Lobe Center
- Thread starter kenny170
- Start date
Lobe seperation or intake centerline?Info I have shows 113 lobe seperation
according to classic inlines a 2 degree change in lobe centers change the rpm rang and peak power by 500 rpm, among a few other charicteristics of the cam,with the lobe seperation alone changing 1 degree I would think the difference would be slight and inpercievable on a stock cam profile.
Howdy Kenny:
In theory, the greater the lob angle separation, the greater the overlap, ( the time both the intake valve and exhaust valve are open) and lower vacuum draw and a lopey idle. Know that this is a generalization. Also note that the exhaust angle of separation on a '67 cam is 102 degrees. To anticipate the effect of a cam change other factors must be considered, such as duration, lobe profile and lift.
I'm curious about what you're looking into it for? What's the rest of the story?
Adios, David
In theory, the greater the lob angle separation, the greater the overlap, ( the time both the intake valve and exhaust valve are open) and lower vacuum draw and a lopey idle. Know that this is a generalization. Also note that the exhaust angle of separation on a '67 cam is 102 degrees. To anticipate the effect of a cam change other factors must be considered, such as duration, lobe profile and lift.
I'm curious about what you're looking into it for? What's the rest of the story?
Adios, David
looked at the chart again and I looked at the wrong # David is right about the numbers. same question though what are you looking for.
kenny170
Well-known member
I have a 1962 Mercury Comet with the 170 in it,I want to improve performance without getting too radical. The cam out of the 67 200 ci is bigger than the one that came in my 170. I want to use the roller rockers that ci sells for the reduced friction and heat if nothing else so I want to be careful how big a cam I put in as the new rockers will add lift. and I can get a nice 200 cam from someone I know and trust for 10 bucks. Snyder has a cam that's almost the same specs as a stock 200 with more lift but it cost a little more than 10 bucks. just looking at all my options before I spend the money. I want the comit to be a cool cruiser with a little pep so I'm looking for low end torque and fuel economy. I was getting 27 miles to the gallon before I made the decision the park it. I'm looking for 30 Plus with the rebuild. I know from the reading I've been doing with ci's technical articles and on this forum that I want to stay as close to a 112 lobe separation is possible. before anyone start saying just yank the 170 and put the 200 in I've made the decision to stay with the 170 this is a semi restoration project,while improvements will be made to upgrade the car and its performance I want it to remain stock looking.
If your 62 has the original 170 engine it is a solid lifter motor and cannot be fit with a hydrualic cam. your 2 choices are to have the original cam reground to a more aggressive spec of find a 65 or newer engine to build.doing the later you can step up to a seven main 200 and gain 30 cubic inches, the earley engine has the small body distributor with the 1/4" oil pump drive which limits upgrading the ignition system. you can confirm the year by looking at the casting number on the passenger side near the starter. original engine would start with a C1DE. could have been changed to replace a worn or damaged engine over the past 51 years :roll: . I bought a 64 with a said 170 and it ended up being a 60 144.
Maybe someone else will chime in but seeing you are looking for a little more umph but want to keep stock apperance and Idle, for max low and mid range torque with smooth idle and a c/4 tranny I would look at the Comp cams 252h or the Isky 256 super cam.
Howdy Back Kenny:
You've given yourself a couple of tail knots in your project parameters and goals. Because an original '62 170 is a mechanical lifter engine. The good news is that you have adjustable rocker arms. The distributor is a Load-O-Matic, vacuum only piece. You could swap in a hydraulic design cam from a '67 200 engine, but the increase in duration is minimal; 240 - 170, 252 - early 200. lift goes from .348" to .368". Note the difference of .020" is not even the thickness of a cover on a book of matches. And running solid lifters on a cam designed for hydraulic lifters may suffered from unusual wear.
The cost of replacing a cam usually requires a cam kit and other parts, usually about $50. Add new timing gear and chain. Replacing cam almost always requires removal of the head. More cost.
May I suggest and alternative to your goal of "a Little more power, and more mileage."
1. go ahead with a valve job. A stock '62 170 has a CR rating of 8.7:1. To attain more mpg a little more CR is the way. Set a goal of at least 9:1, and plan for a thicker head gasket when milling. Also specify at least a three angle valve job with a back cut on the intakes. The back cut functions like a higher lift valve action at no additional mechanical stress. Be sure to disassemble the rocker arm assembly and clean inside and out.
2. add a PetroniX Ignitor to your stock distributor and add 5 degrees of additional advance over stock. Open the spark plug gap to .045".
3. You mentioned "Restoration" which will seriously limit carb choices. The only carb listed for '62 Comets is the Holley 1909- Not to be confused with the more desireable side bowl 1904/08. On a 170 engine the #1909 is rated at 150 cfm. The '62 #1909s also had an automatic choke while all other one barrels had manual chokes. If you're willing to compromise on the restoration goal, you could find a Holley #1904 Glass Side bowl carb from a 1962 ford car engine with a 223 six. These carbs are rated at 170 CFM and compatible with your distributor.
4. Find and clean up an exhaust manifold from a '67 or '68 vintage. Your stock '62 had a very weakly cast exhaust manifold with a 1 3/4" outlet with a flat gasket to seal it to the head pipe. The later manifolds have a 2" outlet and are cast heavier, with a Donut/firewall type gasket. Add a 2" exhaust system with a turbo type muffler and enjoy.
This plan would be good for a solid 10 to 15% increase in power, and tuned right will get great mileage.
Give it all some thought. Start by assessing what you have, how much you plan to spend, what you can do and what must be hired out. then go for it.
Best wishes.
Adios, David
You've given yourself a couple of tail knots in your project parameters and goals. Because an original '62 170 is a mechanical lifter engine. The good news is that you have adjustable rocker arms. The distributor is a Load-O-Matic, vacuum only piece. You could swap in a hydraulic design cam from a '67 200 engine, but the increase in duration is minimal; 240 - 170, 252 - early 200. lift goes from .348" to .368". Note the difference of .020" is not even the thickness of a cover on a book of matches. And running solid lifters on a cam designed for hydraulic lifters may suffered from unusual wear.
The cost of replacing a cam usually requires a cam kit and other parts, usually about $50. Add new timing gear and chain. Replacing cam almost always requires removal of the head. More cost.
May I suggest and alternative to your goal of "a Little more power, and more mileage."
1. go ahead with a valve job. A stock '62 170 has a CR rating of 8.7:1. To attain more mpg a little more CR is the way. Set a goal of at least 9:1, and plan for a thicker head gasket when milling. Also specify at least a three angle valve job with a back cut on the intakes. The back cut functions like a higher lift valve action at no additional mechanical stress. Be sure to disassemble the rocker arm assembly and clean inside and out.
2. add a PetroniX Ignitor to your stock distributor and add 5 degrees of additional advance over stock. Open the spark plug gap to .045".
3. You mentioned "Restoration" which will seriously limit carb choices. The only carb listed for '62 Comets is the Holley 1909- Not to be confused with the more desireable side bowl 1904/08. On a 170 engine the #1909 is rated at 150 cfm. The '62 #1909s also had an automatic choke while all other one barrels had manual chokes. If you're willing to compromise on the restoration goal, you could find a Holley #1904 Glass Side bowl carb from a 1962 ford car engine with a 223 six. These carbs are rated at 170 CFM and compatible with your distributor.
4. Find and clean up an exhaust manifold from a '67 or '68 vintage. Your stock '62 had a very weakly cast exhaust manifold with a 1 3/4" outlet with a flat gasket to seal it to the head pipe. The later manifolds have a 2" outlet and are cast heavier, with a Donut/firewall type gasket. Add a 2" exhaust system with a turbo type muffler and enjoy.
This plan would be good for a solid 10 to 15% increase in power, and tuned right will get great mileage.
Give it all some thought. Start by assessing what you have, how much you plan to spend, what you can do and what must be hired out. then go for it.
Best wishes.
Adios, David
There are several thing you can do to improve performance and still keep the stock look, mild performance cam Degreed to insure optimum events. the later 170 will have larger intake and exhaust valves than the 62 has. mill the head slightly to maintain compression at about 9 to1 with the thicker head gaskets currently available,3 angle valve job. to keep the stock look go with a pertronics unit instead of points , a hotter coil and a little more initial advance. the 170 carb can be replaced for a 200 carb with a 1.20 venturi for an increase of almost 30 cfms, a K&N filter in the stock housing, you can get on their site and look at their filters by size, they should have one that fits. the 63 and later exhuast manifold has a 2" outlet vs a 1 3/4" plus has a donut style gasket which is less likely to leak that would also allow you to slightly increase the exhaust system size for a less restrictive exhaust. all are slight changes that will keep the stock appearance will allowing the engine to make a little more power.
kenny170
Well-known member
I have reread what I wrote earlier and it appears I did not explain myself well. When I said a semi restoration I didn't mean a partial rebuild this is to be a complete ground up rebuild of the automobile it will be a brand new car when I am finished with it but I want the look and feel of the original 62 comit. I was simply trying to explore my cam options.
kenny170":yv5y6fqa said:
Solid lifter engines lacks the oil galley used to supply the hydraulic lifters.
I do understand now. We tend to have a 1 track mind around here ,always looking for that extra pony. I have a friend I see about twice a year who has a very nice original 65 falcon with a 200 that he plans to keep that way. At our last regional show he joked with others saying I am going to have to get away from Charlie before he talks me into Hot Rodding the 200 in the 65.kenny170":36vgr8nc said:
.
kenny170
Well-known member
Yeah you guys were getting a little too vroom vroom on me there. Maybe the next project will be my quarter mile dragsters.64falconsix":umusji4p said:I do understand now. We tend to have a 1 track mind around here ,always looking for that extra pony. I have a friend I see about twice a year who has a very nice original 65 falcon with a 200 that he plans to keep that way. At our last regional show he joked with others saying I am going to have to get away from Charlie before he talks me into Hot Rodding the 200 in the 65.kenny170":umusji4p said:
Howdy Back Kenny:
The '72 170 offers several performance and durability advantages over the '62 170. It will have larger intake (1.64" vs 1.52" intake) and exhaust valves (1.38" vs 1.26" exhaust). It will accept the latter, better ignition systems. A '72 engine will likely have a better points distributor with both centrifugal and vacuum advance, and look like the original '62 system. It can also be upgraded to the 1st generation DuraSpark ignition system, which is pointless- meaning no points. Again, stock appearing.
The later head will also have induction hardened valve seats and a 1 3/4" carb hole (the '62 has a 1.5" carb hole). The block is plumbed for hydraulic lifters, so a cam change is easier.
The '72 will have the a Carter YF carb, rated @ 150 cfm. The same carb on a 200 engine flows 185 cfm. It also has a better, more crack resistant exhaust manifold with a 2" outlet.
The down side is that the '72 170 is down on CR- 8.3:1 vs 8.7:1. For mileage you'll want 9:1 at least.
Be sure to save and swap your '62 adjustable rocker arm assembly to the new engine.
If it were me, I go for the '72 in a heartbeat. And you can keep driving with the original engine while you're building the '72 then make the swap. That will minimize the down time.
Adios, David
The '72 170 offers several performance and durability advantages over the '62 170. It will have larger intake (1.64" vs 1.52" intake) and exhaust valves (1.38" vs 1.26" exhaust). It will accept the latter, better ignition systems. A '72 engine will likely have a better points distributor with both centrifugal and vacuum advance, and look like the original '62 system. It can also be upgraded to the 1st generation DuraSpark ignition system, which is pointless- meaning no points. Again, stock appearing.
The later head will also have induction hardened valve seats and a 1 3/4" carb hole (the '62 has a 1.5" carb hole). The block is plumbed for hydraulic lifters, so a cam change is easier.
The '72 will have the a Carter YF carb, rated @ 150 cfm. The same carb on a 200 engine flows 185 cfm. It also has a better, more crack resistant exhaust manifold with a 2" outlet.
The down side is that the '72 170 is down on CR- 8.3:1 vs 8.7:1. For mileage you'll want 9:1 at least.
Be sure to save and swap your '62 adjustable rocker arm assembly to the new engine.
If it were me, I go for the '72 in a heartbeat. And you can keep driving with the original engine while you're building the '72 then make the swap. That will minimize the down time.
Adios, David
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