Dads62

Anyone using Mast 240 small bore heads or other small bore heads on their LS3? I'm looking at some to bump the compression on my LS3 with a stock bottom end. Feedback and cam info you are running would be appreciated. I can't find a lot of information on a setup like I am looking at.

Thinking about those heads with a .600 to .625 lift cam. Possible intake and possible TB with headers.

mchicia1

iTrader: (5)

There are a few of us on here (myself included) that have been waiting for someone to take the plunge and report back...

The only guy I know of who has these heads is that SIG guy. He had great results in a 5.7 in a heavy sedan with no drag pack trapped in the mid 120s.

I want to try the heads on my G8, I'm just not sure if they are worth $2500 more over ls3 heads when using a mild cam. If a radical cam with radical lift is required to get good results over regular ls3 heads, I'm not buying them.

https://ls1tech.com/forums/11-second...c-h-c-ls1.html

Dads62

I'm surprised no one has them on an LS3 just for the compression bump alone. They have been out for a while so someone has to have them.

mchicia1

iTrader: (5)

The price will drive most away, unfortunately. That is what drove me away. I need to know they make 50+ over stock LS3 heads before I would invest that kind of coin.I would be sorely disappointed if it was only like a 20 hp gain, or you needed some radical cam setup with a vic jr intake to really take advantage of them.

It's not hard to get compression out of ls3 heads, mill .030" and use a .040" cometic = mid to high 11's, so I wouldn't buy them just for compression.

One huge advantage on the MAST heads is they have miles of PTV, so you don't have to flycut to put a big cam in.

Dads62

Fly cutting is a definite deal breaker for me. If I knew I could mill the heads to get 11.5:1 and still have the PTV I would go that route. I was thinking the TSP MS3 110/112 LSA cam would be plenty for what I want.

Can someone verify this would work?

mchicia1

iTrader: (5)

I highly doubt that would clear on a milled ls3 head.

DavidBoren

Buy them. Report back to us. Be a pioneer, sir. Someone always has to go first, it might as well be you.

Personally, for that type of money, if I wanted a 240cc intake runner, I would be using some Mamo-fied MMS235 cathedral port heads.

mchicia1

iTrader: (5)

There is a guy on the GTO board who just bought the "4.0" version. The next size up. I'm waiting for his results.

I just pulled my heads for Johnson 2116 $600 lifters. I'm not pulling them again for quite a while. I'm certainly not spending $2500-$3k for basically unknown heads. I know guys on YB use Mast heads, but they are in radical setups. No one online has really used them in a street setup. I'm sure they're out there, but I haven't seen any.

http://www.ls1gto.com/forums/showthread.php?t=779313

mchicia1

iTrader: (5)

To be honest, I regret not just sending my heads to AI for their porting program while I had everything apart.

I had great results with them in the past.

https://ls1tech.com/forums/dynamomet...-714hp-na.html

Rise of the Phoenix

iTrader: (27)

I'd run the tried and true TFS 245cc cathedral port heads before I'd run those MAST heads. The TFS 245cc heads are about as good as it gets on the larger cubicinch engines.

Dads62

Why cathedral port vs the rectangle port. I looked at the TFS 245 heads but didn't consider them much because they were cathedral port and I have heard that the rectangle port heads were better. I have read the cathedral ports are better in the low end torque which is something I am worried about with a bigger cam. I am not an expert and there is so much information out there I'm not sure which is true and which is not.

I would need to change from my stock LS3 intake to a cathedral intake wouldn't I?

I'm also looking at the PRC 255 heads and milling them to 64cc chamber.

Rise of the Phoenix

iTrader: (27)

Heads that make better low end torque and a bigger cam is a major winning combo. Plus, those heads make great power up top. There is a guy running TFS 205cc heads with a big cam and a LS6 intake on a 346, and he's making over 440 rwhp. I think the TFS cathedral port heads will make more power throughout the powerband over LS3 style heads. I personally would run cathedral port heads until I had the cubic inches to run LS7 heads.

KW Baraka

iTrader: (7)

You gonna mill them yourself or are you letting TSP deliver them to you at 64cc?

I had them do my PRC 260 heads (on my SS) to 65cc. Really nice heads, BTW .

KW

Dads62

Was going to let TSP do it.

Dads62

I think I may have switched philosophies.

Been doing some reading an from what I can tell cathedral port heads make better low end torque than the LS3 rectangle port heads. Since I want to keep as much low end torque I can I'm thinking this may be a better route for me. I realize I will give up some power in the top end but that is of no concern to me since it is NOT a race car.

Here is my new line of thinking.

TPS 237 heads milled to 63 or 64 cc depending on PTV clearance and a cam. What cam is still to be determined and the $64,000 question. Maybe the MS3 238/242 .600/.600 112LSA. I really like the sound of this.

I would have to change from my stock LS3 intake. From what I read the LS6 intake is the way to go. Would stock LS6 be ok for my application or should I upgrade to the FAST intake. If the FAST helps the low end I will upgrade but if its a top end upgrade then it is not worth it to me. Same with TB.

Seems weird to me to put older heads on a newer motor when everyone is going the other direction but from what I can tell this is the type of package that would give me the sound and low end torque I want.

Thoughts?

Rise of the Phoenix

iTrader: (27)

What is your budget on heads? If your budget is large, I'd look hard at the TFS 235cc or 245cc heads. As far as the LS6 intake goes, it's going to be a restriction, that's not debatable. I lean toward thinking it's going to be a restriction in the lower RPM range on heads that flow like the PRC 237cc, TFS 235cc, TFS 245cc, etc. Plus, it sounds like you plan on going with a fairly large cam, so a better flowing intake is going to help everywhere in the powerband.

As far as the cam goes, I'd wait on the cam until you determine exactly what heads and intake you are going to run. From there, have someone do you up a custom grind, or talk to someone like Brian Tooley, Ed Curtis, Vengeance Racing, Texas Speed, Tick Performance, etc. about possibly using one of their shelf cams that may work well with that combo.

DavidBoren

Good call. I am a big fan of the cathedral port heads. I would really look into the TFS220's touched up by Brian Tooley, a Fast intake, and a custom cam.

Dads62

Unless I'm reading it wrong the TFS site says the 235 has a near stock combustion chamber so they would not raise my compression any and the 245 that is the lower cc says it won't work with my bore size. Am I missing something?

I was thinking 2500 to 3k for the heads.

So going with an upgraded intake is prob a good idea. Should I upgrade the TB. I'm thinking might as well do both.

DavidBoren

Would you care to share why you want such large intake runners? We are talking about an LS3 shortblock, right? The TFS220's seem like an excellent match, in my opinion.

Dads62

Yes. Stock LS3 short block. I don't know enough about intake runners so I was not even looking at the size of any of the ones I have considered.

I was mainly looking at combustion chamber size, flow rate and valve angle for PTV clearance.

Flow rate on the 220 seems not quite as much as the stock LS3 head, I would think I would want at least that much flow wouldn't I?

What should I know about runner length?