Ok.. It's head gasket time!

[Jeff K]

Ok, I recently posted about a cooling issue. I bought a tester and there is exhaust gas in the coolant. Head gasket time! I'm taking it to an engine shop next week for a verification. My engine has 70K miles.

My restoration replaced/refurbished pretty much everything in the fuel and cooling system.
The car was running perfectly until this happened. Cold start, warm start, idle etc. I felt it was 100% reliable.

I found this quide about it
http://www.dmcnews.com/Techsection/c...vereplace.html

Assuming this is correct.. some of my options are.

1) Replace it, call it a day.
2) Replace it, send the heads out to be reconditioned. (good shop near me other people on this board recommend) about 300 I think.
3) Replace it, get the hi-performance cams and get the heads reconditioned. (Which will also mean new exhaust... 2K )
4) Find a 3.0L 1990-1991 PRV and get EFI. (I've read a ton about this.. I know it's not a plug and play by any means.)

Then, it's the "while in there syndrome"

Do I do anything to the bottom end too?

I would like more HP of course, but it kills me to put so much money in my wheesy PRV.

Heck, a crate engine from summit racing is cheaper then tricking out my old tired PRV. Of course I do not have anywhere near the skill to fabricate like Nicholas did with his LS1 swap.

Suggestions from the Gurus?

Thanks
Jeff

[Josh]

Interested to see the responses. I would say a combination of #1 and #4. I was looking over the wiring last night and it isn't going to be too tricky, building a wiring diagram currently.

[Jeff K]

Interested to see the responses. I would say a combination of #1 and #4. I was looking over the wiring last night and it isn't going to be too tricky, building a wiring diagram currently.

Hey Josh. If this was year from now, I'd probably be following your guide (that is yet to be made). I'm leaning toward your idea myself. Fix it and swap it later. But.. I'm thinking if the swap might overwhelm me. I'm having a friend help.. he has many years experience. But then again, cams and the exhaust can probably be done in two weekends.. get 200hp and it back on the road soon.

Also, I guess you will need a better exhaust for the 3.0 swap too right? Would this be a DPI Spec 1 exhaust application? What do you plan on using?

[Josh]

Hey Josh. If this was year from now, I'd probably be following your guide (that is yet to be made). I'm leaning toward your idea myself. Fix it and swap it later. But.. I'm thinking if the swap might overwhelm me. I'm having a friend help.. he has many years experience. But then again, cams and the exhaust can probably be done in two weekends.. get 200hp and it back on the road soon.

Also, I guess you will need a better exhaust for the 3.0 swap too right? Would this be a DPI Spec 1 exhaust application? What do you plan on using?

There will be a guide. Just no word on when. My aim is to lay it all out (comprehensive), so it will be as underwhelming as possible.

You are exactly right, cams and exhaust (to compliment your new head gaskets) would all be installed by turning some wrenches. I noted you wanted to move away from K Jet so that is why you were thinking of going this route.

Any exhaust will bolt up that fits the original PRV in the Delorean. i plan to go F/I down the road so I am not going to be super picky with the exhaust, just something that is not stock or Special T. I have gotten most of my parts from DPI and would continue to buy from them for my exhaust. However my budget is not allowing for $2000 to be spent on exhaust at this time. Currently looking for a used setup. But that is off topic to this thread.

[David T]

It's all about the money. Your budget will determine your options. Doing the heads is the minimal option. From there it gets to better cams, better exhaust, Stage II engine, and on and on. My advice is to just get the heads cleaned up and replace the head gaskets. For the additional money you can spend you do not get all that much in improvement. That being said the Stage II is very nice! Doing the minimum you can spend under $1000 if it is all your labor, just gaskets, and grinding the heads flat with a clean-up valve job.
David Teitelbaum

[Ryan S.]

Jeff
mannnnnn... I am so sorry to hear that it's the head gasket. Makes me sick.

David,
What's a typical labor hours or cost for a basic head gasket work? PO replaced mine at 16k ml. What is a typical life expectancy of head gasket and what is primary reason or cause for such failure?

[DMCMW Dave]

Valves can be changed, but not the seats - the mating surface is milled directly into the head. Instead they get lapped, or resurfaced if you will. The machine shop can do it when they mill the heads, or you can try to do it by hand if you have the patience.

The seat are steel inserts.

[David T]

The seat are steel inserts.

Typically the guides are reworked (or replaced if necessary) and the valve seats reground with a "Three Angle" grind. The valves are then ground and then each valve gets lapped into it's seat. Rare that you would have to do any more than that but there are things you can do if the seats are too messed up to fix by grinding. If a valve is bent or burnt they are usually just replaced. That is also not common but does happen. Springs are checked for pressure and replaced if not within specified length and pressure. Again, not common but can happen. I like to lap in my own valves as a check on the machine shop. It is a time consuming task so it is expensive so some shops will skip it to save the customer some money. My time is cheap so I do it myself. All you need is a twiddle stick, some lapping compound a a lot of patience. And a spring compressor.
David Teitelbaum

[DMCMW Dave]

A severe overheat will cause the heads to expand and the exhaust valve seats will fall out, sticking the valves open. If you overheat an engine long enough this is what makes it finally stop running.