Foreign Car Valve Guide Replacement (Mitsubishi 4G64 SOHC 16V 2.4L 4 Cyl.)

I intend to learn about rebuilding a cylinder head. I have never rebuilt a head and there are things I will never understand without advice from someone who has rebuilt engines before. Also, my car is not a good beginning. It lacks popularity amongst builders and lacks industry support. Unfortunately for many engine specialists it’s also a common commuter car and so sadly they see them a lot.

I have a 2004 Dodge Stratus SXT with this engine -- Mitsubishi Sirius 4G64 SOHC 16V 2.4L 4 Cyl. 2,350cc. I have not removed the head from my car yet and it seems to work okay except I have had an engine oil sledge problem all around my engine just below the cylinder head. I plan to tackle numerous associated gaskets. However while I am at it I want to take out my cylinder head and if I have to replace it with a brand new head complete with internal components.

My main problem is with how I plan to remove and install the valve guides. Buying a new head should come with factory press in guides – this would solve the removal and install problem. But, I don’t own a shop (yet) and distributors usually don’t sell to non-wholesale buyers. I don’t know who sells a new bare aluminum head to retail customers.

If I can’t get a new head I have to remove guides. Choices are pounding them out with an air hammer and suitable removal tool or somehow drilling them out by hand. The old guides should be press in iron guides and the head is aluminum. Pounding the old guides should deform the guide bosses in the head. My factory service manual suggests using larger OD guides. But in the real world no one cares about selling guides of different sizes for some nameless engine. In my case should I pound them out?

What about drilling them out? Can I use some kit with valve seat alignment cones and hand drill?

What are core drill bits for? Are they ever used for removing guides?

This kit I am looking at is used with several valve seat alignment cones but comes with a reamer. If I am right I can’t use a reamer to remove the core of an old removable valve guide. How do I find a kit that uses the proper bit and cones? (Radiac Abrasives Carbide Boring Reamer Assembly #7389685 $120)

Ebay less than 300 bucks


you don't do guides on a worthless engine

Removal probably drill until paper thin


install:

Dry Ice

Oven

special purpose installation tool

hammer


Don't bother

If you are going to do this for a living, yo will find you make more money buying and sell a head already done

I believe it's sometimes necessary to heat up the whole head. There are also removal/installation tools. After you do the guides you need to do the valve seats. I'd be taking it to someone that had the right tools. Drilling and pounding isn't the best way. I've done this using shade-tree methods and you can get in over your head quickly, plus you've got 16 of the darn things to do.

edit- gustafson beat me to it!

gustafson said:

If you are going to do this for a living, yo will find you make more money buying and sell a head already done

Click to expand...

You would make a LOT more money with a hot dog cart

hello
I have been an engine builder / heavy eguipment mechanic for a lot of years and my advice is just buy a new head cheaper in the long run with a warranty, as far as making a career from engine machining those days are almost over according to the shop I use everybody is going crate engines nowadays, hope ai was some help

I'm afraid that my post won't help very much, but with "worthless" engines, you just might find a shop that will have the know-how somehow. I had a '98 VW Jetta with the 2.0L gas and I was looking to get it rebuilt. There was a place that specialized in heavy diesels. Cylinder heads five feet long laying on pallets and stuff like that. For some reason, they knew exactly what my engine was and had no problem getting pistons, valve guides, etc., and setting it up. If I were you, I would start calling around if there's no enthusiast support for your engine.

Larry Dickman said:

You would make a LOT more money with a hot dog cart

Click to expand...

The point is you are not doing your customers a favor charging them 500 bucks for a 200 dollar job

There are better more fruitful learning experiences out there.

Use a core drill, drill 3/4 of the way down from the chamber side, then use an air hammer to drive the guides out. By drilling them when you start pounding on them, they will stretch and get thinner, comming out easily without galling. You can recut the seats with Neway equipment without needing really expensive stuff. Take the valves to a rebuilder to have them refaced

First off, you don't know for sure if your guides are bad? Guide wear is somewhat uncommon on newer engines compared to "The good old days". I too am an engine rebuilder and the answers given above are true, it's a dying business in this throwaway world. When I remove iron guides I make sure to remove all the carbon from the port as that can ruin the guide hole when you push the guide out. I like to tap the hole on the spring side and screw a bolt in and push on that. Like someone said above, that stretches the guide and allows easier removal. I like to press the new guides in rather than beating them in with a hammer and punch. I make a support that goes against the valve seat and use an arbor press to push them in. I find you get a much better alignment between guide and seat that way. Everyone has their favorite way of doing things?

Why are you removing the head? The oil leak? Is it minor?
Moreover, what makes you think the guides need to be replaced? Just because it can be done?
All for yanking it apart but then comes the inspection of what needs to be touched and what should not.
Given the post the odds that you can do this and keep the factory alignment are slim to none. Very few experienced engine shops can do this with a 50-100,000 mile run time.
There are head rebuilders out there who take a core and give you another one in exchange for some money.

On the other hand I have hacked motors forever starting with a Elgin outboard in the 60's so I do get the "how can I do this?".
It's not straightforward, it is an art and like all artsy stuff you fail or make a works kinda part on the learning curve.

While I'd go outside on a stock head I do not mean to dissuade you too much. There is so much to be said for trying and learning.
Bob

If this car is a daily driver, why not buy a used head of Ebay or a engine recycling site, and rebuild that while you continue to run the beater? If/when you get the head done, you can do a "simple" swap. Do ensure the head's not warped, and make sure if it's been cut that you can re-time it via the cam drive pulley/sprocket.

From what we can understand of your current knowledge, I would not take a running (if imperfect) car down, who knows when it'll run again? And read as much as possible off enthusiast websites, ditto videos. I've been dinking around with cars for decades, still learning with every new vid or page I read.

I think you should seek out a good mechanic and pay him 50 bucks just to look at and give you advice.

Even with buying a brand new head you have to know how to install it. that takes some careful doing it exactly to the drill.

If you need this car for transportation you could find yourself in trouble.

likely the first thing I would do is check oil pressure / low oil pressure can be a sign the engine has not a very good life span left with not doing the whole thing top and bottom.

No way should you attempt this, you have no clue of what you're getting into. I say this with 41 years experience as an automotive machinist. There are so many things you don't know and so much equipment you don't have. Even if you get the guides in and out without destroying the head (unlikely), you can't finish the id's properly and certainly can't machine the valve seats. Sorry to sound harsh, but it's the reality of the situation.

I would think about "downtime". How long can you do without the car? How many miles on the engine? It is 15 years old. Your slobbering problem on the engine block could be something as simple as a headgasket or bonnet seal or cam seals. If the engine has a lot of miles, take the cylinder head to an automotive machine shop. They will check it for warp,pressure test, surface it if it isn't warped,do the guides and cut the valves and seats(concentric with respect to the guides). If the seats aren't perfectly concentric with the guides, you could lap your ass off, and never get a good seal. You might get away with knurling the guides, which usually gets you 40,000 mile service (if they are serviceable) and then you still have the seats to do, so...take the head to a machine shop or get an exchange head. If you want to learn something, go to a junkyard and get an aluminum head with iron guides and learn on that. Without the proper equipment you could end up spending a whole lot more than necessary and maybe doing the job over. Often times free advice is worth exactly what you pay for it. Hope this helps you make an informed decision. PB

SLO MO beat me to it!

Rock auto sells a head complete with cam for 500 bux.

Ive been a auto machinist for 50 years too......and when my Ford needed a gasket(at least),I just bought a new Chinese head from good supplier ,as mentioned complete with valves ,cam,etc......Even for a gasket job,you get the whole lot delivered while your car is still driving,there are no nasty surprises that make your old head scrap half way thru machining...........and (whisper),my head facing machine wont hold the flatness limit specified,or the finish.

When my Buick head went, bad oil in the coolant, I could spend money on getting it magnafluxed and checked for warp for about $100. Instead for $300 I bought a rebuilt head with valves installed. I think it had the cams installed as well.
i never learned if the head was cracked,warped or the head gasket blown. It did not look blown when removed. The quad 4 was known for warping and cracking.
Bill
D.

Thanks for taking the time to read my post and discuss the topic of rebuilding a cylinder head. I want to consider buying a new bare aluminum head. How do I obtain one if I am not a wholesale buyer?

I realize that even with new parts, including a bare head, you have to ensure the parts are within factory specifications. I will still take the necessary precautions. But where could I get a bare head?

There is a website for quantico cylinder heads and they sell one for $360. But, I don’t know if it is a real business or not. The address is for a uhaul self storage in texas. I have spoken to the salesman and he checked inventory and remarked they have 5 of these heads in stock. Some more info on the website shows a “stocker” from South Africa that manufactures cylinder heads.

I would have to ask before buying but it is likely a bare aluminum head comes with guides and valve seats. They would have been pressed in during manufacturing. If I can buy such a product I would then carefully measure and ensure tolerances, even though it is “brand new”.

As for the topic of servicing a used cylinder head I plan to wait until I am more prepared. The seats and guides are an expensive endeavor if you want to learn to do it with the proper tools and/or machines. With the right equipment I could rebuild cylinder heads whenever I needed to. But I’ll wait until I have the thousands of dollars worth of seat cutters, core drills, reamers, mitutoyo instruments.