WS6ICK2k

Hey Everyone,

At the moment I plan on staying NA H/C/I route. The heads I have decided on are the TFS 220s as cast. My ultimate goals include going FI and I know that these heads would be great for that due to their thick decks.

My concerns are milling, if I mill down the heads to be a somewhat high compression say (60-62CCs) now for a stout NA motor will I be able to use them down the road when I go FI?

Also, what do the majority of you guys do, sell your high compression heads? or can you run dished pistons to offset the difference when you go to a forged short block?

My ultimate goals include either a D1 or F1A.

Exidous

iTrader: (11)

E85 or dished pistons. There are HUGE dish pistons out there 20+cc that will more than make up for the smaller chambers. If you are planning on using those heads for FI and will forge the motor when you add boost just get the proper pistons to bring the CR back down.

The only reason you'd need to sell the heads is if you had already forged the motor and don't want to hastle with new pistons and a rebalance/rebuild.

WS6ICK2k

Awesome the forged short block will be in the near future. That's what I was thinking also didn't know how many people actually went that route.

Exidous

iTrader: (11)

The only time that milled chamber volume vs piston volume matters is when you are concerned about piston-to-valve clearance and/or quench. Otherwise just keep the bottom end stock until you are ready to boost it. If you run the lower CR before the boost you will be giving up some tq. Usually 3-5% per CR pt.

The Alchemist

iTrader: (19)

So if I understand you correctly, you haven't milled the heads yet, and plan to go FI in the future, so don't mill the heads. Leave them as is.

Also, compression ratio isn't as critical in a centrifugal blower as it is in a turbo setup since your max boost won't occur till after max torque (max cylinder pressure) so it's not as critical. Plenty of guys are running close to 11:1 compression with a procharger on pump gas and meth injection.

WS6ICK2k

It's most likely going to be a year or two down the road until I go the FI route. Good to know about the centrifugals, what CR are you running Alchemist? Your car is nasty by the way I have seen quite a few videos on your car. Would you still leave the heads as is for heads cam NA combo now? I know I would leave some power on the table but if it would leave better options down the road I would sacrifice it.

The Alchemist

iTrader: (19)

I have the PI/MAST heads, and ran them as is NA for a year before going FI. When I went FI, it was with the stock motor, then when I went forged, I went with -3cc pistons, which lowered my compression a little bit. They make options for -10cc and even -20cc as well if memory serves me.

One thing to remember is that the beauty in an aftermarket casting is the thicker deck, which adds structural rigidity to the mating surface. I wouldn't want to mill that down.

If you do want to go FI in the future, then leave the heads alone and just enjoy the ca NA now at whatever power level it makes.

Rise of the Phoenix

iTrader: (27)

I agree with just leaving the heads alone if you plan on going FI pretty damn soon. If it's going to be several years down the road, I'd opt to mill the heads as much as I could to get the highest compression you can without running into piston to valve clearance issues.

El_Diablo

iTrader: (9)

My c6z is 11:1. With 11psi, 91 oct, and methanol my d1 was a 300+rwhp bolt on.

Jefro6996

iTrader: (21)

My TFS 220 as cast heads were milled to 62cc so I just went with a -19cc dished piston. Put me just under 10:1, which is where i wanted to be. YOu can always go with a bigger dish to get a lower CR when you do the shortblock.

Rise of the Phoenix

iTrader: (27)

How would a 11.5:1 compression D1SC on e85 do? Too much compression?

Ryans99ls1

iTrader: (16)

I'd run the hell out of that setup. Be more cautious about timing than the compression. Most people will say its too much but on E85 you will be fine. The will have a nasty powerband

rotary1307cc

iTrader: (5)

Keep the aluminum in the deck where it belongs

El_Diablo

iTrader: (9)

See sig....nasty torque with a cenrti and wasnt done yet but for belt slip.

2000SS1979

iTrader: (16)

I got a buddy making nearly 800WHP on a forged LS1 with 11.5 compression on E85. He has been for about 2 years now. It's a turbo car and he hasn't has any issues. I should point out he just switched to E85 last year. He was running 93+ Meth making the same power the year prior.

I'm going the same route as him high compression Turbo. Whatever you decide, you'll have fun with I'm sure of that.

El_Diablo

iTrader: (9)

My car averaged 32 mpg last week, combined..three 1/4 mile passes, some town, mostly highway. Thought it worth mentioning now that e85 isnt much cheaper.

Rise of the Phoenix

iTrader: (27)

Good to know if I ever wanted to go with a Procharger down the road.

The Alchemist

iTrader: (19)

My CR is also mid to high 10s, and it's one of the reasons I made 700ft/lbs of torque on 15psi on a 346.

WS6ICK2k

Great advice in this thread thanks everyone I might just leave them alone to keep my options open, and also run thinner head gaskets. Not looking to lose any integrity of the thicker deck castings even if I do lose some power at the moment NA. These torque curves posted above are insane. Just trying to look down the road and my future goals.

I'm planning on staying on the smaller side cubic inch when I do go forged. Most likely a forged 347 since they have good longevity compared to a lot of the strokers.