Author Topic: Grapes of Wrath $200 engine rebuild  (Read 4690 times)

0 Members and 1 Guest are viewing this topic.

Offline LUFTVOLKS

  • Administrator
  • Hero Member
  • *****
  • Posts: 809
  • BangBusBaby!!
Grapes of Wrath $200 engine rebuild
« on: September 24, 2013, 11:55:40 PM »
I posted this on samba a while back but thought it would be nice for new members to see it here too so here is goes




I’m sure you are wondering what this classic novel has to do with an engine rebuild in a VW forum.  A story of an epic journey almost cut short as they are struck with a mechanical failure that leads to a junkyard repair. This might sound familiar to those of us who put serious miles on their old VWs and have encountered a failure of some sort or another out in the middle of nowhere with no cash but know how. Fortunately there are no bearing spacers or babbit rod bearings needed for our 80 year plus engine design but the ancient engineering allows the use of some caveman approaches with surprisingly good results.

This thread is dedicated to those of us with little to no cash but have a pile of old cores, a mystery engine that has you dreading any long trips away from home, or simply freshen up a high mileage engine before any strange sounds induce a pucker factor level 10.

A little background on my experience with this type of Jode style rebuild. Years ago I worked for a parts house in LA that was known for cheap rebuilds that were a roll of the dice whether you would get 50 or 50,000 miles out of their product. Most reached their warranty of 6 months/6000 miles or the upgrade, 12 months/12,000 miles with the purchase of new heads. As a kid I bought plenty of parts from this place but always was weary of their rebuilds. One day a guy on the club purchased a 1776 and prior to installation we decided to tear it apart and really find out what they put into their builds. Upon inspection we found new main and rod bearings, new rings and a new Brazilian gasket kit. No regrind on the crank, no rebuilt rods, used cam and lifters and a used oil pump. The only machining we could see was that the flywheel was resurfaced, the cylinders were honed and the case and heads were opened for 90.5s, at least it really was a 1776! Gray paint was used on the case, black paint on the cylinders and silver paint on the used heads which had old valves and springs. Not much for your $900 outright in 1990! Being out of cash and needing the engine for his daily driver, some aviation gasket and a new gasket kit was all the budget would allow and the “rebuild” went back together. That engine survived 50K miles of hard teenage abuse before it swallowed an exhaust valve and destroyed the #3 piston and head. A used piston/cylinder and a head from an engine that suffered the same fate donated its usable parts for the benefit of humanity. After a good cleaning, some rings and a German gasket kit, another 20K miles went by before the owner got a real job and turned this engine in as a core for a 1914. A surprising amount of use out of a single relief upright cooler case with missing tin and a teenage lead foot!

Fast forward to 2004 and I start working for the same parts house part time and get to see the old man in action putting together a “rebuild” for the showroom floor.  The same secret to success was used but I did notice him spending a considerable amount of time measuring all the used parts. He would get all upset when a customer would special order an engine and I would actually order the new parts the customer specified and paid for! The profit from a new engine was only $200 while the profit on a “rebuild” was $900!  After seeing a lot of engines being sold and very few coming back for warranty/repair I was amazed how much abuse these little engines could take with so little invested!


DISCLAIMER: There is no guarantee of any kind that this build will survive a break in let alone any real mileage. As with anything, you get what you pay for but sometimes you get lucky!

At the very minimum the following NEW parts should be used for an engine to be considered “rebuilt”:
Main bearings
Rod bearings
Cam bearings
Pistons/Cylinders
Cam
Lifters
Valve guides*
Exhaust valves*
Valve springs*
*With the amount of miles on head cores these days new heads are recommended over rebuilt


Reconditioned parts:
Case,  line bored/thrust cut if needed, decked, case savers
Rods,  new rod bolts/nuts, resized big end with new wrist pin bushings
Reground crank
Resurfaced flywheel

The parts listed above will be in excess of $1K in parts and machining alone.  The following $100 “refresh” is nowhere close to a real “rebuild” and should not be considered as such.


Being that my 1699cc bus engine has hit 70K torturous miles I thought it time for an inspection. While apart I thought it would be a good time to take some pictures and show some tips and tricks on a $100 short block rebuild. Pictures were taken during inspection and mock up but NOT during final assembly. Final assembly included an additional cleaning, degreasing and compressed air drying and all tools used were also cleaned thoroughly. The work bench was covered with masking paper and lint free cloth rags were used when needed. Surgical setting is what you should keep in mind, think CLEAN, CLEAN, CLEAN!!!

The following parts were pulled from my stash but are easily purchased online or at your local VW parts house
Main bearings $45
Rod bearings $25
Cam bearings $10
German gasket kit $20

Here is the subject after 70K miles of heavy loads in a heavy bus with at least 20K miles of mountain roads under its belt.




Compression test reveled #2 was more than 10% below the rest which after disassembly showed to be a result of a fuel washed cylinder. At 60K miles the faulty 36 DRLA was replaced due to a weeping lead plug.






Once the case was opened some mild pitting of the German lifters was the worst of the wear.




Bearings showed surprisingly little wear which I assume was due to the frequent oil changes (every 2K miles) since the case is not full flowed. Most cores won’t be in this condition but as this engine was built using all new parts a bearing/gasket kit rebuild for the short block would be all that was required.





For those attempting this junkyard build there are a few things you need to have to make the job easier. If you are not going to build many engines some of the things shown below are not needed but will make the chances of success greater.

First is a manual of some kind. For the majority of VW owners the Haynes manual is the best bang for the buck. Yes a Bentley is the ultimate but most of us are putting a later engine in an earlier vehicle which would mean several Bentley manuals (read hundreds of dollars) vs. $15 on a Haynes which has all the specs you will need that you could pick up at your local auto parts store.




For any engine build clean and measured parts are the key to success.

I started this blueprinting thread to guide you on the many measurements used for the assembly of an engine.

http://www.thesamba.com/vw/forum/viewtopic.php?t=493320

 The more you measure the better the chance you have of building an engine that will last thousands of trouble free miles.

Below are some of the things I use to clean and measure my parts.



Not pictured is a roll of blue shop rags, a large plastic storage bin, several cans of brake kleen and some assorted metal and plastic scrapers.

If you have a compressor this $6 HF engine washer makes things much easier. If you do use this pressure washer, make sure to use proper eye and ear protection and plan to get wet.




Here are some tools to make breaking down and assembling much easier. Top row left to right: C clip pliers, oil pump removal tool, flywheel lock, and main seal installation tool
Bottom row left to right: True arc pliers, feeler gauges, end play tool, relief valve plug tool, plunger removal tool, torque buddy.




This pic shows a cheapo HF digital caliper, crank gear removal tool and ring compression band.




Not required but a bit more accurate, a dial indicator with magnetic base, snap gauges, micrometer and a homemade rod stretch gauge that I use for ARP rod bolts.





A gallon of chem dip or some acetone will work wonders on dirty hardware.





I first clean the parts in hot water with some dawn dish soap in the large plastic bin using stiff brushes and scrapers. Once the majority of the thick stuff is off I then use the oven cleaner. First I spray it on, then use the stiff brush to break up any other deposits and then let it sit for a few minutes.DON’T LEAVE IT ON TOO LONG OR YOU WILL DAMAGE/STAIN THE CASE! Wash the cleaner off with water then blow all the passages out with compressed air. Use appropriate eye and ear protection when using compressed air!



Offline LUFTVOLKS

  • Administrator
  • Hero Member
  • *****
  • Posts: 809
  • BangBusBaby!!
Re: Grapes of Wrath $200 engine rebuild
« Reply #1 on: September 24, 2013, 11:57:53 PM »
Now you can inspect the case to see if it is still serviceable. Look for obvious cracks behind the #3 as well as any other place there was a lot of oil build up before cleaning. A propane torch will also help in finding cracks as heat will expand the crack and oil will usually weep out.





 The bearings will usually have a size stamp on the back. You can get an idea of when the engine was last rebuilt from the date stamp as well.




Measuring the old bearings will also help to see what the case and crank was last machined to.






DO NOT RELY ON THE BEARING SIZES ALONE! I have pulled apart many engines that did not have the correct size bearings installed!


The thrust surface takes a beating so check to see if a thrust cut is needed.




If you can feel a ridge with your fingernail on the bearing saddles you need to have the case line bored.





Lateral movement in the lifter bore is not good.



 A case can be saved by having the bores sleeved if the rest of the case checks out. With the price of a new case reaching $1K it may be an affordable option.


Check the dowel pin holes. Some high mileage cases have oval holes that don’t hold the pin well. Step dowels are available but if the case has spun a bearing another case should be considered.



Now it’s time to check the main bearing saddle. Torque the six main case nuts and shine a flash light behind the main bearing web.




 If you can see any light passing through the web the case is junk.




 
Depending on how many times the case has been line bored and thrust cut you can make the decision to use the case depending on your application. If the case is found to be serviceable it is usually recommended that you remove the oil galley plugs and REALLY clean the case well. Tap and install NPT plugs to the galleys and tapping for full flow fitting is also recommended at this point.



Now let’s take a look at the crank. Measure the main and rod journals and inspect for cracks. If the crank has a spun rod the rod journal NEEDS to be machined, a polish is just asking for trouble.



If all looks OK a light polishing with super fine emery cloth and some WD-40 will do.  The penny trick in the Haynes manual will help you determine if polishing is needed.

The proper way to check for cracks is to have the crank magnafluxed, since this is a junkyard build this is out of the question. If the crank has been lying around and not supported by its main bearings, checking for straightness is also required.


One thing to mention is the #2 main bearing as there are two different types depending on the type of oil holes drilled in the crank.  On the left is a KS bearing for use on a non cross drilled crank. The bearing on the right is for use on a  cross drilled crank.




Here is a late VW of Mexico cast crank with cross drill oiling. This design offers more oil to the rods (#4 in particular).





69mm 1500 and many aftermarket stroker cranks are not cross drilled requiring the use of the KS bearing to allow full 360* oil to the rods. Below is a 82mm Scat crank that is not cross drilled but has the journal modification to allow full oiling while using   a non cross drilled type bearing.




Now that you have a ton of measurements (you should) you can order your bearings. Even though they are new MEASURE YOUR BEARINGS!!! There have been several times that I have opened a new box of bearings to have a mismatched one inside.

Install your dowel pins.



Measure them once installed as some new dowels are too long and will cause the bearing to pinch once the case is torqued. Measure the hole in the bearing to make sure there is adequate room for the dowel.





Start with the #1 (thrust) bearing. It should fit snugly and have NO movement.
 




The #2, #3. #4 bearing should be the same.




Mark the centerline of the bearing using a marker to make it easier to install once they are on the crank. This step will help you avoid the dreaded pinched bearing syndrome.




Now fit the bearings to the crank, very little lateral movement should be felt. DO NOT FORCE THE BEARING ON THE CRANK!! They should go in easily with no effort.




Now to the tough part, installing the cam and timing gears to the nose of the crank. The lubed #3 bearing is in place and now the cam and timing gears need to be installed. You need to heat the gears to expand them, once heated they will fall into place with little to no effort. A hot plate will usually do the trick as will a propane torch but it takes a bit longer. Here is a pic of the gears installed. DON’T FORGET THE SPACER THAT GOES BETWEEN THE CAM AND TIMING GEAR!



Order of installation
First is the cam gear with timing dots toward the pulley, spacer, timing gear, c clip, #4 bearing, and oil slinger. Remember the dowel holes in the bearing are all off center and go towards flywheel.




Now it is time to inspect the rods. The size and date are also stamped on the back of the rod bearings similar to that of the mains.





Do not use any discolored rods, a black rod is a recipe for disaster.

Torque and measure the big end in several places to see if out of round




check the bushing clearances.




Rebuild rods are cheap insurance if any are in question.

Install the bearing, torque and re measure.



If the bearing tolerance is within spec you can start to install the rod on to the crank. MEASURE EVERY ROD AND JOURNAL.


Apply assembly lube and install on crank with tab up making sure the numbers stamped on the cap match the rod. If using non offset rods with no tab, install with the bearing tangs down then torque to spec. Make sure to use oil on the threads or appropriate lube depending of the fastener to obtain the correct torque value. Here is a pic of the rods installed.




Measure the rod side clearance.




 If some are too tight or loose move them to another journal to see if they fall within spec. 




If not using a new cam and lifters (recommended) you can see if yours are still serviceable.

Measure cam lobes and compare to listed specifications. There should be a small peak at one end of the lobe to promote the rotation of the lifter.



Lifters should rock when put face to face. If rockers do not rock they are worn beyond use and should be replaced.



Reground cam and lifters are inexpensive, but a new performance cam and matching lifters is worth the expense. Matching your cam to the rest of the combo (heads, carbs, exhaust) is VERY important. A mismatched combination WILL be disappointing as well as expensive.

Install the new cam bearings and check the thrust. For years I used to sand the thrust face on a flat surface using 400 grit wet dry paper until the spec was achieved, for straight cut gears this is still the way I do it. I noticed that when the old man would use a new set of bearings he would install the cam and whack the cam towards the flywheel with a rubber mallet. Raby has claimed to use the same method which results in the correct clearance. Below is a pic checking the clearance with a feeler gauge.





Check the timing gear back lash. The easy way is to rotate the crank and see if the cam “walks out” of it bearings. If it does it too tight and a different cam gear is required. Next hold the crank and rock the cam gear back and forth, excessive clearance is also not wanted and a different gear is needed. I have only experienced this problem when using stock cams with riveted gears. Most aftermarket gears do not come in +1, +2, -1, -2 sizes and usually have excessive clearance.



The timing gear and its related components are shown in the pic below.




The stock setup only uses 2 thrust washers but for less timing scatter setting the end play requires the use of additional washers.


Install the gear with spring and washers, put in a distributor and clamp in place.Check the endplay with a feeler gauge and adjust to the desired specification by adding/removing washers.





I’ve encountered countless engines with the distributor timing mark all over the place. This is a result of having the gear dropped in after the short block is complete and no care is taken to the placement of the slot. By following the directions and installing the timing gear BEFORE dropping in the crank you can save yourself a ton of hassles. Having to open up the case to fish out dropped washers is not something you want to do once the engine is installed!

First install the washers, gear, spring, and distributor and clamp into position. Set the distributor body with the timing mark to the 4 o’clock position as shown in the manual. Align the rotor to the mark on the distributor body.



Next grab the #1 rod and hold it in the TDC position and drop it into the case. Align the dowel pins using the marks you put on the bearings earlier.





Install the lifters and rotate the crank ¼ turn clock wise. Install the cam and line up the timing marks on the timing gears




This is how the cam and crank should look.





If your cam lobes are in a different position make sure the gear is correctly installed to the cam. The dot, bolt, and slot in the cam should all line up.






You are now ready to put the case halves together. Apply assembly lube to the main and cam bearings. Depending how long the engine will sit before break in should determine what lube to use. Since I don’t let mine sit for more than a few days I use a mix of STP and Lucas on all bearings. If using a new cam and lifters apply the supplied lube and follow any directions recommended by the manufacturer. For case half sealant I use Kuril and apply a thin coat making sure not to put too much as to block the small oil return slots for the main seal and cam plug. To keep the lifters in the case I use wooden close pins to keep with the Joad style budget build.



Don’t forget the cam plug!



Now place the case half gently to avoid dropping the lifters, put the thick washers and six case studs and hand tighten. Check to see if the crank turns smoothly...it should. Torque the nuts in three steps up to the required spec and check the ease of rotation with every nut you tighten. If the crank starts to get harder to turn STOP IMMEDIATELY AND FIND OUT WHY.

If all went well and the crank turns smoothly, put in the oil pump and finish putting the rest of the 8mm case nuts.



Almost done! Crank end play is next. I start with two shims put them in place and install the flywheel. Using the economy style endplay tool, push the crank towards the flywheel and set the tool.



Push the crank towards the pulley and measure the clearance using a feeler gauge.




Measure your two shims and use your feeler gauge measurement to determine the total stack thickness required to obtain the specified clearance.





Once the final shim stack is found lightly oil the shims and put them in place, oil your main seal on the outside AND the lip that contacts the flywheel and push lightly into place.





Use the seal installation tool with gland nut to draw the seal squarely into position. The seal does not sit flush with the lip of the case but sits a bit lower, make sure it is seated all the way down but DO NOT OVER TIGHTEN and damage the seal.






Install a new O ring into the groove in the flywheel, align the dowel pins and place the flywheel into position. Sometimes a bit of “persuasion” is needed to set the flywheel onto the crank. The use of a large dead blow or rubber mallet usually does the trick. Make sure to use a new gland nut with its matching washer and torque to spec. Here is a pic of the torque buddy in action.



Totally worth the $50 and also works on those stubborn axle nuts!
CONGRATULATIONS!!  Your $100 hillbilly, junkyard, shop floor, whatever you want to call it, short block is complete!



Part II of the wrath rebuild will show the inspection of the pistons, cylinders, and heads. Some additional tools are needed (cylinder hone, valve spring removal tool) as well as some more parts (valve springs, exhaust valves, rings, pushrod tubes). 

The parts for the top end rebuild should not exceed $100 either! Would you believe that $200 for a rebuilt long block is possible? If you ask GEX im sure they would agree!!


I personally recommend the use of NEW OEM heads and a quality piston and cylinder kit but that alone will cost $700. A set of new Chinese heads, pistons and cylinders would run you around $550. If you decide to go the rebuilt head route make sure you get them from a quality machine shop which specializes in VW machine work (not GEX). If you have good cores which is increasingly difficult to find these days, plus the cost of machine work and parts, new heads seem to be the best bet AND if cylinder head temps are monitored and kept within acceptable range they will be able to be rebuilt in the future. Another bonus is that you know exactly how many miles your top end has on it and service at VWs recommended service interval. If you have ever dropped a valve seat/guide or broken an exhaust valve you know that new parts are welcome piece of mind.


If you like to live on the edge and enjoy the kombisutra way of life, stay tuned for part II of the wrath rebuild and let’s see how far $200 and a bit of sweat equity can get you!


Offline LUFTVOLKS

  • Administrator
  • Hero Member
  • *****
  • Posts: 809
  • BangBusBaby!!
Re: Grapes of Wrath $200 engine rebuild
« Reply #2 on: September 25, 2013, 12:02:07 AM »
Here is the thread on samba so you can see the comments made by other readers. More good suggestions and stay tuned for part II!!

http://www.thesamba.com/vw/forum/viewtopic.php?t=513083