View Full Version : HEY SPECTRAS ONLY ????

not guilty
02-04-2003, 02:31 AM
See that you have a bit of info from the OMC KING COBRAS.Would you happen to know the grind specs on the 460 's of the late 80's (ie-lift /duration).
Have a 1988 with twins that say they are 370 hp on valve cover.Any specs from that era would be helpful.
All I can seem to find is duration for BBC cam at 050, not much help for my FORDs.
Thanks in advance. NG
[ February 04, 2003, 02:32 AM: Message edited by: not guilty ]

spectras only
02-04-2003, 10:22 AM
NG , it has been a long time I've looked at cams out of the late 70's early 80's 460. My uneducated guess is around 496 in 502 exh with 220 duration at 0.50 lift.These 460's were rated at 320HP in the 70's with mild cams, and the cobras were rated higher due to increased cam lift and slightly higher compression ratios.I'll check into it ,if I find some info later.I used the A443 cam from motorsport [around 560 lift] for 460's that's a great improvement over previous cams for marine use.I would highly recommend it ,if you're looking for more juice for your deep V boat wink .
[ February 04, 2003, 10:23 AM: Message edited by: spectras only ]

not guilty
02-04-2003, 04:41 PM
Thanks , let me know if you find original specs.
Planning on doing some work on the twins and dont want to bother with exhaust or spring rating to much,gets very exp. x two you know.Just want to freshen them up and thought new cams could be in order,looking for reliability. I think the boat is already powered up enough for a 27 footer !!! jawdrop
BTW that OMC COBRA picture you posted a while back sure looks good blown up and framed in the boat garage . wink You da man. THANKS NG

spectras only
02-04-2003, 05:26 PM
NG , compcams has a rebuildable needle roller S/S magnum rocker arm set with 1.8 ratio that would give you a little more lift compared to 1.73 , without disturbing the engine too much .It cost around $600 CDN = ca $400 US. I may do that to my BBC .

not guilty
02-05-2003, 03:28 PM
Finally found a it in an old manual , all it gave was lift at cam , no dur or seperation . Said in a 340 hp cam was 0.252 in /0.278 ex.
That comes out at 1.73 to .436 in / .481 ex.
Damn man my old 72 maverick had more !!!!!

spectras only
02-05-2003, 04:49 PM
NG, those numbers fit the smog motors eek! .I guess it's time to pull those cams and go right to the A443 cam with heavy duty springs [130# seat pressure] and get the Rhoads antipumpup lifters from summit.The A460 cam is good for low end torque with moderate lift around 496 in .510 exh.Big diff from what you got now. Keep your cast iron SCJ intake that comes with the cobra packages [even though it doesn't match the cylinder head intake ports on the A2A heads wink ].I suggest to grind the EGR bumps in the exhaust port to a smooth ramp to improve exhaust flow.Or hook up with someone who has some 69/70 CJ heads .The CJ have screw in studs [replace them with ARP 7/16's, hardened pushrods and guideplates ,available from ford]to accept aftermarket rockers like compcam etc....

not guilty
02-06-2003, 02:43 AM
OK , had one extra cam out of one of these motors in store room , mic out at 1.73 to in- .490 / ex- .496 . Sounds a little more like it .trying not to get to carrid away with cam because of reversion with stck cast iron exhuast, Deffinately not buying after market ex. One set of heads are ready with humps ground out ,planning on doing other when motor is down .
Know what youre saying about the cast intake , how do you think they compare to edlebrock tourqer II 460,have one now and thougt of getting another and using them if they are about the same performance, just for looks naturally.

spectras only
02-06-2003, 10:56 AM
NG, the 490/496 lift sounds more realistic with the 370HP rating.The edelbrock would be lighter [naturally wink ] ,but the cast iron will outlast your boat and doubt if you'll have huge gains with the edelbrock.I would powdercoat the SCJ if looks is what you're after :D . http://www3.telus.net/spectrasonly/ford460.2jpeg.jpg http://www3.telus.net/spectrasonly/ford460jpeg.jpg here's a 460 in the 19 spectra with SCJ intake ,5600RPM ,"A" berkeley impeller , 72MPH on GPS.That is roughly 500 HP .Not bad for a 460 FORD wink ,eh.
[ February 06, 2003, 11:14 AM: Message edited by: spectras only ]

not guilty
02-06-2003, 09:07 PM
Didnt know if there would be any gain to the edlbrock , just hoped they would be at least equal.
Starting to realize as I look at the bench foll of stuff why possibly my motors dont quit ever seem to equal out in the twin.Out of the bushel basket of spare parts nothing is the same jawdrop .
DAMN it will be a nice experiance to drive this thang with matched motors .... NG

not guilty
02-08-2003, 07:10 AM
OK , as I get further along here I'm re-thinking a little idea
I currently have crane cam in one of the motors going back in this (will be building a mate to this one , has 20 hrs on it)it has a grind of.522/.530 lift -dur 226/230 @.050 nad 112* seperation.Do you think I would have major concern for exhaust water reversion with stock exhaust on this cam. I also have rhoades lifters that seem to really help the idle.
Iwould have to buy hevier springs but would only have to buy one cam as other motor is RTR :D .
Also what do you think of carb.
Thought I had a 750 vac sec marine that I was going to order a mate to , called holley and it turns out its a 850 they dont make anymore, they said it could be paired with a newer and re-jet it.I also have a 830 hp with anular boosters I like a lot (not marine though) that I deffinatly can still get a match to.Do you think these are both too much eek! . Thanks
(motors are 9.2 compression)

not guilty
02-08-2003, 08:21 AM
Heres the donor #1
note 10 qt oilpan thats for sale.
[ February 08, 2003, 08:22 AM: Message edited by: not guilty ]

spectras only
02-08-2003, 12:47 PM
NG, I would match the cam [522/530] you mentioned above.Wouldn't worry about reversion as long as you have flappers installed on your exh tips.Match the 850 carb with 88primaries 94 secondaries on both.Some of the older boats didn't come with "J" tubes like the new 850 marine holleys,just make sure you'll have proper barbron flame arrestors.If you could trade your 850 in ,I would get a pair of new marine 850's .They're set by Holley and ready to bolt on and go. If you want ,call Dave monday through friday at 604-278 1880 for pricing in cdn dollar.I've seen some good prices at summit as well, but ask them for marine application for insurance purposes.

not guilty
02-08-2003, 04:25 PM
Good , I like advice I want to hear !
Except for the carb.Holley tech told me it would be unlikely to match my marine 850.They quit making it and the superseded one also.
I can buy a 830 compitition to match the one I have for $475.00. They are mechanical sec. w/ four corner idle.Dont have a choke but I can put elec. on if needed. NG