What Cam, 454 w/wieand 177
02-27-2003, 08:22 PM
#42
Ginger or Mary Ann?
Charter Member
G4B, those are the same numbers I have when I installed all of my motor specs. Not close to the actual numbers.
My motor dyno results at 30* timing.
My motor dyno results at 30* timing.
Last edited by US1 Fountain; 12-02-2011 at 11:17 AM.
02-28-2003, 01:30 PM
#44
Registered
OK, for those of you who are following this post for any other reason than to see G4B and myself twist in the wind call Dean Nickerson. Not making any judgements here but I am most likely going to go with what he has as a proven setup.
Tim T.
Tim T.
02-28-2003, 06:10 PM
#46
Charter Member #1055/Moderator
Charter MemberThread Starter
US1-What belt gear ratio are you running?
Anyone know what the stock 525sc belt gear ratio is?
Anyone know what the stock 525sc belt gear ratio is?
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02-28-2003, 07:46 PM
#48
Guest
Posts: n/a
Don't do it ,the guys here on the board have you dialed in ,731 or 741 is my choice also ,just listen to these guys and save money and have a screamer ,,,,I've dyno'ed and run all of these three cams ,,,the 761 has some problems in one of our customer boats
the 741 is a h.p making cam very easy on parts
the 741 is a h.p making cam very easy on parts
02-28-2003, 09:53 PM
#49
Registered
Bobby,
I hear ya but there are several variables that I need to overcome first. It is not so much the cam I am worried about but the carb. The dyno numbers that were put up are for the same carb and B&M 250 I have. They came right off that engine and are going on mine. I measured the driven pulley and it is 3.340 which would make it a pn# 15573 which is what the B&M sheet says will produce 6-7 psi boost for a 502. This probably explains why the numbers are higher than what desktop dyno says. The heads were also ported to some degree. I don’t have exactly the same heads or exhaust.
I don’t have a dyno so I would have a hard time making sure the A/F ratios are correct if any jetting changes were made. Reading plugs would probably get me close but the A/F readings in the dyno sheet for the 741 with the 250 look pretty fat down low and a little lean up top. Granted it ran for a season or so but how far from kaboom is it? How much power is being left on the table? What would the long term longevity be running that lean?
The carb, 1050 Dominator, had been previously prepped by Nickerson and subsequent to that worked over again by someone else with new metering blocks and PV, boost referenced etc. The jets that are in it now are 125 front and 135 rear, blocked off PV rear and 4.5 in front. No telling what it needs to get it back to stock. Even at stock it seems that the only way to get the numbers in the ballpark is to go way fat low in order to compensate for the top end. The air bleeds could be messed with but without a dyno you would be using your pistons and valves as guinea pigs. This seems to be the problem with Holleys and blowers.
Nickerson has done many carbs using his cam and specs for the 1050 and has dyno’d them in the shop. He should be able to set the carb up using all of the parts he has used before. Eliminate variables and the results are reproducible.
As much trouble as it is choosing a cam imagine what it gets into asking for jet sizes etc. when there are variables such as exhaust brand, ported heads etc. If Nickerson has setup a particular type of engine with brand X exhaust using X pounds boost with X type camshaft before and I use all the same then it should be pretty close.
Now if someone can tell me what jets to run, PV, air bleeds passage sizes etc. with Lightning headers on 4600 lb boat I will do that instead. There seems to be no easy answers without having done it before and having access to a dyno to record results. Am I making this too hard does this seem like the logical and easy route? Has past experience shown Nickerson’s carbs to be wrong? If it is not quite right I can just send it back to him.
I hear ya but there are several variables that I need to overcome first. It is not so much the cam I am worried about but the carb. The dyno numbers that were put up are for the same carb and B&M 250 I have. They came right off that engine and are going on mine. I measured the driven pulley and it is 3.340 which would make it a pn# 15573 which is what the B&M sheet says will produce 6-7 psi boost for a 502. This probably explains why the numbers are higher than what desktop dyno says. The heads were also ported to some degree. I don’t have exactly the same heads or exhaust.
I don’t have a dyno so I would have a hard time making sure the A/F ratios are correct if any jetting changes were made. Reading plugs would probably get me close but the A/F readings in the dyno sheet for the 741 with the 250 look pretty fat down low and a little lean up top. Granted it ran for a season or so but how far from kaboom is it? How much power is being left on the table? What would the long term longevity be running that lean?
The carb, 1050 Dominator, had been previously prepped by Nickerson and subsequent to that worked over again by someone else with new metering blocks and PV, boost referenced etc. The jets that are in it now are 125 front and 135 rear, blocked off PV rear and 4.5 in front. No telling what it needs to get it back to stock. Even at stock it seems that the only way to get the numbers in the ballpark is to go way fat low in order to compensate for the top end. The air bleeds could be messed with but without a dyno you would be using your pistons and valves as guinea pigs. This seems to be the problem with Holleys and blowers.
Nickerson has done many carbs using his cam and specs for the 1050 and has dyno’d them in the shop. He should be able to set the carb up using all of the parts he has used before. Eliminate variables and the results are reproducible.
As much trouble as it is choosing a cam imagine what it gets into asking for jet sizes etc. when there are variables such as exhaust brand, ported heads etc. If Nickerson has setup a particular type of engine with brand X exhaust using X pounds boost with X type camshaft before and I use all the same then it should be pretty close.
Now if someone can tell me what jets to run, PV, air bleeds passage sizes etc. with Lightning headers on 4600 lb boat I will do that instead. There seems to be no easy answers without having done it before and having access to a dyno to record results. Am I making this too hard does this seem like the logical and easy route? Has past experience shown Nickerson’s carbs to be wrong? If it is not quite right I can just send it back to him.
Last edited by BadDog; 02-28-2003 at 10:01 PM.
