# Have questions about motor building or headwork? POST HERE! **URL:** \ **Category:** Shift518 Automotive\ **Created:** [July 16, 2008, 6:35am UTC](https://forums.speedlife.net/t/have-questions-about-motor-building-or-headwork-post-here/237845 "2008-07-16T06:35:43Z")\ **Posts on this page:** 16\ **Page:** 1
**Author:** ![votblindub](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/votblindub/32/6280_2.png) [@votblindub](https://forums.speedlife.net/u/votblindub)\ **Post date:** [July 16, 2008, 6:35am UTC](https://forums.speedlife.net/t/have-questions-about-motor-building-or-headwork-post-here/237845/1 "2008-07-16T06:35:43Z")
Cossey’s note: This thread is going to be used for any questions anyone on the forum may have about building motors, headwork, and hardware/parts. Like it’s been said before, we have some of the most knowledgable builders in the area on this forum, and I’m sure they’d be more than happy to help out fellow enthusiasts. Please post any questions you may have. Any questions about tuning/ECU’s, please go to the other tuning thread. Thanks in advance guys, and lets keep this thread as clean and informative as possible. /not I found some RS4 intake cams for sale for my car. I’m wondering what my gains would be with those. My car has the same 2.7L V6 motor as the RS4. Eventually I want to have the same bits around the motor as the RS4, so I’m planning to gradually build towards that. ---
**Author:** ![JClark](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/jclark/32/6309_2.png) [@JClark](https://forums.speedlife.net/u/JClark)\ **Post date:** [July 16, 2008, 6:38am UTC](https://forums.speedlife.net/t/have-questions-about-motor-building-or-headwork-post-here/237845/2 "2008-07-16T06:38:30Z")
> [@votblindub](#): > > I found some RS4 intake cams for sale for my car. I’m wondering what my gains would be with those. My car has the same 2.7L V6 motor as the RS4. Eventually I want to have the same bits around the motor as the RS4, so I’m planning to gradually build towards that. Not a tuning question. Voted: Fail. ---
**Author:** ![JClark](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/jclark/32/6309_2.png) [@JClark](https://forums.speedlife.net/u/JClark)\ **Post date:** [July 16, 2008, 6:52am UTC](https://forums.speedlife.net/t/have-questions-about-motor-building-or-headwork-post-here/237845/3 "2008-07-16T06:52:20Z")
> [@BENNYFIZZLE](#): > > Know anyone who can burn chips for the Bosch 413 DME > > :shifty Yes, Tony [forgethislastname]. Works with Seth @ Moon, does a lot of 993 and 996 Porsches but has everything needed for the 413. > [@votblindub](#): > > is this restricted to chip tuning only? No its all tuning, but you asked how much HP you’ll get out of cams. How is Justin supposed to know that? Hardware question, not tuning. ---
**Author:** ![votblindub](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/votblindub/32/6280_2.png) [@votblindub](https://forums.speedlife.net/u/votblindub)\ **Post date:** [July 16, 2008, 6:56am UTC](https://forums.speedlife.net/t/have-questions-about-motor-building-or-headwork-post-here/237845/4 "2008-07-16T06:56:36Z")
OIC, my bad. I should prolly just get my K03’s rebuilt to K04 spec, huh? ---
**Author:** ![JClark](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/jclark/32/6309_2.png) [@JClark](https://forums.speedlife.net/u/JClark)\ **Post date:** [July 16, 2008, 7:10am UTC](https://forums.speedlife.net/t/have-questions-about-motor-building-or-headwork-post-here/237845/5 "2008-07-16T07:10:08Z")
Again…hardware question, not tuning question. ---
**Author:** ![votblindub](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/votblindub/32/6280_2.png) [@votblindub](https://forums.speedlife.net/u/votblindub)\ **Post date:** [July 16, 2008, 12:02pm UTC](https://forums.speedlife.net/t/have-questions-about-motor-building-or-headwork-post-here/237845/6 "2008-07-16T12:02:14Z")
is it always a must to match cams(not highly agressive grind) with other bits like valve train and crank? im just thinking if i’m going to get the car all unbuttoned, i may as well save more, get my turbos done AND throw in the cams in one day. ---
**Author:** ![imported\_hybrdthry91](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/imported_hybrdthry91/32/6315_2.png) [@imported\_hybrdthry91](https://forums.speedlife.net/u/imported_hybrdthry91)\ **Post date:** [July 16, 2008, 12:12pm UTC](https://forums.speedlife.net/t/have-questions-about-motor-building-or-headwork-post-here/237845/7 "2008-07-16T12:12:40Z")
> [@votblindub](#): > > is it always a must to match cams(not highly agressive grind) with other bits like valve train and crank? im just thinking if i’m going to get the car all unbuttoned, i may as well save more, get my turbos done AND throw in the cams in one day. valvetrain upgrades are almost always a must with cams, as is tuning. with your motor since you have to pull it out anyway to change the turbos it wouldnt be a bad idea to do it all at once. another motor question not tuning lol. Justin this thread has pretty much gotten nowhere tuning wise not by any fault of your own, was a good idea though. maybe an FAQ would be a better idea. ---
**Author:** ![imported\_hybrdthry91](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/imported_hybrdthry91/32/6315_2.png) [@imported\_hybrdthry91](https://forums.speedlife.net/u/imported_hybrdthry91)\ **Post date:** [July 16, 2008, 12:20pm UTC](https://forums.speedlife.net/t/have-questions-about-motor-building-or-headwork-post-here/237845/8 "2008-07-16T12:20:20Z")
split the threads, and make a engine building advice thread. engine building, and theory. cams, pistons, rods, machining, stuff can be dealt with seperately. ---
**Author:** ![votblindub](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/votblindub/32/6280_2.png) [@votblindub](https://forums.speedlife.net/u/votblindub)\ **Post date:** [July 16, 2008, 12:38pm UTC](https://forums.speedlife.net/t/have-questions-about-motor-building-or-headwork-post-here/237845/9 "2008-07-16T12:38:00Z")
> [@hybrdthry911](#): > > valvetrain upgrades are almost always a must with cams, as is tuning. > > with your motor since you have to pull it out anyway to change the turbos it wouldnt be a bad idea to do it all at once. Dave actually managed to get to em from the underside. I think if we lower the front subframe we wouldnt have to yank the whole damn motor. can anyone help me out on changing the numbers on the tranny program so that it holds first slightly past 3K before it shifts in S and tip mode? ---
**Author:** ![McBitchin](https://avatars.discourse-cdn.com/v4/letter/m/ecc23a/32.png) [@McBitchin](https://forums.speedlife.net/u/McBitchin)\ **Post date:** [July 16, 2008, 10:49pm UTC](https://forums.speedlife.net/t/have-questions-about-motor-building-or-headwork-post-here/237845/10 "2008-07-16T22:49:14Z")
how much would I need to port the ka24de head to get ~400whp with a 9:1 comp ratio bored out to 90mm (looking into the brian crower stroker kit) with a 57 (gt3076)trim through a 3" exhaust running 20psi? :gay also what would ideal cam duration be? ---
**Author:** ![Cossey](https://avatars.discourse-cdn.com/v4/letter/c/3ec8ea/32.png) [@Cossey](https://forums.speedlife.net/u/Cossey)\ **Post date:** [July 17, 2008, 10:58am UTC](https://forums.speedlife.net/t/have-questions-about-motor-building-or-headwork-post-here/237845/11 "2008-07-17T10:58:33Z")
> [@McBitchin](#): > > how much would I need to port the ka24de head to get ~400whp with a 9:1 comp ratio bored .20 over with a 57 (gt3076)trim through a 3" exhaust? :gay also what would ideal cam duration be? Are you serious? ---
**Author:** ![McBitchin](https://avatars.discourse-cdn.com/v4/letter/m/ecc23a/32.png) [@McBitchin](https://forums.speedlife.net/u/McBitchin)\ **Post date:** [July 17, 2008, 11:00am UTC](https://forums.speedlife.net/t/have-questions-about-motor-building-or-headwork-post-here/237845/12 "2008-07-17T11:00:17Z")
no i only want mid 300’s at 20psi, do you think i should bore it out more than .20 the cylendar walls are real thick on the ka24 so I could probably could bore it out more if needed to meet my power goals, any input would be nice cuz I’m basically shootin in the dark here. ---
**Author:** ![Mk4\_30R\_Ban](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/mk4_30r_ban/32/6347_2.png) [@Mk4\_30R\_Ban](https://forums.speedlife.net/u/Mk4_30R_Ban)\ **Post date:** [July 22, 2008, 7:53pm UTC](https://forums.speedlife.net/t/have-questions-about-motor-building-or-headwork-post-here/237845/13 "2008-07-22T19:53:35Z")
> [@votblindub](#): > > Dave actually managed to get to em from the underside. I think if we lower the front subframe we wouldnt have to yank the whole damn motor. > > can anyone help me out on changing the numbers on the tranny program so that it holds first slightly past 3K before it shifts in S and tip mode? you cannot get the turbos out without removing the engine. simple as that. the motor mounts connect to the subframe so if you remove the subframe the engine will naturally want to follow it… its not as hard as you think. if youve got the space, time, tools and motivation assuming everything goes along smoothly you can do the entire operation in one full days time. but figure atleast 12-16hours total time to do it. your stock tip tranny wont take to the RS4 power very well for a long period of time. and running RS4 cams, without the RS4 casting heads, and RS4 intake manifold, Y-pipe. etc wont get you full benefits. the cams arent necessary either. there are people running 11.2 on full interior, stock cams, stock bottom end, with tons of boost on a B5 S4… its alot to do with the fueling arrangment, JHM motorsport is who im talking about… but your stock tranny will begin to show signs of weakness with anything more than the chip and turbo back with some spirted driving, dont beleive me, see for yourself and let me know how the tranny responds to a k04 turbo/k04 fueling/software treatment ---
**Author:** ![redroof](https://avatars.discourse-cdn.com/v4/letter/r/f1d935/32.png) [@redroof](https://forums.speedlife.net/u/redroof)\ **Post date:** [January 15, 2009, 8:07pm UTC](https://forums.speedlife.net/t/have-questions-about-motor-building-or-headwork-post-here/237845/14 "2009-01-15T20:07:46Z")
> [@1.8tV-Dub"](#): > > how much would I need to port the ka24de head to get ~400whp with a 9:1 comp ratio bored out to 90mm (looking into the brian crower stroker kit) with a 57 (gt3076)trim through a 3" exhaust running 20psi? :gay also what would ideal cam duration be? Yeah I brought this thread back. what. Trick question. You need not port the head to achieve your target. First let’s look at the GT30R map: Assuming 300 feet above sea level, which is roughly here in the capital region, we can state that 14.5psi is the pressure per atmosphere unit measurement. Therefore (20+14.5)/14.5 = 2.38 pressure ratio. Call it 2.4 for simplicity. At 6800rpm you’re moving roughly 40lb/min in the KA24DE, assuming a VE of 95% and a lot of other massive assumptions that simplify shit, because my answer is going to be as precise as your question was. So presto, you end up just kissing the edge of the 78% efficiency island @ 2.4 pr, which means you’ll be within the most efficient zone at redline, at 20psi, at 300ft above sea level. Given the fact that your head’s smaller ports make for shit flow at high rpms, we can cheat around that a tad by installing cams (and valvesprings) that enjoy the mid to upper RPM range, such as a 264 degree unit. Don’t bother with a 272 - you can’t rev enought to take advantage of it. You’ll probably manage to attain your 400whp (~500bhp) target at 20psi, but who knows what fuel will be necessary. Somewhere in there i’d hope there’s a quality engine management system handling all this. May I never hear the word “SAFC”. If you choose to stroke the motor, your rod ratio will go to shit and you’ll end up with a truck motor that wants to rev even less than it did, with much greater piston skirt friction and more sensitivity to detonation. You’ll have kickass bigblock style torque that an ATP 2871r or 3071r would absolutely love, but it’ll kill your ability to make horsepower above 5252. Right where the turbocharger really comes into a wonderful spot and the cams start to help things come alive, your pistons would be screaming for surrender. ---
**Author:** ![TurboTravis](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/turbotravis/32/6406_2.png) [@TurboTravis](https://forums.speedlife.net/u/TurboTravis)\ **Post date:** [February 15, 2009, 3:27am UTC](https://forums.speedlife.net/t/have-questions-about-motor-building-or-headwork-post-here/237845/15 "2009-02-15T03:27:18Z")
![http://i290.photobucket.com/albums/ll257/Allgo5oh/TShirt.jpg](http://i290.photobucket.com/albums/ll257/Allgo5oh/TShirt.jpg) ---
**Author:** ![ScottWZ32](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/scottwz32/32/6500_2.png) [@ScottWZ32](https://forums.speedlife.net/u/ScottWZ32)\ **Post date:** [April 20, 2009, 7:58am UTC](https://forums.speedlife.net/t/have-questions-about-motor-building-or-headwork-post-here/237845/16 "2009-04-20T07:58:55Z")
anybody know how much people generally charge for balancing the rotating assembly of a V6?