Inline 6 running terrible & low compression (deeply technical)

[bmbm]

200 low compression

As stated take a quick look around you can still find used 200's in good running condition priced well. I am running a $125 250 in my 66 and it runs good. I found it on CL. I have seen at least one 200 on the for sale section on this forum but don't remember their location.

 

[DaveLev]

Thank you. I have not yet heard back from the machine shop. I suspected blow by as well, but just not sure. I have not found a used 200 locally. Anyone know of any other in-line sixes that would both up to the C4 transmission?

 

[bmbm]

other sixes

seems like the 250 should might be good to have a suspension lift though or do some modification to the oil pan. and mod the clutch linkage and a couple other things. There is a good post on this forum by jimmyv65 with details.

 

[DaveLev]

I found a 200 about 3 hours away that may be good or bad - unsure. It is only $300, though. There is also one in an older falcon wagon near me that has a fresh rebuild. I don't need the falcon wagon, but if the engine has papers, I may buy it just for that engine and skip doing the head in mine all together.

 

[bmbm]

looking for 200

Sometimes you find good ones cheap. But it can take awhile. Picnpul is good in my area or try car-parts.com.

 

[bmbm]

200 for sale

https://fordsix.com/viewtopic.php?f=86&t=75371
I have a 1968 200 that was rebuilt. It's 0.030 over with new pistons from Classic Inlines. Rods resized with ARP bolts. Block is painted Ford blue with a black powdercoated oil pan. Inside is a comp 260h cam and timing chain. I have a 1980s large log head converted to 2bbl and an autolite 350cfm carb. I have a spare 1968 large log head as a spare. To top it off i have a hooker header with 2 ford mustang 2.5in/out factory take off mufflers. I have a duraspark distributor and module.
The tranny and tcase have been powder coated black with all new bolts. They were rebuilt using wildhorses kits. The tcase (t-shift)also has a gear gawker cover. I will even throw in a spare tcase (j-shift) and whatever else i have that's inline six related.
$1200usd doesn't cover what i have into this in parts alone, so it's a great deal for anyone interested in inlines.

he is way up north maybe in canada I think
you may be close

 

[hucklburry rev2]

I bought a 250 with V8 bell housing pattern for $100 (1980, came with duraspark module), there is a 200 for sale St Louis craigslist for $200, I missed a 250 that just came back from the machine shop for $350. Just some examples to help your search.

They pop up and are inexpensive, you might be surprised run a "wanted" ad on CL, people have them sitting and might email you about it.

Also keep an eye on fordsix classifieds.

 

[bmbm]

CL want ad

Actually that is how I got the 250 I am running now wanted ad on CL. Placed the ad and within a day or two got an email from the guy. Two hour drive but it was low mileage and he had a valve job done. $125 plus some other parts he had. Free to try it.

 

[DaveLev]

None of the vehicles I've found on craigslist have proof of the rebuild, but they all elude to it in the ads and they say the prior owner rebuilt it. Well, I still haven't heard from the machine shop on the head, but I went ahead and photographed the engine for you all to look at and provide analysis.

I learned that it has 60 over pistons, so if the bottom end is toast, I'll probably need to source a new block (unless they sleeve and do 80 over pistons still).

The only concern with the top of the pistons I saw was on the #6 cylinder which had 100 psi during my compression test (far from the worst one). It may be that previously the owner dropped a valve or something, as it has a bunch of score marks. The head did not show any evidence of this. I suspect that someone took a head from a different rig and put it on this bored over block, but not sure - will get casting numbers from head next time I call the machine shop.

Anyhow, here are the pictures (there are many, so sorry in advance).

Please tell me if you see anything out of the ordinary, particularly with the top of the block where the head gaskets were. The driver's side looks worse than the passenger side, but what do I know.

I have not sanded down the top of the block yet, but it has been cleaned with carb fluid and a paper towel to get good pictures.

I don't feel any ridges at the top, and could not visibly see any scoring on the cylinder walls, either. It almost looks like someone recently rebuilt it. Here goes:
The one with 60 psi (#4) and 55 psi (#5):

Bad number 6 with 100 psi (before I cleaned it):

Some funky block off plate on the block - think there is a freeze plug here normally?

The rest of them at TDC or BDC, random order, and all of them after cleaning:

 

[DaveLev]

Well crap. Just heard back from machine shop, and they claim the head has 5-6 cracks in it and have been patched with welds in the past several times. They were surprised I didn't notice it, and want to show me in person tomorrow.

So now I'm looking for a head, but the cost to rebuild a head is the same as buying a complete used running engine. Hmmm...so many choices.

 

[Justafordguy]

Those blocks are bad about cracking too, you better check it closely.

 

[norm02]

FWIW, I just had my entire short block and head rebuilt for around $1k. Mine is bored .040 over and I had the block decked to ensure proper CR since many of the after market head gaskets are thicker than the original.

 

[CraigS]

Not important, but did all Broncos come with PCV? That block off plate looks like it may cover the opening for the old road draft tube on earlier blocks.

 

[needabronco]

Did you ever try the ATF trick? And yes I meant to put some in the engine oil. However you could put some in the vacuum port with a hose and let the engine suck it in. It will clean the crap out of the combustion chamber and valves. BEWARE it will clack, knock, and smoke out your entire street while your doing it. I do this regularly on natural gas engines in the oil field. Natural gas is dirty and causes a ton of build up on valves.

 

[DaveLev]

I bought another head from a yard yesterday for $175. Drove 3 hours and had to pull myself. Paid $35 to hot tank it and this one is cracked too. Flying to another state for vacation and will look for one there. I hate these heads.

 

[CraigS]

where the hell are you? I have 3 sitting around the shop.

 

[DaveLev]

Send private message.

 

[DaveLev]

Thanks to members, I was able to secure 2 different heads at a reasonable price that were within 5 hours drive of me. As you may recall, my compression was the following:

#1 - 130 psi
#2 - 137 psi
#3 - 138 psi
#4 - 60 psi
#5 - 55 psi
#6 - 100 psi

With the newly installed heads, those numbers are:

#1 - 110 psi - lower
#2 - 105 psi - lower
#3 - 107 psi - lower
#4 - 30 psi - lower
#5 - 60 psi - about the same
#6 - 90 psi - lower

Well crap. Looks like bottom end is most likely the problem. If anyone has an inline 6 that runs - a 170, a 200, or a 250 - please let me know. I'm sure several of you have these sitting in the garage when you did your 302/5.0 swaps. Thanks!