Dyno Comparison for TFS 44cc Ported Heads vs PI Ported Heads with same VT Stage 2 Cams

So I was just going through some old Dyno Charts and wanted to share some of the comparisons I found and notes to help those looking to add power to their 2Vs.

Below is a Dyno comparison that Pro-Dyno did back in the day (2007ish) to show what type of gains can be made from Ported PI heads and switching to TFS Heads (Which were ported by Fox Lake).

A Couple of things to note:

- This was on different day's and about a few weeks apart.
- The same VT Stage II cam was used
- I did find out much later that the exhaust valve timings were off due to PI specific cams in a TFS Heads but does show a good comparison as a baseline.
NOTE: The valve timing on the exhaust could be off as much as 10 degrees and MHS has a video on youtube that explains this..
- This is with the Stock PI intake and 78mm BBK TB Combo
- The TFS Heads would have benefitted from a higher lift cam and proper timing - Dan from Pro-Dyno had to tune around the issue in low/mid Timing and Fuel curves as he noted something was odd at the time due to the PI cam in the TFS Head as we now know...
- This would have picked up more HP and TQ with a higher lift on intake and exhaust so could have been a bunch on the table in the low, mid and high ranges since the 2v likes a lot of timing in the low to mid range which launches into the higher RPM range...

Apples to apples it was a great increase and shows the potential for the TFS Heads and setup..


  • Dyno Comparrison Ported TFS vs Ported PI Heads.jpg
    Dyno Comparrison Ported TFS vs Ported PI Heads.jpg
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The best pulls I did after a few tweaks were 357/355 to the tires... car ran 12.20s with the Ported PI Heads and then ran 11.6s with the TFS heads....MPH went from 111 to 116 in 1/4 mile trap speed Naturally Aspirated ...

Working to really see what these heads can do on a 5.3l Ford Racing 5.0 block/stroker.... with a correct TFS Cams ....

Another thing to note is power from 3000 to 4750 was really affected by the PI cams in the TFS heads due to the Exhaust valve events that were off ..... you can see that in the chart where the lines almost overlap in power.... having a lot of experience with tuning this is the point where the rpms launch for timing and fuel trims .... as noted Pro-Dyno had to adjust the timing and fuel trims at low and mid rpm range to compensate and try to tune out some of this..... assuming the same grind with the exhaust events set for the TFS Heads I believe there was another 10-12hp over the current top graph ....with more lift supporting the TFS heads another 20-25 down low and mid curves is possible and 12-16 in the upper range based on PI intake curve I would assume with a slightly better cam profile to match the heads and flow these heads produce..... The ported TFS flow 263cmf at .055 lift and 268cmf at .060 as an example.... If I remember correctly the Patriot Ported PIs were around 228 cmf at .050 as a comparison but dont have the flow numbers anymore.....

So I have been researching various builds and set ups with cam profiles. I found a lot of interesting data on what people have done.

I talked with MHS Team and 400 to tires seems fairly common now with the 5.3l BB Stroker, stage 4 cams with their TFS R heads, long tubes, and Eddy Intake combo....most are pushing 440ish with this set up but haven't seen any dyno sheets for curves.

I reach out to Trick Flow and did some research on their engine dyno builds from the past few years with their 5.3l, TFS R Heads, 11.6 to 1 CR on pump gas and cam profiles...... They put down 466hp and 414tq with their intake using their cam with .580/.580 lift and 274/274 duration building peak power at 6400 rpms and peak tq at 5100rpm.....

I saw they did a second test, same combo with a special comp cam grind of .625/.625 lift with much less duration using a 252/256 duration ....put down 518hp at 6900 and peak tq of 417 at 4700rpms.....

Looking at the 2 results using the 5.3 l and TFS R Heads it seems the flow of the R head combined with the addition of 42 cubic inches will support a lot more airflow and responds drastically with lift and less duration.... basically with going from .580 to .625 lifts on smaller profile netted 52 hp and 3 tq on a much better power curve..... the TQ curve was much flatter and power curve was much broader

I have been trying to reach an old friend who was building his wild NA car based on the eddy intake and back then he was using a corborated setup and put down 408 to the tires....don't remember the tq..... but saw recently that he did a custom cam, 12.5 to 1 CR on pump gas even, and switched to an EFI setup with the eddy intake....he didn't have cam specs but the car put down 500hp and 460is tq....I didn't see the power curve or peaks but really impressive...

I also found a build similar to mine with a bullet intake with the 5.3l using normal TFS 38cc Heads, MHS stage 4 cams, long tubes, and supporting mods and put down 393hp/398tq.... One big thing to note is the stage 4 cam behaved like a stage 2 cam with the larger bore stroker.... MHS claims the stage 4 cam shift the rpm range to 6700-6800 on a stock bore/stroke..... but with the larger bore the peak power and tq cam in under my set up with peak TQ coming in at 4000 and peak power coming in around 5200rpms..... this was with a .575 lift cam..... but the power dipped down well before 6600 so it seem the cam behaved almost like a stage 1.5 to stage 2 cam in that set up...

I am thinking with the added airflow of the stroker and TFS R heads, a higher lift cam but keeping the stage 4 profile would really improve power across the board, especially about 4800-5200 rpms and up..... considering intakes used and lift it could be worth 20-40hp more to the tires....

Still doing some more research on compression, cam profiles, and how to approach my build but thinking the 5.3l combo with the MHS TFS 44cc heads (they upgrade valves, guides, seats, and do some runner touch up... with a .600 to .615 lift on a 111.5 lsa with 236/238 duration would hold the power curve like a stock 281 with heads/cam combo with PI intake and 78mmbbk TB combo and full supporting mods to around 420-440hp and tq....

Having new edge power in a lightweight 2v with 1000 less lbs of weight would make for a super fun street sleeper..lol.. My ultimate goal is to make over 400+ HP/TQ, run in the 10's in the 1/4 and will just be a cruise car for car shows with an occasional trip to the drag strip...

Has anyone else been planning a build for their old play toy?



New Member
Oct 6, 2003
Zeeland, MI
I’m not on here much anymore, but I just found your posts on your research/build interesting. I currently have tfs 38’s on a 20 over teksid block with coyote rods, 9cc pistons, and a port matched svo intake. I currently dynoed at 343/335 on a mustang dyno. You’ll have no problem getting to 400+whp.
So.... I found a very interesting video from youtube - (How to properly select a Camshaft). I searched multiple articles, videos, and sites that talks about duration, lift, LSA, size of engine, head flow, and many other characteristics to no prevail.... but this guy teaches like a professor in layman terms on selection and explains everything in detail in his video on all aspects and has a part 2 as well... needless to say, with head flow information, basic math formulas, goals you are trying to accomplish, and how to get the best cam based on setup.... I finally understand the basic math and how to match cams to a combo without relying on of the shelf cams ... I will explain what I found..
So back in the day, there was always 1 cam that everyone had great results from.... the VT Stage II cams which is now CMS (Cushman Motorsports) .... from single to dual plane cams I fully understand now how heads flow from intake to exhaust flows and how to view at a glance with some basic math what lift you need based on results..... Single plane cams are where the lifts are the same on both exhaust and intake.... this is good when the percentage of flow was over 75% combined based on some simple math.... (go watch the video to learn more) .... basically the stock and ported PIs were well below the 75% threshold ..... when this happens you need more lift on the exhaust that you do on the intake side.... and guess what.... the old VT stage 2.5 cams fit this to a tee... most comp cams and other ran .500 to .550 lift as a single plane design which was off from a design flow methodology.... the VT stage 2.5 cams had .550"/.560" lift, 230/236 .050 duration, 109 LSA .... and they fit under the stock heads.... they are the perfect match for the old PI Heads and worked even better with ported heads...... I pulled a ton of different after market cams and they were the only dual plane cams I found....go figure .....
For my new build, I will have to wait and see what cams I will need based on the head flows for the TFS R heads with the bigger valves for intake and exhaust, improved guides and seats, with a little port work...... I would assume the flow for the exhaust and intake are in the 75% ranges for these heads based on the video which would require a single plan cam design.... It also taught me how to figure out piston speed very simply and where the safe levels are based on basic math .... stroke x desired RMP, then divide by 6.... there is a couple other variable to throw in but 4000 feet per second will be a long-lasting engine for longevity and can select the cam based on rpm range of the engine.... he did note 4500 ftps would be fine but at the upper echelon of range for example the stroker I want is 3.75 x 7000rpm (you can do this for each rpm range fyi) divided by 6 and it would have a piston speed of 4375... that is basically telling me how to select the duration or rpm range of the cam for the stroker..... Ultimately, I will be spinning around 6800 top with shift point around 6300-6500... or about 4125 feet per second for piston speed.... for comparison the 4.6l stock stroke is 3.550 and at 7000 rpms would have a piston speed of 4142 ftps....
I am trying to find my flow chart from Fox lake with the TFS 44cc heads they ported but remember it was still picking up flow just over .650 lift.... where the cfm stops, you back off a bit to find the lift needed to support the heads.... he also has some calculations based on the head flow methods that can show you the max HP the heads can produce but need to gather my specs to figure out exactly..... bottom line.... so many people buy off the shelf stuff and it is very wrong for their set up.... I also noticed that the TFS R heads flow way better that the stock TFS Heads so a custom cam profile is definitely needed...

I noticed the MHS stage 4 cams noted shift points near 7000 rpm.... but with the stroker results the same cam peaked at 5200 rpms..... so basically about 1600 to 1800 rpms lower based on the 42 cubic inch increase from the 281 to 323 stroker.... with the R head it will carry out the RPM and build closer to 6000 peak HP so the MHS stage four cam design with 236/238 lifts @.050 and then finding where there ported head flow numbers are.... I think the lift would come in around .600 to .625 or somewhere inbetween.... I also found a cool video on LSA comparisons with same lift durations and the lower the LSA the more low end power/torque you get without sacrificing top end power.....it was very interesting..... a good mas lsa for a street car NA is between 108 to 112 lsa which would give a slightly choppy idle but great throttle response and low end power........ Higer LSAs from 112 to 114 would smooth out the idle but have show to lose a little low end power/tq by about 5hp or so ..... so the stage 4 MHS cam on the 111.5 lsa with a lift of .600 to .615 is where I will be shooting for... with the added flow it will perform great with my combo and have well over 400ph/tq to the tires.... My math comes in around 415-430 HP and same in TQ to the tires...... that would be with the PI intake as well with some runner clean up and BBK 78mm combo... and that would be putting the power down in the same rpm ranges I was at before from 3200 to 6500rpms....
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I am doing a bit more research on 93 pump gas, How high compression I can run and bleed off compression based on LSA .Overlap... basically the time between duration of the lobes.... think like this 236/238 is a narrow duration where more overlap would be 232/238 for example.... this has an effect on cylinder presser and how to blead off some and at what rpm range from low to high to keep things nice and safe (example would be lowering the LSA to gain low to mid range tq and adjusting the duration for where to want to place top end power)..... goal is to come in right at 195lbs of compression per cylinder which is perfect for 93 octance.... my old CR came in at 13.43 CR with 190 PSI per cylinder if I remember correctly... so 11.5 is extremely safe with a good dyno tune..... going higher may require to lower the dynamic pressure of the engine even though the static pressure is around 12 to 1 for example....you can either tune for 93 and then drop a race gas mix to up the octane a few points or add in octane booster or you can do this with lowering the LSA and with larger overlap on the cam profile... great stuff.... watch the video folks.... you will learn so much... part 1 about 30 mins...same as part 2... all questions answered about how to select a cam.....

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So started buying parts for replacement and upgrades... got the BBK drop in fuel assembly with 300lph pump, new FR500 black rear rims with chrome tip... sent some parts off to paint shop, new power stop front and rear red calipers and new ACC interior and trunk carpets....still waiting to source the 5.0 Boss block but Ford Racing noted late April to May when they come in.....deciding weather to use my ported 44cc TFS heads and have them refreshed or just get the MHS 44cc TFSR Heads that they rework..they wont be available until May as well....cant order cams until I know exactly what the head flow numbers are so will just buy supporting mods for now....car is starting to look new again!

Looking to get the Stall Coverter refreshed as well.....currently have 9.5in 4000 stall single disc...thinking of bumping to 4200....with a locking stall I guess it really doesn't matter much....doing some runner clean up an TB port clean up....lots of little details while I'm in a wait status....did some more research on cam and intake specs... intakes are the limiting factor on these motors...if I cant hit the numbers I want I have an idea to use the Victor Jr EFI with 3160 TB....then take an old pi intake and cut out the bottom flange of the intake to place under the Victor Jr....can get more airflow and make the runner lengths a bit longer to get better TQ and play with rpm peak power....not sure if anyone gas tried that yet.....basically make it adjustable as short runner intakes rob a lot of TQ...and we are so limited on intakes..no reason the 5.3l stroker shouldn't hit 450 hp and over 400tq to tires.....just some thoughts...

Lol...contact MHS brother..
.there are a bunch running around in the 440s to tires...5.3l stokes with victor jr MHS cams....ect.....I haven't seen 1 with a PI Intake yet and not everyone posts on forums...off the shelf parts for intakes and cams are the limiting factors...few have hit 400 plus on stock bore.....go do some homework..



15 Year Member
Dec 1, 2002
Lol...contact MHS brother..
.there are a bunch running around in the 440s to tires...5.3l stokes with victor jr MHS cams....ect.....I haven't seen 1 with a PI Intake yet and not everyone posts on forums...off the shelf parts for intakes and cams are the limiting factors...few have hit 400 plus on stock bore.....go do some homework..


It must be fun living in the fantasy world you are
If fantasy seeing a friends build on dyno hit 408 on a 281 aluminum block 11.5 to 1 CR with victor jr intake corboratted hit over 400 at 6500 rpms then I must bu e in fantasy land... the 4.6 has hit 400hp to tires with 281 but with the short runner intakes the Tq is a limiting factor....there is a dyno chart from a bolt on 01 bullet that hit 393/398 with stock bullitt intake, stock 38cc TFS heads, MHS stage 4 cams, on a 5.3l boss block... that's with headers and a few other supporting mods....the were a few other items he could have done that would put that setup close to 430/430 to tires...using same intake....you obviously have no clue about how to build an engine NA...there are limits to every engines hp...not many found the 281 2vs as it os too easy to just go blower...my engine is currently blower ready and built for 1000 hp....just not interested in that route anymore.....there are 2vs running 9s NA now.... go ask the big boys..