hi guys
what are some thoughts on replacing the cylinder heads on a 1984 3.8 6 cylinder. im going to have to do the head gakets. i put some steel seal head gasket repair stuff in back sometime ago and it held up for awhile but now im having problems again. the car isnt blowing it out the back , but out of the radiator . sometimes the back pressure sounds like a tea kettle. any way whats the thoughts on replacing the heads too, just to be sure . i saw a link on eric's cool cats for a place in florida for brand new ones .
i kinda dont want to do this and pay someone , but i know its going be big bucks. i did do head gaskets on my 1989 continental and i guess if i did that one , this one has to be way easier.
thanks
eddie
I would'nt get new heads. I worked at a machine shop for about five years and I've only seen a 3.8 head crack once, it was a carbed head. I would just have the heads that you have pressure checked and milled. They're a most likely fine.
Just throwing info into the hat for the sake of argument...
The Clearwater Cylinder Heads on my '84 were brand new castings (I believe made in Mexico) and were fully assembled. They tested perfectly flat with a straight edge. There were absolutely no issues with them whatsoever and that's why I recommended them on the site.
My old heads ended up being cracked. There were hairline cracks that would have shown up had we gotten the heads Magnafluxed, but there wasn't a lot of time for a trip to the machine shop. We didn't know about the cracks until the head gaskets were replaced and everything was put back together...fired up the engine and water just poured out both sides of the motor just like a faucet. At that point I was sure glad that we didn't have the heads machined flat!
Sometimes you get lucky with a 3.8 head, sometimes you don't. After a rather slim selection at local salvage yards, I opted to try the CCH head and was extremely happy that I did. For the money it was the best solution for me.
Now...if you have access to a local machine shop and they can test them for you, that would be a good place to start. You'll know real soon whether or not to keep the existing heads. IF you need new ones, CCH is the way to go. IF not, you're all set.
And for what it's worth, I have a set of '88 3.8 heads that ARE good. The reason the engine is bad was a thrown rod. I'll have them tested even..someone may as well use them..I never will.
incase you were asking him, your 88 efi heads wont work on his 84 cfi motor.
I was about to say the same thing
2 more questions on this .... are there any heads available that will give this y 3.8 a little more power and if so would you even notice it? and is it possible to replace the aluminum heads with cast iron ??
thanks
eddie
They dont make cast iron heads for the 3.8.
Really with the CFI engine you are not going to get much more power out of it in that configuration. Also the cylinder heads tend to corrode around the water passage openings making them junk unless the machine shop will weld in new material and level it. If the machine shop finds that they are good you should keep the heads you have. It will save you money. The odds are that the valves are still good along with the guides and you'll only need seals and resurfacing if necessary.
I think over the years there were about 8-10 3.8 configurations, some with balance shafts, some without and various head and intake manifold configurations. I don't have a whole lot of experience with the different configurations but I understand the 91 and up Mustang 3.8s were real good. But then you'll have a lot of wiring issues if you were to install one of the Mustang EFI engines.
actually you're best bet is to just swap in a 88 engine if you're bent on keeping a 3.8. The wiring isn't actually that different and its definitely more powerful than the 87 and back. But, you can built a good strong and descently fast CFI. A few people here have done it.
or a simple top end swap. same eec should / will work fine imho. the rest is rather one step at at time like TB linkage, IAC connector and vac line routing.
you cant swap 87/88 top end. The blocks are different. 88 heads are longer b/c of the balance shaft in the 88 block.
thanks for the info ... i think im going go for new heads, i will decide when i get this apart.
does anyone have a write up or tips on how to do it? i think i can do it with , just taking it apart.
besides replacing the head gasket , i guess i shoulf replace to cfi gasket too and the exhaust intake too. about how long could this take to do ?
thanks
eddie
thats news to me and a lot of other people. what your saying is the 88 3.8 heads do not fit on the 87 and down blocks. the balance shaft has nothing to do with the heads.
click on my diy link below.
lots of cfi stuff in there.
you should buy the 3.8 head gasket kit which will come with all the gaskets you need for the top end.
You need to buy the CFI base plate gasket kit separate, adance has always sourced the best kit for this imho, ive done 3.
I will add that you will need to torque the heads down exactly as the book says, to stretch the bolts correctly... and you need new head bolts. You can't reuse them on a 3.8.
um....yeah....:dunce:
nm what I said. I was apparently thinking of a different time period or something. What I was thinking was that they stretched the block to make up for fitting the balance shaft in there. I think I was thinking of the timing cover wouldn't switch over or something...Idk nevermind ignore my goodyear blimp filling brain fart....
Ford had a LOT of problems with the 3.8 heads. Am original owenr and only driver of a 1984, 3.8 and had the engine rebuilt about 2 years ago at a "high end" rebuilder. After disassembly it appeared heads had been leaking for some time, yet car ran fine, just seemed to loose a little coolant about every 50 miles, but never showed on the ground, in the oil, or out the tailpipe.
FWIW, the lower corners of the heads near the bolts seem to be the major problem. Ford made the material to thin in this area and this is where they seem to crack. Rebuilder initially did head with graphite gaskets, but engine had some issues so redid with MLS and Irontite. So far holding but car only drives about 200 miles at month at 50 miles roundtrip.
Re: Clearwater Cylinder Heads, in my discussion with them, they do NOT have new heads, just reworked.
Search the web, there is a lot on these heads and their problems. IF I had to do over again, I'd s the 3.8.
naw, i get it.
The crank/rods/pistons direct swap into it from a 4.2L.
however, your mentioning the balance shaft is correct in that it is an extra part,,thats about it.
if the 4.2L stuff were swapped in, then the external harmonic would need groomed to fit the 4.2crank.
I know this has nothing to do with the original poster, but good info.
if the original poster was interested in it, the 4.2L bottom end internals could go in and the top end from an 88 3.8 could also go on, kind like a hybrid.
the CFI off a 5.0 could be found and used since the trottle body ports are much bigger, still a bottle neck at the intake but ,, but*** the larger throttle body ports come more closely to matching the intake runners in volume and size.
ANyone who has a CFI car, i tell them to pull the injector screens out, that will cure that "hesitation" we all use to feel when we first get on the gas.
theres so much hard work ive done on this engine, but in the end, i guess I "was" one of those kind of people that just had to learn by doing,, and not actually listening to the good advice i should have listened to so long ago. The engine itself never gave me a problem for over 300k miles but ended up getting a rebuild due to oil light flickering and my knowing it was a valid low oil pres issue.
I really like how simple the design is, its really just meant to be a CAFE compliant car.,,thats about it.
well i started the head gasket repairs today. got the intake off and some of the head bolts on the right side. just have to get the exhaust manifold off next. and then i can get the rest of the head bolts out. will the exhaust be hard to get to ? i didnt look that good at it yet. also one bolt on the intake the one nearest the front of the car was busted off inside the head. it looks like it has been that way awhile as it was like a little pile of dirt. i got some pics to post , im hoping the exhaust will not be to hard. so far this doesnt seem to bad to do .
thanks for listening
eddie
One other issue I'd check if you're not to far along with this.
I just found out my manifold has a porosity problem.
Leaking coolant on the front side where the temp sensor goes in.
Had to pressure test the system overnight to find it.
I'm amazed the amount of coolant that seeps out.
I'd have the intake tested and/or sealed before installing.
headers to Y pipe is not fun,, not fun at all as is the case with most exhaust bolts.
gut the cat while you have the car down. just undo the intermediate pipe,, gut the cat, step on the gas and let nature throw out the garbage.
the 3.8 needs all the help it can get.
good luck on the broke bolt, id make the best of it and just do without.
when you do get the headers off, or off to the side you may find it easier to line up the bolts with the Y pipe bolts loose when reinstalling the heads vs taking the headers off.
either way, Y pipe hardware needs loosened.
with the heads off, make sure to wire wheel the alignment dowel tube thingies that are water passages. Make sure to clean out the area they seat into on the block and the heads so that your head properly seats.
the last thing you want is these things keeping you from getting a good bond.
well i got the header bolts off the left side , and it was not easy. now i just have to get the pipe off underneath the car. it took me about 3 hours as most of the bolts needed PB blaster and some time to soak it up and i didnt want to strip them so i just kept tapping them . now i can get at the rest of the head bolts. it almost looks like you can undo the head bolts that are under the exhuast headers but you cant. im going to do the left side , and then the right side. more info to come.
The l/S was harder on the one I did,actually the exhaust is probably the hardest part of the job.