Mark Adams choise ?
Discussion
Since Mark Adams has been visiting PH lately, i can´t resist asking one never? anwered question : What is the best camshaft choise ?
Basic conditions are : 350i with standard vitesse 3.5ltr engine / mid milage / port matching done / adj. fuel regulator / "maximum" 5500 rpm / open roads and occasional track days / rolling road session to sort out the ignition advance, fuel pressure and maybee flapper spring tension.
I´ve read about kent214/218/piper270* and Hurricane etc.. but i´m still having problems choosing one. Rhoads lifters are ok if they make things better. Double adj. roller chain is good, i guess.
Quality is an important factor of course.
Picked 5500rpm as a maximum rpm...ok? ,AND i don´t want to modify the rockers or valve spring seats(ok, this might be cheap/easy)...
--> No new adj. ECU or Jaguar AFM/injectors due to limited budget...
bengt
>>> Edited by tvr350i on Tuesday 27th August 22:04
Basic conditions are : 350i with standard vitesse 3.5ltr engine / mid milage / port matching done / adj. fuel regulator / "maximum" 5500 rpm / open roads and occasional track days / rolling road session to sort out the ignition advance, fuel pressure and maybee flapper spring tension.
I´ve read about kent214/218/piper270* and Hurricane etc.. but i´m still having problems choosing one. Rhoads lifters are ok if they make things better. Double adj. roller chain is good, i guess.
Quality is an important factor of course.
Picked 5500rpm as a maximum rpm...ok? ,AND i don´t want to modify the rockers or valve spring seats(ok, this might be cheap/easy)...
--> No new adj. ECU or Jaguar AFM/injectors due to limited budget...
bengt
>>> Edited by tvr350i on Tuesday 27th August 22:04
Couple of things to consider first;
1) If you change the cam you MUST re-map the ECU to get the best out of it as worst case scenario it will be undriveable and possibly blow the engine (lean misfire, detonation etc).
2) Any cam swap must have a set of new lifters as both the cam and lifter work harden in use and old hard lifters on your new soft cam will leave you with no cam at all.
3) High lift / go faster cams need heavier springs to maintain control of the valve when its being opened as the accelerations involved are higher. Cams which don't need new springs / machining of spring seats etc tend not to give much improvement probably +10Bhp at the very most.
I run the Rhoads lifters in mine and they do work as advertised ( essentially variable valve lift) but they are noisy all the time. Especially so on a very hot start-up when they clack so loudly every else will comment 'Your engine's k'ned mate'. Depends if you can live with that.
Best of luck
Matt
1) If you change the cam you MUST re-map the ECU to get the best out of it as worst case scenario it will be undriveable and possibly blow the engine (lean misfire, detonation etc).
2) Any cam swap must have a set of new lifters as both the cam and lifter work harden in use and old hard lifters on your new soft cam will leave you with no cam at all.
3) High lift / go faster cams need heavier springs to maintain control of the valve when its being opened as the accelerations involved are higher. Cams which don't need new springs / machining of spring seats etc tend not to give much improvement probably +10Bhp at the very most.
I run the Rhoads lifters in mine and they do work as advertised ( essentially variable valve lift) but they are noisy all the time. Especially so on a very hot start-up when they clack so loudly every else will comment 'Your engine's k'ned mate'. Depends if you can live with that.
Best of luck
Matt
Hi Bengt. Camshaft choice is a matter of personal preference really, but there are a few factors that will help you choose the best one for you.
Kevinday has accurately hit on the heart of the matter.
Unless the existing camshaft is in need of replacement, then this is an expensive and difficult option for getting more power.
The biggest restriction on this engine is actually the small airflow meter, which is definitely better replaced by the Jag item. Contrary to popular belief, these motors actually do like to have an airflow meter and removing it altogether will knock out about 10-15lb/ft of midrange torque.
Anyway back to your question! Larger capacity engines tend to tame camshafts, so you can get away with more radical camshafts in bigger motors without losing good manners. Hot camshafts cannot be used with catalytic converters, which is not an issue for you.
So how do you drive your car? Do you like to rev it (it is safe to 6500RPM, although it is unlikely to be doing anything useful up there at present)?
Personally I don't like Rhoads lifters (sorry Matt - everything else you said is spot on). They make an awful racket at idle and on cold starts, not unlike large ball-bearings dropping into a tin can (lacks class). My dyno tests reveal absolutely no change in torque or power for even fairly hot camshafts.
Although the engine should be safe to 6500RPM, if you prefer to use 5500RPM then you would be better of with a softer cam that gives more mid-range torque and flexibility. If you drive a lot in traffic or slow roads, then you'll appreciate this choice which brings good manners (suggest Piper 270/2 in this category).
The 218 is a nice bright cam in the larger motors. I've got one in my 4.6, and another in the 4.8. The 4.6 is is a cracker to rev, and even idles nicely. However the idle would be a bit ragged in a 3.5, although that can be nice. The 4.8 has amazing mid-range torque, but is not a revver.
If you don't do much time in traffic, and you like to rev it hard then a 214 (slightly hotter still) is fun. Bad manners and a lumpy idle in a 3.5 though.
Hope this is some help, but basically it has to be in the context of how you drive it as well as engine capacity. Let us know more about what you want....
>> Edited by Mark Adams on Wednesday 28th August 20:42
Kevinday has accurately hit on the heart of the matter.
Unless the existing camshaft is in need of replacement, then this is an expensive and difficult option for getting more power.
The biggest restriction on this engine is actually the small airflow meter, which is definitely better replaced by the Jag item. Contrary to popular belief, these motors actually do like to have an airflow meter and removing it altogether will knock out about 10-15lb/ft of midrange torque.
Anyway back to your question! Larger capacity engines tend to tame camshafts, so you can get away with more radical camshafts in bigger motors without losing good manners. Hot camshafts cannot be used with catalytic converters, which is not an issue for you.
So how do you drive your car? Do you like to rev it (it is safe to 6500RPM, although it is unlikely to be doing anything useful up there at present)?
Personally I don't like Rhoads lifters (sorry Matt - everything else you said is spot on). They make an awful racket at idle and on cold starts, not unlike large ball-bearings dropping into a tin can (lacks class). My dyno tests reveal absolutely no change in torque or power for even fairly hot camshafts.
Although the engine should be safe to 6500RPM, if you prefer to use 5500RPM then you would be better of with a softer cam that gives more mid-range torque and flexibility. If you drive a lot in traffic or slow roads, then you'll appreciate this choice which brings good manners (suggest Piper 270/2 in this category).
The 218 is a nice bright cam in the larger motors. I've got one in my 4.6, and another in the 4.8. The 4.6 is is a cracker to rev, and even idles nicely. However the idle would be a bit ragged in a 3.5, although that can be nice. The 4.8 has amazing mid-range torque, but is not a revver.
If you don't do much time in traffic, and you like to rev it hard then a 214 (slightly hotter still) is fun. Bad manners and a lumpy idle in a 3.5 though.
Hope this is some help, but basically it has to be in the context of how you drive it as well as engine capacity. Let us know more about what you want....
>> Edited by Mark Adams on Wednesday 28th August 20:42
Mark, do you think the Jag air flow meter on it's own improves power or do you need the higher capacity injectors as well? I have a Piper RP1 in my 350i, which I believe is no longer available (I think on your advice!). It feels like there is a noticeable surge in power over 3,000 revs, but nothing spectacular below that. I was considering the rising rate pressure regulator next. Will either upgrade give any improvement low down or will they only have an affect higher up the rev range?
Danny
Danny
I have a CDI ignition with a Crane coil so the idle is rock solid at 400rpm if a want(i´ve set it to 600), so i´ll better get used with the thought of a lumpy idle around 1200rpm then ? 
Well it´s NOT revving over 5500 now, hardly over 5000, so it would be nice of course to raise the limit. At least it would sound better on a track day!
Sounds like a Kent218 would do the job? Then rolling road session to sort out the flapper tension and check fuel pressure(CO/lamda test) and optimal ignition advance(possible some homework with the distributor afterwords). Step 2 could be to install the Jag AFM ? and buy some more time on the rolling road... Not too much money involved since whatever is done to the engine you still need the rolling road session...
Maybee it´s better to go for step1+2 directly. Could you tell us more what the Jag AFM would improve Mark?
Ok, no new ECU but then i might aswell go for step 3!
Step3 would be to get one of the swedish LHD 450SEAC´s or a Griff500...
On a track, with new 205´s around, it feels like the car don´t need so much more low rpm grunt due to limited grip, i´ts quite fast around corners compared to "standard" cars, but on the straights it would be nice to get some more speed, and FUN rpm.
Don´t forget, even if updating the cam doesn´t make the 350 a 520, it´s still FUN TO DO IT !!
bengt
>> Edited by tvr350i on Wednesday 28th August 22:24
Well it´s NOT revving over 5500 now, hardly over 5000, so it would be nice of course to raise the limit. At least it would sound better on a track day!
Sounds like a Kent218 would do the job? Then rolling road session to sort out the flapper tension and check fuel pressure(CO/lamda test) and optimal ignition advance(possible some homework with the distributor afterwords). Step 2 could be to install the Jag AFM ? and buy some more time on the rolling road... Not too much money involved since whatever is done to the engine you still need the rolling road session...
Maybee it´s better to go for step1+2 directly. Could you tell us more what the Jag AFM would improve Mark?
Ok, no new ECU but then i might aswell go for step 3!
Step3 would be to get one of the swedish LHD 450SEAC´s or a Griff500...
On a track, with new 205´s around, it feels like the car don´t need so much more low rpm grunt due to limited grip, i´ts quite fast around corners compared to "standard" cars, but on the straights it would be nice to get some more speed, and FUN rpm.
Don´t forget, even if updating the cam doesn´t make the 350 a 520, it´s still FUN TO DO IT !!
bengt
>> Edited by tvr350i on Wednesday 28th August 22:24
The before and after power curves on the 390's 3.9 engine are on www.t-v-r-services.co.uk and showed what changing the air flow, bigger injectors and a sprinkle of MA magic did to the 390's original engine. Gained 25-30 bhp without a cam change.
I'm running a hybrid 218 from John Eales in the Griff now and I think it is spot on for a road car. The 520 is running a nutter 248 which means lumpy idle but massive fireworks from 3000-6500.
The AFM and injectors is the first thing to do as I am a great believer in more power requires more mixture...
Steve
www.tvrbooks.co.uk
I'm running a hybrid 218 from John Eales in the Griff now and I think it is spot on for a road car. The 520 is running a nutter 248 which means lumpy idle but massive fireworks from 3000-6500.
The AFM and injectors is the first thing to do as I am a great believer in more power requires more mixture...
Steve
www.tvrbooks.co.uk
I have one of Peninsula's US imported Cams in my 400... The result is good manners below 3000rpm, and a big kick in the back after. If you are in 2nd or 3rd, wheelspin should you wish to you snap the throttle open near 4000 rpm. ( I get around this feature by running 245 rubber at the back ).
The engine itself will now pull cleanly upto 6000rpm, until it is interupted by the rev limiter at 6250. IF at this point you back off, the car following you gets a loverly flame show out of the exhaust!!! (mpg does not seem to be affected!)
My Cam didnt need replacing, but the engine was comming upto 55,000 miles, so I wasnt going to wait.
As it was though, when the old cam was removed it was starting to show signs of its age on the front lobes.
also, a little Off Toic here, what will one of those chips do to the engine's characteristics ? will it enhance or supress what I currently have ?
I keep being shown chips from Mark, but upto now have resisted the urge to have one fitted.
Oh, and a session on the rollers after this little lot showed 281bhp at the wheels ( Richard Aldous 390Fame was there as the engineer experienced liftoff from the rollers whilst performing a power run! )
Perviously, it had shown 240ish.
Other mods include FSE Fuel regulator, larger exhaust and a full tank of SuperU !!
>> Edited by jvaughan on Thursday 29th August 10:28
The engine itself will now pull cleanly upto 6000rpm, until it is interupted by the rev limiter at 6250. IF at this point you back off, the car following you gets a loverly flame show out of the exhaust!!! (mpg does not seem to be affected!)
My Cam didnt need replacing, but the engine was comming upto 55,000 miles, so I wasnt going to wait.
As it was though, when the old cam was removed it was starting to show signs of its age on the front lobes.
also, a little Off Toic here, what will one of those chips do to the engine's characteristics ? will it enhance or supress what I currently have ?
I keep being shown chips from Mark, but upto now have resisted the urge to have one fitted.
Oh, and a session on the rollers after this little lot showed 281bhp at the wheels ( Richard Aldous 390Fame was there as the engineer experienced liftoff from the rollers whilst performing a power run! )
Perviously, it had shown 240ish.
Other mods include FSE Fuel regulator, larger exhaust and a full tank of SuperU !!
>> Edited by jvaughan on Thursday 29th August 10:28
quote:
Oh, and a session on the rollers after this little lot showed 281bhp at the wheels ( Richard Aldous 390Fame was there as the engineer experienced liftoff from the rollers whilst performing a power run! )
Perviously, it had shown 240ish.
281 at the wheels is pretty incredible, are you sure this wasn't the corrected flywheel figure?
Seems the 218 would be a decent chiose then lads. So, is it possible to use the Jag AFM/Jag injectors together with the 350 "flapper ECU" ? Check tension at full trottle and the try to find a fuel pressure that makes it all work ? According to my calculations, the standard injectors should be able to to the job in the 3.5ltr case, maybee together with the jag AFM ?
bengt
bengt
quote:
281 at the wheels is pretty incredible, are you sure this wasn't the corrected flywheel figure?
Yep, the flywheel figure is closer to 320. Incidently, the dyno I used ( in Andover ) may have been out, 'cos the analogue readout was off the clock ( 250bhp ), it was only the digital readout that gave the peak figure.
I have a nice printout that shows the car leaving the rollers ( and making nice black marks on the garage floor !)
When I get the car back from my Parents Next month, Ill put it on the rollers, and take my cam-corder with me
>> Edited by jvaughan on Thursday 29th August 15:06
quote:
Did Richard put the wedge on the rollers Jason? I'd be interested to hear what he got from his 390
na he could'nt ... some previous owner had buggered the engine up, and it was having a new CAM fitted (joke).
Richards 390 had his new CAM fitted, and it is almost on-parr with my 400. ( it also has similar characteristics )
He didnt have time to get it on the rollers, but I know he intends to when he puts it back on the road.
>> Edited by jvaughan on Thursday 29th August 15:06
Maybe but I think you have to adapt a system upgrade approach to the engine and work from there. If the cam is OK, leave it as is. Get a big plenum with a bigger throttle body so you can get more mixture in, a bigger air flow meter to get more air in, bigger injectors to get more fuel in and a chipped ECU to make sure everything is fine. Not doing everything in the chain will mean that you will not get the full benefit and you are potentially wasting money. It is a tough call especially when the alternative of changing the engine may be more economic.
Steve
Get this running and then see where the next weak link is.
Steve
Get this running and then see where the next weak link is.
Hi Stig,
I havn't got around to putting it on a dyno yet...
Chassis work starts next week, so am hoping to get it fully roadworthy early next year, and start having some fun again!
Rich.
I havn't got around to putting it on a dyno yet...
Chassis work starts next week, so am hoping to get it fully roadworthy early next year, and start having some fun again!
Rich.
quote:
quote:
Did Richard put the wedge on the rollers Jason? I'd be interested to hear what he got from his 390
na he could'nt ... some previous owner had buggered the engine up, and it was having a new CAM fitted (joke).
Richards 390 had his new CAM fitted, and it is almost on-parr with my 400. ( it also has similar characteristics )
He didnt have time to get it on the rollers, but I know he intends to when he puts it back on the road.
>> Edited by jvaughan on Thursday 29th August 15:06
Video of Mark Adams rolling road session, 2.6Mb in MPEG format.
The video shows my SEAC being put through one dyno run. It includes working up through the gears into 4th and the spine tingling run up through the rev range.
Mark Adams is the tall bloke back left.
The video shows my SEAC being put through one dyno run. It includes working up through the gears into 4th and the spine tingling run up through the rev range.
Mark Adams is the tall bloke back left.
quote:
quote:
281 at the wheels is pretty incredible, are you sure this wasn't the corrected flywheel figure?
Yep, the flywheel figure is closer to 320.
That implies a loss of only 12% through the transmission, which seems unbelievably low. Just as 320 from a 4.0 Rover with minor mods seems unbelievably high. Let's see the dyno chart & type.
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