331 Internals

VeNuM · 08-29-2002, 07:10 PM

I'm building a 331 this winter and want to have a rock solid plan going into the winter. I have a stock 302 block which all this will be around. I'm hoping to find a deal on a rotating assembly, which will either be from Scat or Eagle. It consists of Eagle H-beams, Eagle Crank, and SRP Forged pistons. Or I go with the Scat crank and rods. Anybody have a perferance of one of these or another? I'm going to be running it naturally aspirated. Are SRP pistons strong enough or should I pay the extra for the JE ones? Next are the heads and intake. From what I've done and read, the Air Flow Research heads flow the best. I'm not sure what ones will properly fit my application, the 165cc or the 185cc ones. For the intake I'm going with the Performer RPM and upgrading the TB to 70mm and a bigger MAF. Are 24 lbs injectors going to be enough or should I get the bigger 30 lbs? I'm also putting a stud girdle on the bottom end to make it stronger. Does this sound like a good setup? Any feedback would be great.

todd95GT · 08-31-2002, 09:09 PM

I am currently building a 347 for my 'stang. I've spent a lot of time talking with my engine builder, a very reputable and respected person in the field. His experiences with Scat crankshafts is that they NEED to be fluxed and checked before you do anything with them because he has seen more than a fluke share of them shipped as less than perfect. Then again, he has also seen many nodular/cast Eagle cranks come out of the box in the same poor condition.
Personally, I spent the extra and went for a completely forged kit. I picked up an Eagle 4340 forged steel crank and H-beams with SRP pistons, etc. SRP's are just fine for our applications. The regular JE pistons aren't worth the extra difference over the JE-made SRP slugs.
I'm going with 24-lb.hr. injectors and AFR 185 heads. The 185's would be a great choice on the 331 but so would the 165's. Personally, I would (and did) opt for the 185's. They're the same price anyway. When it's in the car, I will have a custom chip burned for it while it's on the dyno. The cam is going to be a custom grind which I will order once the short block is assembled. The stud girdle is a great idea as well. Hopefully you didn't spend a lot of money on that. There are some on the market for under 150 bucks yet some companies still market their's for around 300. A windage tray is a nice idea for some free horsepower as well.
My MAF is a C&L 76 mm with the True-Flo pipe. Throttle body is currently 65mm, will probably go with a 70mm. Sounds like we're on the same page.
Good luck with your combo.

WheelsUp · 09-01-2002, 01:42 PM

Well it looks like your plan is solid,and a 331 is a great stroker,but I am a big fan of Scat products,Eagle is stout also,I like their rods but not their cranks,SRP or JE is a good piston but I am a Ross piston fan,they are light and they are strong.

Heads AFR is a good head and top of the heap right now because of great advertising,and marketing.

I will add this about flow numbers,make sure the cam is matched to the heads. I know most flow figures are always measured at .600 lift,but check the numebers below that also. Because if this is a street car then that is what matters the most the low lift numbers.

The intake you are going with is a great intake but open up your options some,the Systemax is a great intake also.

Lot of options out there good luck with your combo.

VeNuM · 09-01-2002, 02:29 PM

The Ross pistons are kind of expensive and I'm pretty sure a SRP would fit my motor well, being it will be a daily driver. I did consider the Systemax but it looks like I would lose too much low end power. I also considered the TFS intakes but everybody I talked to at shops and car shows steered me away from them and towards the Edelbrock. Last night I talked to some Midwest Ford guys and they claimed nothing is going to flow as good as the AFR heads though the whole RPM range.

302 LX Eric · 09-03-2002, 08:33 AM

I ordered my kit from DSS. I went with a forged 4340 steel crank from DSS. I heard from two different engine builders to stay away from the Eagle cranks at all costs. Another builder told me that all he uses is Eagle. Go figure.

As far as the girdle, the reason some are so cheap ($99) and others as so expensive ($299) is the material differences. The DSS girdle is made from T6 6061 aluminum, which is very strong, light weight and absorbs engine harmonics while maintaining its strength. The steel girdles are very strong, however they don't absorb vibrations nearly as well as the 6061 aluminum. DSS said that they would rather make the steel girdles (better margins), but that they've ended up with broken cranks with the steel versions in testing. Coast on the other hand will tell you that all you need is a steel girdle and that you're wasting money on the 6061 girdle.

My pistons are Probe (aka Coast HP), the Sportsman Race Series pistons w/specail valve relief for my TFS TW heads. Rods are 4340 H-Beams.

Being a CPA, I have a very detailed list of everything that went into my 331 buildup - all the way down to the VHT Ford Dark Blue paint that was used to paint my block. I have cost, part numbers (where applicable), part descriptions, machining costs, etc. all categorized by compents. If you're interested in seeing the list, send me an email or PM and I'll send it to you.

E

08-29-2002, 07:10 PM	#1
VeNuM Registered Member Join Date: Apr 2002 Location: Downers Grove, IL Posts: 464	331 Internals I'm building a 331 this winter and want to have a rock solid plan going into the winter. I have a stock 302 block which all this will be around. I'm hoping to find a deal on a rotating assembly, which will either be from Scat or Eagle. It consists of Eagle H-beams, Eagle Crank, and SRP Forged pistons. Or I go with the Scat crank and rods. Anybody have a perferance of one of these or another? I'm going to be running it naturally aspirated. Are SRP pistons strong enough or should I pay the extra for the JE ones? Next are the heads and intake. From what I've done and read, the Air Flow Research heads flow the best. I'm not sure what ones will properly fit my application, the 165cc or the 185cc ones. For the intake I'm going with the Performer RPM and upgrading the TB to 70mm and a bigger MAF. Are 24 lbs injectors going to be enough or should I get the bigger 30 lbs? I'm also putting a stud girdle on the bottom end to make it stronger. Does this sound like a good setup? Any feedback would be great. __________________ 1989 Black Mustang GT Hatchback, Underdrive Pulles, Electric Fan, Cold Air Intake, Headers, Offroad H-Pipe, Magnaflow catback, Steeda Tri-Ax, Fluidyne Aluminum Radiator, Timing at 14*, 3.73's Coming not so soon: 408w Ricer Hater's Club Member #59

09-01-2002, 01:42 PM	#3
WheelsUp Registered Member Join Date: Aug 2002 Location: At The Track Posts: 20	Internals Well it looks like your plan is solid,and a 331 is a great stroker,but I am a big fan of Scat products,Eagle is stout also,I like their rods but not their cranks,SRP or JE is a good piston but I am a Ross piston fan,they are light and they are strong. Heads AFR is a good head and top of the heap right now because of great advertising,and marketing. I will add this about flow numbers,make sure the cam is matched to the heads. I know most flow figures are always measured at .600 lift,but check the numebers below that also. Because if this is a street car then that is what matters the most the low lift numbers. The intake you are going with is a great intake but open up your options some,the Systemax is a great intake also. Lot of options out there good luck with your combo. __________________ Come to the Track you might learn something

09-01-2002, 02:29 PM	#4
VeNuM Registered Member Join Date: Apr 2002 Location: Downers Grove, IL Posts: 464	The Ross pistons are kind of expensive and I'm pretty sure a SRP would fit my motor well, being it will be a daily driver. I did consider the Systemax but it looks like I would lose too much low end power. I also considered the TFS intakes but everybody I talked to at shops and car shows steered me away from them and towards the Edelbrock. Last night I talked to some Midwest Ford guys and they claimed nothing is going to flow as good as the AFR heads though the whole RPM range. __________________ 1989 Black Mustang GT Hatchback, Underdrive Pulles, Electric Fan, Cold Air Intake, Headers, Offroad H-Pipe, Magnaflow catback, Steeda Tri-Ax, Fluidyne Aluminum Radiator, Timing at 14*, 3.73's Coming not so soon: 408w Ricer Hater's Club Member #59

09-03-2002, 08:33 AM	#5
302 LX Eric or '331 LX Eric' Join Date: Jan 1999 Location: Columbus, Ohio Posts: 2,142	I ordered my kit from DSS. I went with a forged 4340 steel crank from DSS. I heard from two different engine builders to stay away from the Eagle cranks at all costs. Another builder told me that all he uses is Eagle. Go figure. As far as the girdle, the reason some are so cheap ($99) and others as so expensive ($299) is the material differences. The DSS girdle is made from T6 6061 aluminum, which is very strong, light weight and absorbs engine harmonics while maintaining its strength. The steel girdles are very strong, however they don't absorb vibrations nearly as well as the 6061 aluminum. DSS said that they would rather make the steel girdles (better margins), but that they've ended up with broken cranks with the steel versions in testing. Coast on the other hand will tell you that all you need is a steel girdle and that you're wasting money on the 6061 girdle. My pistons are Probe (aka Coast HP), the Sportsman Race Series pistons w/specail valve relief for my TFS TW heads. Rods are 4340 H-Beams. Being a CPA, I have a very detailed list of everything that went into my 331 buildup - all the way down to the VHT Ford Dark Blue paint that was used to paint my block. I have cost, part numbers (where applicable), part descriptions, machining costs, etc. all categorized by compents. If you're interested in seeing the list, send me an email or PM and I'll send it to you. E __________________ 1991 5.0 LX Coupe - 40,750 miles 331 cu. in. / Tremec 3550 / BFG Drag Radials 12.22 @ 114.31 mph - w/1.89 60'

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08-31-2002, 09:09 PM	#2
todd95GT Registered Member Join Date: Aug 2001 Location: Palm Beach Gardens, Florida, USA Posts: 191	I am currently building a 347 for my 'stang. I've spent a lot of time talking with my engine builder, a very reputable and respected person in the field. His experiences with Scat crankshafts is that they NEED to be fluxed and checked before you do anything with them because he has seen more than a fluke share of them shipped as less than perfect. Then again, he has also seen many nodular/cast Eagle cranks come out of the box in the same poor condition. Personally, I spent the extra and went for a completely forged kit. I picked up an Eagle 4340 forged steel crank and H-beams with SRP pistons, etc. SRP's are just fine for our applications. The regular JE pistons aren't worth the extra difference over the JE-made SRP slugs. I'm going with 24-lb.hr. injectors and AFR 185 heads. The 185's would be a great choice on the 331 but so would the 165's. Personally, I would (and did) opt for the 185's. They're the same price anyway. When it's in the car, I will have a custom chip burned for it while it's on the dyno. The cam is going to be a custom grind which I will order once the short block is assembled. The stud girdle is a great idea as well. Hopefully you didn't spend a lot of money on that. There are some on the market for under 150 bucks yet some companies still market their's for around 300. A windage tray is a nice idea for some free horsepower as well. My MAF is a C&L 76 mm with the True-Flo pipe. Throttle body is currently 65mm, will probably go with a 70mm. Sounds like we're on the same page. Good luck with your combo.