Mini-Blog - Stealth cam is in.
Discussion
After a recent rolling road shootout down in Cornwall the power graph made it perfectly clear that things were not as 'nature TVR' intended.
The graph showed that peak torque was strong, 290lbs at 3,600 rpm but peak power was low and peaked too early at 4,500 rpm, an indication that either timing was drastically out or the cam worn - or both!
I went through the history, I have every bill etc from new and the car had never had a cam, as these can wear in as little 30k I was not adverse to having one popped in and upgrade it whilst I was there.
I spoke to many people when selecting the cam (thanks in particular to Quinny) and opted for the full V8 Developments Kent Stealth kit, I ummed and arrred as to who to install it whilst asking many questions on PH when Richard Smith from Dulford automotive gave me a call expressing an interest in fettling the car.
I never considered Dulford although it was on my doorstep because of experiences of previous dealings at the 'Peninsula main dealer' stage of Richard's involvement where I'm sure he won't mind me saying that everything wasn't as had he preferred.
Richard assured me that the whole point of leaving Peninsula and forwarding Dulford was to get back to the grass roots of servicing people that used to enjoy when Peninsula was an indie, come up see the car being done and how we now works etc..
Well.. I opted for the Dulford option and have spent the last two days with them sorting the car and I have to say i was.. well... to my surprise... most impressed.
I was present throughout the job as the car was stripped and Colin must have the patience of a saint because as i know if anyone stood over me working on a car and quizzed I would soon tell them to
off as it is so off-putting but Colin was so fastidious from start to finish it was a real eye opener.
The first thing to do once the ancillaries were removed was to conduct a leak down test to make sure the problem wasn't the case of blowing past the rings etc, they all came back good with only two showing 15% on the exhaust valves the rest were between five and ten, Colin noticed that the front cover had been off before and on checking the history Team Proactive put a new front cover on at 20k for whatever reason so we were dealing with a 57k cam.
Here is a picture of the old and new cams at the same duration, bearing in mind the car didn't miss a beat looking at the lobes you wouldn't think so!
It’s mad how it ran so smoothly but you can see how the low down grunt was there but struggled to deliver at above 4,500rpm – no lift!
The difference in the car is like comparing an eight to a sixteen valve engine which in effect is basically how it has changed!
I have to say a big thank you to Colin at Dulford, his work was superb and the attention to detail was outstanding, right down to little things like resetting the clock after the battery was disconnected.
Here we are timing the new cam in, a bit of a bitch as the new billet gear wasn't in the correct increments thus taking two and a half hours of counter setting to get 111 degrees (the cam is to be set at 112 but you allow for the duplex to stretch)
The car pulls cleanly now to six grand and is very driveable, very very slightly lumpy on tickover but upon pick up the car's manners are superb.
The next thing is to get the car back on the Cornish rollers to see the back to back comparison once all the mods are finished.
A good job well done I have to say.
The graph showed that peak torque was strong, 290lbs at 3,600 rpm but peak power was low and peaked too early at 4,500 rpm, an indication that either timing was drastically out or the cam worn - or both!
I went through the history, I have every bill etc from new and the car had never had a cam, as these can wear in as little 30k I was not adverse to having one popped in and upgrade it whilst I was there.
I spoke to many people when selecting the cam (thanks in particular to Quinny) and opted for the full V8 Developments Kent Stealth kit, I ummed and arrred as to who to install it whilst asking many questions on PH when Richard Smith from Dulford automotive gave me a call expressing an interest in fettling the car.
I never considered Dulford although it was on my doorstep because of experiences of previous dealings at the 'Peninsula main dealer' stage of Richard's involvement where I'm sure he won't mind me saying that everything wasn't as had he preferred.
Richard assured me that the whole point of leaving Peninsula and forwarding Dulford was to get back to the grass roots of servicing people that used to enjoy when Peninsula was an indie, come up see the car being done and how we now works etc..
Well.. I opted for the Dulford option and have spent the last two days with them sorting the car and I have to say i was.. well... to my surprise... most impressed.
I was present throughout the job as the car was stripped and Colin must have the patience of a saint because as i know if anyone stood over me working on a car and quizzed I would soon tell them to
off as it is so off-putting but Colin was so fastidious from start to finish it was a real eye opener. The first thing to do once the ancillaries were removed was to conduct a leak down test to make sure the problem wasn't the case of blowing past the rings etc, they all came back good with only two showing 15% on the exhaust valves the rest were between five and ten, Colin noticed that the front cover had been off before and on checking the history Team Proactive put a new front cover on at 20k for whatever reason so we were dealing with a 57k cam.
Here is a picture of the old and new cams at the same duration, bearing in mind the car didn't miss a beat looking at the lobes you wouldn't think so!
It’s mad how it ran so smoothly but you can see how the low down grunt was there but struggled to deliver at above 4,500rpm – no lift!
The difference in the car is like comparing an eight to a sixteen valve engine which in effect is basically how it has changed!
I have to say a big thank you to Colin at Dulford, his work was superb and the attention to detail was outstanding, right down to little things like resetting the clock after the battery was disconnected.
Here we are timing the new cam in, a bit of a bitch as the new billet gear wasn't in the correct increments thus taking two and a half hours of counter setting to get 111 degrees (the cam is to be set at 112 but you allow for the duplex to stretch)
The car pulls cleanly now to six grand and is very driveable, very very slightly lumpy on tickover but upon pick up the car's manners are superb.
The next thing is to get the car back on the Cornish rollers to see the back to back comparison once all the mods are finished.
A good job well done I have to say.
Edited by Bomber Denton on Friday 4th May 20:04
B@stards stole mine too - same one - before I'd even done 20k. Excellent post - I guess there will be a string of other v8 owners wondering if they've got a stolen lobe too. Corin - did you notice any noise from the worn cam? I noticed a very faint tap that progressed to a buzz at higher revs and sounded as though it was coming from just forward of the gear stick. The increased power delivery of the re-cam'd engine was hardly surprising considering the lack of lobe lift. I had a standard profile cam fitted after discussing the downsides of a more aggressive cam which tended to focus on lumpy tick-over and awkwardness when driving in slow moving traffic. Since I live in the London area the latter can be a regular activity so went for the standard cam.
Just getting mine done at Dave Batty's as well and he said mine was pretty well worn and definately needed replacing and its only done 47500 miles! He said it is accelerated by owners leaving the car idling for long periods of time as the crank doesnt flick up enough oil to the cam below 1000rpm... Glad i'm doing it now though as I only decided to have it done because the heads had to come out to drill some siezed bolts out when fitting a set of ACT manifolds!
- I went with the MC1 cam in the end as a stealth would have required the pistons pocketing and hence would need the whole engine taking apart which I really can't afford!
- I went with the MC1 cam in the end as a stealth would have required the pistons pocketing and hence would need the whole engine taking apart which I really can't afford!
torquemada said:
thenick said:
required the pistons pocketing and hence would need the whole engine taking apart
Err, could someone explain to an ignoramus such as I what piston pocketing means?
recesses in the piston crowns allowing the valves "in" when pushed further down by a higher lift cam.
nice one Corin, ofcourse I would have expected nothing less from Dulford. But you knew that.
andy
tvrmonster.com
hut49 said:
B@stards stole mine too - same one - before I'd even done 20k. Excellent post - I guess there will be a string of other v8 owners wondering if they've got a stolen lobe too. Corin - did you notice any noise from the worn cam? I noticed a very faint tap that progressed to a buzz at higher revs and sounded as though it was coming from just forward of the gear stick. The increased power delivery of the re-cam'd engine was hardly surprising considering the lack of lobe lift. I had a standard profile cam fitted after discussing the downsides of a more aggressive cam which tended to focus on lumpy tick-over and awkwardness when driving in slow moving traffic. Since I live in the London area the latter can be a regular activity so went for the standard cam.
No noise at all from the cam, I reckon you could even get away with a Stealth in London it is that smooth, my car has not yet been re-mapped either, you can pretty much tame any cam with a decent re-map.
torquemada said:
Corin - any chance of letting us know the approx ££££ ? I'm on 66k on the original cam and doing research on the various options.
I went for the complete cam kit from V8 Developments, this consisted of the new cam, new lifters, new Kent double valve springs, billet timing gears and duplex chain and all gaskets to complete the job - cost about £550.
It's pretty pointless doing the job without all this as the followers wear in a concave fashion, the original factory springs were to higher poundage really which contributes to the cam wear, my vernier was also worn.
As for fitting costs, it's really how far you want to go with it? Someone could 'bosch' the cam in using the settings prescribed for the timing gears etc and do the job 'right' and the car will run in an improved fashion but.. and I think this is where some people have come unstuck fitting the Stealth the billet gears need off-setting to acheive the correct degree setting, this took time.
On mine the leak down teat was also conducted, all the rockers, plenum base, rocker covers, front cover etc were chemically cleaned, the sump was removed clean out the strainer etc afterwards to ensure no debris was left after the install and Colin was determined to clean all mounting surfaces to nano-chuff proportions!
This all takes time, and being part of having the job done I can honestly say I wouldn't have it any other way, the car's are worth a reasonable amount of money, the cam kit isn't the cheapest - why skimp?
Bear in mind it depends on who you use and you will need an oil and filter change, coolant change etc so you will need to phone around
You're only two hours away from Dulford it's worth just giving Richard a call (01884 266675) for a chat. If you're down this way before you are welcome to have a go in mine to get a feel for the cam.
I did a LOT of research before choosing the Stealth and I am chuffed to nuts with it.
torquemada said:
thenick said:
required the pistons pocketing and hence would need the whole engine taking apart
Err, could someone explain to an ignoramus such as I what piston pocketing means?
No adjustments were made to any of my pistons, Colin has a tool that enables the valve springs to be done with the heads in place so with the leak down results the heads didn't even come off!
Edited by Bomber Denton on Saturday 5th May 19:39
seasider said:
Someones stolen a lobe .... Edited by seasider on Saturday 5th May 09:53
I was there and saw it in the flesh. Exhaust valve could only have been half open as about one eigth of an inch of the lobe had gone AWOL. Also support Corin's comments about Colin's meticulous work.
really??? This is very interesting... I really wanted a stealth cam but Shaun from V8Developments told me that my 450 would need the pistons pocketing. He said it might be able to be squeezed in but he wouldn't like to try... Currently my car is sitting with the heads off awaiting the cam on tuesday, if I can have a stealth cam instead then I would quite like to know as I can still change my mind! - My car is a 97 450 Chim by the way
thenick said:
really??? This is very interesting... I really wanted a stealth cam but Shaun from V8Developments told me that my 450 would need the pistons pocketing. He said it might be able to be squeezed in but he wouldn't like to try... Currently my car is sitting with the heads off awaiting the cam on tuesday, if I can have a stealth cam instead then I would quite like to know as I can still change my mind! - My car is a 97 450 Chim by the way
Nick, Ive got a stealth going on mine next week (unless im let down again)its a 450 on a 97 but mine has piston pockets - Im sure i was told it was the Big valves that only had the pockets....???
Quinny said:
Just to clarify one point, you went for keyway timing gear where IIRC you have a number of different keyways you can choose to set the cam timing, is this correct???
If you want to get it absolutly spot on you can choose vernier timing gear that is almost infinitly adjustable (witin a certain range)
Hello mate, I did not specify the keyway gear, it's what automatically came when I ordered the complete kit from V8D, the increments weren't two degree sections so timed in on one increment it gave 115 degrees, on the next it gave 109!
We had to offset the cam pulley to get 111.
But as you say now it's there it's 'bob-on'
My old vernier had moved as well.
I had a Stealth cam fitted and it totally ruined my top end of my 450...can't be sure exactly what happened but it was very tappy after fitment, I had the preloads checked twice and even fitted some adjustable pushrods but nothing made it run any quieter. Ended up having it pulled apart and found the top end was a bit of a mess!
I had the topend rebuilt and asked Austec to reuse the Stealth cam, but again it was very noisey so in the end they fitted a 218 cam and everything was back to normal!!
I had the topend rebuilt and asked Austec to reuse the Stealth cam, but again it was very noisey so in the end they fitted a 218 cam and everything was back to normal!!
996dom said:
I had a Stealth cam fitted and it totally ruined my top end of my 450...can't be sure exactly what happened but it was very tappy after fitment, I had the preloads checked twice and even fitted some adjustable pushrods but nothing made it run any quieter. Ended up having it pulled apart and found the top end was a bit of a mess!
I had the topend rebuilt and asked Austec to reuse the Stealth cam, but again it was very noisey so in the end they fitted a 218 cam and everything was back to normal!!
I had the topend rebuilt and asked Austec to reuse the Stealth cam, but again it was very noisey so in the end they fitted a 218 cam and everything was back to normal!!
I spoke to Paul and he told me about this but I have to say I have zero noise. Ruddy (CaptiV8ed) has just done his and it sounds sweet as a nut to me, did you talk to Rob from V8D about the problem?
Bomber Denton said:
Uncle Bulgaria said:
Very intresting, will be good to see how it goes at V Max.
See you there.
See you there.
Were you there at the last one?? Crash helmet, pushing his car around to keep the heat down??
Yes, saving fuel as was running low. Car was running very shite that day turned out to be a blocked cat and a badly blowing manifold.
Car will be 100% for the next one.
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