Felix Posted November 2, 2009 Report Posted November 2, 2009 As for carb cfm ratings of twins. With the twin aisans, any one cylinder will only be able to see just one carb of the pair with the split twin manifold. It is hard to explain, plus difficult to type on the little netbook I've got in front of me atm. Just think from the inlet valves point of view looking up the manifold to the carb throttle plates and what it can see. Read through this link. Keep in mind the DCD weber the guy is running has both throttle butterflies opening at once, whereas the smaller one I run has a primary/secondary so has a lot more bottom end. Sorry altezzaclub for going offtopic in your thread. Let me know and I'll split it. Quote
rob83ke70 Posted November 2, 2009 Report Posted November 2, 2009 Keith, my camshaft in the ke55 is a crow cams 740, I just keep losing the spec sheet and forgetting the specs :) I would NOT reccommend a crow 740 unless you are running upwards of 10.5:1 compression, twin carburettors, elec dizzy regraphed and a decent amount of engine work. I'd go the tighe 104. Do a compression test on your engine first, I have a gauge if you need one, and providing everything is healthy, valve springs and seals can be changed with the head on... we already know how NOT to drop a valve lol. If you need a hand with anything give me a yell. John Kitchen in Bathurst (automotive body maker, fabrications and automotive engineering) who I was working with last week says he's actually met Ivan Tighe, although probably doesn't know him well enough to get mates rates :) I think it seems like a bit of an old school place and they need to be communicated with on the phone. I haven't heard back from them about the Dyna camshaft, I will be ringing them tomorrow to confirm everything and/or pay the bill. I know you've helped me heaps with my corolla, so if you need a hand with anything or some company while you play with your corolla its all good :( Robert. Quote
rob83ke70 Posted November 2, 2009 Report Posted November 2, 2009 I'm quite sure that my next K motor will be faster than the last one too! Robert. Quote
Felix Posted November 2, 2009 Report Posted November 2, 2009 I'm quite sure that my next K motor will be faster than the last one too! Stick the current motor in one of your ke10's and you will improve your power to weight ratio a heap. :) The Tighe 104 gives pretty much an identical power curve as a 113 but with an extra hp or two. Not what Keith is after. From what I gather he wants maximum area under the curve up to 6 grand. It is easy to change valve springs/stem seals with a bit of rope and an overhead spring compressor without having to remove the head. :( Quote
rob83ke70 Posted November 2, 2009 Report Posted November 2, 2009 Keep in mind I'm the sort of person that would pull the engine out and rebuild the whole thing and kind of get carried away... Quote
KE55PIG Posted November 2, 2009 Report Posted November 2, 2009 (edited) the only ting I'm scared of is if me 4k bottem end will hold 8k rpm only need to last till feb march Also i think my twinsshould give me a bit more tunning flexibility and should help my down low under 3k which this car really wont be driven under 3k anyway Edited November 2, 2009 by KE55PIG Quote
KE55PIG Posted November 2, 2009 Report Posted November 2, 2009 Crow Cams grind in a 3k drag car that goes a little something like this, Inlet opens 43 closes 71 Adv Duration 295 Exhaust opens 75 closes 43 Adv Duration 298 Inlet and Exhaust lobe lift .270". Inlet and Exhaust Valve Lift .405" found in a post Quote
altezzaclub Posted November 2, 2009 Author Report Posted November 2, 2009 Felix, I don't mind if it goes off-topic, a Mod can chop it up in a month. Meantime there is lots to learn. That link is good- I also wondered about the turbulence in the manifold under a stock twin-choke when the airflow has to suddenly switch from one direction to another 100 times a second! ..and although your point about each cyl seeing both chokes wide open instead of one choke of a pair of SUs, I also thought the total flow must be greater... obviously in most instances one twin-choke can outperform two carbs. I'm was hoping 1&1/4" SUs would have better low-down performance than 1&1/2s, but maybe a Weber DCD would do it all... We shall see when Rob & I line up beside one another! :( Quote
rob83ke70 Posted November 3, 2009 Report Posted November 3, 2009 wait till my ke11 is done, it will be fast :( I'm itching to get my dyna done in the meantime though, its basically a larger upright K motor (y series) in a mini truck lol. Robert. Quote
KE55PIG Posted November 3, 2009 Report Posted November 3, 2009 if webber are better ill get 2 webbers on my manifold i actuall want to go 2 3k no emession carby on it but can go webbers if recommended Quote
rob83ke70 Posted November 3, 2009 Report Posted November 3, 2009 I *might* put a dcd onto the 5k going in the ke10 as the daily driver yet... will be interested as to how well it goes... I reckon you shouldn't go anything bigger than 260-270 degrees advertised duration and I'm dying of curiosity as to how your twin 1.25" su's work... any bigger than that and you will need to rebuild the engine with additional modifications and probably want to rev it higher and pull more air through and need larger carburettors and so on.... the cycle is rather vicious, it starts with a camshaft and goes from there :) less is always more when driving it on the street and talking about camshafts.... most people go too "lumpy" and the cars are too much of a pig down low and end up being slower than stock. The other interesting thing is the popularity of 5k engines (1500cc) which seems to correlate with 280-300 degree advertised duration camshafts... the larger the engine capacity the less lopey the camshaft will make it, so basically you're getting the same result as a milder camshaft in a smaller engine, hence the pleasing results (compared to 280+ duration in a smaller engine) and the popularity of the larger engines if that makes sense :) Robert. Quote
rob83ke70 Posted November 3, 2009 Report Posted November 3, 2009 Tighe are slow as a quiet week :) but hopefully the job will be good! Robert. Quote
SLO-030 Posted November 3, 2009 Report Posted November 3, 2009 Martin from crow cams recommended a 606 grind for a mid-high revving 4k for daily and spirited driving. will post the specs up. Quote
SLO-030 Posted November 3, 2009 Report Posted November 3, 2009 This is what i could find on the 606. Keep in mind the Power range is for a Ford 1600 4cyl IN. 26/64 Duration 270deg. Duration @ 0.50" 224. L/C 110. Lift .397" EX.66/24 " " " " " " " " Power range 2000 - 5000rpm. Mild cam with fair idle, for improved performance from slightly modified engines.. Quote
coln72 Posted November 3, 2009 Report Posted November 3, 2009 These are the specs for my old cam - Wade 169 the specs are: Lift (at lobe) - 0.269" Ex opens - 75deg closes 36deg Inlet opens - 41deg closes 70deg Great compromise in a 5k, don't know about a 4k Quote
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