Anybody running OTTP Stage 4 cams?
#26
Junior Member
iTrader: (3)
While talking about cams here; we have something strange going on between two similar LSJ engines:
#1; LSJ, ported head, Harrop 80mm and ZZP stage 2 cams. (Cam base circle checked!) Runs quite decent and idles @42KPa with ~7% TB. Run it with 60lb's and also with the stock tune/injectors to check idle and low load behaviour. No issues besides dialing in the tune with new injectors.
#2; LSJ, ported head, Harrop 80mm and ZZP stage 1 cams. Idle and low load is sh*t. Top power is OK though, but this one only idles @53KPa and 11-12%ETB... It should idle with more vacuum due to the milder cams, as stock LSJ cams idle @33KPa.
We quickly checked the cam install with the chain links (OK), but next step will be controlling exact "cam timing with a degree wheel and valve lift. And measure the base circles + lift.
This engine also seems to have an exhaust leak at the header, but that should not influence idle vacuum that much, right?
#1; LSJ, ported head, Harrop 80mm and ZZP stage 2 cams. (Cam base circle checked!) Runs quite decent and idles @42KPa with ~7% TB. Run it with 60lb's and also with the stock tune/injectors to check idle and low load behaviour. No issues besides dialing in the tune with new injectors.
#2; LSJ, ported head, Harrop 80mm and ZZP stage 1 cams. Idle and low load is sh*t. Top power is OK though, but this one only idles @53KPa and 11-12%ETB... It should idle with more vacuum due to the milder cams, as stock LSJ cams idle @33KPa.
We quickly checked the cam install with the chain links (OK), but next step will be controlling exact "cam timing with a degree wheel and valve lift. And measure the base circles + lift.
This engine also seems to have an exhaust leak at the header, but that should not influence idle vacuum that much, right?
#28
Junior Member
iTrader: (3)
Yeah, LSA affects vacuum and so does duration. But should be the other way around. The milder Stage 1 cams should pull more vacuum than my stage 2's...
The stage 1's do 10KPa less vacuum on his engine and needs ~11%ETC to idle @875rpm. Weird..
Last edited by Speedytec; 06-03-2014 at 01:14 PM. Reason: edited
#30
Junior Member
iTrader: (3)
ZZP Stage 2's have 111 LSA => pulls 42KPa vacuum @idle in my engine
Stock LSJ cams have 107,5 LSA and those gave me a 33KPa vacuum
His Stage 1's have 109 LSA and that is right between those 2 , but it only pulls 53 KPa vacuum. Probably due to the 11%ETC opening that his engine needs to keep idling...
(And we checked some old logs of his engine with stock LSJ cams fitted; also ~33KPa. :-/)
Checking cam profile and timing coming days.
#33
Junior Member
iTrader: (3)
Stage 2 cam 16in (merc) vacuum will be 54KPa vacuum. => ~46KPa MAP reading. (Close to my measured 42KPa MAP)
Custom cam 12in = 41KPa => 59KPa MAP value
Stock cams 19-20in = 65KPa vac => 35KPa MAP; right what we measured on both stock engines. Think the LSJ cams and my Stage 2's were/are timed right...
#38
Junior Member
iTrader: (3)
cams measure base circle 30mm, so ok. Now to check actual cam timing..
#40
Junior Member
iTrader: (3)
My engine idles & drives quite nice with stock GM injectors, his stage 1 cams not...
This weekend measuring cam lobe centers to rule that out.
#41
Junior Member
iTrader: (3)
So we did some measurements of the ZZP Stage 1 cams in the car. We repeated a few times with different measurement set-ups, but results were the same:
Degree wheel on the pulley, zeroed on TDC position and a measuring gauge on the valves.
Measured the crank degrees from start lift (0.050" on the gauge) to end lift at the same 0.050". Divide by 2 to get the lobe centerline degrees.
EXH: open @151*, close @346* => Lobe center = 248.5* ATDC => 111.5* BTDC (ZZP specs = 115*)
INT: open @-1*, close @193* => Lobe center = 97* ATDC (ZZP specs = 102*)
Lobe sep. angle = (111.5* + 97*)/2 = 104.25* (ZZP specs Stage 1 = 109* LSA)
These 5* less LSA degrees will create more valve overlap and very likely the cause of our poor vacuum and the idle bahaviour. Shame, as we especially bought ZZP cams because they are said to be accurately degreed for the LSJ... :-/
Degree wheel on the pulley, zeroed on TDC position and a measuring gauge on the valves.
Measured the crank degrees from start lift (0.050" on the gauge) to end lift at the same 0.050". Divide by 2 to get the lobe centerline degrees.
EXH: open @151*, close @346* => Lobe center = 248.5* ATDC => 111.5* BTDC (ZZP specs = 115*)
INT: open @-1*, close @193* => Lobe center = 97* ATDC (ZZP specs = 102*)
Lobe sep. angle = (111.5* + 97*)/2 = 104.25* (ZZP specs Stage 1 = 109* LSA)
These 5* less LSA degrees will create more valve overlap and very likely the cause of our poor vacuum and the idle bahaviour. Shame, as we especially bought ZZP cams because they are said to be accurately degreed for the LSJ... :-/
#43
Supporting Vendor
iTrader: (1)
Getting accurate cams from comp has been difficult at best. We're working with them on some new fixturing for their machines but it's in process. Add to that the base circle issues and misboxing and it's been a real struggle. If you were to buy an LSJ cam by part # from a random vendor who isn't checking them, the chance of it being accurate isn't very good.
We've had a lot that were close and we shipped them. This is the unfortunate reality of the state we're in.
Currently we've taken LSJ cams out of stock. we have piles of them if someone wants a deal and knows how to use them with adjustable gears. Brand new, boxes say the right things, cams aren't what they say tho.
We've had a lot that were close and we shipped them. This is the unfortunate reality of the state we're in.
Currently we've taken LSJ cams out of stock. we have piles of them if someone wants a deal and knows how to use them with adjustable gears. Brand new, boxes say the right things, cams aren't what they say tho.
#45
Senior Member
iTrader: (1)
Why not run comp XE264HR-13, at the very least those arent regrinds and you shouldnt have any issues with the lash adjusters.
113400 - Cast core version Hydraulic Roller Camshafts
113400 - Cast core version Hydraulic Roller Camshafts
#46
Supporting Vendor
iTrader: (1)
Why not run comp XE264HR-13, at the very least those arent regrinds and you shouldnt have any issues with the lash adjusters.
113400 - Cast core version Hydraulic Roller Camshafts
113400 - Cast core version Hydraulic Roller Camshafts
The above cams would not be as spec'd when you receive them.
#48
Former Vendor
iTrader: (4)
Getting accurate cams from comp has been difficult at best. We're working with them on some new fixturing for their machines but it's in process. Add to that the base circle issues and misboxing and it's been a real struggle. If you were to buy an LSJ cam by part # from a random vendor who isn't checking them, the chance of it being accurate isn't very good.
We've had a lot that were close and we shipped them. This is the unfortunate reality of the state we're in.
Currently we've taken LSJ cams out of stock. we have piles of them if someone wants a deal and knows how to use them with adjustable gears. Brand new, boxes say the right things, cams aren't what they say tho.
We've had a lot that were close and we shipped them. This is the unfortunate reality of the state we're in.
Currently we've taken LSJ cams out of stock. we have piles of them if someone wants a deal and knows how to use them with adjustable gears. Brand new, boxes say the right things, cams aren't what they say tho.
Why not run comp XE264HR-13, at the very least those arent regrinds and you shouldnt have any issues with the lash adjusters.
113400 - Cast core version Hydraulic Roller Camshafts
113400 - Cast core version Hydraulic Roller Camshafts
#49
Senior Member
iTrader: (1)
Getting accurate cams from comp has been difficult at best. We're working with them on some new fixturing for their machines but it's in process. Add to that the base circle issues and misboxing and it's been a real struggle. If you were to buy an LSJ cam by part # from a random vendor who isn't checking them, the chance of it being accurate isn't very good.
We've had a lot that were close and we shipped them. This is the unfortunate reality of the state we're in.
Currently we've taken LSJ cams out of stock. we have piles of them if someone wants a deal and knows how to use them with adjustable gears. Brand new, boxes say the right things, cams aren't what they say tho.
We've had a lot that were close and we shipped them. This is the unfortunate reality of the state we're in.
Currently we've taken LSJ cams out of stock. we have piles of them if someone wants a deal and knows how to use them with adjustable gears. Brand new, boxes say the right things, cams aren't what they say tho.
#50
Senior Member
iTrader: (1)
Not sure what you mean "but why?". Regrinds are the only way car's that don't have a large aftermarket normally get into the aftermarket camshaft game, and typically when there are issues with running out of base circle for more aggressive profiles you can just hardweld the cam. I just had a set of LE5 cams reground to Kelford's EVO 9 272 cam design only in a single pattern setup, no issues there, just gotta know your lift limits more than anything. I stopped at .425/.425. No reason to run any higher than that unless the head supports it.