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Turbo Engine Re-Build

24K views 170 replies 7 participants last post by  CrucialProspect 
#1 ·
New to the forum here, but always referenced it’s material. Little background info, I have a built and stripped down ‘04. Been running an ancient hp performance twin 50mm turbo through a built mvb 4r70. I’ve raced this car off and on for 10 years, and just two years ago I’ve decided to take it off the street completely.

Figured I would run a cold compression test at the end of the season. I figured if it was getting tired, I’d go ahead and do some upgrades. Engine was originally built in 2008. Kellog crank, Manley rods, -18cc diamond pistons, ported pi heads. Since then I’ve put on trick flow 38cc to bump compression, and a secret sauce set of bump sticks. I’ve only had 15psi through it, and it has been dead reliable for 6 race seasons.
Originally I had 190psi cold, within 10% all cylinders. Now I have 170psi average, with cylinder 4 at 125 psi and cylinder 8 at 135psi. I believe that’s all I need to convince me.

I hope to be able to keep crank, rods, heads and cams. I may change pistons for higher comp (I’m running 114 octane) if they don’t mic round anymore. Also, I’m tossing the block to go to the aluminum block for weight savings.

Since I’ve been out of the engine building game for this long, what is some current advice/tips/tricks? This engine was built when the terminator was the best out there, and cams were all re-grinds. I know the game has changed and the aftermarket has a solution for every problem. The same suggestions would be welcome for bearings, rings, gasket brands, etc. there are some upgrades I’d like to do such as mmr’s billet timing guides and maybe adjustable cam gears, but a lot of others that I probably don’t need. And as much as I respect other engines, It will stay twin turbo 2v 4.6!
 
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#2 · (Edited)
... Originally I had 190psi cold, within 10% all cylinders. Now I have 170psi average, with cylinder 4 at 125 psi and cylinder 8 at 135psi. I believe that's all I need to convince me.
You are reading the tea leaves correctly the rings their ring seal are tired and need to be freshened up. In the rings department you want to use a TotalSeal AP Steel or Stainless Steel top. With today's ring technology I would opt for the AP Steel Top. TotalSeal also offers a Tool Steel Top ring, a little more pricey but also a little better. That said the AP steel ring is the right pick 95% of thtime.

For a second ring you want a TotalSeal cast iron second with a Napier cut edge that helps squeegee excess oil the oil ring missed off the cylinder walls. This will help avoid detonation used by the oil's presence in th combustion event.

For your oil ring (and all your rings) you want to use a 0.005" oversize ring set. The oversize will also apply to the oil ring expander / rail combination. It will provide a little higher oil ring tension which is good for blown engines - again it is another assist in keeping unwanted oil out of the combustion chambers. If anyone attempts to persuade you to use a low tension oil ring they are uninformed about building supercharged race engines. Politely acknowledge their contribution and go elsewhere for your engine building counsel.

I hope to be able to keep crank, rods, heads and cams. I may change pistons for higher comp (I'm running 114 octane) if they don't mic round anymore. Also, I'm tossing the block to go to the aluminum block for weight savings.
As long as they pass inspection (and they should) there is no reason the crank and rods can not be reused as long as they are both the forged steel variety. All Kellog cranks were forged steel so you are good to go there as long as you are sure it is a Kellog. If the rods are Manley H-Beams they are forged 4340 steel and reusable. Be sure to have their big ends checked for concentricity. your machine shop has the required equipment to make this determination. If the big ends need to be rebuilt then freshen them otherwise they are good to go. If they use 8740 rod bolts you ought to replace them with ARP 2000 bolts. Small cost but a big improvement in bolt toughness.

Your pistons will need to be changed out. Unless specifically called out on the original custom piston order all pistons from that time period are highly likely to have thin skirts which collapse under supercharged loading allowing the piston to rock in the bore and rounding the faces on the rings and progressively reducing their sealing quality. This could be part of your compression variances ad losses cylinder to cylinder. I can not recommend the Gibtec piston highly enough for your application. The piston was designed is a Solidworks 3 space model to remove all material that did not contribute to piston strength and integrity, Pistons, H-13 heavy wall tool steel pins, locks and the piston rings I described earlier are all available in a single $1,200 package. No matter how you look at it they are a stunning piston and they come with skirt wall thicknesses of 0.187" to 0.200" which is really important to preventing skirt collapse and premature ring seal failure.

You ought to modify your crank counterweights to be round rather than the OEM disproportional shape Ford used to get additional mass down they for balaoncing purposes. Your rotating assembly will need to have the crank rebalanced for the new pieces. By cutting the counterweight just enough to get a radiuses surface you make room for additional piston skirt which helps stabilize the pistons in the bore (just like the heavy skirts) and extend ring life. Your crank balancer (if it is not your machine shop) will add tungsten to the counterweights to bring the assembly back into balance.

O would give serious thought to using either E85 or pure methanol for your fuel rather than race gas. The cheapest and best fuel by far is the methanol. E85 is a close approximation but race E85 begins to cost like the high octane race gasolines. You can usually find methanol locally for less than $200 for a 50/55 gallon drum. Methanol will require you to go to methanol compatible injectors and a much higher capacity fuel pump bt it is the King of race fuels. For all intents and purposes it is detonation free, allows very high compression ratios in boosted engines and provides a chilling effect at the point of injection that can reduce incoming charge temps at the intake valve below zero!

You will have to purge the system of methanol after each weekend of racing but that is easy. Switch to a gasoline table in you EFI system, drain the tank, pour in some gas fire the engine and wait for the fuel system to purge the remaining methanol from the lines with the gas from the fuel tank and you are done. When you are ready to race reverse the process. Drain the gas fill up with methanol fire the engine and run it to purge the gas from the fuel lines.

Since I've been out of the engine building game for this long, what is some current advice/tips/tricks?
See abovee and below ...

This engine was built when the terminator was the best out there, and cams were all re-grinds. I know the game has changed and the aftermarket has a solution for every problem. The same suggestions would be welcome for bearings, rings, gasket brands, etc. there are some upgrades I'd like to do such as mmr's billet timing guides and maybe adjustable cam gears, but a lot of others that I probably don't need. And as much as I respect other engines, It will stay twin turbo 2v 4.6!
Something you might want to consider is the use of 4V heads for a race engine. There are a number of benefits you realize beyond improved breathing. Possibly the most significant is the ability to change camshaft Lobe Separation Angle (LSA) without buying new cams. Once you get close in duration the final improvements usually come down to LSA and actual cam phasing (advance or retard) of the selected profiles. To change LSA on 2V engines requires the purchase of new cams. To change LS on a 4V engine requires re-timing of the intake vs exhaust cam. One is your physical efforts and the other is your wallet. It would be very unusual to hit the LSA correct for your engine car combo right out of the box or even after one or two attempts, hence the 4V suggestion. An extra added attraction is the 4V head has stunning flow capabilities and requires much less lift (0.420" to 0.470") to get the job done which makes everything valve train related live and work better.

Block-wise, Look for an Aluminator block. They were the standard offering on 05 - 10 3V Mustang GT's. Ford's internal testing has shown the Aluminator blocks to more than doubled the duty cycles of any other aluminum 4.6L block they have produced. It has many improvements in internal block webbing, main web structure, main caps and most importantly casting process.

This is how to identify an Aluminator block. Look for a casting ID like in the pic below on the rear passenger side of the block by the #5 side bolt;

Font Electronic device Gas Number Symbol


Bearing-wise you want to run King MB5281-SI bearings. A lot of resellers of bearings will want you to run the black hard race bearings. Those are great for NASCAR style high banked oval racing where the engine will run at high rpm for hundreds of miles each race. They are not good for short duration high load applications like supercharged drag racing. The SI bearing gives optimal service in this environment. You also want to get a King MB1329-SI bearing. It is a fully flanged #5 upper (and an unusable lower) from an early 90's LNG 4.6L engine Ford has offered. It provides a fully flanged upper and lower insert for your build instead of th emultipiece erector set approach Ford took on the other 4.6L engines.

Head gaskets - just use Cometics.

Ed
 
#3 ·
Lots of good information there Ed! I shy away from 4v just to be a purist, I may not make as much power, but it’s all it’s ever been and I like the uniqueness.

It was all arp 2000 hardware at the time, so I’ll have to upgrade what can be, as well as any differences in the block main studs.

I do have the aluminator block so first order of business is to make sure the sleeves are good or can be made good. I’ll take your advice on the pistons, maybe not run such a huge dish.

I’ll definitely look into ethanol or methanol, I’ve seen the benefits, just have 0 experience
 
#4 ·
Typical daily driver blocks will be a pristine standard bore block. We have seen blocks with over 100K on the clock that you can still see the original crosshatch in the cylinders. In general we size pistons 0.001" larger than the bore and hone the bores to fit the piston that will go into it.

Here is a thread I did about why you want to overbore the block as little as possible, click here =>Why You Want to Use Standard Size Bores

Ed
 
#5 ·
Until I get a dial bore gauge on it I won’t know but agree with the fact that standard bore is best. That’s why I was considering a new sleeve.

I will price out those pistons and bearings, I see the cobra dowel upgrade on the block is pretty good insurance. I have the cobra hv pump, but do like the boundary gear. I would like to chase down the cloyes or comp adjustable cam gears.

A lot of this is dependent on the tear down, until I see what the crank, rods, etc look like and measure out before I order anything.

My main concern is finding someone competent to do the machine work in this area. I’m not aware of anyone local that can sleeve, and align boring and using a torque plate is probably unheard of. I will need the block hot tanked and checked, rotating assembly balanced (and that thing you recommended with balancing) possibly sleeves to get standard bore. I can do all assembly and bearing checking and measuring myself.
 
#6 ·
Call LA Sleeve and ask them for the names of the dealers they have in your local area. BTW what is your local area?

One of the other Reasons Gibtec's are attractive is that Gibtec will make pistons in 0.001" increments so you are not bound to a 0.010" or 0.020" oversize selection. It allows you to get much more life out of a block when you don't need to take a big bite out of the liner walls for your new pistons.


Ed
 
#7 ·
I’m trying to get my area added on the settings, northern kentucky.

Any reason to get skirt coating, anodizing, or any other finish on the pistons? My originals had a Teflon coating, and I’m not sure if it’s worth that much in my application?

Also, is there any reason to go with Darton sleeves? Are the factory replacement dry sleeves sufficient enough?
 
#8 ·
I'm trying to get my area added on the settings, northern kentucky.

Any reason to get skirt coating, anodizing, or any other finish on the pistons? My originals had a Teflon coating, and I'm not sure if it's worth that much in my application?

Also, is there any reason to go with Darton sleeves? Are the factory replacement dry sleeves sufficient enough?
With the advice from Ed about the skirt coatings, I sent my Gibtec's to Line 2 Line. If you look at my build thread here, I have some pics. The idea of their coatings are to wear where they need to in order to keep a nice seal for the PTW clearances.
 
#10 ·
Well, dig up some bones tonight looking at the old build spec sheet. Some mistakes I misquoted earlier, the oil pump is the Melling 10176 standard volume pump, so I’ll contact boundary and get the appropriate gear.

Also it only states the main studs as arp-156-5403 which I believe is an older 8740 2 bolt main style. I will try and find the 4 bolt main kit and side bolt kit I need, I believe they are sold individually.
 
#13 · (Edited)
I've got arp part numbers for head studs, mains, rods, and side bolts for the aluminator block if anyone wouldn't mind verifying?

ARP 256-4201
ARP 156-5002
ARP 156-5901
ARP 256-6301
You will find a complete ARP fastener listing for the 4.6L engine in the Terminator Table of Contents.(TToC)

Ed
 
#20 ·
Apologies, I overlooked replying to your question about what size to specify on the order for the new pistons.

If your largest measured bore dimension is 3.554 (as you documented) you need to allow for the hone to clean up that largest bore also. That means about an additional 0.001" needs to be removed from the liner bringing it to a diameter of 3.555 inches. Because a standard bore is 3.552 inches the cleaned up bores are actually 0.003" over standard bore (3.552).

Piston manufactures actually cut piston to wall (PTW) clearance into the finished piston so you don't have to or want to do the mental gymnastics to add the PTW clearances to get a finished bore size. The manufacturer already did it for you. That said because of manufacturing variances even on premium CNC manufactured billet pistons like Gibtec's, you can still detect small differences of less than 0.001 inches. This is the reason you still want to fit each piston to its final bore exactly the same as we pin fit wrist pins to pistons.

This is the absolute correct way to manage piston fit on a performance build. It takes more effort but the finished product shows the benefits of the additional attention to detail. Wait for the pistons to arrive, figure out the assembly puzzle to normalize the bob weights across all crankpins without barbaric grinding on rods and other premium components. Tell your crank balancer what bob-weight you want your crank balanced to and then hone the cylinders to fit the pistons you have assigned to individual cylinders.

Ed

p.s. Remember when you are measuring anything with a micrometer your body heat will be added to what ever you hold in your hand whether it is a mic or a piston. I recommend using a fixture to hold the piston and then measuring it's size. It doesn't take much body heat to change the size of an aluminum piston by 0.001". Not only that but when you hold the mic, it is absorbing your body heat also and it is changing it size also.

Best practices will use a fixture to hold the piston and when you hold the mic you will hold it for the least amount of time possible with the fewest number of fingers possible. As soon as you have measured the piston, you should set the mic back down onto a heavy top, temperature stable table made of aluminum, steel or granite and not touch it until you are ready to measure the next piston.
 
#17 ·
Wait for the pistons to arrive and then the order of battle will look like this;

● Weigh all pistons, pins etc,
● Measure all piston diameters,
build your bob weight map of components mixing and matching to equalize the bob weights of all piston / connecting rod sets,
● Size each bore to the piston you assigned to it in the bob weight calculation process,
● Clean everything and begin assembling.

Life will be happier (not to mention the engine build) and you won't have nasty looking grinding marks on rods you would prefer not to have done those barbaric things to.


Ed
 
#21 ·
Thanks Ed! I’m taking it to a machine shop this week to verify the bores can be cleaned up with a hone, then will place the call to gibtec and let him know my final bore size. Glad he has to do the math instead of me!

I’ve been told to give a 4-6 week lead time for pistons, so I want to take my time pulling the old one apart, fix up a couple issues, and I’m really debating Kevin’s idea for a oil bypass regulator for feeding turbos.
 
#22 ·
Sometimes Gibtec can give you an early delivery at this time of year so the anticipated 4 to 6 week delivery could get shortened up possibly to something less than 4 weeks.

Be careful about machine shops.

Many think in standard bore size increments of 10/20 or unbelievably 30 thousandths of overbore for these engines. If you find your shop thinks that way you will either have to help him find new religion (improbable) or you will need to find a new machine shop (much better choice) that will follow your direction and fit each piston to its final bore destination finishing the bores in 0.001" increments for uniform piston to wall (PTW) clearance. Also be cautious about shops that tell you to bore the block first and order the pistons second. These guys view you the way farmers view sheep. The farmer is after the sheep's wool and the machine shop is after your money. It will not be a good experience for either of you and more importantly you will get your engine's cylinder bores sized incorrectly.

When you encounter shops like these, the basic value for value exchange you entered into with the shop will have been breached by the shop but they will still demand payment because they are coming from a close enough is good enough mentality. If you have the slightest inkling that your shop behaves this way just politely leave and find a new shop. Arguing with them about how to do the job will have no effect on what they do and it will piss off both of you. It is a real world example of the old saying about, you can bring a horse to water but you can't make him drink.

Another one to be cautious of is, the use of torque plates. Make sure they use them and use your head studs torqued to the spec you will be using (ARP 2000 studs to either 85 or 90 ft/lbs) and importantly the torque plates need to have gaskets between the head and the block. Used gaskets are fine but the gaskets must be used to duplicate what the block will see at final assembly or else your bores are not going to be round. All these sorts of things represent extra steps for the shop in the completion of the work you are purchasing and for many shops steps they don't like to take because of the extra effort and time. Again if your machinist or shop is sitting in the wrong pew in the wrong church don't waste your time trying to change his religion — find another machinist with the right religion.

BTW if you have a first name I'll use it instead of your screen name,



Ed
 
#23 ·
Thanks again Ed, I had a nice long talk with them and they have a well understanding on minimizing the enlargement of the bores beyond stock size. They are also well versed on aluminum blocks and sleeve wall thicknesses. Unfortunately, mod motors aren’t their cup of tea.

However, like our conversation, regardless of make, model, shape, or size, the same principals hold true. I’ll have the old gaskets ready to go by the anticipated time of arrival on pistons. All I wanted from this shop initially is to get a second professional opinion on what it’s going to take to get them nice and shiny!

-Matthew
 
#24 ·
I understand, Matthew Stay close to them. While principles remain unchanged the idiosyncrasies of various manufactures engines can call for special attention during preparation and final machining / assembly. Those 'special' preps do not always translate across manufacturers. Sounds like you have a good handle on it though.


Ed
 
#26 ·
If the shop is a credible shop they should understand the importance of them and already have them, Matt — sort of like stones for hone, it is a shop responsibility and investment in the business if they want to do these types of engines. You should not be required to get them or pay for the shop getting them. That is all part of and included in the price of the honing. If your shop assesses a fee for the use of the plates or does not have the plates it becomes yet another decision point where the question, is this the right service provider, needs to be addressed.


Ed
 
#27 ·
Any thoughts on exhaust gaskets and fasteners? I recently had copper gaskets, I can prove they leaked, and some “so called” locking header bolts. With the hotside being sent out to be re-coated, I’d like some ideas on how to make this a leak free connection in the future!
 
#29 ·
Any thoughts on exhaust gaskets and fasteners? I recently had copper gaskets, I can prove they leaked, and some "so called" locking header bolts. With the hotside being sent out to be re-coated, I'd like some ideas on how to make this a leak free connection in the future!
Thick exhaust flanges, especially for turbo cars, go a long way towards good sealing. You should have at least a ⅜" flange and now a number of fabricators are offering ½" flanges. The gasket leakage is frequently attributable to flange warpage during the heating and cooling process. Thicker flanges are harder to warp.

The exhaust stud locking hardware is focussed on not loosening up and working its way out. It's design was not focussed on improved clamping load it was focussed on not loosening. Thick flanges, heavy washers and proper torque specs will be your friends.

Ed
 
#30 ·
Lost some weight today. Here are some “real world” numbers. The kit weighed 29.6lbs in the box, everything I cut out to mount the tube front weighed 45.6lbs. A savings of 16lbs.

While the weight savings are nice, I’m going to really enjoy all this added opened up space!
 

Attachments

#31 ·
Ed, I am unfortunately the owner of the 3/8 flange. I’ve sent them out to be (re) thermal coated, and plan on getting new bolts. I’d like to put a flat edge on the flange to see if it’s still straight and true. I may end up measuring the depth allowable in the head for the manifold bolt, and try to find a longer one for increased clamping load.
 
#32 · (Edited)
On many of the heads I have looked at, Matt, Ford did not use the entire bolt hole depth for threading. They often stopped a quarter of an inch or more short of bottom. You might want to check yours and see how much thread engagement you have and how much you can increase it.. If there is more unused hole depth a bottoming tap can frequently give you a quarter of an inch to sometimes ⅜ of an inch more thread engagement.

If the flanges are warped slightly a light surface cut may be helpful. If they are warped a lot, new flanges might be in order. If you go the new flange route you might want to investigate the half inch thick alternatives. A lot of the exhaust high priests might tell you you are running the EGT's too high which is what is causing the warpage problem. A little more fuel can help that problem.


Ed
 
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