Indeed! Watching endlessly Graham’s channel I wanted to ditch my 1700 XFlow build and go Race CNC head 185bhp RL31 or WR40 Pinto - only now to see i’d be missing out by a massive margin what i’d be using for 99.85% of the time on the road - mid range torque. Awesome test Graham! 🙌 torque over peak power unless super smooth wide and long straights track or oval racing
@@luka_theoldfartI'm in the same boat. My Pinto is nakard so I'm trying to work out what combo will work for me a usable power is the name of the game as far as I'm concerned.
Another fantastic informative video Graham, I just wondered do you ever use the head gasket and head bolts more than once in all of the head changes. 😀😀
i usually use either early non stretch bolts or ARP studs, in theroy you could reuse a MLS gasket but i never do. with these tests i didnt keep swapping heads, i ran all the cams with one head, swapped head then ran all the same cams again
Keep coming back to this and previous video - the difference (on graph at least) between 40/41 and 4.75 seem very slight. Both reach almost same 4200rpm peak torque plateau, and last to almost 6k - with 4.75 seemingly dropping less in torque til redline. Was the bottom end more gradual as well as per graph or that was you feeding in the dyno differently from 3-4k? Any big differences low down? How would these react with a more restrictive choke to hopefully boost low end velocity a bit more?
Given that the only change was to swap two similar "rally" cams not sure I would call those "slight" differences, Load is feed in exactly the same way on each cam. just like most rolling roads, You give the engine full throttle, the dyno will hold rpm down to starting point, wait a couple of seconds for things to stabalise, then hit the go button and the dyno controls acceration rate upto the upper rpm limit set.
Depends on your goal, if you’re going to run twin 40,s modified head and something like a bcf2/3 90-100 bhp but it will have NO torque to speak of. Chuck a mad mad cam in it they will do over 130 bhp at a million revs with zero torque. I have a plan in mind to build a stealth 1600 using a 1300 block, just haven’t got round to it yet
@@PenguinMotors Thanks for the reply reading what you have written I think I will build a Kent 1600 in stead sounds like a better option with a modified head with twin 40,s and a decent cam
Hello Graham, do you think the torque/hp characteristics of the BLF 40/41 + CNC-head, would be the same with a 32/36 weber carb.? Except that they would be lower. Or would you advice a different cam in that case?
@@PenguinMotors Thank you, i'm struggling to choose the ideal cam for burton CNC-head-small bore ashley-32/36 carb., that later on (or maybe never) can be replaced for IDF-carbs (DCOE =no option here for lhd escort mk2 and MOT rules)
i did run 40/41 on 38 dgas and twin 45 doce, at about 2700 the Dgas was down nearly 30 lbft, @ about 4000 it was down 10lbft. your going to be in the same position whatever cam you go with. i would be temped to fit a GTS1
@@PenguinMotors That is some interesting info! Thought about a high torque cam like BF134, because i like low down torque, but maybe the GTS1 is a better compromise torque/hp. Thanks for spreading all this information, is much appreciated !
It takes about an hour and several burnt fingers to swap a cam on the dyno, i dont usually time them, i just swing the cam timing on the vernier, takes a good few runs to find the sweet spot but you end up with what the engine actually wants rather than an arbitory book figure
Everyone thinks yeah gimme the biggest numbers but im sure 95% of us would miss the torque and driveability of a less tuned engine as no one is driving around at 7000 rpm for sustained periods on the roads. Like you say its about the specifics of what you are using the car for. V8 rover please tuned for tree stump pulling torque for me... Great vid Graham
One of the videos where it’s 100% safe to click Like before even seeing it!
Must take you hours to run these tests. Thanks for putting the effort in.
Thank you!, I ran 9 different cams back to back it literally took at whole weekend two 12 hour days
Great illustration of heads and cam combo dyno runs - theory is one thing, but in practice is even better 👍🏻
Indeed! Watching endlessly Graham’s channel I wanted to ditch my 1700 XFlow build and go Race CNC head 185bhp RL31 or WR40 Pinto - only now to see i’d be missing out by a massive margin what i’d be using for 99.85% of the time on the road - mid range torque.
Awesome test Graham! 🙌 torque over peak power unless super smooth wide and long straights track or oval racing
@@luka_theoldfartI'm in the same boat. My Pinto is nakard so I'm trying to work out what combo will work for me a usable power is the name of the game as far as I'm concerned.
The problem there is everyone has a different idea of what usable power is
@@PenguinMotors hit the nail on the head there.
That 40/41 and older cam combo is certainly a good graph, in a light older car that must make for a good drive
Long live the mighty Pinto!!! ❤
There is so much to it, for the right combination that works well enough.
Good as always. Why this bigger overlap cam is better lowdown?
overall duration also plays a part, but you cant always trust timing figures quoted!
Amazing comparison would love to know what size chokes and jets the blf40/41 was run on
All these tests were done on 38mm chokes.
Another fantastic informative video Graham, I just wondered do you ever use the head gasket and head bolts more than once in all of the head changes. 😀😀
i usually use either early non stretch bolts or ARP studs, in theroy you could reuse a MLS gasket but i never do. with these tests i didnt keep swapping heads, i ran all the cams with one head, swapped head then ran all the same cams again
Cheers for that Graham.
Keep coming back to this and previous video - the difference (on graph at least) between 40/41 and 4.75 seem very slight. Both reach almost same 4200rpm peak torque plateau, and last to almost 6k - with 4.75 seemingly dropping less in torque til redline. Was the bottom end more gradual as well as per graph or that was you feeding in the dyno differently from 3-4k? Any big differences low down?
How would these react with a more restrictive choke to hopefully boost low end velocity a bit more?
Given that the only change was to swap two similar "rally" cams not sure I would call those "slight" differences, Load is feed in exactly the same way on each cam. just like most rolling roads, You give the engine full throttle, the dyno will hold rpm down to starting point, wait a couple of seconds for things to stabalise, then hit the go button and the dyno controls acceration rate upto the upper rpm limit set.
Hi Graham. Love the videos. How does trumpet length affect the power curve ?
Andy.
it tends to just raise or lower the upper part of the curve and only at or close to full throttle
Hi there I was thinking of building a Kent 1300 for my escort how much power can you get out of a 1300 with a good cam head and carb
Depends on your goal, if you’re going to run twin 40,s modified head and something like a bcf2/3 90-100 bhp but it will have NO torque to speak of. Chuck a mad mad cam in it they will do over 130 bhp at a million revs with zero torque. I have a plan in mind to build a stealth 1600 using a 1300 block, just haven’t got round to it yet
@@PenguinMotors Thanks for the reply reading what you have written I think I will build a Kent 1600 in stead sounds like a better option with a modified head with twin 40,s and a decent cam
unless theres a really compelling reason to stick with a 1300, it makes far more sense to go 1600
What about 6 degrees of advance on WR40-41 and CNC Head ????
With all the cams I swung the cam timing to get best compromise between torque and all out hp
Hello Graham, do you think the torque/hp characteristics of the BLF 40/41 + CNC-head, would be the same with a 32/36 weber carb.? Except that they would be lower.
Or would you advice a different cam in that case?
torque will be a lot lower everywhere, even down the bottom of the rev range there will be a significant loss
@@PenguinMotors Thank you, i'm struggling to choose the ideal cam for burton CNC-head-small bore ashley-32/36 carb., that later on (or maybe never) can be replaced for IDF-carbs (DCOE =no option here for lhd escort mk2 and MOT rules)
i did run 40/41 on 38 dgas and twin 45 doce, at about 2700 the Dgas was down nearly 30 lbft, @ about 4000 it was down 10lbft. your going to be in the same position whatever cam you go with. i would be temped to fit a GTS1
@@PenguinMotors That is some interesting info! Thought about a high torque cam like BF134, because i like low down torque, but maybe the GTS1 is a better compromise torque/hp.
Thanks for spreading all this information, is much appreciated !
i have quite a few engines in for rebuild so no spare time at the moment, but i do plan on doing test GTS1 against BF134 FR30 etc
how long does it take you to swap a cam, time it up + set clearances
It takes about an hour and several burnt fingers to swap a cam on the dyno, i dont usually time them, i just swing the cam timing on the vernier, takes a good few runs to find the sweet spot but you end up with what the engine actually wants rather than an arbitory book figure
Everyone thinks yeah gimme the biggest numbers but im sure 95% of us would miss the torque and driveability of a less tuned engine as no one is driving around at 7000 rpm for sustained periods on the roads. Like you say its about the specifics of what you are using the car for.
V8 rover please tuned for tree stump pulling torque for me...
Great vid Graham
More rover stuff is in the pipeline