Trying to find out more info about the thrasher heads and cam package

[mike24]

So......... $900.00 = 38 hp? as far as heads?

what about the ones with titanium springs and such? the $1900?? ones

Im still not clear on the "trim levels of heads they offer. and prices, gains....etc.

and will the blower cam work with a turbo?

[RiceCooker]

<BLOCKQUOTE>quote:</font><HR>Originally posted by TheCardinal:


Thrasher clearly states "These heads will now support an extra 38 HP on a normally aspirated engine, but it's much more difficult to put a number on the HP gain with an artificially aspirated engine as various factors such blower over/under drive and displacement, intake tract restrictions, and your exhaust system will affect the power gain. "<HR></BLOCKQUOTE>

Stating something and having proven numbers to back it up are two totally different things. Lets keep in mind that the proven #'s come from a s/c motor, not n/a. Even though the L36 and L67 motors are almost identical, the differences really make up for a lot. Motors w/ a power adder make use of a p & p a lot more than n/a motors. Just remember how much James gained from his head job (not perverted) w/ the stock cam? None. You can have all the specs and speculations that you want, but until it's been proven it's only speculation. Also, the biggest volumetrix efficiency is not always the best. Just ask Agostino Racing.
Just b/c Thrasher has been working w/ the series II more than SSM, doesn't mean that they know more. SSM devoted it's time to n/a and juiced motors, where Thrasher devotes it's time to forced induction (L67 and turbo 3.8's). Those are two totally different sciences. Remember, speculation is just that, not proof. I'm sure Thrasher is competent in what they do and I would really like to see what the Thrasher package has to offer but they are not experienced in n/a applications. We just need another pioneer to try the package. The only thing I would have added to the SSM heads would be the titanium springs and retainers.
As far as math dictating performance, keep in mind that math does not account for discrepancies and differences from one motor to another.

[bluecmaro96]

i called thrasher a while ago and the guy told me that most 3.8 owners would only need the 3 main options and that costs just under 900.00 i know that i will go with thrashers package before anyone elses. no disrespect intended.

[Modd]

It must be great to have these options ,my 3.4 has nothing to offer . Custom is a word that means $$$$$ and i wish i was bickering over what cam and heads will offer me :D

[Dominic]

get your hands on PSCalc and run the figures for yourself... they line up mathematically and math doesn't lie if all figures are true.

I personally dont like the supersix head design, its too overbored in the exhaust and not enough in the intake, and the cam is too aggressive for street - much less the computer - no matter how cool it sounds.
Sorry Ricecooker, your car is doing a lot better than it was stock, but their gains didn't impress me much. At least it sounds cool though...

[HAZ-Matt]

Here's the cam you really need:
http://www.projecttransam.com/coates.htm
http://www.coatesengine.com/

[ September 18, 2001: Message edited by: HAZ-Matt ]

[Magnus]

<BLOCKQUOTE>quote:</font><HR>Originally posted by TheCardinal:
I don't agree with you Magnus.

Supersix doesnt provide any volumetrix efficiency numbers with their heads, and due to their undersized intake valve they are not nearly as efficiency.<HR></BLOCKQUOTE>

undersized intake valve? They offer the same intake valve that Thrasher does, stock valves. The only thing thrasher offers is an oversized valve which may be good for a high boost application, it won't do much for an NA motor.

Lets look at costs:

Supersix:
Heads: $489
3-angle valve job and assembly: $219
Total: $708

Trahser:
Heads: $511
3-angle valve job and assembly: $358
Total: $869

Now with Trasher, you can get an oversized exhaust valve and stiffer springs to run more lift. To run just the oversized exhaust valve (you need the titanium springs) it will cost you an additional: $505.30

To just run the springs (which you can use with supersix heads btw) will cost you: $363.24

Now lets compare the heads both using stock valve sizes:

First, Strangely.. both Supersix and Trahser have different stock flow results. So we are going to compare both their stock results to their ported results.

I have been looking at port volumes all morning and the numbers just are NOT matching up. Super six shows an increase in port volume while thrasher shows a decrease.. So lets just compare the flows.

Supersix:
Lift StockInt StockExh PortInt PortExh
0.05 34.60 28.90 36.20 30.00
0.10 62.40 54.70 64.40 55.30
0.15 91.10 86.60 92.80 85.80
0.20 116.3 116.9 123.9 115.6
0.25 142.7 136.5 152.3 145.0
0.30 164.1 149.6 170.5 160.4
0.35 179.0 155.2 188.0 180.0
0.40 189.6 158.1 202.3 186.0
0.45 196.9 161.4 214.3 188.8
0.50 199.6 163.0 220.1 193.0
0.55 197.8 164.0 226.2 194.4

Trahser
Lift StockInt StockExh PortInt PortExh
0.20 111.8 102.5 124.7 111.0
0.30 154.6 133.9 167.5 146.5
0.40 176.0 144.8 185.0 168.8
0.45 182.5 147.1 208.6 173.8
0.50 186.5 146.6 211.2 182.1

Flows at .50 lift
StockInt StockExh PortInt PortExh
Supersix: 199.6 163.0 220.1 193.0
Trahser : 186.5 146.6 211.2 182.1

Gains at .50 lift
Intake Exhaust
Supersix: 20.5cfm 10.3% 30.0cfm 18.4%
Trasher : 24.7cfm 13.2% 35.5cfm 24.2%

Now, what does this say? Which set of heads is better? I dunno, its hard to tell because the stock flow rates from each company are different. Trasher gains more from their baseline results, but Supersix has more flow according to their tests..

So with info like THIS.. and not.. oh this company has been doing it for so long and that company has just sarted, etc. etc... use facts and #'s.

[3.4 slow to go]

larger runners= higher rpm performance, better top end
smaller runners =more torque/excelleration up to a certain rpm

[bluecmaro96]

magbus no affense but all that says is supersix cam is 800.00 because the package is 1500.00 and if the heads are 700.00 the cam would have to be 800.00 and thrashers heads are around 900.00 and cam is 300.00. i dontcarhow aggressive a cam is there isnt one in this world worth 800.00

[Magnus]

Ya know, when I first opened this thread.. I thought.. SWEEET.. another GREAT technical post. Lets bust out #'s and compare results.

Then, I open it today and I realize that countless people have turned this topic into what I think is crap. Many of the responses are not really helping James. A lot of the cost replies could have been put in their own topic. Or, you can just go to Supersixmotorsports.com or Thrasher Heads

Supersix cam is $289 plus a $45 refundable core charge.

bluecmaro96, you are forgetting about charges for both upper and lower intake porting.

Many of you are not realizing that the Supersix package comes with both upper and lower intake that has been ported!

Supersix heads are still cheaper than Thrasher. Supersix cam is cheaper than Thrasher. With Supersix you can get your cam to a custom grind, can you do that with Thrasher? Will thrasher to upper and lower intake work for you?

I have said this before and I will say it again. The only thing Thrasher offers that no one else does is an oversized exhaust valve and titanium springs/locks/retainers.

WHICH I might add you could buy FROM thrasher and have them put on your super six heads.. OR.. you can wait for Tom at supersix to figure out what he plans on doing with the spring dilema we have.

So, many of you want to give your money to Thrasher for what reason? You do not know. You just THINK that they make better heads because they have been doing it for a while. Let me tell you, its not that dificult to CNC a port. You just make it bigger, it doesn't take a rocket scientist to do that, it takes a machine, a good programmer and some test work. Supersix did that. They have flow results. I posted the flow results. Use the facts to make a decision.

Please, lets keep this topic ON TOPIC and help James out. If you do not feel like clicking the links I have pasted for you regarding prices and availability or any question you might have that does not help james in any way, please.. make your own topic.. we WILL help you.