Mast LS7 vs PRC LS7
11-05-2011, 09:05 PM
#21
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I'm am also interested in this debate.. What head will help give him a nice power curve ? I know it depends on what he wants to do with the engine purpose wise. I am debating my top end setup for my build also.
11-07-2011, 10:00 PM
#25
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1599 each bare vs 2400 assembled.
Head: LS7 12° 4.125" - 4.200" Large Bore CNC ( $1399.99 ) 510-206 (2) $2799.98
Intake Valves: 2.200" 5/16 Hollow Steel Race Valve (5.450") ( $23.99 ) 442-200 (8) $191.92
Exhaust Valves: 1.600" 5/16 Solid Steel Race Valve (5.450") ( $15.99 ) 421-600 (8) $127.92
Rockers: Large Bore Rocker Stand for GM LS3/L92 Rockers ( $39.99 ) 491-005 (2) $79.98
Springs: Dual .650 Lift Springs ( $375.00 ) 906-101 (1) $375.00
Retainers: Ti Dual Spring Retainer ( $11.99 ) 931-101 (16) $191.84
Locators: Steel Dual Spring Locator ( $47.99 ) 930-101 (1) $47.99
Locks: Machined Steel 7 Degree ( $35.99 ) 932-701 (1) $35.99
Total $3,850.62
11-08-2011, 02:45 PM
#26
If you want the better quality the Mast cylinder head is really nicely done. There is a lot to cylinder heads and much of it is going to be that which is expressly understood by the only builder/machinist/port engineer... and those like him/her. There are so many principles involved beyond flow numbers that when people start throwing flow numbers around I really begin to question their opinions. Horsepower is a product of how much air is drawn into the chamber- yes, but it is also a product of the shape of the port entry, the path of the air and stability of the air as it travels through the throat, enters the bowl and finally approaches the valve. Then there is the valve placement in the bore (centerline), valve job, the shape of the chamber, the location of the spark plug, etc... Consider that while the air has to be there, it has to be "high quality" air or, in other words, highly efficient in how it flows. We have to remember that the combustion process is also a part of how well a cylinder head works and this involves how the air/fuel is burned. Also throw in the fact that the designer of the cylinder head has years of education, data, research and new development all the time. I would be willing to bet the physical weight of a Mast LS7 head is actually substantially more than the TSP which indicates to me the casting is thicker or perhaps cast from a denser alloy. I believe the Mast has a thicker deck as well. Another excellent choice for an LS7 style head in an aftermarket heavy duty casting would be Allpro.
The GM LS3 is junk and other than being fit for a factory application, I wouldn't put them on any engine of mine. I would option for a large, well designed cathedral port or an LS7...or better such as a C5R, the new CT/DR or Mozez or LS-R. The aftermarket LS3 such as Mast builds has greatly improved valve centerlines which makes them a more refined and much more potent cylinder head.
But, after all this good to say about Mast, I have only dealt with ETP and Cary (Performance Inductions) prior to the merger with Mast. I tried to call Mast yesterday, three seperate times and no one answered. I guess every company has their shortcomings but if I can't get someone on the phone to make a purchase, I may look elsewhere. I didn't call to leave a message, I called to talk with someone and get some information.
11-08-2011, 06:08 PM
#27
^^^ Call Shawn at Virginia Speed. He might be able to help you out....
Mast was a little challenging to deal with for my heads. He may have something around the shop you need...
Mast was a little challenging to deal with for my heads. He may have something around the shop you need...
11-09-2011, 04:25 AM
#28
Nice looking work on the subframe.
If you want the better quality the Mast cylinder head is really nicely done. There is a lot to cylinder heads and much of it is going to be that which is expressly understood by the only builder/machinist/port engineer... and those like him/her. There are so many principles involved beyond flow numbers that when people start throwing flow numbers around I really begin to question their opinions. Horsepower is a product of how much air is drawn into the chamber- yes, but it is also a product of the shape of the port entry, the path of the air and stability of the air as it travels through the throat, enters the bowl and finally approaches the valve. Then there is the valve placement in the bore (centerline), valve job, the shape of the chamber, the location of the spark plug, etc... Consider that while the air has to be there, it has to be "high quality" air or, in other words, highly efficient in how it flows. We have to remember that the combustion process is also a part of how well a cylinder head works and this involves how the air/fuel is burned. Also throw in the fact that the designer of the cylinder head has years of education, data, research and new development all the time. I would be willing to bet the physical weight of a Mast LS7 head is actually substantially more than the TSP which indicates to me the casting is thicker or perhaps cast from a denser alloy. I believe the Mast has a thicker deck as well. Another excellent choice for an LS7 style head in an aftermarket heavy duty casting would be Allpro.
The GM LS3 is junk and other than being fit for a factory application, I wouldn't put them on any engine of mine. I would option for a large, well designed cathedral port or an LS7...or better such as a C5R, the new CT/DR or Mozez or LS-R. The aftermarket LS3 such as Mast builds has greatly improved valve centerlines which makes them a more refined and much more potent cylinder head.
But, after all this good to say about Mast, I have only dealt with ETP and Cary (Performance Inductions) prior to the merger with Mast. I tried to call Mast yesterday, three seperate times and no one answered. I guess every company has their shortcomings but if I can't get someone on the phone to make a purchase, I may look elsewhere. I didn't call to leave a message, I called to talk with someone and get some information.
If you want the better quality the Mast cylinder head is really nicely done. There is a lot to cylinder heads and much of it is going to be that which is expressly understood by the only builder/machinist/port engineer... and those like him/her. There are so many principles involved beyond flow numbers that when people start throwing flow numbers around I really begin to question their opinions. Horsepower is a product of how much air is drawn into the chamber- yes, but it is also a product of the shape of the port entry, the path of the air and stability of the air as it travels through the throat, enters the bowl and finally approaches the valve. Then there is the valve placement in the bore (centerline), valve job, the shape of the chamber, the location of the spark plug, etc... Consider that while the air has to be there, it has to be "high quality" air or, in other words, highly efficient in how it flows. We have to remember that the combustion process is also a part of how well a cylinder head works and this involves how the air/fuel is burned. Also throw in the fact that the designer of the cylinder head has years of education, data, research and new development all the time. I would be willing to bet the physical weight of a Mast LS7 head is actually substantially more than the TSP which indicates to me the casting is thicker or perhaps cast from a denser alloy. I believe the Mast has a thicker deck as well. Another excellent choice for an LS7 style head in an aftermarket heavy duty casting would be Allpro.
The GM LS3 is junk and other than being fit for a factory application, I wouldn't put them on any engine of mine. I would option for a large, well designed cathedral port or an LS7...or better such as a C5R, the new CT/DR or Mozez or LS-R. The aftermarket LS3 such as Mast builds has greatly improved valve centerlines which makes them a more refined and much more potent cylinder head.
But, after all this good to say about Mast, I have only dealt with ETP and Cary (Performance Inductions) prior to the merger with Mast. I tried to call Mast yesterday, three seperate times and no one answered. I guess every company has their shortcomings but if I can't get someone on the phone to make a purchase, I may look elsewhere. I didn't call to leave a message, I called to talk with someone and get some information.
What brand and size intake runners would you use for a boosted 427 lSX block ?
Would the TFS 245 be big enough?
I do like the mast ls3 heads and they would give me more supercharger manifold options than the ls7 heads for sure. I guess the cathedral port would give me plenty of options as well.
For me there is $1000 difference in price between the mast and trick flow heads however I do wonder what the performance difference would be between the two and would the mast be worth the extra dollars. Both brands are supposed to be excellent quality.
cheers
Jason
11-09-2011, 12:13 PM
#29
I am surprised you would recommend a cathedral port head?
What brand and size intake runners would you use for a boosted 427 lSX block ?
Would the TFS 245 be big enough?
I do like the mast ls3 heads and they would give me more supercharger manifold options than the ls7 heads for sure. I guess the cathedral port would give me plenty of options as well.
For me there is $1000 difference in price between the mast and trick flow heads however I do wonder what the performance difference would be between the two and would the mast be worth the extra dollars. Both brands are supposed to be excellent quality.
cheers
Jason
What brand and size intake runners would you use for a boosted 427 lSX block ?
Would the TFS 245 be big enough?
I do like the mast ls3 heads and they would give me more supercharger manifold options than the ls7 heads for sure. I guess the cathedral port would give me plenty of options as well.
For me there is $1000 difference in price between the mast and trick flow heads however I do wonder what the performance difference would be between the two and would the mast be worth the extra dollars. Both brands are supposed to be excellent quality.
cheers
Jason
https://ls1tech.com/forums/drag-raci...aulic-cam.html
11-09-2011, 12:18 PM
#30
11-09-2011, 07:07 PM
#31
The TFS is a very good head and would be excellent for boost. If you go with an aftermarket LS3 port, Cary's heads are the cats meow. But, I say if you are going to go LS3 you might as well go LS7- better port entry and line of sight to the valve meaning more potential overall. BUT, there are some very fast cathedral ports out there! There is a thread on here right now of a guy running a TFS head in the 8.90s with a 3050ish race weight stock suspension 4th gen and a hydraulic cam! Greg Good has done some very fast cathedral ports too which I believe were based on an ETP casting which is Cary's stuff or Mast now. Check this link:
https://ls1tech.com/forums/drag-raci...aulic-cam.html
https://ls1tech.com/forums/drag-raci...aulic-cam.html
Thanks for that link and your input; that link certainly opened my eyes up and I guess that with the TFS 245 and a bit more cam there would be a few more ponies to be had N/A.
With boost I assume this combo would make huge power and probably be more drivable on the street or in my case off road.
Would I be correct in thinking that cylinder head port design and choice is less critical in a boosted application?
I also wonder if the cathedral port or rectangular port would have the upper hand with boost added.
If this 427 tfs 245 engine combo in the link; used the Mast ls3 heads how much extra power do you think it would have? My guess would be probably no more than about 20hp and a similar gain in torque.
I have all but ruled out the LS7 heads because with a P/D blower I have far more choices with the ls3 or cathedral heads. If I was looking at a turbo or a centrifugal blower set up; I would certainly use the LS7 heads, my choice of heads has now been narrowed down to the tfs 245 or the mast ls3 and I need to weigh up the H/P vs $ value and the cathedral vs square port flexibility of manifold choices and roller rocker options.
What heads do you run on your LSX 438 that is listed in your signature?
Cheers
Jason
Last edited by gouldy; 11-09-2011 at 07:10 PM. Reason: typo
11-09-2011, 11:49 PM
#32
Performance Induction (Mast) LXR-275 which is a cathedral port. I had the Super Victor manifold from my previous engine which I got before any of the LS3 or LS7 stuff hit the streets. It was also a Christmas present from my dear mother so it has some sentimental value (as goofy as that may sound). I know the cathedral ports can be fast, so I stayed with it. They are Cary's latest and best effort cathedral head. I ordered those direct from him prior to his merger with Mast and I absolutely trust his word. Excellent guy to work with too; very personable and accomodating. I just fired it a couple weeks ago and I can tell you it feels very strong on the street but I should have some track data this Friday. Fwiw, my old engine was 404cid, ETP-225 heads, 239/243 cam, 850 carb, pump gas and the car at a 3200 race weight, 3.89 gear, drag radial, full exhaust, footbrake ran a best of 10.110 @ 133.49.
Always thinking towards the future....If I ever change heads on the LSX it will be to a C5R style port like Cary's (Mast) PXR. I hope to work with him on that project too. My current heads/intake will most likely be transferred to an engine going in my C-10 build. But honestly, that thread on the 8 sec hyd roller 4th gen really makes me want to work harder to make my current stuff as good as it can be.
Last edited by melsie68; 11-09-2011 at 11:55 PM.
11-10-2011, 06:44 AM
#33
I find it interesting that the op in the 8sec thread claims that he has out of the box standard TFS 245 and is making 650-670hp.
Maybe he is trying to make these heads sound a lot more standard than they really are.
Maybe he is trying to make these heads sound a lot more standard than they really are.
11-10-2011, 06:59 AM
#34
TECH Regular
I just bought a set of PRC's and cam from Texas Speed. Next month I will be putting everything I bought from them on my GTO.
When I received the heads, I opened up the boxes and all I can say is WOW! very nice work. They machined the heads to match what cam I decided to go with so I know that it will work.
I can't say anything bad about TSP, because they never tried to sell me anything more than I needed. I really appreciated that.
When I received the heads, I opened up the boxes and all I can say is WOW! very nice work. They machined the heads to match what cam I decided to go with so I know that it will work.
I can't say anything bad about TSP, because they never tried to sell me anything more than I needed. I really appreciated that.
11-10-2011, 07:05 AM
#35
I was recently told that TFS are making an LS3 head and they are still working on some final port work but should be ready soon.
Does anyone know anything more about these heads?
Does anyone know anything more about these heads?
11-14-2011, 09:16 PM
#36
Fwiw, I ran my car Friday (this is a cathedral port motor) to a best of 9.85 at 138.43 for the day. Again, I am not sure what your goals are, but at my weight that mph translates to somewhere betweem 730-745hp. I use the mph because my 60-foot and 1/8th mile times are way off from the mph and 1/4 mile ET. Once I get the car to leave better it should run into the 9.60's. I am still a hydraulic roller and pump gas.
Best of luck to you.
11-14-2011, 09:38 PM
#38
TECH Fanatic
While I would say the Mast product is a better one for a number of reasons, I believe you would only really see the benefit in an N/A application. The port designs, chamber design, valve placement and spark plug location in the Mast heads are all a product of years of development by Cary Chouinard. If you look at the repertoire of heads Cary has worked on, the fact that he was one of the first to produce aftermarket heads for the LS platform and such puts a lot in his favor. There is far more to a cylinder head that flow numbers and you can take that to the bank. There are heads out there which can flow more air but make less horsepower. But without getting into all that, a boosted engine just needs a solid casting that will take the stresses involved. If you were building an all-out class motor, then yes you would want the best port available and in that case an LS7 port would not be my first choice. In summary, I think the PRC will get the job done. I would have my local machine shop check the guide fit and valve job though.
...looks aren't everything either...I would be willing to bet the Mast casting is more robust in a number of areas and you can bet the material used is what they say it is AND is a USA casting.
...looks aren't everything either...I would be willing to bet the Mast casting is more robust in a number of areas and you can bet the material used is what they say it is AND is a USA casting.
