timing in ? . what chya think

Old 07-01-2007, 01:54 PM
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CHEVYMATT
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Default timing in ? . what chya think

i have a 400 bored .60 over with afr 210 heads fully cnc'd to 221 i have .125 domes and 64 cc heads i have a bowtie intake anyway .. with my throttle wide open and all plugs out i have 160psi at 6 compression strokes while cranking seems a little low to me .. my cam is 256 266 @ .050 with 625 625 im running 1.6 rockers to give me 666 666 lift . im not happy with the performance of this . im checking my valve springs to see if they are set up right even thou i know it wont affect cranking pressure. i run 105 mph in the 1/8 and 122 in 1/4 and weigh 3100 and has a 5000 convertor/glide with a 4.10 gear. it seems to struglle above 6000 rpm's and i think i have some issues to look at. im open for a cam swap even if i only go solid not solid roller like i have now... any help or examples would really help im sort of stumped where to go now ... thanks oh my cam is on a 105 and i have it installed straight up at 104 ... my deck heigth is about .015.........ok now today i noticed that if i have the timing at less than 36 degrees it acts like i have a miss but if i bring it up to 42 it sounds and runs fine , but it didnt do this a few weeks ago it just started it .. i ran it at a 11.11 at 123 before at 32 degrees now it'll hardly run there . come on guys im depending on you professionals .. thank you.
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Old 07-01-2007, 03:15 PM
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mytmouz
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What type balancer are you running? If it's stock it could be that the outer ring is slipping, causing the timing to be off.
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Old 07-01-2007, 04:48 PM
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CHEVYMATT
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Default timing

i have a sfi approved fluid balancer for rp raceparts on ebay . i dont believe it's mounted in rubber i think its all steel connected..
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Old 07-01-2007, 05:39 PM
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bbchevy
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Default 400?

If you only have 160 PSI Compression,then thats a VERY Good Place to start?I just did a 408ci SBC,+.040 400 with a .150 dome piston,and it had 250-260 psi.comp.Why are you using a cam with a 105?You ned to have at least 108-110.Maybe your blreeding off some comp.with the Cam profile???Have you check your Valve springs?I'll look for the # on the Cam i just installed,i know its a Lunati.But,i will get you a Grind #?Your on the rite Track?I beleive?
Later
Greg 8)
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Old 07-01-2007, 06:18 PM
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Default comp

i went with a cam on a 106 but it's installed a 104 straight up via crane. . i didnt degree it i just installed it.. i do not like the psi thou. i thought a 106 would help with cylinder bleed off to help with pump gas compression.. . i should of just put a cam on a 110 in it. thanks
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Old 07-02-2007, 11:21 AM
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Dragginby
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My old 408 with AFR 210 made 587hp @ 6800rpm. The cam was an ultradyne 278int & 281exh @ .050 and 630 lift int &ext. My motor ran in a 2900lb car 135mph. There is something wrong with your motor. Not sure if it timing or what. My motor made most HP @ 36 degrees total timing.
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Old 07-02-2007, 12:12 PM
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davis419b
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Since the compression is way down it is possible the cam is in wrong. Without degreeing it it is hard to be sure, never had a sbc with a cam in under 108.
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Old 07-02-2007, 03:15 PM
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ok today i installed another msd box and still a problem i also removed distributor and inspected for damage or movement , but still if i put timing at 36 it acts like it has a miss and has lack of responce, but at 42 it's nice.. but im going to remove the engine and degree the cam as well as check things out.. keep up the info.. thanks guys
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Old 07-02-2007, 03:34 PM
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I have heard of getting the wires from the distribtor to the MSD box on backword and it makes the timing do weird things. Try switching them and see what happens. There is a rule of thumb that should happen if the wires were in fact backwards but i dont remember what it is. Send a PM to Bill Hendren im sure i have seen him post it before
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Old 07-02-2007, 05:15 PM
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Default well

when i had it hooked up backwards it sounded like a funny car . so called msd and it hooks up opposite of what you think . i thought it was purple to purple but it not . i do have it right .. thank you
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