I did a compression test, these are the results:

1 130
2 125
3 100
4 95

5 130
6 125
7 120
8 30

I don't know if I numbered them correctly, I started on the drivers front with #1, passenger front is #5.

Is the fact that the rear cylinders low related to the oil issues? My gauge doesn't have numbers, but the pressure is always fairly high on the guage.

So, what's my next step? I haven't wet tested #8, I'll do that as soon as I can figure out what to use to squirt some oil in there with.

Should I move to a leakdown test next? I eventually want to rebuild the engine, but wasn't quite ready yet. Should I go ahead and pull the valve covers?

I have a weiand action plus intake that I haven't put on yet, and I wanted to get a timing kit for it. If I did that and got tmeyers pistons and had the cylinders bored (if they need it), and had the valves checked and fixed, would I run into problems with anything else? Oh, guess I might as well upgrade the cam to, lol.

Really my main goal is to get it running for hunting season, but if I could do all the stuff above without too many problems I may go ahead.

Oh, 79 f150 4x4 400 w/factory air

thanks in advance!

 

I put a little oil in #8, got 40 psi. I didn't put much in, I used an antifreeze tester filled about half way up.

 

not looking good. Really shot rings or a valve? does it blow much smoke?

 

gonna need to pull some heads and work the engine. its not gonna get any better!

 

no, it doesn't smoke. No white smoke at least, maybe a little black. When there is snow on the ground it spits out black liquid. Well, probably all the time, but you can see it on snow.

What all do you mean by "work the engine"?

I have a bunch of questions, but I think I asked too many to begin with. Maybe better luck with a list.

1. What is the next step?

2. If I get new pistons from tmeyer (kb2347 9.3 cr), straight up timing, mild cam (rv?), and weiand action plus intake, and have the valves fixed, will I blow something else up? Would I need to upgrade any other components?

3. Can I have the engine bored .30 over and just get bigger rings to go on tmeyers pistons? I would only do this if it needs to be bored.

4. If the main problem is the valves, about how much does it cost to have them repaired or replaced? Do you need special tools or equipment to do this?

 

See my comments beside your questions.


Work the engine means recondition/rebuild.


1. What is the next step? Take off heads for a look.

2. If I get new pistons from tmeyer (kb2347 9.3 cr), straight up timing, mild cam (rv?), and weiand action plus intake, and have the valves fixed, will I blow something else up? Would I need to upgrade any other components? Not much left, maybe waterpump and balancer

3. Can I have the engine bored .30 over and just get bigger rings to go on tmeyers pistons? I would only do this if it needs to be bored.- You need to get the pistons to suit the rebore. Ideally the workshop should be able to measure how much needs to be taken out to clean it up before machining so they can have the pistons for final measurement.

4. If the main problem is the valves, about how much does it cost to have them repaired or replaced? Do you need special tools or equipment to do this?
you would need at least some form of spring compressor to remove /replace the valves. There are valve guides and valve seats that need a machine shop to repair if faulty so you cant do that your self. In a rough world if you had an identical valve to suit a failed one and the seat/guide was ok you could cheat and relap the replacement valve. This would be a get out of jail card and definitely not the performance option, but a relatively realistic thing to do to keep it running until later. Cant help with costs to fix heads as I am in Australia. Some of the US guys should be able to help there. Hope this helps.

 

You need to take it a machine shop and just have them rebuild it to your specs. New bearings, possible turning crank, and the head work is best left to a professional. Don't know when your hunting season starts, but should have it done before then. Things are slow around here and very little, if any, backlog.

 

How much would all of that cost?

 

Would I create more problems if I kept running it the way it is?

 

Depends on why you felt the need to compression test it in the first place. What was it doing or were you just interested? Can you afford a rebuild? (who ever can??) and if not how long before you can? Does it still do what you require? I put a new cam, lifters and heads on mine and it went better, but all the better go seemed to highlight a low oil pressure and when I rebuilt the bloody thing it needed a +030 bore just to clean it up and the pistons were standard! No hint of blow by though, but it was a lot easier to turn over before I rebuilt it than after (which was a good thing).

 

I just did it because it didn't have much power and uses a lot of gas. If it will just continue to be powerless but not cause more damage I'll probably just wait until January when hunting season is over. I mostly just use it to hunt and the occasional trip to home depot or the scrap yard.

I'd love it if it had 800 hp, but I can live with 170 since I really don't drive it much.

If I can put it off til after hunting season I can really go through it and do it right. Right now I don't have much time and I haven't put any money aside for it, so I'd really need to do the minimum to get it running.

I was planning on building a shop in the next month or two, but we found out we're pregnant, so I'm putting that on hold for a while. The main purpose of it was to be able to tear the truck apart and have room to work on it at my leisure, where my wife couldn't see it, lol.

Thanks for the help.

 

good luck with the family. Thats a tough one choosing over hunting or doing up the truck. I like both. It's the same old story, money! By the way it probably only has a portion of that 170hp you referred to if it's that bad. Try to put some money aside and don't thrash it too much. What do you hunt?

 

Not sure about stock rebuild of head but worst case scenerio is about $500 or less on head rebuild. If everything is decent and just a few valves should be around 300 bucks. congrats on the little one on the way. no one can really prepare for pregnancy. congrats and good luck.

 

Thanks! We're pretty excited. She got pregnant last year but had a miscarriage and has had a really hard time with it. Now she just traded sadness for all day "morning sickness". We're taking that as a good sign though.


Wow, I thought I was being funny. I knew it was low, but not that low!


I mainly bowhunt for deer, but I'm open to just about anything. My dream hunt is bowhunting for elk.

Is that per head or for both? How much is a set of aftermarket heads?

 

170hp is the SAE rating which I believe is with every drive i.e.powersteering, alternator etc, loaded up on the motor to get its rating. This accounts for a big drop in the early 70's when they changed how they measured it. The motor didn't change much at all and was originally in the mid 200's. Never done Bowhunting. Shot at (and missed some of them) a few deer when I lived in New zealand along with Ducks rabbits and possums but all with rifles, shotguns etc. All the best.