Well it looks like it may be time to tear my engine apart. McMark was kind enough to point out my lack of compression this weekend. It looks like I have about 110 lbs on 2 cylinders, and 120 on the other 2. The motor has 64,000 miles on it (original), but it did sit for 17 years in a garage by the ocean. A guess is that the cylinder walls have pitted. I am thinking about rebuilding the top end. I realize there are some who disagree with ever taking this approach, but being that the engine has relatively low miles I hope it will work out. If I do choose this method, what would you all suggest in the way of cylinders/pistons sets, etc. I am running the orig Djet, so would going with the 96mm setup still function properly? I'm not trying to stray too far from stock (or to spend too much $$$), but wouldn't mind a little extra power. Thanks for any advice.

Brian

Hi
Well if you are loosing compression it might be in the rings.
My sugestion is to drop the egine pull the heads and hone/rering, clean up heads.
A low miler, this should freshoin it up lots. Just the heads might work out OK but the gains are probably in the rings. Either do it right or drive it as is and wait for it to fall out.
Good luck with it
Cheers
Joe

QUOTE

Either do it right or drive it as is and wait for it to fall out.

What do you mean? All or nothing? When you say the rings may be bad, I assume the cylinder walls have to be honed or machined? Sorry, but all this is new to me. I'm still trying to understand the basic mechanics of it all.

Woops
Let me explane myself better. I am looking at a $ side of things, best bang for your buck.
A head job is XXXX$ with heads off to do the rings is just X$ more, but its guarenteed you are right in specs. I am worried you go through all the trouble of tearing down the heads and after find no great compression gain or power.
When you change the rings, you have to hone the cylinders...by a tool or take them to a machine shop. I realy don't know how motor friendly you are, this might not be the easiest thing to do, but the same logic applies if your paying someone, pay a little more and have the ring/cylinders renewed.
Did I help or make it worse ?
Cheers
Joe

You will have to modify the stock D-jet to get it to work with the 1911cc displacement (96mm P&Cs). The 96es that fit 1.7 heads are also pretty thin, and don't seem to last very well. So it might be a good idea to either swap to 1.8 heads, or to have the "registers" in the 1.7 heads flycut to fit the heads to fit the 1.8 version of the big-bore kit.

--DD

If it's got 64k miles with no rebuild, it's probably going to need valve guides too. If you don't do it now, you'll do it within the next 10k miles.

My recommendation would be to do a top end rebuild, providing the bottom end is solid. Get the heads done correctly. Replace all seals. New rod bearings, rebush the small end of the rods, Euro P & C's if you can afford it. This would probably take you to at least the 100k mile mark, or more.

If you want to cheap out on it, get the cylinders honed, new rings, replace whatever seals you can afford that don't come with the engine gasket set. This will buy you around six to ten thousand miles.

It all depends on how many times you want to do it.

Either way you will run into some ALA's (As Long As). Like repack the CV's, trans output flange seals, any exhaust issues, and fuel line/pump/filtration/tank issues, rear brakes, painting all sorts of stuff, engine bay seals, blah blah blah

QUOTE

Either way you will run into some ALA's (As Long As). Like repack the CV's, trans output flange seals, any exhaust issues, and fuel line/pump/filtration/tank issues, rear brakes, painting all sorts of stuff, engine bay seals, blah blah blah

Luckily I've done most of that! I will definately be attending to the surface rust in the engine bay though. I want to do as complete a top end rebuild as possible, so I will definately look into the valve guides.

Dave:

QUOTE

You will have to modify the stock D-jet to get it to work with the 1911cc displacement (96mm P&Cs). The 96es that fit 1.7 heads are also pretty thin, and don't seem to last very well. So it might be a good idea to either swap to 1.8 heads, or to have the "registers" in the 1.7 heads flycut to fit the heads to fit the 1.8 version of the big-bore kit.

I'm not sure I follow. This is a stock 2.0. If I go with the 96mm cylinders won't I have 2056cc of displacement?

Brian

Sorry, there. For some reason I thought you had a 1.7, not a 2.0. Oops! You are correct, 96mm bore x 71mm stroke gives you 2056cc of displacement.

You will still have tinkering to do with the D-jet; if you're ready for that then go ahead. If not, then stay with the stock displacement (and cam!!) and just bump up the compression. About 8.5:1 should still work with what passes for "super" grade fuel around here.

--DD

Dave,

Are you saying that if I go with stock euro pistons, that I need to run different fuel?

So what is the real advantage in the 96mm? What is the approximate payoff for the additional displacement? Will either of these options shorten the life of my engine? And while I'm in the question asking mood , how many miles do these engines normally last?

Parroting what I already said in the PP Board:

Won't you even try starting the engine first before considering a rebuild, and all the $$$ that will entail? I mean, it's only got 64K on it; the engine might not be as bad as you think. Mind you, this is assuming that it's still in the car (you didn't indicate otherwise).

Me? I would:

• Do an oil change
  
• Get a fresh battery on-board
  
• Flush out the fuel lines & install new fuel filter
  
• Have some new spark plugs in-hand
  
• New air filter
  
• Purge & bleed the brakes
  

After doing all the above (and whatever else others might suggest), remove the old plugs and crank the starter to get the oil circulating & pressure to build up in the block. By then the fuel pump should have pressurized the FI system.

Now comes the Act of Faith: install the plugs (please, DON'T cross-thread them, or you'll be in a world-o-hurt) and wires, whisper a short, reverant prayer, and give her a crank. I've seen garage queens that have sat longer bark, pop, and shake themselves to life, none the worst for wear.

Again, only if it were me ...

yes, yes and yes.

higher compression (can) mean higher grade fuel. i run 9:1 on my engine and i run 91 gas. i'm sure i would get away with 89, but i've never tried.

going to a 2056 with euro P&C will give you more HP, even with the stock D-Jet. you'll need to fiddle a little bit with a few components, like the MPS, but it has been done before.
ask Geoff for advice, he's running a 2056 with stock D-Jet ...
and Lyressa is running the same setup as well.

as long as the heads turn out to be ok, a top end rebuild (new P&C) is easy and affordeable.
if the heads are cracked, you'll have to fork out more $$$ for machine work.

all in all, i vote for the top end rebuild with the 96mm euro P&C.
same price, more HP!

Andy

PS: did you find that vaccuum leak?

QUOTE (Rouser @ Mar 14 2005, 05:41 PM)

Won't you even try starting the engine first before considering a rebuild, and all the $$$ that will entail?

he's driving it. i saw the car (and the engine), both are in good condition. the engine sounded good, small vaccuum leak somewhere, but other than that ran just fine ...

obviously, i didn't do a compression check tho.
Andy

QUOTE

Me? I would: Do an oil change Get a fresh battery on-board Flush out the fuel lines & install new fuel filter Have some new spark plugs in-hand New air filter Purge & bleed the brakes

Done, done, done, and done. I spent the better part of the summer on the things you've mentioned and more. It's been on the road since late september or so. Not that it's running that poorly, it's just that I want it to run great. You're right though, I could probably continue driving for some time "as is"

QUOTE

going to a 2056 with euro P&C will give you more HP, even with the stock D-Jet. you'll need to fiddle a little bit with a few components, like the MPS, but it has been done before. ask Geoff for advice, he's running a 2056 with stock D-Jet ... and Lyressa is running the same setup as well. as long as the heads turn out to be ok, a top end rebuild (new P&C) is easy and affordeable. if the heads are cracked, you'll have to fork out more $$$ for machine work. all in all, i vote for the top end rebuild with the 96mm euro P&C. same price, more HP!

Thanks once again Andy! The 96mm does seem to be the way to go. Do you know what the HP difference is??? I have a feeling my heads will be good. BTW, I took your advice and removed the brain and scraped out and de-rusted the "hell hole" As I suspected good metal under a little surface rust . When I pull the engine for the top end job, I was planning on adressing the greater surface rust issue in the engine bay. Do you think por15 in there would look like bad? I was also thinking I would take out that fire mat stuff. I've heard it does little good anyway. And about that engine life...

I'm running a 2056 with #73 webcam and 8.2:1 compression. Believe it or not, it runs great on regular gas (I was surprised as I expected to need mid-grade). I think this combo is worth about 15hp over stock.

Demick

QUOTE

I'm running a 2056 with #73 webcam and 8.2:1 compression. Believe it or not, it runs great on regular gas (I was surprised as I expected to need mid-grade). I think this combo is worth about 15hp over stock. Demick

Are you running carbs or FI? I'm planning on maintaining my Djet setup. If you're running Djet, how much tweaking did it require to get it dialed in? Thanks.

I think that the #73 webcam is tuned for FI, but I'm not sure.

I have a split duration version of a web 73 that works very well for stock FI with a stock or 96mm bore and around 8-8.5:1 CR.

The straight pattern web 73 works ok, but having a dual pattern cam with the TIV head is the first step at making bigger power with cooler temps.

Going to a cam with a tad more duration and lift will cool the heads off (as much as 50 degrees) and will really help with down low and midrange power. I have seen improvements with gas mileage as well.

Jake (or anybody reading), what is the easiest way to increase compression without increasing displacement (ie: boring out)? I'm kinda confused with this subject.

QUOTE

have a split duration version of a web 73 that works very well for stock FI with a stock or 96mm bore and around 8-8.5:1 CR. The straight pattern web 73 works ok, but having a dual pattern cam with the TIV head is the first step at making bigger power with cooler temps. Going to a cam with a tad more duration and lift will cool the heads off (as much as 50 degrees) and will really help with down low and midrange power. I have seen improvements with gas mileage as well.

How much more involved is it to change the cam if I'm already doing the cyl/pist, etc.?? I have never messed with this stuff before, so it is all new to me. BTW, from some of your previous posts I get the feeling you are against the top end job altogether.

QUOTE (BPGREER @ Mar 14 2005, 06:42 PM)

Are you running carbs or FI? I'm planning on maintaining my Djet setup. If you're running Djet, how much tweaking did it require to get it dialed in? Thanks.

I'm running d-jet. I did have to do some adjustments to the MPS. I used a wideband O2 sensor to take readings and make adjustments accordingly.

You'll have to split the case to change the cam. If you go that route - use Jake's split duration cam.

Demick

Ok, heres my pennies worth( don't have 2 cents today). 110 and 120 ain't great, but ain't that bad either. Depending on driving habits, frequency of oil change and valve adjustement, proper dwell and timing, and properly tuned d-jet, you could get another 10,000 or another 50,000 miles from your engine. You'll never know till you do it. Your 2 liter should be good for at least 100K!! If you really want a bigger engine, find a 2.0L core, take the time and build it right, while driving and enjoying your car, (after all, thats what they are about). Then take a weekend and swap motors.

That said, The 96mm's is where I go next, with stock d-jet(except with an mps tweak).

There are different opinions about a top end rebuild, Some say ,loose bottom, tight top. Others disagree. If you do a top end only, go from the rod bearings up. It takes very little more time and money to replace rod bearings, when doing a top end.

QUOTE (vsg914 @ Mar 14 2005, 07:51 PM)

Ok, heres my pennies worth( don't have 2 cents today). 110 and 120 ain't great, but ain't that bad either. Depending on driving habits, frequency of oil change and valve adjustement, proper dwell and timing, and properly tuned d-jet, you could get another 10,000 or another 50,000 miles from your engine.

It just depends on what you tolerance is for "problems". As it ages your engine starts going down on power and starts running a bit "funny". How long you want to live with that depends on the person. I agree that 110 or 120 psi isn't a severe case. But it is about a 25% loss in compression. You can take that engine to it's bloody edge, or you can rebuild it and bring it back to life. Factor into that the increased chance for catastrophic failure as the engine ages and engines at this point are really starting to enter the "rebuilt-it" territory, IMHO.

Just drive the damn thing!

to get back to the orginal post, i would do more tests, like a leak down test, the compression is really not that unreasononable, i've have worse. the leak down will tell where the problem is. you said 110/120, what is #1,#2 #3 #4?

QUOTE (jd74914 @ Mar 14 2005, 07:06 PM)

Jake (or anybody reading), what is the easiest way to increase compression without increasing displacement (ie: boring out)? I'm kinda confused with this subject.

Flycut the heads. You don't want to go more than 9.5/1 for FI though.

QUOTE (Triaddave @ Mar 14 2005, 08:34 PM)

to get back to the orginal post, i would do more tests, like a leak down test, the compression is really not that unreasononable, i've have worse. the leak down will tell where the problem is. you said 110/120, what is #1,#2 #3 #4?

How does it run and feel?

Another general barometer is oil consumption. If you use more than a quart every six hundred miles, it's rebuild time.

dude, drive your car until the engine won't go any more. not driving your car SUCKS. if you can, build another engine while you drive the snot out of that one.

QUOTE

How does it run and feel? Another general barometer is oil consumption. If you use more than a quart every six hundred miles, it's rebuild time.

It's difficult to say how it drives, as I have nothing to compare it to. This is the only 914 I have driven. I would have guessed the car to have more "pep" than it does. If it leaks any oil, it is a tiny quantity, because I have never seen a drop on the floor where its parked. The oil does however get very dark, very quickly. Like say 500 miles after an oil change. What I am concerned with is letting it go, and setting myself up for an avoidable major failure. I agree with vsg914, that properly rebuilding another one while running this one, would be the best way to go. However, that seems like a much more expensive proposition, if a top end job would be pretty sufficient. Brad drove it a few months back and said "yep, it drives like a stock 2 liter motor with 64,000 miles on it." I'm not sure if that was a positive or negative comment. I didn't give it too much thought at the time, and don't want to bother him now. I will definatly give some thought to all options, they are very much appreciated. If there were only one answer things would be boring.

QUOTE

dude, drive your car until the engine won't go any more. not driving your car SUCKS. if you can, build another engine while you drive the snot out of that one.

Maybe you're right. If I spend the time trying to make it perfect, it may never see any of the wonderful windy roads out there. This option is starting to sound good. Wait a minute!...are you the guy that used to talk me into ditching classes? Thanks alot man, I could have been a doctor by now and bought a real porsche.

QUOTE (Jake Raby @ Mar 14 2005, 07:00 PM)

I have a split duration version of a web 73 that works very well for stock FI with a stock or 96mm bore and around 8-8.5:1 CR. The straight pattern web 73 works ok, but having a dual pattern cam with the TIV head is the first step at making bigger power with cooler temps. Going to a cam with a tad more duration and lift will cool the heads off (as much as 50 degrees) and will really help with down low and midrange power. I have seen improvements with gas mileage as well.

Interesting point Jake. One of the first things I have noticed is cooler running temps. My gauge barely gets to 1/4 in a half hour of running. It was up to 1/2 prior to the rebuild.

Thats due to increased efficiency... EVERYTHING follows efficiency and the camshaft is the start of the snowball in that category!

You should see what happens to a head temp gauge when just a couple of changes to the combo are made...

FYI- My 3 liter engine runs head temps of 275 degrees and only has FOUR cooling fins on the heads! I finally got the oil to 230 degrees yesterday... With Synthetic oil it won't go over 215...

Thats 195HP at the rear wheels fellas... 230 at the flywhel on pump gas!