View Full Version : Reprofiled xe cams?
How do these work? Im assuming the dont add any metal to them only remove? But then ive read they may not be suitable for standard pistons?
If they have only removed material why would they hit?
Cams in question are 288degree autosprint cams
George g
06-05-09, 01:39 PM
IIRC, they grind some off the back (lowest part of the cam) and make them slightly more agressive, so the valve opens quicker, so could possibly clash with the piston if you are very unlucky. but not 100% sure on that one...
George g
06-05-09, 01:44 PM
like this - the red line is new profile, the black is the old.
http://img150.imageshack.us/img150/9281/camgq2.png
Looking at that it makes sense, cheers
If i turn the engine over by hand first and it clears it should be ok shouldnt it
wouldnt use autosprint tbh matey. not that good. try QED
gaznovalet
06-05-09, 03:37 PM
IIRC, they grind some off the back (lowest part of the cam) and make them slightly more agressive, so the valve opens quicker, so could possibly clash with the piston if you are very unlucky. but not 100% sure on that one...
spot on ive just sold a set to novaxe235 on here and mine used pocketed pistons incase they clashed and caused any damage, that pic is spot on + rep.:thumb:
Geordie-Chris
06-05-09, 03:55 PM
wouldnt use autosprint tbh matey. not that good. try QED
Why are Autosprint 'not that good'? What experience have you had of their products?
I run them in mine and they are fine, and his customer service is spot on, very very helpful guy and reasonably priced too.
tom reid
06-05-09, 04:01 PM
We've had about 10 Autosprint cams, Ford, Vaux, Jag, with no issues, I do know that sometimes you can get a wonky cam from any supplier, but having seen the man at work, I doubt if you'd get one from him.
I think what Phil means is the Grp N and 420's from QED are a better option.
they are for the money. as the saying goes ' you get what you pay for'
well i got these at a good price, people think they will go with standard? If they dont clas turning over by hand they should be ok?
George g
07-05-09, 09:16 AM
in theory, yes. but if its very, very close then with how fast everything moves and how close everything is together, all it takes is a few thou wear off the bottom end bearing and it could all be over as the piston will touch the valve.
my local engineering place charged me £30 to deepen the pockets on x16xe pistons so might be worth ringing around
M.E.D do pocketing on pistons, and SBD used to but when i enquired couple of years ago their machinest had just retired, and dont know if found a replacement!lol
http://www.ddv-motorsport.nl/nl/nokkenassen.htm
i tried to translate the ddv site, could be wrong with some words though...:
basicly you change the diameter and the hight of the cam.
so a OEM cam has a 34mm diameter with a 43.5mm profile. 43.5-34= 9.5 mm lift. you change the diameter to 30 and the profile (cam tip) to 41..
41-30=11mm lift.
the 2mm extra play on the valvesteem you fill up with shimms.
dont think you can get shims for hydraulic followers though, so think thats why they tap alot more or.....dont last as long
tom reid
08-05-09, 06:38 PM
dont think you can get shims for hydraulic followers though, so think thats why they tap alot more or.....dont last as long
Wrong and wrong,Oh and what about "A fool and his money are easily parted"lol
yes im a fool...retard.
ok then..where do you get shims from for a hydraulic lifter, as only shims ive EVER seen are for converting hydraulic buckets to solids or proper solid lifters/shims.
tom reid
08-05-09, 09:34 PM
Make them yourself or get them made
just seems like more things to go wrong with a shim and a hydraulic follower.
+ i cant see many people having acces to hardened steel tbh or willing to pay for shims to be made.
just seems like more things to go wrong with a shim and a hydraulic follower.
+ i cant see many people having acces to hardened steel tbh or willing to pay for shims to be made.you seem to forget some people will happily spend 10k+ on an engine. the price of shims doesnt matter
dumpycorsa
09-05-09, 03:03 AM
I'm running an Autosprint big valve head and 288deg cams. They don't tap and the car goes very well. In my opinion let the results do the talking. My engine will be on the rollers soon. When it does I'll post the results up and you can draw your conclusions from that if you like.
The cam lobes on the 288 cams are dumpier than standard xe cams. They clear on standard pistons but would recommend checking valve clearances using plasticine. Remembering that your lifters won't be primed so the clearance maybe reduced further. Things like how much has been skimmed off of your head/block will have a big effect on clearance so Autosprint can't guarantee clearance on every engine. There isn't a great deal with standard cams TBH.
Better safe than sorry. This is what Geoff at Autosprint will recommend
i know people spend that much on engines, ive spent £7k on mine, and i built that myself!
also people who spend that much on engines, wont dick about with regrind and shimming hydraulics. theyd go straight on to a solid profile cam and solid lifters
dumpycorsa
09-05-09, 03:46 AM
i know people spend that much on engines, ive spent £7k on mine, and i built that myself!
also people who spend that much on engines, wont dick about with regrind and shimming hydraulics. theyd go straight on to a solid profile cam and solid lifters
What pistons and rods have you chosen to use? C/R?
If I was to replace my engine it would probably cost in excess of 6k in parts. I built mine too:p .Glad I paid Autosprint prices else that could be alot higher. QED and Sbd have the reputations and experience no doubt about that but you pay for it.
I'm still on hydraulic profiles purely so it's more friendly to drive in traffic and gives peak power respectively low down the rev range. It's nice to have the option to step up another level if you feel you're getting bored/used to the power.
I wouldn't use ANY hydraulic lifter in a high revving engine, total waste of time as they simply can't take it which has been proven time and time again.
My Arrow solids were £200 and another £50 for the shims from SBD, I'm on Omegas and Eagle rods, will probably see 8500rpm tops.
Anything seeing those sort of revs that will be used on track should also be dry sumped IMO
dumpycorsa
09-05-09, 11:18 AM
I wouldn't use ANY hydraulic lifter in a high revving engine, total waste of time as they simply can't take it which has been proven time and time again.
My Arrow solids were £200 and another £50 for the shims from SBD, I'm on Omegas and Eagle rods, will probably see 8500rpm tops.
Anything seeing those sort of revs that will be used on track should also be dry sumped IMO
If you're running a hydraulic profile you'll be making peak power along time before 8,500rpm. Solids are a must when pushing 8k plus no doubt. Been advised not to take hydraulic lifters past 7,750rpm but I'm sure with the Autosprint 288 duration cams peak power will be much lower than that.
i used to run 8000 rpm on a stock c20xe without problems.
my current xe is running 7600 rpm, with hydrolic lifters and 280 cams. i'm not running with adjustable camwheels, and she stays at the 170ish hp line from 5 till 7000 rpm before going downhill.
arrow rods and CP slipper pistons 11.5:1
im running solids, QEd valves, etc etc etc
newman cams, arrow solids. should peak at 8k, went for newman as heard kent say there cams make peak at so many revs, but if it doesnt(and you gen have right components) they will just say engines not to spec. piper didnt seem to know enough about there own cams, and mates have used newmans before and where they have said peak power is, it is.
mayhem - you've been lucky if lasted at 8k rpm. rods dont like much over 7.5k(stock anyway)
Powered by vBulletin® Version 4.2.5 Copyright © 2024 vBulletin Solutions, Inc. All rights reserved.