A Little Guidance On An Engine Build Would Be Appreciated

[ForceFedFan]

Im currently into my first 4.6L engine build, I finished tearing down the engine tonight. I must add that I am not new to building engines by any means, I am however new to mod motors, and to be honest new to Ford. My past engine building experience was mainly focused around pushrod SBC & BBC's so a DOHC 4.6L is new territory to say the least. After tearing down this 50k mile motor I found that all the cylinder walls were in great shape w/ no scratches, clearly visible hash marks from top to bottom and no ridge at the top of the cylinder. Additionally, all the main and rod bearings look virtually brand new w/ no signs to indicate abnormal wear, scratches or debris. All crank journals looked perfect. I plan to start taking measurements and checking the roundness of things tomorrow but I highly suspect to find everything to be w/in acceptable tolerances. I'm hoping to get by w/ just a normal block cleaning, a light cylinder hone and start dropping in parts after everything is balanced. From everything I have read, the tolerances of a mod motor are tighter than a conventional pushrod motor. After a considerable amount of searching I have been unable to come up with many clearance/torque/bolt tightening sequences specs. I do not have a shop manual for this car. Can anyone point me in a direction on the internet where I may be able to find the CORRECT information I need? I'm putting a fair amount of money into this build (at least from the parts list I've already accumulated) so I need to do this right the first time, obviously. Is there a preferred Main/Rod bearing that is used in these motors or can anyone enlighten me on past experiences be it positive or negative. Any advice on parts/brands to steer clear of would be greatly appreciated. I've looked at swapping cams but anything other than the stock 98 cams is probably of out the budget at this point. Is the 98 cam swap worth doing, the specs aren't that much different from what I can tell. Ford Racing sells a timing chain replacement kit, for $600, is this something that really needs to be done? Are the factory guides and chains something to be concerned about on a 50k mile motor? Any other advice specific to this motor would be greatly appreciated. This car will be mainly a street car w/ occasional trips down the strip. Thanks in advance, Brian.

 

[Quick Strike]

Why the tear down if everything is ok? What are your hp goals and power range desired? Other then ptw clearance, the stock clearances are great. Use one of the good links to the Ford manual. It has all of the clearances and procedures.

 

[ForceFedFan]

Hydrolocked it and bent one rod. I couldn't believe how clean the internals were. This motor actually came out of, and is going back in, an 03 Mach 1. It's getting long tubes, pulleys, cai, possibly cams, and dyno tuned. Realistically, if it made 400 hp in N/A form I'd be happy. I want to build it to handle a 200 shot more than once. I'm probably leaving compression alone but would like to add a turbo or procharger at some point in the near future. I realize w/ the high compression I'm limiting myself on how much boost it will be able to handle, I doubt the car will ever make more than 600hp, but I'd like to build it to be able handle 800hp for reliability's sake. Where are the links to the Ford manuals?

 

[01yellercobra]

So you have a Cobra engine in the Mach or is it the original Mach engine? The 03/04 engines aren't high compression and use iron blocks.

If it's a Mach engine you'll need head work, cams, and a short runner intake to see 400hp. The lack of cubes kills the 4.6 power potential. N/A at least.

 

[ForceFedFan]

It is a Mach engine w/ the higher compression and aluminum block. I have an 03 terminator as well and had considered replacing the blower on it and putting the ported Eaton on the Mach until i saw the 14,000 parts I needed to do it. I do intend to clean up the ports but they're not getting a full port job, just enough to smooth them out and remove any casting flash. Are the 98 cobra cams worth dropping in? I found an almost new set for $125. I didn't realize there were other intake options other than stock, do any of them produce real gains?

 

[01yellercobra]

There is the Sullivan intake, but that's made for high revs. The ported short runner I was referring to is a modifed stocker. They cut open the bottom, shorten and port the runners, then weld it back together. I had a ported intake on my last engine and it seemed to help.

Ths 98 cams are worth a few horsepower. And easy enough to drop in while the engine is apart. Just remember you only need the intake cams.

Who ported the eaton?

 

[Quick Strike]

I know many consider 450 HP as a good safe limit for the stock Mach shortblock. You will need all forged internals if you want an 800 HP shortblock. Depending on auto or standard, your engine may already have the forged crank. The forged 03-04 cobra rods will get you there with ARP 2000 capscrews, and forged pistons are available off the shelf from a number of manufacturers used in engines that see 800-1000 HP regularly. Then it is a matter of ARP main and head studs and reusable side bolts. Then there are the machining costs to balance the assembly and fit the new parts. A good aftermarket oil pump is another key. I personally like king bearings. I had about $7500 in my long-block as listed here without the non-engine related parts (clutch, radiator, etc). Reliable big power is possible, but not cheap.

I would see if there is a link to the manual in the stickies above, or search manual links for a recent download.

 

[SlowSVT]

If you hydrolocked the engine chances are you bent more than a rod. I would look at the crank and block very carefully. It may have shifted the crank and the linebore. Don't do anything for this engine until you confirm nothing bad has happened downstream. All it takes is a one or more .001's of an inch and you got problems. Look for micro cracks on the bearing saddles.

Other than the stupid tight PWC clearance the mod motors clearances are similar type engines. Use the factory clearance and torque specs as a baseline, some builders will stray for the factory clearances somewhat like the piston, valve guide clearance and head torque........ bearing clearances not so much.

 

[speeddemon2000]

You will find more DYI engine build info over at modularfords.com. There are a number of guys that have done their own builds. Ed over there is a great resource and highly encourages people to do their own builds. Also one thing to keep in mind if you hone these engines you are supposed to use torque plates. If you change to ARP mains you will need to have the block align honed, if you keep the stock rods and change to ARP2000 rod bolts you will need to have the big ends on the rods checked for roundness. Mine had to be machined when I went to he ARP2000 rod bolts.

 

[ForceFedFan]

I do have the factory forged 8 bolt crank. I picked up a set of Manley 14318-8 I-beam pro rod's and a set of ARP head and main studs. I've already got the Steeda Pulley's (Have an extra set if anyone needs them) Trying to decide on pistons/rings. I went over the block and crank pretty good and couldn't see any problems but I realize there is only so much you can see with the naked eye. I guess I'll find out if the crank is ok when I take it to have the assembly balanced, it did clearance the piston skirt w/ the counterweight, that aside, all the journals look ok. I had to order a new set of micrometers yesterday so I can't even set up a dial bore gauge until they get here. I like your build list Quick Strike, how important do you think the billet oil pump upgrade is. The N/A aluminator comes w/ a standard pump and the S/C version has the billet oil pump. I see a lot of complaints about the standard oil pump but none related to anyone having one fail.

 

[Quick Strike]

There were quite a few threads with pictures showing shattered standard gear pumps both here and on mofo. It may be more related to the stress the larger sc puts on the end of the crank. I thought it was worth the extra bucks in my case. I would have paid full price for the billet gear pump if I had not found a guy that decided against a build he had planned. You should be ok with the standard cobra pump if staying na or going turbo.

Similarly, you won't need AP (stainless) top rings if staying na. A molly ring would seal faster with less chance of problems in a na application.

 

[ForceFedFan]

I had almost decided against moly rings because of the cylinder wall finish required to get them to seat. Do you think gapless rings are a bad idea on a daily driver?

 

[Quick Strike]

I remember a hot rod article comparing different rings in the same Chevy 350 engine to be used in a street strip application. The gapless rings were better by 5 hp then any other rings.