Best Cam To Suit Hillclimb Car

[acox99 74 1 Cars]

While im on a role for new topics, whats the best cam for a hillclimb car, it wont be road legal and will hopefully run TB's, but will still retain hydrolic lifters, what sort of thing should i go for, a re grind of the original or something mild from say cat cams or kent cams?.......sorry another question, how easy is it to convert to solid lifters or isnt it worth it if its not a serious lots of money spent race tuned engine

Edited August 29, 2006 by acox99

[boombang 2]

You talking 8 or 16valve here?

 

If 8valve then its on solid lifters as standard.

 

It can be VERY expensive to convert a 16valve to solids but its doubtful a reground cam profile being offered by one of the main companies would be for solids.

 

If you are going for over 200bhp reliably and are willing to spend a lot on the rest of the engine (thousands) then go for it - but decent power is still made on hydraulics.

 

Its very hard to be competitive with an Mi though as it puts you into a tough class with engines that have far more and cheaper tuning options.

 

If you are just looking for a good start to hillclimbing, try a road going class first, even though it restricts you to an 8valve - otherwise you can try all you like but the 300bhp super-mod monsters will eat you alive.

[acox99 74 1 Cars]

im talking 16v, so will want to keep hydrolic lifters, im not worried about being compatitive as just want to have fun and a nice track daya dn sprint car to play with, and in the future maybe a turbo technics kit, but thats a long way off.

[smckeown 1]

i assume a hilclimb car would benefit from a hike in mid range torque. What mods are you allowed to run ? Best value for money would be a suitabble catcam (not too wild) and r1 carbs i'd say. Obviously TBs and mappable ECU will get you a better torque spread according to what people say on here.

 

Have you also considered lowering the gearbox ratios ?

 

cheers

sean

[petert 586]

If you're going to race it, dump the hydraulic lifters and fit solids. The same as hydraulic Mi16's, you don't need a lot of cam timing to make good power, but the solids will give you the headroom to rev to 7500+ reliably. It may just be so you can save a gear change on a particular corner and stretch it out a few hundred RPM. Hydraulic lifters will bite you if you abuse them. Find a pair of cams that has 10 deg. less duration (@ 0.050" lift) on the exhaust. Something like 235 inlet, 225 exhaust.

[acox99 74 1 Cars]

cheers, im still new to all this so dont really understand all the cam duration and lift, and degrees etc, can you fit the solid lifters out of an 8v engine or do you have to get the specially made?

[Dom9 2]

You would need to either buy a solid lifter kit from Matt at QEP or another of the cam manufacturers or I believe it is possible to fabricate your own, although this might be a bit difficult. I believe Petert made a post about it some time ago if you do a search. You won't be able to use the 8v buckets.

 

If you give Matt a call, he is a friendly and helpful chap and he will talk you through all the options. Unless you have significant budget and really want a lot over 200bhp, then you would probably be best sticking with the hydraulics IMHO.

[petert 586]

..... and really want a lot over 200bhp,

 

you obviously missed my point. It's not about hp but reliability. The std. inlet and exhaust cams have a duration of 214 deg. @ 0.050". Check out the Catcam wesbsite for suitable grinds.

[Dom9 2]

No, I understood your point Pete... I just don't see that the hydraulic lifters are particularly unreliable at the sort of rpm required to make 200bhp (if that is his target)... I guess solids may help with oil surge etc and allow him to rev higher, but if he doesn't need LOADS of power, he doesn't need to rev beyond the capacity of hydraulic lifters and then he doesn't need to uprate anything in the bottom end...

 

But yes, I agree that if he is going to build a race engine then he should go for the solids not just for the extra power but for the reassurance as well!

[huxley309 0]

If your using 16v on hydraulics dump the 205 and use a 309

[acox99 74 1 Cars]

i want a race engine, but a race engine on a budget, im only a student so cant afford to get the expensive specialist stuff like solids and big cams, wont rev above 7400, thats a good limit isnt it. would standard bottom end and hydraulics take that? hopefully will be running tb's as well, it needs a bottom end re-build as big end bearing has gone, just want a mild engine running around 200, but i want it reliable as well, i already have a stripped out 205 in good condition.

[veloce200 3]

i want a race engine, but a race engine on a budget, im only a student so cant afford to get the expensive specialist stuff like solids and big cams, wont rev above 7400, thats a good limit isnt it. would standard bottom end and hydraulics take that? hopefully will be running tb's as well, it needs a bottom end re-build as big end bearing has gone, just want a mild engine running around 200, but i want it reliable as well, i already have a stripped out 205 in good condition.

 

but you could afford to rebuild if it went bang right? with second hand bits perhaps?

ecu, bike tb's, diy solid lifter conversion loads of compression and the biggest cams you dare. std rods and crank will do 8200 easy intermittent.

[acox99 74 1 Cars]

Yep, i would have no choice but to rebuild, how much would it cost to do solid lifters? the way you say it makes it sound easy, so all the bottom end really needs is a good re-build and a balance before it can take those types of revs.

[veloce200 3]

how much would it cost to do solid lifters? the way you say it makes it sound easy, s

do a search for this, I think PeterT has covered it before. not sure myself being possessed of only 8 valves I have solid lifters as standard

[Bam 0]

are you talking about xu9j4z?

 

276° 112° 10,5mm 2,4mm

 

timming will be:

inletvalve opens at:

26°

close:

70°

 

outlet

70/26

 

idle running >1200 rpm,exhaust emission will be very bad.

 

the 10,5mm lift is max without any cylinderhead work. i have heard lifts over 11mm!

 

this one is also nice:

286° 110° 11,2mm 2,6mm 33/73 - 73/33

 

...but i think you will lose lot of torque under 3500rpm!will not ridable in city rather for sprints or race.

 

 

cheers

[acox99 74 1 Cars]

not so bothered with low end torque as it wont be road legal, just want mid to top end power, it will have a head off a 1.9 that has had:

 

Head face skimmed to ensure its true

Valve seats recut 3-angled on a proper Serdi cutter

Valves cut to match

Valve guides checked

New stem seals

Lifters bled down

Lifter faces prepped to allow new cams to bed in properly

 

what else is advisable to be done to an other standard engine?

 

Is that the 286° 110° 11,2mm 2,6mm 33/73 - 73/33 a fairly mild cam, not sure what it all means?

[Bam 0]

hi, *gape*

 

 

>Is that the 286° 110° 11,2mm 2,6mm 33/73 - 73/33 a fairly mild cam, not sure what it all means?

fairly mild? no, rather a fastroad or race cam.(not road legal)

 

Is that the 286° 110° 11,2mm 2,6mm 33/73 - 73/33 a fairly mild cam, not sure what it all means?

 

286° = overall angle

110° = spread

11,2 = max cam lift

2,6 = max cam lift @ TDC top death center

 

33 = inlet valve opens @ 33°

73 = and close @ 73°

 

-very loooong opend valves, that is important to get power.

 

i'm not sure how to explain,in english.

but important is: that a cam lift over 10,5mm -you have to millcut the head (cam will not rotate before )

 

i'm not 100% sure, but the stock cam has 264°;spread down know; max lift 10 -10,5mm;1-1,3mm tdc cam lift.

[Bam 0]

>what else is advisable to be done to an other standard engine?

to get bigger inlet valves -puma racing...(?)

or convert to compressor or turboengine

 

i have widend also the inlet/outlet ports and polished, polished the complete valves, have removed 0,6mm from cylinderhead (to get more compressionratio) but now i'm know..it's better to change the pistons to get more compressionratio.(D6C) or 11,5:1 pistons (overbore 88,5mm)

 

cheers

[acox99 74 1 Cars]

cheers, that helped a bit, starting to understand how it all works, will prob start to understand more when i get stuck and take it all apart, whats the max overall angle/ duration you can use with hydraulics?

[Bam 0]

hi,

> whats the max overall angle/ duration you can use with hydraulics?

the overall angle says nothing(!) about a cam -all facts are important.more lift (also tdc) = valve will open father.

so its possible to get more oxygen into engine at higher rpm. dont will throttle. airflow speed around <100m/s are best..

 

 

the cam that i suggest you is a race cam, also you should change the gearbox (s16).think the cam will begin to pull ex around ~4500rpm and higher (pretty hard ).but below, engine will spitting and run untrue.(like tractor).more overall angle is not advisable -you need a good speed/powerband. with more overangel move the powerband into "later" (rpm).this cam will pull around 8200-8500rpm,another cam with more overallangle...think will pull about 6000- >9k or later/higher, don't sure if its usefull for you?!

 

the hydraulicengine have very mild tdc camlift. more than 1,3mm are not roadlegal (cause exhaustemission).enginenoise will be louder anyway .

 

if you have any question i will try to answer in english

 

mik

Ps: forget to say...use a bigger tb, like vag v6 or golf gti II 16v and very short intakepiping or flatsliders (?).

Edited September 5, 2006 by Bam

[Bam 0]

PPS: ...if its possible to use a xu10 crankshaft... use it . middle pistionspeed will be healtful. you are running with xu9 crankshaft@7000upm 20,54m/s. with xu10 crankshaft@7000rpm = 20,06m/s.

constant >20m/s will damage your engine.

Edited September 6, 2006 by Bam

[Mattsav 1]

You can have 10.8mm of lift without modifying the head for lobe clearance.

 

Fist you need to work out your budget.

From there you can build an engine spec.

The spec needs to considered as a whole engine (Induction, exhaust, cams, CR etc etc) or you'll end up wasting money.

[VisaGTi16v 1]

Hi Matt,

 

Looking at the Catcams for the xu9j4 then does that mean you can only use the 4900527

at most before having to modify the head? The spring details link says max allowed lift is 11.5mm but maybe thats just regarding how much the spring itself can do, I dont know much about them.

 

I have Piper "fast road" cams in my Visa which are only 264/264 and 9.91mm lift. Speaking simplistically, this sounds a lot less than the 283/275 and 10.8mm lift of your 4900527 which looks like a straight swap into the head with all OEM parts and using the standard hydraulic lifters? Do you have a price on them out of curiosity?

 

cheers

 

Darren

[VisaGTi16v 1]

Strange I cant edit! Anyway, from whats said on the previous page and the fact I have to drive my car to events so need it to pass emissions, I could probably only get away with the 4900526 to keep the exhaust lift at TDC down a bit

[Mattsav 1]

The Springs limit lift to 11.5mm The head casting limits it to 10.8mm

 

If your on std injection then just the inlet from 4900526 is the way to go.

 

If you on mapped Injection/Carbs/TB's the 4900527 will fit striaght in.

 

4900528 need the head relieving for lobe clearance and the piston/valve clearance is very close.