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Thread: Turbo Engine Re-Build
10-27-2019,†09:49 AM #1
Turbo Engine Re-Build
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!
10-27-2019,†12:30 PM #2
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 ó 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.
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.
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;
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 ó just use Cometics.
Last edited by eschaider; 10-27-2019 at 12:40 PM. Reason: Fixed broken pic links
10-27-2019,†01:16 PM #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
10-27-2019,†04:06 PM #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
10-27-2019,†06:59 PM #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.
10-28-2019,†02:57 AM #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.
10-28-2019,†06:06 AM #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?
10-28-2019,†10:34 AM #8
10-28-2019,†10:45 AM #9
10-28-2019,†06:51 PM #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.
10-28-2019,†08:22 PM #11
I’ve got arp part numbers for head studs, mains, rods, and side bolts for the aluminator block if anyone wouldn’t mind verifying?
10-28-2019,†09:21 PM #12
10-28-2019,†09:24 PM #13
10-29-2019,†05:02 AM #14
Thanks again Ed, I had to exit enhanced mode to find the stickyís and TOC. A wealth of knowledge for sure!
11-03-2019,†01:22 PM #15
I finally did my bore measuring today. I set my micrometers to 3.5520 and zero’d the dial bore gauge. Here are the results!