line 6 last weekend but mine is a 66 Mustang. The 66 in-line 6 platform is different from the 66 v8 platform so I intend to do a complete rebuild and keep the L6. I was intending to do a full rebuild anyway but was hoping to delay that. My engine is super clean, good oil, good flow of coolant but I was diagnosing rough running and noticed massive blow by when I pulled the PVC hose and blocked the vacuum line at the manifold. The engine was running well but it stalled and seized. I just hope the crank is ok. The balancer is way too close to the block so I think the thrust bearing is hooped.

[@NightWrencher]

Tough break! You should swap in a 300 instead of that 200 and put a turbo on it! That sniper 1 barrel would be too small so you'd want to swap to a 4bbl intake with a bigger sniper. And upgrade the fuel system and build the turbo hot side. And them cold side and then hope the transmission survives. But aside from that itll be a breeze!

[@onitramt77]

I agree with other comments about trying a garage rebuild. Shouldnt be expensive if you reuse most parts. You can always pull it and try a rebuild and then get it running outside the car before putting it back in. If it still wont fire off after you rebuild it, you can always do a V8 swap at that point. Half the work will already be done if you have the engine pulled. If it works, you save money by not replacing the engine. If it doesnt, you lose a little money but save a bunch of labor by not putting it back in to see if it runs, finding out it doesnt and then having to pull it again to do a swap.

[@givemeaname1999]

That’s a tough one. I vote for a cheap V8 swap. Unfortunate part of that route will always be cheap means you are never sure what you are getting. But you know what you have. Good luck

[@noboltsleftbehind]

Very true, it can be hard to find good used engines. I've had good luck in the past buying running/driving donor cars, though that ends up being a whole project in its own.

[@tonydargon3918]

If the bores are not worn too far throw a set of cheap rings and bearings in and send it 👍

[@callofgeorge]

hey man. spoke with you on insta a little. ya, with it burning oil and blowing air past the rings, you def have a block/piston/ring issue. could be as simple as new piston and rings with an at home hone job. that's what i had to do with my 200 when i redid it.. this was after it was rebuilt by a machine shop.. one more reason i don't trust other people working on my stuff.

[@noboltsleftbehind]

Yeah, that’s what I was afraid of. Machine shop quoted me thousands and I’d still have to tear the whole thing apart myself and reassemble. And it sounds like we’ve had the exact same experience with shops. No one else is going take care of your stuff like you will.

[@callofgeorge]

truth. if you decide to try to fix that one, let me know. i've rebuilt and built a few engines including 2 of these 170/200 inline 6's and would be glad to help where i can. should be able to tell if its salvagable just by pulling it apart. depending on damage, it may be a fairly cheap fix. i wanna say the one cylinder/piston i had to fix ended up costing $2-300 and i was back up and running. @@noboltsleftbehind

[@noboltsleftbehind]

@@callofgeorge thanks man, I appreciate it and definitely will do if I decide to save the i6

[@sidney9534]

If there's no catastrophic damage, I think it will be easy to fix this at home for cheap. Seems like the PO maybe messed up the head "rebuild"? Valves need lapping maybe? Rings are cheap and can be changed without removing the block from the car (at least on most engines). I "rebuilt" (refreshed) my Honda ZC engine (see on my channel), it was easier than I thought. The hard part is setting up fuel and ignition, and you got that sorted already, so I wouldn't let mechanicals stop me - it's just legos. Doesn't need to be machine shop level perfection, if it's got fresh rings and lapped valves, it will run fine.

[@noboltsleftbehind]

Could need just need some valve lapping, I think I may even have some compound left over from the one time I’ve tried it. I’m not entirely sure if I can pull the oil pan and get the pistons out without pulling the engine, I know there’s a crossmember down there but it might be worth a shot. Good advice 👍

[@jeffreyrigged]

@@noboltsleftbehind you will have to at least pull it up some or its going to hit. Me i wouldnt put money in a 6.

[@noboltsleftbehind]

@@jeffreyrigged good to know, I'll plan on pulling it out if I go that route. Though if I have to pull the engine, I'm not sure I'll want to put it back in. Haha.

[@jeffreyrigged]

@@noboltsleftbehind I'd go v8

[@tmacdagreattv]

V8 swap! Thats what I did I’m 1967 inline 6

[@msryder9265]

Did you even get a chance to try out the holley sniper. Having a 66 bronco with the 170 I am thinking about getting the full sniper setup.

[@noboltsleftbehind]

Yes, I drove it around for maybe 20 miles or so. Seemed to work well, self learned and everything. The only issue I had with it was the fuel pressure regulator squeaking.

[@sidney9534]

18:53 correct me if I'm wrong, but isn't pushrod lenght irrelevant? That's what valve clearance adjustment does. Did you adjust valve lash?

[@noboltsleftbehind]

These Ford inline 6 engines doesn’t have adjustable valve lash unfortunately, at least not from the factory.

[@sidney9534]

@@noboltsleftbehind whaat? That's nuts, how can it even work? You shave off material from pushrod or rocker or something?

[@noboltsleftbehind]

@@sidney9534 I think you’re supposed to measure the precise pushrod length with one of those measuring tools and order the ones you need. Or switch out the assembly for an aftermarket adjustable set, haha.

[@jeffreyrigged]

@@noboltsleftbehind you are right. Alot of engines dont have adjustable valve lash. It actually makes a stronger valve train. Most gm bop cars where this way.

[@IMRgarage]

Did you sell the sniper ?

[@noboltsleftbehind]

Yes I sold it

[@xozindustries7451]

Did you do a leak down test on all the cylinders before you pulled the old head? In the end it’s your car and do what makes you happy, but if it was me I’d find a V8 explorer and pull the 5.0 efi motor out, put it in this with a good overdrive transmission, make it a good driver for pretty cheap, keep the efi and use an aftermarket ECU

[@noboltsleftbehind]

I stopped after the first two, both had almost no compression. That's actually a pretty good idea, I wonder how well that auto transmission will fit in the Mustang's tunnel? I'm pretty sure that 5.0 should fit without removing the shock towers.

[@xozindustries7451]

@@noboltsleftbehind I’m sure there’s a lot of information on the forums on how to do it, you won’t be the first person to try it, probably a complete build list somewhere. I’m not a ford guy, I owned one fox body and hated it 😂

[@jeffreyrigged]

@noboltsleftbehind ​ A 5.0 should drop right in. 302 and a 289 are pretty much identical. You do not want the explorer gt40p heads and the 4r70w out of a explorer is 4wd/awd. You would be better to find a 302 and 4r70w/aod out of a 2wd truck, ltd/mgm/towncar, tbird/cougar or mustang. The gt40p heads you cant find headers to easily fit. The best is a maf engine but you could wire up any to be maf pretty cheaply. The aod/4r70w is no bigger than a c6 so it should fit in the tunnel. Also if you want a better head you can get the knock off aluminum ones for super cheap. Way cheaper than getting a special header or manifold for gt40p heads. You could also swap in a t5 if you didnt want an automatic from a later mustang or tbird/cougar. Depends on what you want.

[@repair-and-despair-garage]

I think we have all been there on a project but it sounds like you already made your decision on moving away from the 6 cylinder. In the end it will always be better with a v8 and more power

[@noboltsleftbehind]

Yeah, I think you’re right

[@rustypliers74]

I don’t like how she gallops

[@noboltsleftbehind]

It’s no bueno. As of now I think it’s been decided to put the inline 6 engine out to pasture.

[@carlosdonestevez7532]

Dude this is stupid. Get an 80s model 302 from a junk yard. There roller lifter motors make great power and have great reliability. Not to mention it will bolt right in. You'll just need a new bell housing for the transmission or, better yet, upgrade to a c6. You're wasting money.

[@noboltsleftbehind]

I see what you’re saying, but it’s hard for me to believe a 40-year-old motor sitting in a junkyard is going to be anything near reliable. I guess reliability is all relative.

[@carlosdonestevez7532]

@@noboltsleftbehind there running engins typically sold with a thirty day warranty. They don't want to sell you junk it's bad for buisness.

[@rkkuhlmann]

Bummer for sure but I think you're on the right track. Sounds like dropping in another known running inline 6 would be the best bet for now. Get the body work and little odds and ends done, enjoy driving it while you conjure up a plan for a different motor/drivetrain down the line.

[@noboltsleftbehind]

It’s certainly the quickest and easiest way to get back up and running, should be able to have it out and back in in a day. There’s a couple for sale here in the LA area, I’ll be checking them out this week.

[@michaeldowney8429]

Barry, kudos to you for one of the best series of videos on KZbin. I stumbled onto your channel and have been super impressed. Keep up the amazing work brother!

[@noboltsleftbehind]

Dude, thank you so much! I appreciate ya

[@jimdavis4356]

What? Hemi? Are you kidding? But you KNOW Hemis!! 😮

[@noboltsleftbehind]

Haha I’m not sure how well it would fit between those shock towers but I love the idea

[@busyend]

Swap to a gen 2 or 3 coyote sir. Find a donor car like you did before.

[@noboltsleftbehind]

Coyote would be awesome, definitely at the top of the list for cool factor. I think they need pretty serious engine bay surgery to fit though, as far as I know I'd have to cut out the shock towers and re-built the front suspension. The exhaust sound alone though might make it worth it.

[@andynicoll8566]

Drop a 283 or like motor in it and be happy!

[@keninhb2196]

Great video, as always! Seal up the garage, looks like we might be in for rain starting Sunday!

[@noboltsleftbehind]

Dude, seriously! I have my sand bags ready. Luckily my neighborhood usually doesn’t flood too bad.

[@PowerfulRoman]

LS swap!

[@noboltsleftbehind]

Haha, never a bad way to go

[@infamousnova]

Ewwww

[@jeffreyrigged]

I like them to be powered by there maker if possible.