Can a top end rebuild be done on a 2.7?
 

Well I have been lurking here for awhile and the compression tests and leakdown tests that I have performed so far are pointing to a top end rebuild. (125K on odometer) But I have a few questions and dilemias. Money is kind of tight and I could afford to do the top end but not the entire rebuild right now. So maybee a few of you 2.7 owners could chime ind and give some advice.
1. I believe that I have alumisil cylinders. I pulled the bottom oil screen off and peaked into the cylinder and I found a grey materiel similiar to a primer color on my cylinders. I have ok compression right now 120-13o PSI so could I just scotchbrite and re ring?
2. The infamous head studs. So Far I do not believe that I have any pulled studs. MY car is a Ca car and it has been updated with the 11 blade and ssi headers. From what I gather by removing the heads and cylinders I will be messing around with the head studs to much and unless I put case savers in they will pull within the next 10 K miles after a top end??? Is this true? I dont have the money right now for all of the maching work on the bottom end along with the new head studs etc etc etc.
3. Should I just remove and ebuild the heads and leave the cylinders on??

Any advice and thoughts and advice would be appreciated.

You can't count on success with only a top end. The headstuds will probably pull shortly after you finish the rebuild. I would either do a complete job or get another engine.

-Andy

Thats what I was afraid of. Its kind of a bummer. As far as I can Tell my bottom end is still good. Good oil pressure, no bottom end or piston knocks, all I really need to do is the valve guides, It seems as if a $600 DIY job is going to turn into a 5k rebuild. I wish that there were a jig that would allow the time serts to be drilled and installed without having to split the cases.

Are you sure that the case savers have not already been installed? With the alt/fan out I believe that you can see the ends of the studs it a mirror and a flashlight.
The first Porsche shop that I worked at did a case saver job without splitting the case on a drill press with a stack of boards to support the engine. I really wouldn't recommend it. There were a lot of metal shavings inside the engine, the boss thought that we got MOST of them out.
I didn't work there very long, most of what I learned there was how NOT to do things.

I like the idea of removing the fan. So let me see if I understand this. Take the alt fan off and inspect the stud holes in the case.; If there are no case savers etc I would expect that the stud threads to be completely flush with the outside diameter of the stud hole. With case savers since they drill the hole oversize before installing the insert, there should be a small gap between the case and the stud, I would think about enough to slide a dental toothpick into, unless the inserts are flush with the deck?

It will not take your imagination....you will see them.
On the plus side if you do it it will be done right...
May be some one ha done it all ready ?? ??
Mat be I missed it what are you comp. readings, I would be more concerned with them then a leak dwn test................mo

The comp readings are what has me thinking that it may be time for a rebuild. I did three different compression readings. Remember that the car sat for a number of years without being driven, in very moist air by the ocean. The first go around after I got the car running on a 24 hour stone cold motor with outside temp around 55 and at 1400 feet of elevation: three were in the 120-130 range and three were in the 105-110 range. Then I did a valve adjustment and did another cold compression test with the same results. After doing a few searches I found an article in the FAQ section, "is it time to rebuild". At the end of the section it talks about carbon build up and expansion of the cabon with moist air. So I did a leak down test on my suspect cylinders, once again on a stone cold motor, and I was in the 75% leak down. The next thing that I did was the carbon removal via the suction side off of the distributor. I used sea foam and followed the instructions on the can. After the car was warmed up to around 175 I did a compression test on my bad cylinders and found then to be in the 120-130 range. I did not do a leak down yet as I have been trying to find a clapping sound that is coming from cylinder#1.
So correct me if I am wrong but I feel that cold compression is very important as, cold compression is what starts a car. I do understand that the rings will expand as the metal heats up.And when the car is hot it will run to its full efficiency.

Does it smoke on start up? At WOT? Does it run well? What are the leakdown readings now?

Is it power?

HMM cold comp is valid only for a cold eng. and no, you want comp with eng. warmed up

The smoke at start up is almost nothing. A quick puff and then nothing. I really have to look for it. It almsot seems more like a quick mist rather than a smoke (I also have a 2.2 that smokes on startup). I am waiting on the tools from pelican parts to remove the valve springs. I suspect that I may have a broken spring on the #1 cylinder. After I get the noisefixed I will do another decorbinizing treatment with the GM top end stuff. Then I will do a warm compression test and leakdown test.

Personally,,,if that is the only thing wrong I would let it ride out for awhile,
A Friend of mine buys and sells airplanes,,,recently he picked one up with lots of comp loss ( not valve ) he ran it for awhile couple a months ,,,,all evened out !!!!!

I would be concerned about that noise without looking to jump into a rebuild. It makes sense to find the noise first. Do you know headwork? Even the experts on PP take their heads (intact) to a speacialist who dismantles/refurbishes them (all six). I commend you if you do the work and get it running smooth and not smoke.

I would be curious what a wrench would say about yhis project (ie best case-one bad spring-would they think it is doable?).

Even writing this, the best advice would be to rebuild it. Oops sorry -did I just waste 8k of your money?

Good luck.

Regards,

Still sitting here, in this rain waiting for the parts from pelican:confused::confused:

So what is the typical cost to have a magnesium 2.7 case "fixed" with case savers? Oil bypass modification? Anything else?

Wayne's book details the costs, but are those estimates real/current world?

Further, what are typical charges for the work recommended on the heads? New guides, anything else?

I don't see $8 or even 5K - but maybe I'm optomistic because I am tearing down my 2.7 right now.

Oil mod, line bore, cyl landings straitned out, new oil pomp,stud inserts, and some other options..dowl pin, ventilate,

I just recently had my '74 case re-worked for $1250. All necessary mods done to it.

who did it?

It is more $$ to do a mag case, but in the end it is 30 lbs lighter I am told....and in the long run it will cost just a grand more....the dwn side to it is the O.S. bearings will set you back a 400.00 bill......did mine a couple yrs ago. I might have gone with a AL case but they were very exp. then. Seems like they have come dwn in price......on the flip side all my numbers match up to the birth certificate so maybe thats worth a buck or to more..
For sure only send it out to some one that dose this on a regular basis and not Motor Masters

Jeff Hines. Very pleased with his work and customer service.