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Rebuild Advice To all For what it's worth!.


Dad
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I get many calls and emails on suggestions and pricing for rebuilding the 2.6 Turbo engine.

One of the many questions that I get are about pistons. Cast, Hyper eutectic or forged. The stock cast pistons have taken quite a beating and hold up well. The hyper eutectic pistons are usually available in a ½ pont higher compression. They are manufactured to be stronger than a cast piston. The forged pistons are the strongest available but they are a lot more costly. You can get them in stock compression of 7.0-1 or higher compression of 8.0-1 and of course forged pistons can be custom made. Generally if you are running high boost then stick with a lower compression piston. This does not always come into play but for most street engines you can go higher compression with lower boost. You can run higher compression with high boost levels but you must have a fuel management system, If you lean it out you can quickly destroy the pistons.

For the record I have customers using the Hyper eutectic pistons with 10 lbs boost all day and up 15 lbs for racing. Anything higher and I would suggest forged pistons only.

I would also run the chrome molly rings only, Much stronger top ring that can take the higher cylinder pressures than the cast rings, Hastings,& sealed power are quality rings. I have read quite a few post where people have had trouble with total seal rings so I stay away from those for the 2.6.

Replacing the timing components is a must. If you are going to keep the balance shafts intact then you better replace the balance shaft bearings.... higher mileage engines run a greater risk of spinning one of these bearings which will put debris all through the oil system. I myself suggest removing the balance shafts. Less weight, higher oil pressure Plus added HP as you don't have to turn the shafts anymore. Most have experienced very little vibration.

Replace the oil pump with a new OEM pump. Small investment on a high dollar build.

 

Fel-pro gaskets seem to be the big choice in gaskets, the 88-89 year set has a better head gasket than the early sets, The Ajusa metal shim gasket looks to be a very good gasket also.

SCE Makes the copper Titan head gasket that looks very promising although I have not heard any reports on them as they are new on the market. Solid copper head gaskets and o/ring cut into the block will seal very well in high boost engines but not suggested to run daily street use as some have trouble sealing the water jackets, best for Drag race only.

 

If you are replacing the heads I would suggest the Marnal (Spain) cylinder head, Seems to be the best replacement head, Get the NON jet valve head. Be sure to use the TURBO valves as the exhaust valve is Stellite faced, You can also get stainless valves that are .05mm larger head diameter than stock and have undercut stems for better flow.

 

There are a few people on the site that handle reground camshafts. They usually offer a choice of grinds for you depending on your intentions..Street only, Race only, street/strip etc.

Most all recommend the Schneider valve springs.

 

New head bolts are recommended or to really have some holding power go with ARP Head studs. Also ARP rod bolts, No need for the ARP Main studs as you can't bolt the oil pick up on without either reusing 2 bolts or drill and tap the arp stud. The stock Main bolts should be fine.

 

 

 

I think I have most of the parts covered,, if not I can edit later... Lets get to the Machine work part. I am also listing an estimate of what some of the work will cost in our shop. Your shop could be higher or lower in price. Now one thing that you need to do after you pull that engine is to Flush the oil cooler and lines. A lot of debris can be trapped in those and can trash your new rebuild.

I suggest Hot tank the block, Magnaflux for cracks...Be sure it is the wet method where the block is totally sprayed with and an ultra violet light is used to check for cracks.. Stay away from the powder method as it would be useless on a block. Most blocks that I come across have very little wear in the cylinders. Sometimes just a hone and re- ring will do. But to get it to perfect clearance you may need to bore it. Just go the next oversize... not right out to 040 for example.. No real gain in 040 over 020. And you want to save that block in case it has to come apart again. You want to be sure that the shop will allow about .003 to be honed from the block after boring. If they have access to a torque plate that is an added bonus. It takes us over an hour to properly hone the block, some shops bore almost right to size and then quick hone job.... not good.

Be sure that the main bores are checked. And most important give the shop your gear cover and a few bolts so they can bolt it to the block and resurface it. Just a clean up cut of a few thousandths as these engines are prone to head gasket problems.

Re cleaning of the block and a new set of brass soft plugs ( no more rotting plugs) This should cost about $360.00 to Prep the block.

 

Cleaning the crankshaft, Magnafluxing ( Again the wet method) Check straightness and check the journals for size and out of round. If it checks ok, polish and you are all set. Should cost about $75.00 to prep the crank.

Try to keep your original crank as the turbo cranks are NITRIDE hardened. Only grind them if absolutely nesc. A few nicks or scratches should be ok if the journals are on size and round. A nick or scratch after polishing will just be a small oil pocket. No need to worry, but of course it's the machinist call after all you are putting your faith in his judgment and experience.

 

The connecting rods on these engines are quite beefy. There are aftermarket rods out there but are pricey and in my opinion the stock rods if properly set up can take all you can throw at them, In fact the entire lower end of these blocks can be virtually bullet proof if set up right.

 

Magnaflux rods, Recondition bottom end of rods with new ARP rod bolts- be sure the shop cuts the parting lines (where rod and cap meet) on both the cap and the rod. Some shops cut corners and will only cut the cap. Have them press your new pistons on, check alignment and you are ready to go. This works fine in stock and mild street engines. Should run about 145.00

 

If it's in your budget then have the shop polish the beams and stress relieve ( shot peen) the rods. This will help to keep the rods from fracture. Definitely needed in higher horsepower engines. Expect to pay about 100.00 more for this. ( Be advised that you must have these balanced)

 

Some prefer to have the small pin ends of the rods set up for floating pins. This in my opinion may not be worth the cost. The only benefit is that you can remove and install the pistons on the rods yourself.. One other benefit is the shop if equipped right can re set the center to center distance ( Rod length) back to spec and have all of them the same length. Be sure that the shop can bore these to get the center distance correct that they can Burnish or roll in the bushing and that they drill an oil hole in the top of the rod to lube the pin. If you use floating pins then YOU must use pistons that have grooves and lock Ring for the wrist pins, such as JE or Wiseco. You can use those same pistons in a press fit rod... just don't install the snap rings. Expect to pay about 125.00 to have the rods bushed and bored..

 

If you are not replacing the head then have yours cleaned and pressure tested, have the guides checked or replaced, the head resurfaced.. Just clean up cut and the valves and seats ground. Be sure that they know to set the valve stem height ( tip of valve to spring seat) this should run

$200.00 to $250.00

 

You could have them do some porting on the heads, these heads require little to help them flow better... May cost $100.00- $150.00

 

Best also to disassemble the rocker assembly to clean the shafts and rockers and inspect them. Approx $66.00

If you are installing performance cam, springs etc... be sure that they set up the valve installed height, spring seat pressure and also check for spring coil bind, and that the seals and guides have enough clearance to the retainer. Please give the shop your cam specs when you give them the head. Most shops just go the hourly rate for this.

 

And last... Have the rotating assembly balanced. Give them your crank, pistons, rods, flywheel, pressure plate if you have it and front pulley. Should cost about $175.00

 

And of course assembly. Re wash all the parts prior to assembly. Check bearing clearances, Crank end clearance, and ring gap... I have found that you may want to increase the top ring gap on high boost engines.. to .020 for example. Most shops charge hourly rate for assembly and it depends on far they are going with assembly.. From short block to long block to entire engine.

 

Be sure the oil system is properly primed with oil before start up either with a pressure tank or by turning the engine over with plugs out and injectors disconnected.

 

I hope I have covered everything and that this will help you in your rebuild. Again these are my opinions and your machinists may not agree but that's life! Have a great 2006

 

Dad

Engine Machine Service Inc.

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