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First Engine Rebuild - Decisions?

Old 11-20-2017, 03:38 AM
  #61  
Performance Developments
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Originally Posted by blade7 View Post
We are of the opinion, if you contain the crank flex at the front of the engine where the cams are driven, you control and hold the designed cam timing positions. Same can be said for the 944 engines. The recent engine we built for Patrick's WTA project included a damper incorporated into the cam drive system.
A high output 944 3.0 16v turbo build was well documented on here a couple of years ago. It was quite telling the crank specialist involved only polished the crank. Do you think the standard 3.0 S2 damper is adequate for an 8v 3.0 turbo road car?[/QUOTE]

I don't know.

Every engine is different. Some dampers are what could be called "wide band" and can help many engines, but I have no idea about the stock S2 damper. I guess you could say one is better than none, until something breaks. We did a high amount of development and testing with some extremely expensive equipment loaned to us by a company that travels the world doing this type of work for OEM's. From this testing we developed the 4 and 6 cylinder dampers.
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Old 11-20-2017, 03:42 AM
  #62  
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Originally Posted by Dave W. View Post
Have you considered a simple approach? see http://crank-scrapers.com/Porsche_944.html This will help keep the oil in the pan and reduce windage losses.
These would work if the oil was slung around by the crank. Unfortunately the crank swings around in mostly air and an oily mist as the oil is stacked up against the wall of the block where any scraper will do nothing to help. Great for making money to unsuspecting customers. Like selling tickets to look for the Lock Ness monster.
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Old 11-20-2017, 12:42 PM
  #63  
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Now I didn't design the crankcase scraper or have one yet, but I do see how it would help collect the "mist" and help decrease the aeration of oil. More so in a 2.5 block without windage ports.
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Old 11-20-2017, 11:13 PM
  #64  
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Originally Posted by Humboldtgrin View Post
Now I didn't design the crankcase scraper or have one yet, but I do see how it would help collect the "mist" and help decrease the aeration of oil. More so in a 2.5 block without windage ports.
Glad this is straight forward

But I do really appreciate everyone's input. I'm down the path of "if it can't hurt" then do it. A scraper can't hurt and my logic tells me it would provide some benefit. I assume the crank is picking up oil constantly and throwing it around the block. Knife edge will be a no go. I'll get a price and opinion for bull nose from my crank guy but most likely leave as is. Critical items are bigger oil cooler and oil temp gauge so I can keep an eye on things. I like the idea of doing windage (because the factory did it) but if it can't be done it will run fine without it. Like others have stated, maybe change the oil more frequently.

FWIW I already had the S2 damper on car. It did not have one originally but I put one on because engine had a lot of vibration compared to my 2.5. Many threads on this but it did not make any difference in vibration feel ( I didn't expect it too) But again thought...can't hurt.
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Old 11-21-2017, 12:04 PM
  #65  
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you might look into getting the RS barn damper.
specifically designed for the 3.0 engine, and more importantly NEW.
balancers with the rubber in them like the 944S/S2 units wear out...the 928 guys report incredible, noticeable differences in engine smoothness/vibration when fitting a NEW damper.
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Old 11-21-2017, 01:19 PM
  #66  
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The dampener has nothing to do with the vibration, the balance shafts do, maybe you had one balance shaft not keyed in correctly? The dampeners function is to help aid the crankshaft in not twisting when accelerating.
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Old 11-21-2017, 02:13 PM
  #67  
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Originally Posted by Performance Developments View Post
A high output 944 3.0 16v turbo build was well documented on here a couple of years ago. It was quite telling the crank specialist involved only polished the crank. Do you think the standard 3.0 S2 damper is adequate for an 8v 3.0 turbo road car?
I don't know.

Every engine is different. Some dampers are what could be called "wide band" and can help many engines, but I have no idea about the stock S2 damper. I guess you could say one is better than none, until something breaks. We did a high amount of development and testing with some extremely expensive equipment loaned to us by a company that travels the world doing this type of work for OEM's. From this testing we developed the 4 and 6 cylinder dampers.[/QUOTE]

Thank you for your reply. I guess Porsche had a reason for using that damper or a DMF on the larger capacity engines.
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Old 11-22-2017, 06:56 PM
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I have this oil pressure relief, did some searching but couldn't find answer.

Is there a way to check this or clean this?

No reason to think its not working but since I'm in hold mode. I didn't even know it existed until today.

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Old 01-15-2018, 10:31 PM
  #69  
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Not too much progress but I rebuilt the head. New seals, ground the valves and made sure everything is within spec, got the crank and rods back, After a few phone calls JE found a set of rings for me. Apparently the set that came with the pistons are no longer made but the found some alternatives. Waiting on new crank bearings.

Just to make sure I'm not missing anything on setting the ring end gap Using the JE Spec, Min would be "bore" X .005" for top ring. 4.095*.005 = .020"

According to the porsche manual the gap would be .02 - .04 with a .08 limit. That is a mm figure works out to .0079" to .0157" - with a .031" limit.

Quite a bit of difference. Thoughts on this? I plan to go with the JE numbers using JE Street Moderate Turbo.
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Old 01-16-2018, 02:32 AM
  #70  
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That sounds good, .020" top and .024" second ring with steel sleeves.
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Old 01-16-2018, 11:17 PM
  #71  
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Thanks Dave.
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Old 01-20-2018, 03:27 PM
  #72  
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Going slow but made some progress. JE sent me enough rings for 8 pistons, so I decided to try the old school hand file method. Certainly not the fasted method, but I was pleased with the results of my first attempt so I proceeded. My main concern was keeping the ends square but it wasn't too hard. I few times I got off a bit, but pretty easy to square back up. by the 3rd piston I had a pretty good feel for how many file passes it took to remove to get close to spec, so it didn't take too long. I also only filed one end so I had a nice machined end for reference. My high tech file mount is below.....holding the ring versus a file gives better feel IMO.

Have a question. Are the second rings generally lighter than the top rings? The top and second rings that came on the engine seem almost identical. The set I got from JE are not. The top ring was stiffer than the second ring. Also there was no indent on the second ring to determine top and bottom. It did have a size stamp on them. For now I have the size stamp side facing up which I assume is correct (I will verify with JE). Frankly by looking I cant see any bevels or anything that would make a difference but want to do it right. The top rings had an indent to mark the top side of the ring.

All rings are gapped on on the pistons using the JE guide. Did .020 on top and went .023 on second.

First photo shows gap out of the box .008. Second is .020.








Ping Pong table leg made nice file stand. Made sure I filed towards center and de-burred ends when done.



Old Rods on left - new Mitsu rods on right
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Old 01-20-2018, 03:37 PM
  #73  
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clean that block deck before putting on a HG!
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Old 01-20-2018, 05:12 PM
  #74  
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Originally Posted by V2Rocket View Post
clean that block deck before putting on a HG!
Yea....it just got too damn cold so I moved the block in the basement. Can't do too much cleaning down there on the carpet. Just happy the wife isn't complaining about and engine in our house. It did allow me to double check all the cylinder clearances.
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Old 03-11-2018, 04:11 PM
  #75  
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Crank Scraper finally arrived so assembly has started. Crankshaft installed.

Question on the oil pump. I disassembled the pump. When I put it back together (using loctite 574 around the edge) and tighten up the screws, the pump wont spin. If I back off the screws its spins. do you put oil in there and then tighten? I was trying to keep oil out of the system to give the 574 best adhesion.
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