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#46
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Re: Camshafts for the EG33.
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My need to build engines for other uses, has diminished as my capacity to do it has, but I have leaned a lot over those 50 odd years in Auto Engineering and like to assist those that are doing it now. I leave the building to my son, who you may meet one day at Wakefield Pk. with a Peugeot 306, with a mid mounted turboed 4lt Toyota V8. Quote:
I will apply this theory to Tony's engine to get the best usably result. Cheers and beers. Harvey.
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One Arm Bloke. Tell it like it is! 95 Lsi. Bordeaux Pearl, Aust. RHD.149,000Kls Subaru BBS wheels. 97 Liberty GX Auto sedan. 320,000Kls. 04 Liberty 30R Auto Premium. 92.000kls. |
#47
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Re: Camshafts for the EG33.
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P.S. Are you able to stick the stock engine into your computer and see what it comes up with at 10 / 15 psi with the stock manifolds. Would be interested to see how close it is to reality. Turbo is a GT35R, from here: http://www.turbobygarrett.com with a 0.82 rear. Last edited by bazza; 08-05-2012 at 09:05 AM. |
#48
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Re: Camshafts for the EG33.
Cams in the mail today to my shop, will keep you posted on progress. Can't wait
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#49
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Re: Camshafts for the EG33.
Let us know when you decide on a profile.
M |
#50
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Re: Camshafts for the EG33.
Will do mate. Thanks for your advice also.
Some great info here: http://www.tighecams.com.au/helpful-hints.htm Good selection of cams: http://kelfordcams.com/applications.aspx Last edited by bazza; 08-07-2012 at 08:40 AM. |
#51
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Re: Camshafts for the EG33.
Matt, my mate sent over the info about his EG33 billet cams. Massive duration!!
Intake: 318 duration (advertised) 235 duration @ 50 thou 9.9mm lift Exhaust: 339 duration (advertised) 235 duration @ 50 thou 10.0mm lift P.S. My cams still at shop... waiting... always waiting. |
#52
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Re: Camshafts for the EG33.
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An aggressive cam profile will tend to have faster valve openings and closings. Jack's cams by comparison have 244 @ .050 duration but with 268 advertised duration. VERY fast opening and closing ramps with very rapid valve acceleration. |
#53
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Re: Camshafts for the EG33.
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I've spoken again with the guys about my cams this morning, looks like they'll be able to do something along the lines of 220 @ 50 with around 8.1mm intake and 8.9 mm exhaust. It should be just enough of an increase to get the engine to where I want it performance wise which is to flow to 6500-7000 rpm and not drop off at 10-14 psi (although at 14 psi ti didn't drop off... it hit a brick wall!). Thanks to LAN for his assistance and guidance with these. Funnily enough on the Kelford site, this type of duration and lift cam is good enough for a 4 cylinder EJ to see 8000 rpm... good sign. Already thinking of version 2 of my cam regrind... I've still got 2 spare sets of stock cams to play with and given how easy they are to remove, could swap and change to suit different tracks if I ever wanted to (assuming the regrinds all go to plan): http://www.subaru-svx.net/forum/showthread.php?t=54965 Also my other mate has just installed his EG33 into his RS Liberty. He had some cams done as well - however it would seem these have been welded as the lobe heights have increased. One of my other mates in the mean time has scored an epic picked up a perfectly good eBay EZ30R on ebay for $1250 for his Impreza... fun times, H6 FTW!!!! But anyway... cam stuff for the RS Liberty EG33: Inlet: 255 deg advertised Exh: 265 deg advertised Duration @ 0.50 thou Inlet: 199 deg Exh: 215 deg Lobe centre: Inlet: 112 deg Exh: 116 deg Intake lobe height 39.97 (39.1 stock) Base circle 31.61 Inlet: 8.4mm Exhaust lobe height 40.25 (39.9 stock) Base circle 31.71 Exh: 8.5mm This car will run NA mode for a while until he gets around to putting a turbo on - so the results will be very interesting. Last edited by bazza; 08-20-2012 at 11:08 PM. |
#54
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Re: Camshafts for the EG33.
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So while we do want enough duration (and therefore overlap) to aid in scavenging and help the engine to make power in the upper realm, too much overlap can also be bad, particularly with forced induction. Yes, there is a fine line between fast opening/fast closing and increased engine wear. The cam specs you've quoted would likely be very gentle on the valves and seats. Less spring tension could be run in fact, as valve bounce would likely be non existant As a rule, most hydraulic profiles are far more gentle than mechanical profiles (except for the intial 'takeup' designed to eliminate the valve lash in a gentle fashion), as the hydraulic buckets can't cope with modern (race oriented) fast acting lobe profiles. They will simply collapse. |
#55
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Re: Camshafts for the EG33.
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Also thanks, good to know about the differences. |
#56
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Re: Camshafts for the EG33.
Okay, excitement to the max!!
Regrind specs, being ground up now: Inlet: 270 advertised 220 @ 50 thou 7.9mm lift Exhaust: 275 advertised 220 @ 50 thou 8.7mm lift So some improvements across the board - should do the trick |
#57
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Re: Camshafts for the EG33.
Did they say what the valve timings, or lobe centers, would be.?
Harvey.
__________________
One Arm Bloke. Tell it like it is! 95 Lsi. Bordeaux Pearl, Aust. RHD.149,000Kls Subaru BBS wheels. 97 Liberty GX Auto sedan. 320,000Kls. 04 Liberty 30R Auto Premium. 92.000kls. |
#58
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Re: Camshafts for the EG33.
Yes, I've got all that info
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#59
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Re: Camshafts for the EG33.
Upon receiving my fancy ground cams back, I was able to see clearly the issue people spoke about but never explained in the numerous cam threads here - and that is when the cam "rides the journal and not the lobe", which made zero sense to me at the time as the actual bearing journals are around 28mm and the regrind takes the cam down to 29-30 mm depending of course.
This shows a section of the camshaft next to the lobe - the bucket is wider than the lobe if you recall. So if you grind the base circle down to much the bucket will ride the cam shaft rather than the lobe at this point which from memory it is cylinder 1 and 2 (intake only). I think this was the issue LAN talked about his thread with the early cam issue. Makes sense? Mine for interest sake is a just clear so it should be fine - if not, nothing 2 mins with the file couldn't solve. Last edited by bazza; 09-11-2012 at 10:40 PM. |
#60
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Re: Camshafts for the EG33.
Well, a little bit of a hicup - mail damage to cams so had to be sent back to be fixed etc. All solved now so we can proceed. Not a major issue as I spent the time working on other areas of the racecar.
But here they are, nothing really to look at. Getting closer to having it running. For interest sake there has been a huge amount shaved off the base circle but somehow the buckets still contact the cam even without them containing oil - so with oil pressure I expect this to work very nicely. Hydraulics ftw!!! |
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