All Small Six Engine Check Up and Tests

[MustangDadDrake]

Hi all,
Last summer you guys helped me to replace my timing chain, rear main seal, oil pump, and screen. I have done some minor upgrades since then but I have a feeling something doesn’t sound quite right.

I have this video showing some spark plugs I recently installed and some idle revving and driving.

Video

I am hoping some better ears can tell me if I have anything to test or fix. (My speedometer makes a tick noise around 30mph, try to ignore that).

I plan to do some tests this long weekend and I’ll post my results.

Oil Pressure Test (previous test shown pressure at 20psi after warm up)
Compression Test (last years test attached)
Tune w/ Vacuum
Any other tests?

As you will notice I have an SCV carburetor installed on my 68, however I rebuilt the carburetor and did the drop a load modification.

I suspect there to be carbon build up causing the sound or an oil pressure problem caused by old rings.
Other notes: my engine has not been getting up to temp even after 15-20 min warm up and drives. I have a plan to replace the thermostat. Also when I reinstalled the damper I did not mark it properly so my tuning is done by ear or vacuum gauge for now.


I appreciate everyone’s input and I won’t be afraid to try anyone’s suggestion.

 

[bubba22349]

For some reason I am not able to read you attachment report might be that my IPad is getting to be to old for that format. What's the compression test readings? Have you done a cylinder test by pulling one plug wire at a time and noting the RPM drop? You might still be able to fix that speedometer problem easy if you will unhook the cable housing at the back of the Speed O Meter and pull out the inner drive cable out and use some white grease to lub it up good or replace it if there are any signs of damage to the outer housing or the inner drive cable. If you leave it working like that very much longer eventually either the inner drive Cable is going to break or it will take out the Speedometer head. Best of luck.

 

[MustangDadDrake]

Thanks for the reply as always.
I will also do the cylinder test. What kind of rpm drop am I looking to see?

I will grease the speedo cable thanks for the tip. My mini tach and converted voltmeter finally shipped from rocket man mustang so I’ll grease it up when I put the new gear in.

also I thought I attached the old compression test results but maybe they aren’t showing up.

 

[bubba22349]

RPM drop would be something like 30, 50, or 75 or more RPM for a wire pulled the more it drops the better that cylinder is working. If there isn't any drop or very little than you have a weak or dead hole caused eigther by having less compression per the others or an ignistion problem i.e. a bad plug wire, Distribitor cap, or a bad or fowled spark plug. Best of luck

 

[MustangDadDrake]

Here are the compression results from last year:

Cylinder	Dry	Difference from Highest Cylinder (Dry)	Wet	Difference from Highest Cylinder (Wet)	Dry to Wet Difference
1	155	20	165	20	10
2	175	0	180	5	5
3	175	0	185	0	10
4	170	5	185	0	15
5	170	5	170	15	0
6	165	10	180	5	15

 

[bubba22349]

Hi MustangDadDrake, thanks for posting those Compression Test results, that refreshes my memories some of your past repair project replaceing the dampener. Did you also put in a new timing chain set during that repair? If so was this Compression test done before or after that timing chain set? Though it doesn't look too bad on that #1 front cylinder its enough of a difference on the dry C test that it could give you some trouble i.e. it is putting out less power then the others cylinders by enough to be able feel it (it's like its out of balance) The wet C test is also showing a problem with no change on #5. I think you have found the problem to why it's running the way it is, a new set of rings and fresh valve job could help if the cylinders are still in good enough shape. By getting a rering kit it is also fairly inexpensive giving you a compleate gasket, new set of rings, and new Rod bearings, for one lower price, plus you can also add the main bearings if you wanted, the new bearings would also get your oil pressure up some more. Best of luck

 

[chad]

any ideas on mileage? Thinking 'just the top end' so as to allow motor to stay, the head is pretty portable & wrk there of good benefit. Rings done right there, once head is off a cyl wall inspection (& even a hone, depending, w/a drill)...?

 

[MustangDadDrake]

Bubba: Yes i changed out the timing chain when i had the pan off and the compression test is with the old chain.

Chad: I am not sure on the mileage, it is safe to assume the odometer has gone over two cycles.

Ideally, I would like to rebuild this engine but I had not planned to for a few more years. Would it make sense to replace these parts now? I think it would be a cool project to try. The bottom end stays in the car correct?

With the stock head off, could I get it ported and put back on without doing anything extra to the bottom end? Would this be a good time to replace the cam as well?

Kinda going down a rabbit hole here

 

[bubba22349]

You could try doing the compression test again but it likely won't be much different it should give a little bit higher readings. Yes it would be a wise thing to do right now if you needed to depend on and use your Mustang very much ie like a daily driver, if not you could probably get by for a couple years with limited use if you don't mind how it's running. Yes you certainly could do an overhaul / ReRing with the block in still in the car. And because you are reasonably good at twisting wrenches, plus some previous experience, I am confident you could do the short block overhaul over a weekend and if you have some extra helpers that's all the better too. There are ReRing Kits that give you most all of the parts you would need at a low cost, i.e. a new set of rings, new Rod bearings, and a full gasket set for about $110.00 to $130.00, or ReRing Kits that add the main bearings for $150.00 to $180.00 range and you can usally barrow the tools you might need at one your local auto parts stores. Basic overhaul job after the head and oil pan are removed is as follows,

1. First ridge ream the top of cylinders,
2. Then remove the piston and Rod assemblies.
3. Hone the cylinders with a ball type hone.
4.A. Optional but this would be a good time to install that new camshaft if you are going to.
4 B. Install a new set of lifters with the cam.
5. Clean up the Pistons (De-Carbon) using a ring grove cleaner, plus also get the carbon cleaned off the tops, and clean rods,
6. Install the new Rod bearings & rings.
7. Then clean the crankshaft Rod throws and wipe down / clean cylinders,
8. Reinstall the piston Rod assemblies you will need a ring compressor for this.
9. If you want also install new main bearings
10. Checkout or replace the oil pump.
11. Reinstall the oil pan.

Yes the head could be ported, plus a fresh 3 angle valve job and back cut intakes, opened up carb hole to 1 3/4 or more, center exhaust port divider or even do the same mod's on a replacement late model head if you wanted there is lots that you could do to unlock some more power in a head. Probally would add some more time that the engine is apart unless you had another head that was ready to bolt on. And yes the camshaft could also be replaced while its apart with a little extra labor time and would add a cost of about $200.00 to $250.00. A few other optional parts that are reasonable in cost a full new set of freeze plugs for the block and head (good idea to change them if yours are very old) , a can or two of Ford Corporate Blue paint if needed. Yes you can get down the rabbit hole in a hurry. Hope that is some help best of luck.

 

[MustangDadDrake]

This is beautiful information thank you and thank you for the compliment, what an honor!

I do not use this car as my daily driver and drive it every once and a while and not very far. So i could wait but this project sounds very exciting to me and not that expensive.

I found the rering kit online: http://www.northernautoparts.com/part/ek-er0373

Question on the large log, wouldn't i need to take the block out to fit it with a large log head, to mill the gasket surface?

So many different ways i could go with this, ill need to continue to plan it out.

 

[bubba22349]

That's looks like a really good re ring kit and it even it comes with both the rods an mains togeathe and has lots of other options you can add. I do like using the Molly Rings not all the standard kit parts are excellent. Yes there are many advantages to using the big log heads from 1977 up with their larger intake valves and larger ports and logs and more, the best of them by a small margin is the latest ones 1980 to 83. I will add more to this later tonight of some more you can easy things you could do to maximize its power within a low budget.

 

[chad]

I'd slo a bit till that post-TC kit and a re-compression assessment. The head may not even need off (1 - 3 in #9 post above - no need, etc).
"...continue to plan it out..."
Indeed
1 thing at a time, 1st things 1st, etc.

 

[B RON CO]

Hi, I am wondering what exactly you are looking to fix. Are there any symptoms like lack of power, stumbling, maybe it won't rev up, etc?
What plugs are you running? I don't know why you are getting the small flecks on the center electrode. I wonder if the plugs are too hot, or you have too much timing advance.
I would like to see the engine running with a vacuum gauge hooked up, as well as a new compression test. These two tests tell a lot about the condition of the engine, but nothing about worn bearings, wrist pin and rod knocks
I would not be in a big hurry to get a rebuild kit. If you rebuild the engine, ie rings and bearings with a new cam most of the time the top of the block is not decked.
If you are planning on a rebuild I recommend Tom Monroe's book How to Rebuild Small Block Fords. There is a lot of info on how to check and measure the parts, and what to expect from a machine shop.
Good luck

 

[wsa111]

If you have aluminum specs on your plugs you have too timing or a very lean A/F mixture causing detonation.

 

[bubba22349]

With rebuilding the log head there are procedures that can increase the power output. Such as a good 3 angle or Serdi radius type valve job, along with the back cutting of the intakes and even putting a small radius on the edge of the exhaust valves too. On porting the biggest bang for the buck is doing the valve bowls, and since we can't reach much further up into the intake ports on the log heads. This is were the later model 1977 up log heads really help by having bigger intake ports, bigger intake valves already and their larger log all working togeather to help the engine to breathe better. They also have the larger carb mounting hole going into the log again giving much better breathing then the early heads even if you ported them. You can also go with a still bigger intake valve like a 1.820 or bigger and a 1.50 exhaust which helps too. You can add the center exhaust port divider that helps with flow and cuts out some the heat that would heading up into the carb bowl, full porting of the exhaust ports would help the flow too. About the only drawback to these late heads is the bigger combustion chambers dropping the CR down from your current 8.7 to 1, so that's why they get milled down to bring back up the compression ratio. In your area of SoCal a 9.0 to 9.2 to 1 would work well and still allow you to run on Reg 87 or if you wanted to use 89 or 93 then you could use more copression yet. Below is a 1982 200 short block and head combo that I have been working out the specs on lately to get to a 9.2 to CR might give you an idea or two on building yours up. It's also going with the new 264 / 264 cam grind.

Estimated Head CC.'s Needed
In this below short block example the rebuilt 1982 head is now at 60 CC's and needs to end up with a 53 CC Combustion Chamber to get to a desired 9.2 to 1 CR looks like about another .035 mill cut is whats needed to remove 7 CC's more.

Short Block
I am estimating a .035 deck milling amount based on what has been found to be an average for the 1963 1/3 to 1968 200 six short blocks the trouble with this is the block decks can very just like the head chambers some are thicker than others until we measure we won't know. Or we would need to assemble the engine with the new pistons first before doing any deck milling. The Stock Ford 200 dished piston on average is - .019 down the hole from the block deck surface, plus the stock 200 Ford piston has a 1.511 compression height (CH) i.e. the center of the piston pin to the top of the piston. Together with the stock steel shim head gasket these early 200 six'es were right in the sweet spot for quench distance on a NA engine at .041 (.035 to .050) or we could go another .006 (Pistons + .011 out the hole) on the milling and adjust the heads CC's to compinsate.

The stock CR for a 1982 200 Six is even lower at 8.6 to 1. The block is getting bored to .020 over the new cast replacement Pistons with 6.5 CC's dish (or a flattop piston could be used for less deck milling). The new replacement Pistons have a CH of 1.500 so that's another - .011 that the Pistons are going down the hole for a total of - .030. To get to 9,2 to CR we want the piston setting at + .005 above the blocks deck surface using a Victor Renz head gasket .046 thick making an estimated mill cut needed of .035. With this combo of 6.5 CC's dished pistions, the block milled .035, and the Victor head Gasket it now puts us right back in the .041 quench distance of those early 200's. You could be much more exact if you knew by first measuring what the piston to deck height is for the short block after you remove the head and before disassembling the short block. To do this better and faster always measure the block deck height accurately (down the hole) of both the #1 and #6 cylinders at exact TDC.

Also Check out the posts by Bones92 goes into some very good details of a very low budget Overhaul not a 200 but the principals are still the same. https://fordsix.com/threads/budget-rebuild-rehab.80834/

 

[MustangDadDrake]

Hey guys, thanks for all the replies and sorry for the delay. Bubba thanks for all the great information I will use this when the time comes, really great stuff as always. I am not necessarily trying to fix anything, I just want to be confident that my engine is running well.

I ran the compression test today and did a tune with a vacuum gauge.

My vacuum reading is at a steady 18. The specs were still on my plugs and it is not running hot and it is running cold as the temp sensor always stays low, and when i put a thermal gun to the engine it never got over 150, i plan to replace the thermostat and see if that changes things.

My dry results:
1:135
2:145
3:130
4:147.5
5:145
6:137.5

Wet results (second # is the second test because the numbers were off, i think i put too much oil in the cylinder to get that high of numbers, not sure...)

1: 137.5/180 (add too little oil first time???)
2: 160
3:180
4: 260/215
5:210
6:175

Quite large jumps with the oil added, thinking i added too much because 260 and 210 don't really make sense to me.

 

[drag-200stang]

Do not over do that oil thing, your at 2,765.36 pounds of load on your rod at 260 psi.

 

[MustangDadDrake]

Alright, yea I won’t any more ha. I think luckily my engine survived. I took it out for a drive this morning and was about normal.

 

[Econoline]

Was the engine up to temp, all plugs out, throttle wide open when you performed the tests? 150 degree engine temp isn't going to help anything, fix that for sure.

 

[MustangDadDrake]

Yea engine was warmed up and plugs out. I did not check the throttle.

Edited to include some photos of the spark plugs and vacuum gauge.