OK, turns out it's not the cam timing, it's the cam grind that's off!!

Lesson learned: With this sort of valve train if you decrease the base circle of the cam then you have to increase the valve stem length too or the rockers fall off!!! Hence the low power reading, only 8 inlets opening!

New cams and 32 extended valves on order now.

Bugger.

Bugger.

Bugger.

At least the rockers didn't jam something up and snap the timing chains. One did come through the top of the rocker box though!

Oooopppppssss!! Sounds expensive John! :eek:

 

Hope this sorts it for you :bow:

By how much were the cam lobes reduced John, I would have thought that the rockers would take up a couple of mm ? the rockers must be a snug fit inside the cam covers to beat its way through them due to the extra travel.

This will sort it, proven in the NZ jet boats and stock cars so should be fine.

Think the base circle has prob lost maybe 4-5mm.

Prob wrong to call them rockers, they're sort of followers that the cam runs on top of and the lash adjuster and valve are underneath. It smashed through the cover because it fell off and got caught by the cam, not because of the extra travel. Lucky escape really!

Bloody hell John, i'd heard the rumours at ZFest that you weren't coming because you'd blown the V8 up, glad it's not total destruction! Hope you get it sorted out soon :D

OK, turns out it's not the cam timing, it's the cam grind that's off!!

Lesson learned: With this sort of valve train if you decrease the base circle of the cam then you have to increase the valve stem length too or the rockers fall off!!! Hence the low power reading, only 8 inlets opening!

New cams and 32 extended valves on order now.

Bugger.

Bugger.

Bugger.

At least the rockers didn't jam something up and snap the timing chains. One did come through the top of the rocker box though!

 

Sorry to hear this offically. I got the unofficial heads up from Jim last week. I have just been down there today picking up my engine which had to be re done due to... err ... a camshaft problem:rant:

So you are not alone with that scenario:x:

 

All is well now with mine thanks to Jim and Charlie .... and with NO thanks at all to the E**ing Muppets at David Newman camshafts:headvswal

Tell me about it! I heard what they did to yours, shocker.

I'm just thinking of mine as a 'design iteration' :rolleyes:

No damage done really, just a pain having to pull the engine again.

not got a clue what you are on about . but it sounds a real shame.

 

Was it something you did wrong??

not got a clue what you are on about . but it sounds a real shame.

 

Was it something you did wrong??

 

Wot are you doing on here???

Havent you got lots of fog light ducts to get made:smash:

 

:D:D:D:D

Wot are you doing on here???

Havent you got lots of fog light ducts to get made:smash:

 

:D:D:D:D

 

:rofl: :rofl:

 

Ive got 2 pairs made up :wack:

not got a clue what you are on about . but it sounds a real shame.

 

Was it something you did wrong??

 

No Dave. Here is a serious answer.

The only thing John and me did wrong was we each decided to go down an engine development route that few if any had gone down here in the UK.

That meant we wer'nt able to just order a complete engine package "off the shelf" so to speak like you can from Kyle Puckett in the USA.

A natural danger of doing our own thing was (for me at least) that we wouldnt get it 100% right 1st time.

The Engine builder we both chose(CTM Performance and associated guy Big Jim Racing) have been very supportive.

 

My "problem " was caused by a sub contractor, Newman Cams.

However Its all been put right now and Im sure Charlie at CTM and Jim at Big Jim Racing will do the same for John,s engine.

What he said!

Except in my case it was piper cams :rolleyes:

What he said!

Except in my case it was piper cams :rolleyes:

 

did'nt know piper did custom grinds john:confused:...and i would of thought being piper they would of picked up on the drivetrain problem when orded

is the setup the same as the sr20?

 

in which case you might want to look at rocker arm stoppers aswell which can stop the arms jumping off at high revs which i take it you are aiming for

 

i understand about the treading new ground. i am fitting a toyota 1 uz into my 200 with a pair of gt28s.

 

i would love to see your car sometime john as you are only just down the road from me (i used to work in stourport)

 

i would have loved to have fitted the nissan v8 but funds were limited at the time and the lexus engine is easyer to come by.

 

pete

Yeah, you'd have thought they would! They will do custom grinds if you pay enough, that's what's so annoying, it wasn't cheap.

 

Not sure about the SR20, never seen one open. Once it's running again you're welcome to drop over, I'm actually moving to stourport in November. I think the lexus engine is a bit smaller too, saw one in the back of a mini a few weeks ago with a huge turbo on it. Scary stuff!

excelent stuff.

 

the lexus has a slightly lower capacity and the valve angle is a bit steeper so the heads are not as wide. hence its a bit smaller. makes less power though.

 

are you still doing chips mate btw

Yes, still doing chips.

excelent.

 

ill be needing one once the zed is running correctly

 

can you pm me details or post me a link for cost etc. ill be running what most would call stage 1- 15psi +exhaust and filter

 

ta

 

ps sorry to hijack the thread:)