User Tag List

+ Reply to Thread
Results 1 to 37 of 37

Thread: Pinto Cam Selection...Race....

  1. #1
    Tyre Kicker

    Join Date
    Nov 2017
    Location
    USA
    Posts
    9
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Pinto Cam Selection...Race....

    Hi Everyone,

    Looking for some help selecting a cam. I've been looking reading a bunch, but would appreciate the help!

    2.0, CP pistons, cosworth rods, 205 block
    Ported head, big valves
    Locked distributor
    R1 bike carbs

    Desired power band 4000-7500 (Occasionally higher, but that is what I shot for)
    I'd like it to idle ok, but this is a race car, so not of great concern.

    Power goal is 180hp or so. This car runs a Hewland LD200, so much more then that would cause issues.

    Thanks!
    Jim
    Attached Thumbnails Attached Thumbnails 34795282_10156634798149203_5192490790848299008_n.jpg‎  

    Last edited by JSGAuto; 17-10-2018 at 12:18.

  2. #2
    Racer Decade Plus User

    Join Date
    Mar 2010
    Location
    Edinburgh
    Age
    46
    Posts
    3,641
    Thanks
    68
    Thanked 234 Times in 230 Posts

    Re: Pinto Cam Selection...Race....

    Kent Ht1e, with 11.5 - 12:1 compression.

  3. #3
    Mechanic

    Join Date
    Aug 2015
    Location
    Leeds
    Posts
    767
    Thanks
    34
    Thanked 27 Times in 27 Posts

    Re: Pinto Cam Selection...Race....

    http://www.turbosport.co.uk/showthre...ighlight=There a bit of discution here about the cam above.

  4. #4
    TURBOSPORT SPONSOR Turbosport Subscriber
    Turbosport Moderator
    Turbosport Administrator
    Graham's Avatar
    My Race Car
    My 1st Project
    Join Date
    Feb 2006
    Location
    Ely, Cambs
    Age
    56
    Posts
    25,110
    Thanks
    310
    Thanked 2,476 Times in 2,250 Posts

    Re: Pinto Cam Selection...Race....

    kent RL31 cam. wil give very close to the power of ht1 but a much better spread of power and not need as much compression

  5. #5
    Tyre Kicker
    My Race Car
    Join Date
    Sep 2018
    Location
    Australia
    Age
    48
    Posts
    28
    Thanks
    1
    Thanked 7 Times in 5 Posts

    Re: Pinto Cam Selection...Race....

    Hi From Aus,

    The latest engine packages I'm doing are around 250@50, lifting to around .480" with lash, around 300 deg inlet & 290 deg exhaust. Last one made 189hp and 162ft lb, peak power was at 7000rpm.

    The RL31 looks nicer than the HT1E for that sort of power level IMO

    Warren

  6. #6
    Tyre Kicker

    Join Date
    Nov 2017
    Location
    USA
    Posts
    9
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Re: Pinto Cam Selection...Race....

    Quote Originally Posted by Graham View Post
    kent RL31 cam. wil give very close to the power of ht1 but a much better spread of power and not need as much compression
    What kind of compression could I get away with?



    Thank you everyone for the replies! I am currently reading up on the different cams!.....Winter is coming here...looking forward to some motor projects!

    Jim
    Last edited by JSGAuto; 18-10-2018 at 15:51.

  7. #7
    Racer Decade Plus User

    Join Date
    Mar 2010
    Location
    Edinburgh
    Age
    46
    Posts
    3,641
    Thanks
    68
    Thanked 234 Times in 230 Posts

    Re: Pinto Cam Selection...Race....

    You need a very good head and the equivalent of 38mm chokes in DCOES to get 180hp on an RL31, in reality most engines achieve 160-170hp with one, given you're are running forged pistons you have many more cam options that require higher compression, other cam to look at is a burton BF63, but for a light race car looking for power between 4-7500rpm or sometimes higher as you say, Ht1e wouod definately be my choice, on a decent flowing head and properly set up carbs you'll see 180hp no problem. If you were using cast pistons and were limited to around 10.5:1 compression, wanted more low down grunt then id say an Rl31 but not for your application.
    Last edited by Erikmex; 18-10-2018 at 16:33.

  8. #8
    Racer Decade Plus User Forest_rallying's Avatar

    Join Date
    Feb 2013
    Location
    Derbyshire
    Posts
    2,438
    Thanks
    92
    Thanked 393 Times in 348 Posts

    Re: Pinto Cam Selection...Race....

    There's a graph sheet somewhere on this Forum where Onyd had 190bhp out of a Pinto with the RL31 cam on his static dyno, the engine was fitted with 36mm chokes.

  9. #9
    Tyre Kicker
    My Race Car
    Join Date
    Sep 2018
    Location
    Australia
    Age
    48
    Posts
    28
    Thanks
    1
    Thanked 7 Times in 5 Posts

    Re: Pinto Cam Selection...Race....

    Quote Originally Posted by JSGAuto View Post
    What kind of compression could I get away with?



    Thank you everyone for the replies! I am currently reading up on the different cams!.....Winter is coming here...looking forward to some motor projects!

    Jim
    That particular engine had 10.9-1 comp ratio. As stated, carbs were 45's and prepped (eg: my cnc chokes & modded aux vents etc).

    The key is in the cylinder head design. Interestingly enough, I did dyno a HT1E with a cylinder head from another specialist over here, it made the same hp a little higher in the range, but much less torque and a worse curve.

    I will post some pics of the dyno runs when I work out uploading images to this page!

    Cheer
    Warren

  10. The Following User Says Thank You to wozzah1975 For This Useful Post:


  11. #10
    Tyre Kicker
    My Race Car
    Join Date
    Sep 2018
    Location
    Australia
    Age
    48
    Posts
    28
    Thanks
    1
    Thanked 7 Times in 5 Posts

    Re: Pinto Cam Selection...Race....




  12. #11
    Tyre Kicker
    My Race Car
    Join Date
    Sep 2018
    Location
    Australia
    Age
    48
    Posts
    28
    Thanks
    1
    Thanked 7 Times in 5 Posts

    Re: Pinto Cam Selection...Race....

    Quote Originally Posted by Erikmex View Post
    You need a very good head and the equivalent of 38mm chokes in DCOES to get 180hp on an RL31, in reality most engines achieve 160-170hp with one, given you're are running forged pistons you have many more cam options that require higher compression, other cam to look at is a burton BF63, but for a light race car looking for power between 4-7500rpm or sometimes higher as you say, Ht1e wouod definately be my choice, on a decent flowing head and properly set up carbs you'll see 180hp no problem. If you were using cast pistons and were limited to around 10.5:1 compression, wanted more low down grunt then id say an Rl31 but not for your application.
    Haven't had much luck with a BF63 in my engines, 170-175hp normally pulls it up (with everything else being equal to the 189hp package I mentioned above), probably due to the wide lobe centres, and because it has so much advertised duration compared to the RL31 (especially on the exhaust) its pretty doughy down low in comparison. I'd suggest it has far less aggressive ramps than the RL31 also. Not something I'd recommend

    Warren
    Last edited by wozzah1975; 19-10-2018 at 05:45.

  13. #12
    Racer Decade Plus User

    Join Date
    Mar 2010
    Location
    Edinburgh
    Age
    46
    Posts
    3,641
    Thanks
    68
    Thanked 234 Times in 230 Posts

    Re: Pinto Cam Selection...Race....

    Ht1e it is then

  14. #13
    Racer Decade Plus User

    Join Date
    Mar 2010
    Location
    Edinburgh
    Age
    46
    Posts
    3,641
    Thanks
    68
    Thanked 234 Times in 230 Posts

    Re: Pinto Cam Selection...Race....

    Quote Originally Posted by wozzah1975 View Post
    That particular engine had 10.9-1 comp ratio. As stated, carbs were 45's and prepped (eg: my cnc chokes & modded aux vents etc).

    The key is in the cylinder head design. Interestingly enough, I did dyno a HT1E with a cylinder head from another specialist over here, it made the same hp a little higher in the range, but much less torque and a worse curve.

    I will post some pics of the dyno runs when I work out uploading images to this page!

    Cheer
    Warren
    It will do with only 10.9:1, Ht1e needs 11.5 minimum

  15. #14
    Tyre Kicker
    My Race Car
    Join Date
    Sep 2018
    Location
    Australia
    Age
    48
    Posts
    28
    Thanks
    1
    Thanked 7 Times in 5 Posts

    Re: Pinto Cam Selection...Race....

    Quote Originally Posted by Erikmex View Post
    It will do with only 10.9:1, Ht1e needs 11.5 minimum

    Agreed, I normally like 11.8-12:1 at least on something HT1E size. The one I posted the dyno pics above is on my custom cam I mentioned, which is similar to an RL31.

  16. #15
    Racer Decade Plus User

    Join Date
    Mar 2010
    Location
    Edinburgh
    Age
    46
    Posts
    3,641
    Thanks
    68
    Thanked 234 Times in 230 Posts

    Re: Pinto Cam Selection...Race....

    I see, i think if he was looking for something with more low down grunt an Rl31 would be the way to go but its a race engine where he wants power between 4-7500+, for that sort of powerband i think an HT1e will outperform an Rl31, my engine makes 196hp with one.

  17. #16
    Tyre Kicker
    My Race Car
    Join Date
    Sep 2018
    Location
    Australia
    Age
    48
    Posts
    28
    Thanks
    1
    Thanked 7 Times in 5 Posts

    Re: Pinto Cam Selection...Race....

    Quote Originally Posted by Erikmex View Post
    I see, i think if he was looking for something with more low down grunt an Rl31 would be the way to go but its a race engine where he wants power between 4-7500+, for that sort of powerband i think an HT1e will outperform an Rl31, my engine makes 196hp with one.
    That's my point. If he wants 180hp, rl31 should do, and you're right, ht1e will make more but at the sacrifice of lower rpm. I'm seeing 207hp @2020cc on a custom hybrid version of a ht1e with my latest cyl head design. 48 webers, tony law big bore pipes and 11.9-1.

    I'm in the process of changing the lobe centre line and giving it a bit more comp (into the 12s). Will post a thread on here when I'm done

    Cheers
    Warren

  18. The Following User Says Thank You to wozzah1975 For This Useful Post:


  19. #17
    Tyre Kicker

    Join Date
    Nov 2017
    Location
    USA
    Posts
    9
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Re: Pinto Cam Selection...Race....

    Thank you everyone, I appreciate the discussion.

    Top end is certainly the goal. I am finding that this car is losing the race due to lack of top end. I am getting passed on the long straights, I just don't have the high end power to keep up. (top speeds are currently 125mph @6900...before I run out of track). Reaching top speed from the last shift is the problem.

    Although, I won't ignore the low end. This is a road racing car. It does excellent at low speeds & corner exits. (and braking, I am 1200lbs)

    Currently the car has a stock-ish cam in it, and a mild head.(Previously ran a class with tight rules) Really, I think ANY head/cam package is going to make a significant difference.

    As I said before, I am power limited to the trans. So the RL31 cam sounds like a better fit. Power can reach my goal without hurting some lower grunt.

    I recently acquired a head with some work done & the larger valves. I'll post some pics to get some opinions on that as well!

    Thank you!
    Jim

  20. #18
    Racer Decade Plus User

    Join Date
    Mar 2010
    Location
    Edinburgh
    Age
    46
    Posts
    3,641
    Thanks
    68
    Thanked 234 Times in 230 Posts

    Re: Pinto Cam Selection...Race....

    You will need a very good head for 180hp on an RL31, what cam do you have currently?

  21. #19
    TURBOSPORT SPONSOR Turbosport Subscriber
    Turbosport Moderator
    Turbosport Administrator
    Graham's Avatar
    My Race Car
    My 1st Project
    Join Date
    Feb 2006
    Location
    Ely, Cambs
    Age
    56
    Posts
    25,110
    Thanks
    310
    Thanked 2,476 Times in 2,250 Posts

    Re: Pinto Cam Selection...Race....

    Currently the car has a stock-ish cam in it
    presumably nothing like as hot as the rl31 then.

    thing is if the head isnt that good then even an HT1 isnt going to much if anything over 180bhp

  22. #20
    Tyre Kicker

    Join Date
    Nov 2017
    Location
    USA
    Posts
    9
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Re: Pinto Cam Selection...Race....

    Cam Specs Attached.
    Attached Thumbnails Attached Thumbnails Stock_cam_spec.jpg‎  


  23. #21
    Racer Decade Plus User

    Join Date
    Mar 2012
    Location
    Belgium
    Age
    56
    Posts
    2,118
    Thanks
    7
    Thanked 197 Times in 169 Posts

    Re: Pinto Cam Selection...Race....

    Max power will be more related to the head work than the cam only. You just need a good head. Good heads make round 190 Bhp and little more, average heads always get stuck +/- 170 - 175 Bhp and even lower.

    For a light race car you can get use of the HT1e because compared to the RL31, BP300 you will be able to run higher in RPM (not making more power) but the engine will not stop willing to make more revs. That's what we found when I changed the HT1e back for an RL31. I'm talking in combination with a GOOD head. Torque was better, smoother in low RPM but occasions where you wanted to stay in 3th gear until you make it to the next corner (no time to change gear), the engine came to a limit of his RPM and dropped down where the HT1e was able to keep going for an other 500 RPM. In a light car it will not matter much the lower RPM is weaker. It's not an 850 Kg Escort, more like 450 Kg space frame with nice gears

    Getting past in the straight line by the same engine is usual you don't have the same power. Again, this is headwork, only minor cam selection.

    BTW, very nice car, I wish a had a car like this

  24. #22
    Racer Decade Plus User

    Join Date
    Mar 2012
    Location
    Belgium
    Age
    56
    Posts
    2,118
    Thanks
    7
    Thanked 197 Times in 169 Posts

    Re: Pinto Cam Selection...Race....

    If you don't have a serious head (not home build, forget about it) than RL31 will indeed be the most forgiven cam. It's always working.

  25. #23
    Racer Decade Plus User

    Join Date
    Mar 2010
    Location
    Edinburgh
    Age
    46
    Posts
    3,641
    Thanks
    68
    Thanked 234 Times in 230 Posts

    Re: Pinto Cam Selection...Race....

    Quote Originally Posted by onyd View Post
    Max power will be more related to the head work than the cam only. You just need a good head. Good heads make round 190 Bhp and little more, average heads always get stuck +/- 170 - 175 Bhp and even lower.

    For a light race car you can get use of the HT1e because compared to the RL31, BP300 you will be able to run higher in RPM (not making more power) but the engine will not stop willing to make more revs. That's what we found when I changed the HT1e back for an RL31. I'm talking in combination with a GOOD head. Torque was better, smoother in low RPM but occasions where you wanted to stay in 3th gear until you make it to the next corner (no time to change gear), the engine came to a limit of his RPM and dropped down where the HT1e was able to keep going for an other 500 RPM. In a light car it will not matter much the lower RPM is weaker. It's not an 850 Kg Escort, more like 450 Kg space frame with nice gears

    Getting past in the straight line by the same engine is usual you don't have the same power. Again, this is headwork, only minor cam selection.

    BTW, very nice car, I wish a had a car like this
    Exactly my point, he's looking for top end, RL31 is a great cam, but its a rally cam.

  26. #24
    Racer Decade Plus User

    Join Date
    Mar 2012
    Location
    Belgium
    Age
    56
    Posts
    2,118
    Thanks
    7
    Thanked 197 Times in 169 Posts

    Re: Pinto Cam Selection...Race....

    exactly, he is looking for top end AND this is a very light car, not to compare with Escorts. But as we both know, top end, full power will only be reached when you got a good head. If you don't have a pro build head, you will not make full power and best is not to use HT1e.

    We have always been talking about camshafts for Escorts in the past. Every car need a different engine and now we are talking about very light cars. So different cams as well.

    For any home build engine, my experiences are indeed the same as Graham have, the RL31 is always working. I've been using this cam in my very early days of home build engines and was always spot on. If you engine is not making power in the right power band with this cam, it's not a camshaft issue.

  27. #25
    Tyre Kicker

    Join Date
    Nov 2017
    Location
    USA
    Posts
    9
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Re: Pinto Cam Selection...Race....

    Pics of the head that I have.

    Try to look past the crustyness, It will be cleaned up.

    What do you think?

    I don't know any cyl head people here, and the Pinto is not a popular platform in the states. Finding an expert would be difficult.
    Attached Thumbnails Attached Thumbnails 20181020_092839.jpg‎  

    20181020_093130.jpg‎  

    20181020_093252.jpg‎  


  28. #26
    Racer Decade Plus User

    Join Date
    Mar 2012
    Location
    Belgium
    Age
    56
    Posts
    2,118
    Thanks
    7
    Thanked 197 Times in 169 Posts

    Re: Pinto Cam Selection...Race....

    Esslinger Engineering

  29. #27
    Tyre Kicker

    Join Date
    Nov 2017
    Location
    USA
    Posts
    9
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Re: Pinto Cam Selection...Race....

    Quote Originally Posted by onyd View Post
    Esslinger Engineering
    When I called (last winter), they said they were no longer supporting the 2L.

  30. #28
    Racer Decade Plus User

    Join Date
    Mar 2010
    Location
    Edinburgh
    Age
    46
    Posts
    3,641
    Thanks
    68
    Thanked 234 Times in 230 Posts

    Re: Pinto Cam Selection...Race....

    Head looks very basic in my opinion, someone in the UK like Vulcan Engineering, SRD etc could ship you a head im sure.

  31. #29
    Racer Decade Plus User

    Join Date
    Mar 2012
    Location
    Belgium
    Age
    56
    Posts
    2,118
    Thanks
    7
    Thanked 197 Times in 169 Posts

    Re: Pinto Cam Selection...Race....

    OK, did not know they where no longer supporting the 2 Ltr.

    Try Stephan at Vulcan engineering and ask for a stage 4 head

  32. #30
    Tyre Kicker
    My Race Car
    Join Date
    Sep 2018
    Location
    Australia
    Age
    48
    Posts
    28
    Thanks
    1
    Thanked 7 Times in 5 Posts

    Re: Pinto Cam Selection...Race....

    Quote Originally Posted by onyd View Post
    Max power will be more related to the head work than the cam only. You just need a good head. Good heads make round 190 Bhp and little more, average heads always get stuck +/- 170 - 175 Bhp and even lower.

    For a light race car you can get use of the HT1e because compared to the RL31, BP300 you will be able to run higher in RPM (not making more power) but the engine will not stop willing to make more revs. That's what we found when I changed the HT1e back for an RL31. I'm talking in combination with a GOOD head. Torque was better, smoother in low RPM but occasions where you wanted to stay in 3th gear until you make it to the next corner (no time to change gear), the engine came to a limit of his RPM and dropped down where the HT1e was able to keep going for an other 500 RPM. In a light car it will not matter much the lower RPM is weaker. It's not an 850 Kg Escort, more like 450 Kg space frame with nice gears

    Getting past in the straight line by the same engine is usual you don't have the same power. Again, this is headwork, only minor cam selection.

    BTW, very nice car, I wish a had a car like this
    Providing you're not sacrificing acceleration just for the sake of hanging on in a certain gear, yes, I can see the advantage. But if you do sacrifice acceleration/mid power that just means your car is further back in a given race track scenario to begin with. Ideally you have the best of both worlds.

    And I completely agree, a decent cylinder head is the key.

    Warren

  33. #31
    Racer Decade Plus User

    Join Date
    Mar 2012
    Location
    Belgium
    Age
    56
    Posts
    2,118
    Thanks
    7
    Thanked 197 Times in 169 Posts

    Re: Pinto Cam Selection...Race....

    From test work I've done, there was no difference in usable mid range to top power band between the RL31, Piper A8 and the Ht1e (it did was in different RPM ranges). Despite all 3 cams have different timing and lift at TDC. I feel (again in a good head) the A8 was the best compromise for a rally car. For road races in the light car, the HT1e advance must be seen. It's not possible the cam will drop out of his power range in any situation when you got a light car (not even in an Escort if you make no mistakes, later more about this one), correct gears and the speed to keep it there. It's still pulling very strong in mid range.

    The biggest difference between both RL31 and HT1e (these cams where most different, A8 is in between) is the fact it is much easier to setup your carbs (less lift at TDC), easier to drive at light load from stage to stage, easier when the tail of you Escort was hanging out where it did not had to be and you suddenly find yourself in a very low RPM range etc.... Things you will not find in a road racing lights cars.

    When headwork is not top, all start to be different and when you can't tune carbs as some of us can, the difference between RL31 and HT1e will start to be bigger also. Most people will have a better engine with HT1e and fuel injection because of the poor carb tuning they can expect from some local Rolling Road tuners ( I do not recommend trying to tune a HT1e with a rolling road anyway).

    For any car equipped with a camshaft like an RL31 it can build a set of DCOE's, put jet in it, balance and set CO screws with my eyes blindfolded and I will be within 95% of the power you will ever find. Not so for a HT1e, I prefer a good dyno to find the best compromise. Hope you got the picture.

    First question, do I have the correct head?
    Last edited by Dyno; 24-10-2018 at 07:47.

  34. #32
    Racer Decade Plus User

    Join Date
    Mar 2010
    Location
    Edinburgh
    Age
    46
    Posts
    3,641
    Thanks
    68
    Thanked 234 Times in 230 Posts

    Re: Pinto Cam Selection...Race....

    I must post of video of my car pulling from 2500rpm with an Ht1e and 48's-40mm chokes.

  35. #33
    TURBOSPORT SPONSOR Turbosport Subscriber
    Turbosport Moderator
    Turbosport Administrator
    Graham's Avatar
    My Race Car
    My 1st Project
    Join Date
    Feb 2006
    Location
    Ely, Cambs
    Age
    56
    Posts
    25,110
    Thanks
    310
    Thanked 2,476 Times in 2,250 Posts

    Re: Pinto Cam Selection...Race....

    Quote Originally Posted by Erikmex View Post
    I must post of video of my car pulling from 2500rpm with an Ht1e and 48's-40mm chokes.
    i bet you have to feed the throttle in carefully though,

  36. #34
    Racer Decade Plus User Forest_rallying's Avatar

    Join Date
    Feb 2013
    Location
    Derbyshire
    Posts
    2,438
    Thanks
    92
    Thanked 393 Times in 348 Posts

    Re: Pinto Cam Selection...Race....

    Quote Originally Posted by Graham View Post
    i bet you have to feed the throttle in carefully though,
    With your slippers on!

  37. #35
    Racer Decade Plus User

    Join Date
    Mar 2010
    Location
    Edinburgh
    Age
    46
    Posts
    3,641
    Thanks
    68
    Thanked 234 Times in 230 Posts

    Re: Pinto Cam Selection...Race....

    Yeah but still accelerates and cruises ok, would behave better with smaller chokes, an RL31 with 38mm chokes will still bog if you crack the throttle too quickly. For any kind of competition use i cant fault the HT1e, previosuly had an RL31 and found it a really good cam but lacking top end.

  38. #36
    Racer Decade Plus User

    Join Date
    Mar 2012
    Location
    Belgium
    Age
    56
    Posts
    2,118
    Thanks
    7
    Thanked 197 Times in 169 Posts

    Re: Pinto Cam Selection...Race....

    Quote Originally Posted by Erikmex View Post
    Yeah but still accelerates and cruises ok, would behave better with smaller chokes, an RL31 with 38mm chokes will still bog if you crack the throttle too quickly. For any kind of competition use i cant fault the HT1e, previosuly had an RL31 and found it a really good cam but lacking top end.
    That's correct, HT1e is still drivable, not an over the top cam for a good head and will indeed pull wel from low. But of course not as an RL31. For this light car (if good head is fitted) it has more benefit over RL31

  39. #37
    Pole Position Decade Plus User
    Turbosport Administrator
    Miniliteman's Avatar

    Join Date
    Feb 2004
    Location
    the Netherlands
    Posts
    4,888
    Thanks
    38
    Thanked 611 Times in 558 Posts

    Re: Pinto Cam Selection...Race....

    Quote Originally Posted by JSGAuto View Post
    I don't know any cyl head people here, and the Pinto is not a popular platform in the states. Finding an expert would be difficult.
    Hello,
    spoke to someone in the US who is in the FF / S2000 racing scene.
    He suggested Quicksilver, Butler, Ivey; or ask on the www.apexspeed.com/forums they have a Formula Continental Pinto section.

+ Reply to Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts