R6_C5_CLS55

Quick question. I have a line on a ATI F1R head unit that is "Reverse Rotation" but I am not sure if that is what I need. Can someone enlighten me, or do I need to call ATI?

Thanks,

--Sean

Shinobi'sZ

That would be a 10/4 good buddy. The blower pully faces the back, it is reverse rotation. Do a search on F1 or Ebay on this forum, there was a lot of discussion about it 2-3 mos ago.

R6_C5_CLS55

Thanks for the help Shinobi. Looks like it might be the one for me.

--Sean

Shinobi'sZ

Just want to let you know. The F1R is a serious..SERIOUS...head unit. I would consider a D1, unless of course you are building the motor around the F1R head unit. If you are going to use an F1, make sure your motor is setup to handle it. I have seen these things blow many a head gaskets...even with ARP Head Studs. I would recommend a low compression motor, O ringing the block..or using 1/2" studs (or both). The F1R will make 18lbs of boost easy. Good Luck.

boblackhardtop

unless you're running more than 16lbs there's no need for the F1R.
2nd also make sure the outlet is the same proper angle that will fit our car.

XCELER8

Call Procharger and tell them the serial number on it, they will tell you exactly what it was designed for.
Jon

R6_C5_CLS55

I am building a forged 348 motor around the F1R or F1C. I have talked with my tuner about o-ringing the heads and using the 1/2 inch ARP studs (and even the higher strength ones of they are available) as well as trying out some hand worked AFR heads with the 3/4 inch deck, coated pistons, and high-end engine internals (pistons, rods, rod bolts, bearings, etc.). Hopefully it will stay together.

Shinobi'sZ

Sounds like you are on the right track. If it were me I would prefer O ringing the block vs. just the heads. But I think Rob Raymer O ringed the heads with some success. The block has to be hogged out or messaged to fit the 1/2" studs. Brian from AP engineering is now a vendor on this board (first saw him on LS1tech). Over there he was advertising a different type of stud that had a much higher tensile strength than the ARPs. Do a search or send him a PM he might still have some.

XCELER8

I agree with Shin. but, I know the AFR heads are really good but you might want to go with some 6.0 heads to help lower some of the compression.
Jon

mdhmi

God point. I would think they can also given you the service history of the head-unit.

APE is a sponsor, however, AFAIK, Brian no longer works there.

Mark

R6_C5_CLS55

Shinobi, I will see about the head studs from Brian at AP Engineering. I think a combination of O-ringing and larger or higher strength studs along with well machined surfaces and cometic gaskets should work.

XCELER8, if I get the 76cc combustion chamber AFR 225 heads (P/N 1630), I should already be at 8.5 :1. If not, I could supplement with dished pistons, but I don't think I will need to.

R6_C5_CLS55

I'm not sure about the orientation angle. I know this came off of a Rousch Mustang. Supposedly it was only on there for 150 miles. I asked the guy for the serial number so I can check it out with ATI.

--Sean

XCELER8

Sean
Have your engine builder help you pick heads that match the cam and blower setup. Your are having a HUGE blower go in so that will produce around 700-800rwhp easly with mild 15-17psi. So, your motor really has to be strong. Also might want to think of getting a forged crank if you are going to get anymore than 800+rhwp just to be safe. Also, the 8.5 compression sounds pretty good. A lot of people will tell you that anything over 16psi has a history of lifting heads. Even the best companies still have issues.
Jon

Shinobi'sZ

Hold on a sec..dude. I would not recommend using that large of a chamber if you can reach the desired CR with a dished piston. I have 77cc LS6 Heads, if you want to save some money I can give you the guys name and number who did my heads and also who does all of A&A Corvette's heads. He is awesome, and it won't cost you $2400.

The only reason I went big CCs on my heads and cometic .065" MLS gaskets is because I had a forged short block that was not really designed for FI. I used Diamond Pistons with only the valve reliefs. The valve reliefs only equate to 2cc. If I was building a FI motor solely I would have used 12-15cc dish and my stock LS6 heads...maybe a Stage I and some aftermarket dual valve springs. I am not saying it is not OK to do head work to reduce compression ratio, it is just not the best way to do it. Most vendor tuners are going to try and argue this because they make money selling you heads. I am not making a dime...so just consider that. Use the Ross Piston (or another) Compression calculator...keep in mind your deck height when calculating compression ratio.

R6_C5_CLS55

Shinobi,

Thanks for the input. Are you saying that getting a lower CR for more boost using cylinder head combustion chamber volume is not as effective as dished pistons - even if the heads are cast that way? The AFR 225's are supposed to come in either 66cc or 76cc ported CNC heads. If I wanted to try out the AFR's, would it be better to get the 66cc heads and lower the CR with dished pistons? Aside from the AFR's, Stage II LS6 heads are the next best option, or Stage II LQ9's?

If I used 66cc heads, I thinK I will need 9.6cc dished pistons for 8.5 :1 or 6.8cc dished pistons for 9.0 : 1.

--Sean

XCELER8

Here is my car for example, MTI is building my car for 9.1:1 compression. I have LQ9 Stage 2 heads. The ATI F1C SC @ 10psi will make me about 650-700rwhp with a semi conservative tune. The 9 compression is so you car wont bog on the bottom end. What he is saying is save some money for the heads and put it somewhere else.
Jon

R6_C5_CLS55

XCELER8,

I have seen your car at MTI and I have seen some of the parts going on it. I will be watching closely what happens to your car and the results. You are sort of my guinea pig / test case. MTI has a deposit on my shortblock, I just haven't specified what I want in the block yet.

If you are only going to run 10 PSI, why are you using the F1C head unit? It seems like you would be better off with the D1SC. Also, it looks like you are going to use the side mounted intercoolers. Why? I know this is ATI's experimental set up with the fans, but it seems like the front mount intercooler is the way to go. I think the fans will be a hinderance at highway speed as they will block some air flow unless they can flow more CFM than would normally pass through thte intercooler at speed. At low speed or on the dyno, they will be effective, but are not really needed then. Are you doing anything in particular about trying to keep the heads sealed?

--Sean

XCELER8

Thanks, I see how it is, use me as a test dummy like I have not had enough pain thus far..LOL
I trust MTI's opinions. The blower was a special deal that David/Jayson gave me since it is the prototype blower and ATI setup for my car. The twins are 4.5 inchs thick, a full inch thicker than ATI's normal setup as well as larger piping strong bracket MTI made and 8 rib setup. The ratio in this setup is 5.73:1 which means it will rev up and be into boost MUCH quicker than all the D1 and F1 units. Its like a turbo graph. It also leaves the whole front open for the new DeWitts Alum. radiator. The twins are good for around 800rwhp which I dont plan on exceeding. (at least while I have a stock crank) The deal they made for me I could not turn down. We are using ARP studs and cometic (sp) gaskets. No real reason to O-ring since I dont plan on having high boost. I got the new front end to help open up the air flow. I am not sure how the fans will do on highway speeds, but since I have 4.10 gears keeping it on the road will be next to impossible. So, you saw all my parts huh...LOL, I know there is a TON of them there along with my new LG Long tubes/body kit/sc/all those engine compents. Wish I was there to see it go in. Please keep me posted cause I cant even hear it after it starts.. LOL so you have to give me a play by play.
Jon

Shinobi'sZ

I am not saying that taking material out of the chambers to increase the chamber size is not as effective as using a dished piston...that would mean I did something ineffective..and I did not. My CR with Cometic MLS gaskets is 8.94:1. It certainly effectively lowered my CR. What I am saying is that the way FI motors are designed from the ground up is by using a dished piston, maintaining the proper quench, and a well designed head.

The only disadvantage from an engineering stand point in using the 6.0 liter head (IMO) on a 346cid is that the chamber diameter is larger than the bore size. Whereas the diameter of an LS6/LS1 head is more closely matched to the stock bore size. When going to a 6.0L head the bores will mismatch and there is a pocket. However many do this and it seems to work fine. But if given a choice between a 76cc LS6 head and an 76cc LQ9 head, on a 346cid, I would use the LS6 head.

As far as the AFR heads are concerned. I haven't seen the 76cc head yet? Have you? The 205s are nice looking heads, off the shelf great. They come with big valve springs, and a thicker deck. I know a lot of people making a lot of boost using LSx parts. I haven't seen any applications where a blown head gasket would have benefitted from a thicker deck at this point (not saying it won't, just haven't seen it). The LSx heads lift because they have 1 less Head Bolt than the old SBC (IMO). So most of the blown head gaskets I have seen, have either been poor tuning (detonation) or over 16lbs of boost.


If it were me I would go with 67-69cc heads and whatever dish necessary to achieve the desired compression ratio. I was thinking a 12cc dish w/67, and .054" GM MLS gaskets. With I believe the 270K PSI head studs and either O ringing the heads or going all the way between block and heads.

MelloYellow

If this helps, I believe the 76cc AFR's are on indefinite hold and no longer planned for the 205's last I heard.