PDA

View Full Version : Need Advice On Forging Bottom End



GAZ
11-12-08, 04:31 PM
I have a 03 mach 1 with 7550 miles on it that I'm about to S/C . Only an Eaton M-112 for now but will probably upgrade later. Maybe nitrous later also. My goal for the street is 600 rwhp but I do not want to worry about the bottom end if I put nitrous to it. SO from what I have been able to figure my crank is a forged unit since I have a manual trans, that should be O.K. But what about pistons and rods? I have been looking at the 4340 h-beams rods with ARP cap screws. With Mahle 16 cc dish pistons. Should be around 9:1 with my stock heads? Looking for help/advice on selection of all three components.
Thanks Greg

RogerL
11-12-08, 06:46 PM
there is a lot to consider when approaching the 600rwhp.

not just the piston brand but the ring width. Many of the pistons available today have the narrowest widths that work fine for motor only applications and mild nos. Consider your cam lift as pistons will need valve reliefs if you go too high. Rods also have improved greatly and i have seen scat, probe, and high end such as oliver all perform fine. Its the clearances that have to be opened up to allow the motor to work without spinning bearings. Bearings should be coated and H bearings used.

Some other items to consider are these: stock oil pumps have cast gears, while the aftermarket, along with certain ford items, have billet gears to keep from breaking under hard acceleration. Main bolts should be ARP as the stock ones are torque to yield. Stock head bolts are torque to yield. Many buy the basic ARP head stud kit, but ARP makes a 2000 kit with that number on the top of every stud. My guess is that they made that kit to keep the heads from lifting under a load. Piston rings are another avenue. the basic kit ring set has a low tension oil ring and moly top ring. Fine for a basic motor, but there are much better rings out there with stainless steel top rings and higher tension oil rings that will last. Also, gas porting the piston will keep the top ring working much better.
thats enough for now, i hope this helps you in getting a solid motor together!

GAZ
11-12-08, 07:59 PM
there is a lot to consider when approaching the 600rwhp.

not just the piston brand but the ring width. Many of the pistons available today have the narrowest widths that work fine for motor only applications and mild nos. Consider your cam lift as pistons will need valve reliefs if you go too high. Rods also have improved greatly and i have seen scat, probe, and high end such as oliver all perform fine. Its the clearances that have to be opened up to allow the motor to work without spinning bearings. Bearings should be coated and H bearings used.

Some other items to consider are these: stock oil pumps have cast gears, while the aftermarket, along with certain ford items, have billet gears to keep from breaking under hard acceleration. Main bolts should be ARP as the stock ones are torque to yield. Stock head bolts are torque to yield. Many buy the basic ARP head stud kit, but ARP makes a 2000 kit with that number on the top of every stud. My guess is that they made that kit to keep the heads from lifting under a load. Piston rings are another avenue. the basic kit ring set has a low tension oil ring and moly top ring. Fine for a basic motor, but there are much better rings out there with stainless steel top rings and higher tension oil rings that will last. Also, gas porting the piston will keep the top ring working much better.
thats enough for now, i hope this helps you in getting a solid motor together!
Thanks for the great input! So the ring width is how far it seats into the piston groove and protrudes into the bore? What piston brand/ring combo do you prefer? What is the purpose of the gas porting? The clearances on the rod bearing needs opened up? Coated and H bearings? I was planing a mielling oil pump. Along with a billet trigger wheel and gears. For sure the ARP main bolts and head bolts did'nt know about the 2000 series, you prefer them at this power level?

RogerL
11-13-08, 04:46 PM
Thanks for the great input! So the ring width is how far it seats into the piston groove and protrudes into the bore? What piston brand/ring combo do you prefer? What is the purpose of the gas porting? The clearances on the rod bearing needs opened up? Coated and H bearings? I was planing a mielling oil pump. Along with a billet trigger wheel and gears. For sure the ARP main bolts and head bolts did'nt know about the 2000 series, you prefer them at this power level?


Most likely you will have to have the pistons you purchase modified for the higher hp. I was referring to the thickness of the ring pack, not the lateral(depth). The minimum ring size would be 1.5, not 1.2, and 3.0 on the oil pack. Total Seal in Phoenix has the capacity to modify ring widths, gas port, and supply the tougher top ring along with the rest. Gas porting helps keep the top ring pushed out and works better as you accelerate. The melling oil pump has a select brand (billet gears) and you have 2 choices, the difference being the oil pickup tube size, stock and cobra.
I dont ck forums much, but just thought i would offer some basic advice. Take your time, get the right parts, dont rush anything.