Time to rebuild, Opinions / Suggestions |
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Time to rebuild, Opinions / Suggestions |
BPGREER |
Mar 14 2005, 04:35 PM
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#1
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Member Group: Members Posts: 131 Joined: 29-September 04 From: SAN FRANCISCO Member No.: 2,857 |
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 |
MecGen |
Mar 14 2005, 05:14 PM
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#2
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8 Easy Steps Group: Members Posts: 848 Joined: 8-January 05 From: Laval, Canada Member No.: 3,421 |
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 (IMG:http://www.914world.com/bbs2/html/emoticons/beerchug.gif) |
BPGREER |
Mar 14 2005, 05:23 PM
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#3
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Member Group: Members Posts: 131 Joined: 29-September 04 From: SAN FRANCISCO Member No.: 2,857 |
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. (IMG:http://www.914world.com/bbs2/html/emoticons/wacko.gif) |
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MecGen |
Mar 14 2005, 05:34 PM
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#4
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8 Easy Steps Group: Members Posts: 848 Joined: 8-January 05 From: Laval, Canada Member No.: 3,421 |
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 (IMG:http://www.914world.com/bbs2/html/emoticons/beerchug.gif) |
Dave_Darling |
Mar 14 2005, 05:56 PM
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#5
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914 Idiot Group: Members Posts: 15,047 Joined: 9-January 03 From: Silicon Valley / Kailua-Kona Member No.: 121 Region Association: Northern California |
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 |
IronHillRestorations |
Mar 14 2005, 05:58 PM
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#6
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I. I. R. C. Group: Members Posts: 6,759 Joined: 18-March 03 From: West TN Member No.: 439 Region Association: None |
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 |
BPGREER |
Mar 14 2005, 07:23 PM
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#7
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Member Group: Members Posts: 131 Joined: 29-September 04 From: SAN FRANCISCO Member No.: 2,857 |
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:
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 |
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Dave_Darling |
Mar 14 2005, 07:26 PM
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#8
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914 Idiot Group: Members Posts: 15,047 Joined: 9-January 03 From: Silicon Valley / Kailua-Kona Member No.: 121 Region Association: Northern California |
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 |
BPGREER |
Mar 14 2005, 07:31 PM
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#9
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Member Group: Members Posts: 131 Joined: 29-September 04 From: SAN FRANCISCO Member No.: 2,857 |
Dave,
Are you saying that if I go with stock euro pistons, that I need to run different fuel? |
BPGREER |
Mar 14 2005, 07:33 PM
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#10
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Member Group: Members Posts: 131 Joined: 29-September 04 From: SAN FRANCISCO Member No.: 2,857 |
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 (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif) , how many miles do these engines normally last?
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Rouser |
Mar 14 2005, 07:41 PM
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#11
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Anti-Post Whore Group: Benefactors Posts: 597 Joined: 30-December 02 From: Citrus Park, Florida Member No.: 54 |
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:
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 ... |
SirAndy |
Mar 14 2005, 07:42 PM
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#12
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Resident German Group: Admin Posts: 41,806 Joined: 21-January 03 From: Oakland, Kalifornia Member No.: 179 Region Association: Northern California |
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! (IMG:http://www.914world.com/bbs2/html/emoticons/beerchug.gif) Andy PS: did you find that vaccuum leak? |
SirAndy |
Mar 14 2005, 07:45 PM
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#13
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Resident German Group: Admin Posts: 41,806 Joined: 21-January 03 From: Oakland, Kalifornia Member No.: 179 Region Association: Northern California |
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. (IMG:http://www.914world.com/bbs2/html/emoticons/cool.gif) Andy |
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BPGREER |
Mar 14 2005, 08:09 PM
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#14
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Member Group: Members Posts: 131 Joined: 29-September 04 From: SAN FRANCISCO Member No.: 2,857 |
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"
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 (IMG:http://www.914world.com/bbs2/html/emoticons/smilie_pokal.gif) . 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... |
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Demick |
Mar 14 2005, 08:34 PM
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#15
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Ernie made me do it! Group: Benefactors Posts: 2,312 Joined: 6-February 03 From: Pleasanton, CA Member No.: 257 |
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 |
BPGREER |
Mar 14 2005, 08:42 PM
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#16
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Member Group: Members Posts: 131 Joined: 29-September 04 From: SAN FRANCISCO Member No.: 2,857 |
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. |
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jd74914 |
Mar 14 2005, 08:48 PM
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#17
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Its alive Group: Members Posts: 4,795 Joined: 16-February 04 From: CT Member No.: 1,659 Region Association: North East States |
I think that the #73 webcam is tuned for FI, but I'm not sure.
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Jake Raby |
Mar 14 2005, 09:00 PM
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#18
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Engine Surgeon Group: Members Posts: 9,398 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
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. |
jd74914 |
Mar 14 2005, 09:06 PM
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#19
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Its alive Group: Members Posts: 4,795 Joined: 16-February 04 From: CT Member No.: 1,659 Region Association: North East States |
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.
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BPGREER |
Mar 14 2005, 09:20 PM
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#20
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Member Group: Members Posts: 131 Joined: 29-September 04 From: SAN FRANCISCO Member No.: 2,857 |
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. |
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