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By Dobie - 10 Years Ago
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After some soul searching and number crunching I've decided to keep the 292 in my '55 Merc. I got a good set of '57 B heads with the matching 4 barrel intake and exhaust manifolds to replace the restrictive '55 pieces. I could just swap those out and get a fairly good HP increase, but I suspect the cam that's in there now may be damaged by the PO setting the valves at 0 lash. I don't know how long he ran it like that before I got the car, but a vacuum gauge indicates a possible burnt valve or 2. So, I'm soliciting suggestions for a good grind for this rig. I'm looking to move the torque curve a tad higher in the RPM range, don't want anything too radical. The car weighs about 3600#, has a T-85 with OD and a 4.09 axle. I figure with that ratio I can afford to swap a little bottom end for more torque at normal highway speeds. Would also like suggestions for the advance curve. What says this august college of y-block knowledge?
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By charliemccraney - 10 Years Ago
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You mean '57 G heads?
The cam may be fine, but it is a good time to upgrade if you're going to do it.
In general:
2teens @ .050" will have a smooth idle and be a step or two up from a stock cam.
220s @ .050" will have a definite performance sound and perhaps a slight lope and should be absolutely tolerable for a cruiser.
230s @ .050" will have a lope, probably about the borderline for what is tolerable for street use.
If you want to retain the 4.09 gear, you probably should go no bigger than 220s @.050, to have a better chance that you are in the power band while cruising in overdrive.
RE the advance curve, 36 degrees total, with 12-14 initial, all in by 3000rpm is a good starting point. Fine tune from there.
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By Dobie - 10 Years Ago
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Yup, G heads. Typo. Great info! Thanks Charlie.
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By 57RancheroJim - 10 Years Ago
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I've been really happy with my Isky E4, 216@.050. The torque curve seem to work out fine at lower and mid RPM's. I have 3.89 gears, T85 OD trans. Thats just my seat of the pants dyno..
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By Talkwrench - 10 Years Ago
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Agreed > RE the advance curve, 36 degrees total, with 12-14 initial, all in by 3000rpm is a good starting point. Fine tune from there.
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By Dobie - 10 Years Ago
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57RancheroJim (10/21/2015)
I've been really happy with my Isky E4, 216@.050. The torque curve seem to work out fine at lower and mid RPM's. I have 3.89 gears, T85 OD trans. Thats just my seat of the pants dyno..
3.89 is effectively 2.72 in OD. With a 4.09 axle it works out to 2.86 and change so I should be OK even with the hills around here. The E4 is one of my candidates. Do you know who supplies Isky's lifters? I'm trying to steer clear of the offshore stuff.
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By 56vikki - 10 Years Ago
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I had Bubbas ignition recurve my 64 F100 dizzy but haven't tested it yet as my current 292 with t-85 OD block is frozen!
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By 57RancheroJim - 10 Years Ago
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I understand your concern about the off shore parts. I didn't get my lifters from Isky, I used ones I had bought many years ago from a guy who had high quality lifter. valve springs etc. Sorry I don't recall his name but I don't think he is in business anymore. I had also bought F code valve springs and one piece retainers from him. I would ask Ted or contact John Mummert about them.
With the 3.89 and OD it's fine on California freeways and pulls most hills with no problem. If I'm driving in the mountains or canyon roads I just keep it locked in conventional drive..
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