Help me choose a cam
Discussion
I have a 4.5 which is currently in bits during a resto, which took longer that expected (long story).
Before the resto the car was pushing out 261bhp and 299lbs ft. It has larger valves, but not big valve. So the larger valves and a bit of porting has given the car decent figures but appears to have moved the torque a bit further up the rev range, which is about right, right? More flow - peak torque moves up? That's my understanding, but prepared to be put right (this IS pistonheads after all). It is running a standard 500 cam as all 4.5's have.
In the 4.3 Griff I had years ago, I remember the torque being more prominent and being lower down, which I like. Can I move (and hopefully increase) the torque lower down with a different cam? Or am I stuck with that kind of delivery now with the valves and porting?
Does anyone know of a cam that could do what I want? I will give Kent and Piper a call tomorrow and pose the scenario and see what they say, but I thought I'd run it by you guys first.
Thanks
Cad
Before the resto the car was pushing out 261bhp and 299lbs ft. It has larger valves, but not big valve. So the larger valves and a bit of porting has given the car decent figures but appears to have moved the torque a bit further up the rev range, which is about right, right? More flow - peak torque moves up? That's my understanding, but prepared to be put right (this IS pistonheads after all). It is running a standard 500 cam as all 4.5's have.
In the 4.3 Griff I had years ago, I remember the torque being more prominent and being lower down, which I like. Can I move (and hopefully increase) the torque lower down with a different cam? Or am I stuck with that kind of delivery now with the valves and porting?
Does anyone know of a cam that could do what I want? I will give Kent and Piper a call tomorrow and pose the scenario and see what they say, but I thought I'd run it by you guys first.
Thanks
Cad
Pupp said:
MC1 is a torque monster but might be very close to what you have - have a look at some of the Real Steel offerings too
I'll Google it. Thx. I'm getting my springs, followers, etc from Real Steel. Will get the cam there too if they have the one I need. But have a feeling I'll be needing to go to Piper/Kent direct for something. Time will tell.
caduceus said:
Pupp said:
MC1 is a torque monster but might be very close to what you have - have a look at some of the Real Steel offerings too
I'll Google it. Thx. I'm getting my springs, followers, etc from Real Steel. Will get the cam there too if they have the one I need. But have a feeling I'll be needing to go to Piper/Kent direct for something. Time will tell.
Pupp said:
Are you factoring in mapping work/cost if thinking of something very different Cad?
Haven't looked that far down the road yet Gary. Trying not to spend too much on the engine as the bodywork/re-spray is going to eat up most of my budget. I'm hoping I can just install a new cam and set up the timing, and that's it.
This is my power graph for my 450 with Powers Performance 885 cam.
This is at the wheels so add anything from about 17-20% to get the flywheel figures,
At 20% this equates to
300bhp
350ft lbs torque.
My drag strip times are competitive and on a par with some fast 5.0 cars so that's proof enough for me.
Torque comes on at around 2000 revs and pulls very nicely from there.
ClassiChimi said:
This is my power graph for my 450 with Powers Performance 885 cam.
This is at the wheels so add anything from about 17-20% to get the flywheel figures,
At 20% this equates to
300bhp
350ft lbs torque.
My drag strip times are competitive and on a par with some fast 5.0 cars so that's proof enough for me.
Torque comes on at around 2000 revs and pulls very nicely from there.
I have no doubt the car is plenty fast though! This is just from a technical standpoint. Someone please correct me if I'm wrong.
I had almost exactly the same build as yours, main cat in, lucas system, but not a perfect map. Got 280hp and 405 nm on the hub dyno, translated to fly hp.
I really do love you too Ole 
Math ain't my strong point
and I will stretch the figures as far as possible in my favour
My cars really really really fast
Ok I'll try and be serious for a moment.
First off Dom's Dyno reads bloody low in my estimation,, but then I would say that,,
Ok if we use say 15% as drive train loss to calculate back to the fly then it's more like
290 Hp
333 torque.
Its a simple fact if I'd had some sticky tyres and half a brain I could have got my car into the high 12's at Shakey earlier this year.
On one run my terminal velocity was 110mph and that's because I got the forth gear change right but the time was slow because I got wheel spin off the line.
When I did the 13.1 my terminal velocity was only 107mph ( I think?) good start but hit the limiter in third I seem to remember, bugger!
If I put it all together properly the time would have come even on cold T1R's, my burn outs were a waste of time as I didn't really get the tyres smoking,, just a touch of steam
I have had the engine re built Ole,,, and I did tell Dom I was the man and it better be f
king quick,,
I've been working late,, I should get to bed but I'm enjoying this,,,
Have I interpreted my graph wrong, just look at that Air Fuel Ratio, you beautie
I feel my car has huge compression Ole, I might be wrong but it roars from the induction and I think that's the key,
Its also had a crank re grind so I don't know if that's anything to do with it.
My gut instinct from driving one or two other great Tvr's 5.0 examples
Is my engine lacks a bit of grunt low down and never recovers compared to the 5.0 but it's got good Hp and spins freely, no vibration so it revs to the limiter effortlessly and that gives it an edge, coupled with extra advance and what seems like really good suck even though I'm on standard trumpets 38mm it's really pulling hard even at high revs.
The 5.0 I've driven all vibrate more when the revs rise and feels like it's running out of steam but in reality they are still slightly faster.
The 5.5 N/a monster I've driven as well as the 5.0 Griff on throttle bodies were and are in another stratosphere entirely,,, what a privilege that was
Something like your car now that it's being breathed on, fantastic I'd imagine.
So anyway Ole,, I know I'm an optimist,,,,, I have to be ! But what's wrong with my gragh, it's fairly pedestrian as they go?
Mate I need to come out on one of your drives,, you can feel the might of the beast yourself dude.
ETA I've always noticed engines with higher Bhp than mine tend to have slightly less torque curve than mine, fully de Catted but not a Clive Y mine had less torque but did feel very sightly faster at high revs but I reverted back to main cat in and it's been full of torque ever since.
I'm sure my drag times would be quicker with de Catt as your thrashing the engine at higher revs so getting the power benefit, I'm sure if I went to big trumpets and de cat Clive Y and a re map I'd have close to 320 bhp or more but I don't really need it and if I lost any of the torque I'd be gutted
When talking with Dom over the rebuild at the time I said I came from a Speedway motor bike engine background as a kid, methanol, compression and bombs under your arse, nothing feels as good or as quick in its own way. I digress
I just said torque, it's a road car, I rarely thrash the engine, dismissed bhp as for two strokes, I love them to mind
The blocks been decked and heads skimmed, the times don't lie so somethings going in the right direction.
The Kent 885 is not the biggest lift cam and you can tell when searching for Bhp as you drive it but the torque has st you up that much you just want to slow down anyway.
It's a good alrounder and for that I like it lots.
Math ain't my strong point
and I will stretch the figures as far as possible in my favour My cars really really really fast
Ok I'll try and be serious for a moment.
First off Dom's Dyno reads bloody low in my estimation,,
but then I would say that,, Ok if we use say 15% as drive train loss to calculate back to the fly then it's more like
290 Hp
333 torque.
Its a simple fact if I'd had some sticky tyres and half a brain I could have got my car into the high 12's at Shakey earlier this year.
On one run my terminal velocity was 110mph and that's because I got the forth gear change right but the time was slow because I got wheel spin off the line.
When I did the 13.1 my terminal velocity was only 107mph ( I think?) good start but hit the limiter in third I seem to remember, bugger!
If I put it all together properly the time would have come even on cold T1R's, my burn outs were a waste of time as I didn't really get the tyres smoking,, just a touch of steam
I have had the engine re built Ole,,, and I did tell Dom I was the man and it better be f
king quick,, I've been working late,, I should get to bed but I'm enjoying this,,,
Have I interpreted my graph wrong, just look at that Air Fuel Ratio, you beautie
I feel my car has huge compression Ole, I might be wrong but it roars from the induction and I think that's the key,
Its also had a crank re grind so I don't know if that's anything to do with it.
My gut instinct from driving one or two other great Tvr's 5.0 examples
Is my engine lacks a bit of grunt low down and never recovers compared to the 5.0 but it's got good Hp and spins freely, no vibration so it revs to the limiter effortlessly and that gives it an edge, coupled with extra advance and what seems like really good suck even though I'm on standard trumpets 38mm it's really pulling hard even at high revs.
The 5.0 I've driven all vibrate more when the revs rise and feels like it's running out of steam but in reality they are still slightly faster.
The 5.5 N/a monster I've driven as well as the 5.0 Griff on throttle bodies were and are in another stratosphere entirely,,, what a privilege that was
Something like your car now that it's being breathed on, fantastic I'd imagine.
So anyway Ole,, I know I'm an optimist,,,,, I have to be ! But what's wrong with my gragh, it's fairly pedestrian as they go?
Mate I need to come out on one of your drives,, you can feel the might of the beast yourself dude.
ETA I've always noticed engines with higher Bhp than mine tend to have slightly less torque curve than mine, fully de Catted but not a Clive Y mine had less torque but did feel very sightly faster at high revs but I reverted back to main cat in and it's been full of torque ever since.
I'm sure my drag times would be quicker with de Catt as your thrashing the engine at higher revs so getting the power benefit, I'm sure if I went to big trumpets and de cat Clive Y and a re map I'd have close to 320 bhp or more but I don't really need it and if I lost any of the torque I'd be gutted
When talking with Dom over the rebuild at the time I said I came from a Speedway motor bike engine background as a kid, methanol, compression and bombs under your arse, nothing feels as good or as quick in its own way. I digress
I just said torque, it's a road car, I rarely thrash the engine, dismissed bhp as for two strokes, I love them to mind
The blocks been decked and heads skimmed, the times don't lie so somethings going in the right direction.
The Kent 885 is not the biggest lift cam and you can tell when searching for Bhp as you drive it but the torque has s
t you up that much you just want to slow down anyway. It's a good alrounder and for that I like it lots.
Edited by ClassiChimi on Thursday 30th June 01:25
Edited by ClassiChimi on Thursday 30th June 01:37
Edited by ClassiChimi on Thursday 30th June 01:57
Edited by ClassiChimi on Thursday 30th June 02:15
Thanks for the replies all.
I had a little chat with Piper cams yesterday and the chap recommended this cam saying it should move the peak torque a bit lower down, which is what I'm after.
Will give Kent a ring today, and Real Steel for their offerings.
I'm not after crazy BHP, just more torque and coming in earlier. But with the medium big valves I already have, I'm not sure I'm going to get what I ideally want. As more flow equates to more bhp and torque higher up the rev range. Apparently...
I had a little chat with Piper cams yesterday and the chap recommended this cam saying it should move the peak torque a bit lower down, which is what I'm after.
Will give Kent a ring today, and Real Steel for their offerings.
I'm not after crazy BHP, just more torque and coming in earlier. But with the medium big valves I already have, I'm not sure I'm going to get what I ideally want. As more flow equates to more bhp and torque higher up the rev range. Apparently...
I'm not sure about that Tommo, mine was mapped using super unleaded.
Unleaded is fine in my engine and according to Jay at Powers it's ok to use on a daily basis but I was advised to avoid Wide Open Throttle unless using super, risk of pinking.
If you read some of Chimpongas posts he points out that using super unleaded for gentle driving is a waste of money,,
Having ran mine on unleaded for over 8 months now I tend to agree.
I never feel the need for WOT driving on the roads so unleaded works for me
Unleaded is fine in my engine and according to Jay at Powers it's ok to use on a daily basis but I was advised to avoid Wide Open Throttle unless using super, risk of pinking.
If you read some of Chimpongas posts he points out that using super unleaded for gentle driving is a waste of money,,
Having ran mine on unleaded for over 8 months now I tend to agree.
I never feel the need for WOT driving on the roads so unleaded works for me
This is the dyno I had done before the resto
As you can see, peak torque is at 4k revs. As I don't like revving the nutts off any engine (one reason why I didn't like the ajp in the Cerb) I'd prefer getting the most ooomph lower down the range. Not bothered about it running out of puff earlier either.
One question - why does the dyno measurement only start at 2150 revs?
As you can see, peak torque is at 4k revs. As I don't like revving the nutts off any engine (one reason why I didn't like the ajp in the Cerb) I'd prefer getting the most ooomph lower down the range. Not bothered about it running out of puff earlier either.
One question - why does the dyno measurement only start at 2150 revs?
caduceus said:
Thanks for the replies all.
I had a little chat with Piper cams yesterday and the chap recommended this cam saying it should move the peak torque a bit lower down, which is what I'm after.
Will give Kent a ring today, and Real Steel for their offerings.
I'm not after crazy BHP, just more torque and coming in earlier. But with the medium big valves I already have, I'm not sure I'm going to get what I ideally want. As more flow equates to more bhp and torque higher up the rev range. Apparently...
Looks good to me, my general feeling is the 450 is a nicely balanced engine and slightly more like the 4.0 engine in character compared to the 5.0 just less grunt almost everywhere but spins up faster so you end up in a similar place.I had a little chat with Piper cams yesterday and the chap recommended this cam saying it should move the peak torque a bit lower down, which is what I'm after.
Will give Kent a ring today, and Real Steel for their offerings.
I'm not after crazy BHP, just more torque and coming in earlier. But with the medium big valves I already have, I'm not sure I'm going to get what I ideally want. As more flow equates to more bhp and torque higher up the rev range. Apparently...
So I'm assuming you want power from as low as 1800-2000 revs and onwards Cad, big ask but cams called Stump Puller must offer something, great term
As I drive mine to fetch milk and collect kids from school to cruising all day on the motorway I can see why you're after that instant low grunt, mine set up as it is needs to be at 2100 revs to feel the power of which I think is just right, below that revs I'm pottering anyway.
as most tend to go for a power cam I'm very interested in this thread so whatever you choose keep us informed of your findings. Alun
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