Discussion
Never heard of that one carbon14 said:
I mean the Kent h234. Duration 310. Power band 2500-6000 rpm. Hope this helps ID.
ok mate sorry can't help you Edited by carbon14 on Sunday 25th May 21:24
But try V8 Developments
Talk to Rob he is the Cam Master Edit to add talk to him about the H 404
Edited by Pasco on Sunday 25th May 21:48
When TVR Power was developing the Taraka conversion they experimented with different cams. I have one of those cams in my car.
I’m fairly sure that the H234 is the cam Dom said mine was based upon. What profile changes, if any they made, I don’t know. I suspect it’s identical.
In a car without any other modifications it made 277bhp on high octane. It was horrible to drive; you really had to drive to keep it above 2500rpm all the time. The delivery made it feel faster than normal, but in reality, it wasn’t.
TVR Power gave up trying to make it run nicely with Lucas and dizzy. They finally settled for a milder profile for the Taraka.
I got fed up with it too. It was either put a milder cam in, or replace the dizzy and Lucas with an aftermarket ECU. I took the latter option, with a few breathing mods.
This totally transformed the car. The drive is now very acceptable, but not quite as smooth as mild cams. It will pull cleanly from 1100 rpm in 5th. It’s not so good at 1st or 2nd gear trickling along in traffic. But you can drive around this without difficulty.
Once you get going it makes 317bhp and 340ft/lb on low octane. The power curve reaches 317 at 5500 and the curve goes flat to 6000rpm. There’s 280ft/lb at 2000rpm and it climbs rapidly to 300ft/lb by 2700. It never comes under 300 again. 340ft/lb is between 4000 and 4500rpm.
The amount of valve opening overlap helps make it a noisy and very nice sound. Fully decatted, but with standard silencer it’s 110db.
With an aftermarket ECU then it’s a great cam as long as you don’t do much traffic driving. Great fun and I recommend it.
If you are going to use the original Lucas and dizzy then I can’t stress this enough. Don’t fit this cam. You cannot get the Lucas to cope with that much overlap.
I’m fairly sure that the H234 is the cam Dom said mine was based upon. What profile changes, if any they made, I don’t know. I suspect it’s identical.
In a car without any other modifications it made 277bhp on high octane. It was horrible to drive; you really had to drive to keep it above 2500rpm all the time. The delivery made it feel faster than normal, but in reality, it wasn’t.
TVR Power gave up trying to make it run nicely with Lucas and dizzy. They finally settled for a milder profile for the Taraka.
I got fed up with it too. It was either put a milder cam in, or replace the dizzy and Lucas with an aftermarket ECU. I took the latter option, with a few breathing mods.
This totally transformed the car. The drive is now very acceptable, but not quite as smooth as mild cams. It will pull cleanly from 1100 rpm in 5th. It’s not so good at 1st or 2nd gear trickling along in traffic. But you can drive around this without difficulty.
Once you get going it makes 317bhp and 340ft/lb on low octane. The power curve reaches 317 at 5500 and the curve goes flat to 6000rpm. There’s 280ft/lb at 2000rpm and it climbs rapidly to 300ft/lb by 2700. It never comes under 300 again. 340ft/lb is between 4000 and 4500rpm.
The amount of valve opening overlap helps make it a noisy and very nice sound. Fully decatted, but with standard silencer it’s 110db.
With an aftermarket ECU then it’s a great cam as long as you don’t do much traffic driving. Great fun and I recommend it.
If you are going to use the original Lucas and dizzy then I can’t stress this enough. Don’t fit this cam. You cannot get the Lucas to cope with that much overlap.
Here's a cam comparison table - you cam is on it..
http://www.btinternet.com/~jon.wolfe/kentcamdata.h...
The H404 would be similar..
I have the Mechanical 404 from V8 developments and it's spec is similar to the Mech 248 Kent cam ..
When originally fitted it was a pig but it needed a very fine and detailsed mapping job and now it drives like a pussy cat. No one will be ablt to supply a map off the shelf - it will need to be tailored.
Power - yes it will have more but the gains will not be that mind blowing .. compared to something slightly milder.
I would alway recomment you call Rob at V8 Developments and describe how you want the car to drive and he will tell you the correct cam.
http://www.btinternet.com/~jon.wolfe/kentcamdata.h...
The H404 would be similar..
I have the Mechanical 404 from V8 developments and it's spec is similar to the Mech 248 Kent cam ..
When originally fitted it was a pig but it needed a very fine and detailsed mapping job and now it drives like a pussy cat. No one will be ablt to supply a map off the shelf - it will need to be tailored.
Power - yes it will have more but the gains will not be that mind blowing .. compared to something slightly milder.
I would alway recomment you call Rob at V8 Developments and describe how you want the car to drive and he will tell you the correct cam.
Thanks to all,
Uncle Fester,
1. did you have the valve springs exchanged when h234 fitted? Kent recommends it, but by reference to the standard rover v8. The question is does a tvr500 pre-serp engine already have upgraded valve springs ?
2. Also by reference to the standard rv8, if the upgraded springs are fitted kent says it requires the head to be machined. Same question as above: does the tvr 500 cylinder heads require such additional work to fit the h234 ?
C14
Uncle Fester,
1. did you have the valve springs exchanged when h234 fitted? Kent recommends it, but by reference to the standard rover v8. The question is does a tvr500 pre-serp engine already have upgraded valve springs ?
2. Also by reference to the standard rv8, if the upgraded springs are fitted kent says it requires the head to be machined. Same question as above: does the tvr 500 cylinder heads require such additional work to fit the h234 ?
C14
Edited by carbon14 on Monday 26th May 20:52
carbon14 said:
Thanks to all,
Uncle Fester,
1. did you have the valve springs exchanged when h234 fitted? Kent recommends it, but by reference to the standard rover v8. The question is does a tvr500 pre-serp engine already have upgraded valve springs ?
2. Also by reference to the standard rv8, if the upgraded springs are fitted kent says it requires the head to be machined. Same question as above: does the tvr 500 cylinder heads require such additional work to fit the h234 ?
C14
It wasn't me that put that cam in. My car used to belong to James Agger in 2004. It's a serp. The engine started making a funny noise on him, so he gave it to TVR Power and told them to do whatever was needed.Uncle Fester,
1. did you have the valve springs exchanged when h234 fitted? Kent recommends it, but by reference to the standard rover v8. The question is does a tvr500 pre-serp engine already have upgraded valve springs ?
2. Also by reference to the standard rv8, if the upgraded springs are fitted kent says it requires the head to be machined. Same question as above: does the tvr 500 cylinder heads require such additional work to fit the h234 ?
C14
Edited by carbon14 on Monday 26th May 20:52
I have the invoice. Ouch.
New liners, main bearings, pistons, cam and all the valve gear, uprated clutch. The block, heads and crank are almost the only original things left.
Efectivly, I have a brand new TVR Power engine with about 7 or 8K miles on it.
I have had V8 Developments improve the breathing. The H234 cam is only an improvement if you improve the rest of the breathing to allow the cam to work.
You are sacrificing the advantages of cams like the stealth with its wide spread of torque. These can work well with little other modifications.
With big cams like the H234 and the H404 you must develop the whole engine. Rob designed the H404 cam and told me that he never intended it for road use beyond driving to and from a track, mostly track day type use. For a while he even stopped selling it because people were putting them in road cars and then becoming dissatisfied. They hadn't done the rest of the work they need.
The H234 is intended for supersports competition use only and is slightly worse. Kent do a full race cam that is wilder, but the H234 is really for motorsports that require a wider power spread than full race cams provide.
Unless you have an engine that is otherwise modified to support this an H234 you will regret fitting it for road use. I have done a fair bit, and feel that there is still more to do. I am having more done next month and V8D are predicting 340bhp, but there will still be more to do after that.
The advent of new ECU's have allowed us to tame cams that were once the preserve of track only cars. I feel we need to redesign the available profiles to fully exploit this.
Will you be using the car for road or track and what other modifications have you done, or intend to do?
I think the last cars to leave the TVR factory and run a 234 as standard where the Wedges, more specifically the SEAC's 
. It is an 'old' cam and I think more modern grinds like the ones from V8D have moved on a little bit since then tbh.
Agree with the comment about the dizzy and wild cams you really need 3D ignition to tame the wilder cams for a road car IMHE.
. It is an 'old' cam and I think more modern grinds like the ones from V8D have moved on a little bit since then tbh. Agree with the comment about the dizzy and wild cams you really need 3D ignition to tame the wilder cams for a road car IMHE.
I've been running the H234 cam since the start of 2004. My experiences are very similar to those of Uncle Fester - it is NOW very drivable and suits my style. However it took a couple of elements to achieve this.
Please note that I'm not an expert in any of the work done - I used Mark Adams & Dave Porter to do all the clever stuff. However I thought a summary of my experience & work carried out may be of interest.
Prior to any work being started, we RR'd to get baseline (as straight out the factory) power readings of 257bhp & 291lbft.
The first element of work included the following :
. fitted H234 cam (supplied by TVR Power - we think supplied to them by Kent but can't confirm)
. reset cam timing to suit & lifter pre-load set
. new followers & steel rockers
. modified plenum chamber for larger inlet
. rebuilt & reset throttle linkage (re-sted vacuum advance pipe to suit)
. Throttle slotted to make adjustable
. Trumpet base & inlet manifold modified for better airflow
. Pre-cats removed
At RR this delivered 288.8bhp & 390.1nm (sorry can't remember the conversion to get lbft). However the drivability was crap - particularly around town, at low speed it would start hunting at anything less than 2,200rpm. On the open road it was OK but ran out of steam too soon with peak power at 5,600rpm and peak torque at 4,400rpm.
The second element of work (June 2006) included the following :
. replaced Lucas injectors with Bosch (needed better fueling as above approx 4,500rpm it was too lean as the Lucas units couldn't push enough fuel through)
. Mark Adams diagnostics & mapping session on a RR + supply of a Tornado chip
On the rolling road we got 299 bhp and 315 lbft. More importantly the drivability issues had all been cured. The car now pulls cleanly from < 1,500rpm with a nice wide power band that keeps pulling hard to 6,500rpm. Unfortunately I've managed to lose the RR chart so can't be specific on peak power & torque.
I'm really pleased with the car and the cam choice. It drives superbly, is pretty quick, quite 'revvy' for a V8 and pulls like a train. I'm very interested in Uncle Fester's comments on the dizzy though as we didn't touch anything electrical. Perhaps you'd share some more info UF ?
Moto
Please note that I'm not an expert in any of the work done - I used Mark Adams & Dave Porter to do all the clever stuff. However I thought a summary of my experience & work carried out may be of interest.
Prior to any work being started, we RR'd to get baseline (as straight out the factory) power readings of 257bhp & 291lbft.
The first element of work included the following :
. fitted H234 cam (supplied by TVR Power - we think supplied to them by Kent but can't confirm)
. reset cam timing to suit & lifter pre-load set
. new followers & steel rockers
. modified plenum chamber for larger inlet
. rebuilt & reset throttle linkage (re-sted vacuum advance pipe to suit)
. Throttle slotted to make adjustable
. Trumpet base & inlet manifold modified for better airflow
. Pre-cats removed
At RR this delivered 288.8bhp & 390.1nm (sorry can't remember the conversion to get lbft). However the drivability was crap - particularly around town, at low speed it would start hunting at anything less than 2,200rpm. On the open road it was OK but ran out of steam too soon with peak power at 5,600rpm and peak torque at 4,400rpm.
The second element of work (June 2006) included the following :
. replaced Lucas injectors with Bosch (needed better fueling as above approx 4,500rpm it was too lean as the Lucas units couldn't push enough fuel through)
. Mark Adams diagnostics & mapping session on a RR + supply of a Tornado chip
On the rolling road we got 299 bhp and 315 lbft. More importantly the drivability issues had all been cured. The car now pulls cleanly from < 1,500rpm with a nice wide power band that keeps pulling hard to 6,500rpm. Unfortunately I've managed to lose the RR chart so can't be specific on peak power & torque.
I'm really pleased with the car and the cam choice. It drives superbly, is pretty quick, quite 'revvy' for a V8 and pulls like a train. I'm very interested in Uncle Fester's comments on the dizzy though as we didn't touch anything electrical. Perhaps you'd share some more info UF ?
Moto
Moto said:
I've been running the H234 cam since the start of 2004. My experiences are very similar to those of Uncle Fester - it is NOW very drivable and suits my style. However it took a couple of elements to achieve this.
Please note that I'm not an expert in any of the work done - I used Mark Adams & Dave Porter to do all the clever stuff. However I thought a summary of my experience & work carried out may be of interest.
Prior to any work being started, we RR'd to get baseline (as straight out the factory) power readings of 257bhp & 291lbft.
The first element of work included the following :
. fitted H234 cam (supplied by TVR Power - we think supplied to them by Kent but can't confirm)
. reset cam timing to suit & lifter pre-load set
. new followers & steel rockers
. modified plenum chamber for larger inlet
. rebuilt & reset throttle linkage (re-sted vacuum advance pipe to suit)
. Throttle slotted to make adjustable
. Trumpet base & inlet manifold modified for better airflow
. Pre-cats removed
At RR this delivered 288.8bhp & 390.1nm (sorry can't remember the conversion to get lbft). However the drivability was crap - particularly around town, at low speed it would start hunting at anything less than 2,200rpm. On the open road it was OK but ran out of steam too soon with peak power at 5,600rpm and peak torque at 4,400rpm.
The second element of work (June 2006) included the following :
. replaced Lucas injectors with Bosch (needed better fueling as above approx 4,500rpm it was too lean as the Lucas units couldn't push enough fuel through)
. Mark Adams diagnostics & mapping session on a RR + supply of a Tornado chip
On the rolling road we got 299 bhp and 315 lbft. More importantly the drivability issues had all been cured. The car now pulls cleanly from < 1,500rpm with a nice wide power band that keeps pulling hard to 6,500rpm. Unfortunately I've managed to lose the RR chart so can't be specific on peak power & torque.
I'm really pleased with the car and the cam choice. It drives superbly, is pretty quick, quite 'revvy' for a V8 and pulls like a train. I'm very interested in Uncle Fester's comments on the dizzy though as we didn't touch anything electrical. Perhaps you'd share some more info UF ?
Moto
The electrical difference is that the distributor ignition system is removed and replaced by one driven by a new ECU that controls a number of functions, chiefly the fuel injection and ignition.Please note that I'm not an expert in any of the work done - I used Mark Adams & Dave Porter to do all the clever stuff. However I thought a summary of my experience & work carried out may be of interest.
Prior to any work being started, we RR'd to get baseline (as straight out the factory) power readings of 257bhp & 291lbft.
The first element of work included the following :
. fitted H234 cam (supplied by TVR Power - we think supplied to them by Kent but can't confirm)
. reset cam timing to suit & lifter pre-load set
. new followers & steel rockers
. modified plenum chamber for larger inlet
. rebuilt & reset throttle linkage (re-sted vacuum advance pipe to suit)
. Throttle slotted to make adjustable
. Trumpet base & inlet manifold modified for better airflow
. Pre-cats removed
At RR this delivered 288.8bhp & 390.1nm (sorry can't remember the conversion to get lbft). However the drivability was crap - particularly around town, at low speed it would start hunting at anything less than 2,200rpm. On the open road it was OK but ran out of steam too soon with peak power at 5,600rpm and peak torque at 4,400rpm.
The second element of work (June 2006) included the following :
. replaced Lucas injectors with Bosch (needed better fueling as above approx 4,500rpm it was too lean as the Lucas units couldn't push enough fuel through)
. Mark Adams diagnostics & mapping session on a RR + supply of a Tornado chip
On the rolling road we got 299 bhp and 315 lbft. More importantly the drivability issues had all been cured. The car now pulls cleanly from < 1,500rpm with a nice wide power band that keeps pulling hard to 6,500rpm. Unfortunately I've managed to lose the RR chart so can't be specific on peak power & torque.
I'm really pleased with the car and the cam choice. It drives superbly, is pretty quick, quite 'revvy' for a V8 and pulls like a train. I'm very interested in Uncle Fester's comments on the dizzy though as we didn't touch anything electrical. Perhaps you'd share some more info UF ?
Moto
The limiting factor with the distributor is that the ignition advance controlled in such a way that it is impractical to alter the advance at one RPM and engine load without it altering it at them all. You would get into redesigning and re-engineering the distributor.
The consequence is that faced with a number of competing requirements a best, safe distributor setting is found. In avoiding settings that will damage the engine at one RPM/load, you compromise maximum power, torque economy or drivability at others. In practice you end up setting maximum advance at an RPM and everything else is dictated by the original design of the distributor.
With a modern ECU, the amount of ignition advance can be set for any RPM and engine load. Each setting is independent of the others. This allows the tuner to set the optimum for each.
In the case of our engines, there is an air flow meter that impedes air getting into the engine. This can be dispensed with by using a modern ECU.
The modern ECU also allows much better diagnostics.
With very similar engines (I have a V8 Enhancements Y Piece that you don’t mention) I am getting about 20 bhp and 25lb/ft torque more than you. But that is at lower rpm (safer for the engine) and on regular 95 octane compared to the more expensive fuel you must use. Mapped for high octane V8 Developments predicted about 340bhp. Throttle pick up is also snappier than a distributor car.
In addition, the car uses less fuel because the ECU turns the fuel off altogether when not needed. It also pulls from lower RPM.
Any cam such as the 234 404 piper 300 etc, does really benefit from mapped ignition, these cams are very fast road cams bordering on race cams, they are very very poor at low rpm cylinder filling, ie, if you think your engine is a 5 litre tvr, it is only 5 litre when the cylinder is full of air, these cams at low rpm will make your engine shrink to as little as a 3 litre, to overcome this you need to run a lot of advance at idle, reduce the advance at around 1200 to 2000 rpm and then ramp the advance back up again, on a race/track engine it doesnt really matter if you have a dizzy as it will barely drop below the 3000 rpm (on cam mark) but if you trying to use this kind of cam on the road definetly invest in mapped ignition.
Edited by v8 racing on Thursday 5th June 20:21
Plus to make it tick over - you need the mixture very rich.. because of the big fuel drop out due to slow stalling air flow.
With a mapable ECU - you can also set the cranking timing completely seperate from the main map - with a wild cam you would normally need a bigger battery because of heavy springs and kick back .. should help.
With a mapable ECU - you can also set the cranking timing completely seperate from the main map - with a wild cam you would normally need a bigger battery because of heavy springs and kick back .. should help.
Thanks for the additional info.
It's great to think that I could now find another 20+ bhp by fitting another ecu & replacing the dizzy. At the moment I don't think I will as I'm really happy as it is..... but I guess never say "never" !
Out of interest, what would the rough cost be ?
It's great to think that I could now find another 20+ bhp by fitting another ecu & replacing the dizzy. At the moment I don't think I will as I'm really happy as it is..... but I guess never say "never" !
Out of interest, what would the rough cost be ?
There is another consideration to using a 234 cam, and that is the difficulty of getting them through an emissions test. When used in conjunction with very large ported heads, the gas speed through the ports is even lower, leading to extremely high hydrocarbon levels. Better Bosch injectors do help here however.
Also the camshaft needs to be considered in conjunction with the whole engine package, since larger engines tend to tame wild cams. Other factors that affect this are exhaust manifold design/size, head porting, inlet systems, etc. The 234 is also very sensitive to being properly timed, and a couple of degrees can change it from a flyer to a stinker.
A mappable ignition is definitely a good option, and there are gains of 15-25 BHP to be had typically, again according to the individual engine. Wilder camshafts can be tamed to some extent too whilst they are "off cam".
For my clients who have already invested in Tornado software, larger airflow meters, injectors, etc., then I would recommend adding the Omex 200 mappable ignition system to achieve this. It's a lot cheaper and easier than replacing the whole system, and retains the fuelling sophistication of the Lucas unit. Additionally all Omex ECUs are European type approved ('e' marked) for legal use on road vehicles.
There's nothing in the 14CUX unit that stops it being suitable for wild camshafts. The upper limit of the system is somewhere around 470 BHP with suitable injectors and airflow meter (this has been established on several forced induction motors, both turbo and supercharged) although it does need mappable ignition in this environment.
The only negative of retaining the Lucas unit is that you are stuck with me to map it.
Also the camshaft needs to be considered in conjunction with the whole engine package, since larger engines tend to tame wild cams. Other factors that affect this are exhaust manifold design/size, head porting, inlet systems, etc. The 234 is also very sensitive to being properly timed, and a couple of degrees can change it from a flyer to a stinker.
A mappable ignition is definitely a good option, and there are gains of 15-25 BHP to be had typically, again according to the individual engine. Wilder camshafts can be tamed to some extent too whilst they are "off cam".
For my clients who have already invested in Tornado software, larger airflow meters, injectors, etc., then I would recommend adding the Omex 200 mappable ignition system to achieve this. It's a lot cheaper and easier than replacing the whole system, and retains the fuelling sophistication of the Lucas unit. Additionally all Omex ECUs are European type approved ('e' marked) for legal use on road vehicles.
There's nothing in the 14CUX unit that stops it being suitable for wild camshafts. The upper limit of the system is somewhere around 470 BHP with suitable injectors and airflow meter (this has been established on several forced induction motors, both turbo and supercharged) although it does need mappable ignition in this environment.
The only negative of retaining the Lucas unit is that you are stuck with me to map it.
Mark Adams said:
For my clients who have already invested in Tornado software, larger airflow meters, injectors, etc., then I would recommend adding the Omex 200 mappable ignition system to achieve this. It's a lot cheaper and easier than replacing the whole system, and retains the fuelling sophistication of the Lucas unit. Additionally all Omex ECUs are European type approved ('e' marked) for legal use on road vehicles.
If a Lucus unit has already been mapped by you will that map still be valid if a mapped ignition system is added or will your map also then need to be re optimised ?Mark Adams said:
There is another consideration to using a 234 cam, and that is the difficulty of getting them through an emissions test. When used in conjunction with very large ported heads, the gas speed through the ports is even lower, leading to extremely high hydrocarbon levels. Better Bosch injectors do help here however.
Mark - good to see you back on here.Looks like I'm doomed with my new cam
steve-V8s said:
This is slightly off topic but some while ago Rob aka V8 Racing did a superb summary of a number of cams listing performance and drivability. Had a search for it but no joy, anybody know where I can find it ?
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