How to generally pick the right cam

[Blackbirdsrt78]

I know I am opening up a can of worms here because there is alot to what makes a cam work the way they do. So...I am trying to pick a cam that will be streetable and will compliment the supercharger. I guess I am saying I want to keep the fuel economy and have power. I know there is a trade off somewhere. Idle is important I want a normal Idle maybe on the edge of rough and smooth. I will be using oversized valves that are stock length so a little more lift may be ok. Duration is one thing that I dont fully understand if at all. Does duration mean just how long the valve is open. more duration means more time for air fuel mix to enter the combustion chamber?

What ever cam I am getting I will be getting the full kit that has timing chain lifters springs ect. This is how I did my last slant six car although my father picked the cam and never explained why he choose it. lol

 

[Blackbirdsrt78]

I have also heard from FABOland that slant six Comp Cams eat distributor gears. I ran one in my Barracuda for years and never had timing issues or ate up distributor gears. but that was many years ago that we purchased that cam.

 

[greymouser7]

http://www.onallcylinders.com/2013/...tuning-and-upgrading-for-maximum-performance/

Camshaft Selection

A supercharger can overcome inadequacies in a stock cam up to about 4,500-5,000 rpm. You will typically find that performance with a blower will not be significantly enhanced below these speeds with a cam change. However for optimum performance at higher rpms, a more aggressive camshaft will provide substantial power increases.

For best performance with a blower, you should look for a cam that has higher lift and longer duration on the exhaust side. Street performance with a blown engine is usually best with a cam that is ground with a 112- to 114-degree lobe separation. With the use of an aftermarket camshaft, follow the camshaft manufacturer’s recommendations for valve springs. Blower cams can typically be run “straight up.” Note that a blower has tendency to lessen the rough idle of radical cams.


Supercharger Guidelines for Stock Engines
1.7.0:1 to 9.0:1 static compression ratio, with an effective compression ratio below 12.0:1 (review Boost Basics Part 2 to learn more about effective compression ratio): The optimum static compression ratio is 8.0:1.2.3-5 psi boost level: This range of boost has proven to be the best compromise for power and reliability for engines using cast pistons, cast crank, and small cam, according to Weiand.
3.Engine rpm: When using stock cast pistons, the engine should be limited to a maximum of 4,500-5,000 rpm. Exceeding this limit may over-stress the cast pistons causing failure. Blueprinting an engine using the proper components will allow higher rpm reliability and will maximize a supercharged engine’s potential.
4.Detonation (pinging): Detonation is the single most destructive force in a supercharged engine and steps must be taken to eliminate it. This may include lowering boost level, retarding timing, installing a boost timing master, increasing fuel flow to prevent leanout, and/or using a fuel additive to raise octane level. The cooling system also needs to be in good condition to prevent overheating, which may lead to detonation.
Ignition System Settings

Blown engines make great power in the low-and mid-rpm range. That means most late model OEM electronic ignition systems have the capability of working well with a supercharger and will be fine if you keep your driving under 5,500 rpm. Set initial ignition timing at 6 to 10 degrees BTDC. The distributor advance curve should be calibrated to give a total advance of 28 to 34 degrees by 2,500 rpm. If detonation is encountered, a boost/retard system that works with manifold vacuum & pressure is recommended. It is also a good idea to run your spark plugs one or two heat ranges colder than normal with a blower to reduce the chances of detonation.

Carburetor & Induction Considerations

At full throttle a blown engine can require 50 percent more air than an unblown engine and as a result needs a larger carburetor(s) in order to make maximum power and boost. If your blown engine is primarily driven on the street at moderate engine speeds (under 4,000 rpm) you won’t need a larger carburetor(s).
Typically the carburetors(s) will need to be enriched by 5 to 10 percent on the primaries and 10 to 20 percent on the secondaries. The idle mixture screws may need to be enriched by one or two turns. In either case, the carburetors need to be jetted properly to prevent a lean condition. A lean condition can lead to overheating and detonation.

For initial start-up, it’s better to have a slightly rich condition to help prevent the engine from overheating. After initial start-up, check the spark plugs for proper reading (color) and adjust the carburetor(s) accordingly. You want to see a medium to dark tan color.
-----------------------------------------
Comments: Jake L. August 25, 2014 at 5:28 pm
I wish someone would really detail supercharger performance. For instance, why does everyone focus on pressure (psi)? It is not directly related to air density, which is the real factor controlling output. Maybe I’m missing something here. It seams to me that pressure is more an indication of a restrictive intake/bad cam timing than it is supercharger output.
I also find it interesting when people remark that a supercharger doesn’t perform better with aftermarket heads. This does not make since to me. Obviously the optimum intake to exhaust ratio is very different NA vs boosted and every head designed for NA has to be modified for good results for boost. Maybe I’m way off here, but it seems to me that it could be explained by relating a smaller engine with forced induction to a larger NA motor in terms of intake/carburetor/exhaust. Then relate that to temperature because if forced induction.
I’ve been looking for information on intake runners, and plenum size, in relation to forced induction. I can’t find a reason why I shouldn’t apply intake valve pulse wave tuning with the intake runners. Also the low lift air flow and overlap scavenging principal still seem to apply. The intake charge probably moves a little faster in total, but from what I’ve read overlap and low lift at the valves move air around the speed of sound. So that should be just as important boosted or NA.
The second to last issue I’ve come across is LCA. Everything I’ve read references using cams ground at 112-114 LCA. I’ve seen several cams that still have 25* or more overlap while others have 1-5 degrees of overlap. Just mentioning LCA seems very incomplete.
The last one. I can’t find anywhere that details carburetor function for a roots supercharger. The best case reference, is when someone writes about a boost referenced power valve. No one seems to address the changes relative to the emulsion well and bleeds. I know, a person does not have to make these changes to make the engine run, but most of us are not ok with just bolting on a carb and leaving it to run like junk when running NA, why do that with a supercharger? ‘Because it is not as obvious,’ seems like a crap excuse to me. No one seems to want to divulge how to do it right. I just want people who feel that way to know, that mindset is the type of ignorance that created the middle ages. The carburetor’s days are numbered, share the information before it is largely lost.

Reply



Ted
December 20, 2014 at 1:31 pm


What you need is the inside scoop on the size numbers inside a Holley Blower Carb. I don’t have them myself. The 112-114 LCA is for a low boost motor, when the boost goes up higher a 110 LCA . The Boost Reference of the carbs to the lower manifold gives you the true engine vacuum reading and stops blower roll up and down idle speeds because under the carbs there is always a vacuum messing up the power valve. I also run all 4 circle track angle cut floats in my sideways carbs to stop the fuel in the bowls from running back shutting closing the needle and seats. Good heads less restrictions = more power, Remember its easy to move the air but to keep the fuel mixed with the air going in the engine it will stick to any walls in can find and drip. I called cam cams the other day to compare a stock bbc solid flat cam 11-106-3 which was getting 12mpg on the highway to a small hyd blower cam 11-404-4 they said they think I would get even better mpg with the blower cam, and I could run solid lifters on it with .012″ lash clearance. I myself just don’t trust hyd lifters. You Never what to hang a intake valve open= back fire into intake and up ! No one knows all the facts of why things work on one car better then another too many variables, its always trade off of different things to learn what works for you !


------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------


http://www.ehow.com/how_7959078_choose-cams-supercharger.html

Determine where you want your power-band to be. Positive-displacement or "Roots-type" superchargers tend to produce massive power at low rpm and taper off higher in the rpm range; centrifugal superchargers (which are really just belt-driven turbos) work only in the rpm range.

Acquire a cam with more exhaust lift and duration. This is quite possibly the most crucial element of supercharger camshaft selection, since the supercharger cannot push more air in if there is already exhaust gases in the cylinder. Most performance cams use more lift and duration on the intake side to pull more air in; you will want to utilize a cam with exhaust lift and duration at least ten percent higher than the intake.

Specify your cam with the wide lobe separation angle to ensure the lowest possible overlap. Overlap is the amount of time in degrees that the intake and exhaust valves are open at the same time, and excess amounts of it can work against your supercharger by allowing exhaust backpressure to negate supercharger pressure while the valves are open. Avoid any cam with more than 30-degrees of overlap.
. A slightly lower (about one-degree) lobe-separation angle will increase cylinder pressure and low-rpm torque without adversely affecting the engine's octane tolerance or idle quality.

 

[greymouser7]

http://www.kcams.co.nz/Menu/Selecting-A-Camshaft.php


Supercharged / Turbo Charged

Supercharged engines typically have a shorter intake, longer exhaust, and wider lobe center angle (LCA).
Supercharged engines can continue pushing charge into the cylinder longer than an Naturally Aspirated engine, and also the greater pressure differential between the manifold and the cylinder means the cylinder is filled quicker. This means they like a shorter intake duration on a later centerline, compared to thier NA counterparts.
Higher cylinder pressure after combustion means more gas to get rid of, so the exhaust valve is opened earlier than on an NA engine. This means longer exhaust duration, on an earlier centerline.
Early exhaust centerline and late intake centerline means a wider LCA. This means there is less overlap which also helps stop the pressurized intake charge being lost out the exhaust valve.

Turbo Charged engines are more complicated.
Before the turbo charger reaches an efficient speed the engine behaves much like an NA engine, albeit a low compression one. This means to get the cylinder filled efficiently and producing good amounts of exhaust gas to 'spool up' the turbo the ideal would be a relatively tight LCA. However once the turbo has 'spooled up' and is efficient the engine behaves more like a conventional supercharged engine and wants a wider LCA.
Turbo engine camshaft selection, and the overall performance of the engine, is greatly effected by the turbo selection.
It is easier to get a turbo to spool up at lower rpm by choosing a smaller exhaust turbine housing than by manipulating cams. This means the cams can then be optimised for 'on boost' performance.
Typically higher boost levels, and higher rpm, require more cam duration. The main difference between supercharged and turbo charged engines, is that turbo engines do not flow from the intake out the exhaust, at overlap, as easily as a supercharged engine, and therefore tend to open the intake valve earlier. So turbo engines tend to have a longer duration intake than a supercharged engine, but still shorter than an NA engine.
The turbo charger should be selected before the camshaft, remembering that a turbo, much like a supercharger, can restrict power if it is not big enough.

 

[greymouser7]

http://www.automotiveu.com/BlowerTuning.htm

By: Henry P. Olsen

Setting up the fuel and ignition systems to get a blown engine to run properly may take some time, but the results are worth it. The engine must be built with the supercharger in mind, the compression ratio, as well camshaft should be matched to the application and designed use. Always select the camshaft to match the rpm band the engine will normally be operated in, a race cam may make power at high rpm but it will not run well at lower engine speeds. There are a few “set-ups” not used on a normally aspirated engine that can make all the difference in how the engine runs. The camshaft lobe separation that seems to work best for a supercharged engine is 112 to 114° along with a split duration camshaft where the intake lift and duration may be mild yet a more aggressive exhaust cam profile. This type of camshaft can be used on a supercharger since you are blowing the air in to the cylinder; this type of camshaft creates more horsepower without hurting low rpm torque. Using tools such the OTC/SPX PerformanceGas or MicroGas exhaust gas analyzers and advance timing lights allows us to tailor the fuel and ignition advance curves to unleash all the horsepower the supercharger is blowing into the engine.

Blow through carburetor supercharged set-ups

The first concern for an engine using a blow-through supercharger where the carburetor is under boost pressure is fuel pressure. A special fuel pressure regulator that is boost pressure referenced along with a high pressure/volume fuel pump to keep the fuel pressure correct for this type of supercharger system must be used. The boost referenced pressure regulator senses the boost pressure and then regulates the fuel pressure to keep the fuel pressure at a set amount above the boost pressure. The pressure that we use most is 5 ½ to 6 lbs. over the boost pressure, so when you have 6 lbs. of boost the fuel pressure would be 11 ½ to 12 lbs. The floats used in the carburetor on a blow thru supercharger must be made of nitrophyl or of some other solid material, brass or hollow plastic floats will collapse from the pressure the supercharger puts into the fuel bowls. The 2 main ways of pressurizing or blowing through the carburetor are #1 where the carburetor is in a pressurized box and #2, is the use of a hat in place of the air cleaner on top of the carburetor. If the carburetor is not inside of a “box” but using a hat to pressurize the carburetor bowls & venturii, the throttle shafts will have to have seals installed to keep the fuel from blowing out thru the clearance in the throttle shaft. We always recommend a marine type of flame arrestor be used inside the air box or hat to defuse the air-charge, if this is not used the air charge blowing from just one side of the carburetor will cause the air/fuel mixture to be incorrect as the boost changes.

The idle and off-idle systems are the hardest part of the fuel system to get the fuel curve correct with a blow-through supercharger system, extreme care must be taken to properly size the idle fuel and air restrictions in order to obtain the correct idle and part throttle fuel mixtures. The reason this care must be taken is because this type of supercharger is pressurizing the idle air bleeds thus blowing the fuel into the engine thru the idle system. The rest of the carburetors fuel circuits operate in a normal fashion. The fuel mixture at idle speeds and cruise speeds seen most are idle CO of 1 to 3%. The cruise mixture on a low boost, mild cam engine would be 1 to 1.5% CO while the high boost pressure hot cam cruise mixture is 3% CO. A power mixture of 6.6% CO (12 to 1 air/fuel mixture) is used on most engines, yet you can go richer if needed to help control detonation.

Pull-through Carburetor Supercharger Set-ups

An engine using a carburetor on top of a supercharger uses a standard set up for fuel pressure; the fuel pressure we use most is 5 ½ to 6 psi. The most important point is to use a high volume fuel pump along with fuel lines large enough to keep fuel pressure constant at all engine loads.

Selecting the correct carburetor

Selecting the correct carburetor for a supercharged engine is very important; the fuel curves for a low boost engine versus a high boost engine make proper carb selection very important. The Demon carburetor line from Barry Grant Inc. offers carburetors designed for use on supercharged applications; these carbs are in their Race Demon series of carburetors. These carburetors come with removable sleeves; this feature allows you to change the carburetor airflow (cfm), so if you change boost pressure, engine size, or cam, you can resize the carb for the new engine without buying a new carb. The Race Demon series carb also has changeable air bleeds and idle feed restrictions; this feature makes it easy for your tuner to dial in the fuel mixture curve for the engine’s needs.

The blower Mighty and Race Demon carburetors have power valves with vacuum tubes that allow the power valves to be boost referenced, just connect this port to boost pressure and the power valve can see engine load or vacuum instead of the vacuum created by the supercharger. A boost referenced power valve helps make it possible to get the fuel mixture curve correct for all engine loads and should be used on any high boost street driven engine. One of the more common problems I have seen is with the engine at idle speed; the engine will go into a supercharger roll (the engine speeds up the slows down then speeds up….). This supercharger roll is caused by the superchargers vacuum signal to the power valve not being the actual engine vacuum, but the vacuum created by the supercharger. The power valve reads the higher vacuum created by the supercharger, this vacuum closes the power valve, causing the fuel mixture to go lean, the engine then slows down due to the lean air/fuel mixture so the vacuum signal from the supercharger causes the power valve to open as the superchargers vacuum drops, so again the engine again speeds up due to the richer air/fuel mixture, rolling from rich to lean causing the engine to speed up then slow down.

The fuel pressure we use most is 5 ½ to 6 lbs. and we always suggest a high volume fuel pump that can supply enough fuel to keep the pressure constant at all engine loads. We have seen Holley style carbs where we had a fuel leak from the plugs on the metering block; this was caused by a carb air scoop creating a high pressure in the fuel bowls pushing fuel past poorly fitting metering block plugs. The cure for this was to epoxy the plugs in the metering block and putting a few vent holes in the carb scoop to help lower the air pressure (this problem has not been seen by us on Demon carbs or on AFB style carbs).

AFB style carbs on a low boost pressure - mild blown engine can work well, but since they do not offer a boost referenced power system, care must be taken to avoid overly lean fuel mixtures, especially at off-idle to part throttle. A street driven dual 500-cfm afb set-up can be a very good running set-up on a mild blown engine that gives a great appearance and also can run well under normal street driving conditions. The 500 & 600-cfm carbs can be modified to avoid an off-idle lean condition, so they can work well on a low boost pressure single or dual carburetor set-up, but we avoid the 750 and 800 cfm AFB’s on street driven blown engines because of a lean at part throttle problem that is inherent with this type of carburetor.

Jetting a supercharged engine with the MicroGas

The method we use to determine and then obtain the correct air/fuel mixture (jetting) is on an engine is the use of a tool from OTC/SPX tool company, the PerformanceGas and MicroGas portable exhaust gas analyzers, both units have provided us with accurate data that allows us to obtain great results. The CO reading that an exhaust gas analyzer provides is an accurate indicator of the air/fuel mixture (jetting). Jetting or obtaining the correct fuel mixture on a supercharged engine is different on a low boost engine when compared to a high boost application. On a low boost application the air/fuel mixture is almost the same as a normal hot rod fuel curve, but when a set-up is used with a lot of boost, the fuel mixtures used can be much richer. On a low boost engine the power mixture we use is a CO reading of 6.6% or a 12 to 1 air/fuel ratio, but when using a lot of boost a power mixture 0f 11.5 to 1 air/fuel or CO reading of 8.0% is not uncommon. This richer mixture can help in controlling detonation created by the high boost pressure, but if you go too rich you will lose power. The cruise mixture on a mild cam low boost pressure engine would be 1% TO 2% CO (14.1-13.8 TO 1 air/fuel ratio) but on a hot cam high boost engine the target mixture would be 3% CO (13.4 to 1 air/fuel ratio).

A blown engine will require the accelerator pump to be tailored to its needs; some engines will need a quicker accelerator pump squirt, others will need more accelerator pump volume. Always avoid drowning the engine with too much accelerator pump. A street driven supercharged engine with 2 Holley style carbs will very seldom need 50cc pumps on the primary side of the carbs.

 

[greymouser7]

Intercoolers / cooling the charge

The act of compressing the air charge into the engine creates heat; it is not uncommon to see air charge temperatures in the 200 to 250 degree plus range. This heating of the air charge hurts engine performance by reducing the air density. By cooling the air charge you can gain back about 1% in horsepower for every 11 degrees you can drop the air temp, by using an intercooler, it is easy to get a 10% increase in power or more.

Ignition system set-ups with a supercharger

The ignition system used on a supercharged engine must be up to the job; the higher the boost pressure, the more ignition output is going to be required to fire the spark across the spark plug gap. This higher ignition output will also require the wires and the rest of the ignition system to be up to the job of delivering the extra ignition output to the spark plugs. Always consult the ignition supplier of the product you are using for the recommended spark plug gap when using a supercharger; use these specs as a guideline for where to start. Some experimentation may be needed to find the spark plug gap that works best for your engines demands and the air-fuel mixture inside the cylinder. The use of a engine ignition analyzer to check the condition and output of the ignition system can confirm if the ignition system has enough spark output to handle the extra ignition output needed to fire the sparkplugs because of the higher combustion chamber pressures created by the boost from the supercharger. The ignition system analyzer we use to check a ignition system is the Vision Premier or the Genisys Scope Module from OTC/SPX, either unit allows us to easily check the output and condition of the ignition system.

An MSD ignition system such as a #6btm (boost timing master) may use a spark plug gap of up to .042” with 6 psi of boost. The higher the boost (combustion chamber pressure) the smaller the plug gap, we have seen spark plug gaps of as small as .018 - .022” on a high boost engine with a Msd ignition system. (Note a 9 to 1 non-supercharged engine may use a plug gap of up to .055”.)

The ignition advance curve, in general, is quicker yet shorter than an engine without a supercharger, this helps give better throttle response until the boost pressure kicks in. The advance curve most seen is an initial timing of 18 degrees with a total of 32 degrees; this is just a starting point and must be tailored to each engine. MSD can supply a boost retard ignition system, which allows an advance curve that can supply enough advance to give good throttle response yet, as the boost comes in, it can retard the timing to avoid detonation. The boost retard system can retard the timing from 1 to 3 degrees per pound of boost and total retard can be as much as 20 degrees. A vacuum advance should only be used in a low boost application and should be limited to 10 degrees of advance with engine vacuum above 10 to 12 inches of vacuum. The best way to check and set the advance curve is on a distributor test stand, then confirm the results with an advance timing light such as the type we use from the Black Light series of timing lights supplied by OTC/SPX Tool Company.

Ole’s Carburetor & Electric

120 Camino Real

San Bruno, CA 94066

650.589.7377

olescarb@aol.com

 

[Blackbirdsrt78]

Thats why you are my best friend.

 

[Blackbirdsrt78]

so from what I have read in that arcticle. I will not be raising the compression ration because it will raise it self under boost. supercharging smooths out rough idle cams...and the exhaust side should have higher duration and lift about 10%. and an LCA no more than 30 degrees.

 

[greymouser7]

Thats why you are my best friend.

You're my boy blue!

http://moodyeyeview.files.wordpress.com/2012/08/blue.jpg

http://i.imgur.com/xlCqLD7.jpg

 

[Blackbirdsrt78]

So I started the search for a cam like this....no luck...Custom grind?

 

[greymouser7]

http://spokane.craigslist.org/pts/4825879096.html

200hp Mopar slant six builder - $200 (CDA)


•safety tips
•prohibited items
•product recalls
•avoiding scams
Professionally built Mopar 225 slant 6 motor: 10:1 pistons, 260 degree cam Engine made an estimated 200HP and was running healthy when the number 5 main bearing spun So I'm selling it as a rebuilder. $200 firm (might trade for large bore revolver).(208)691-8767. No texts or emails. Thanks! aftermarket direct connection aluminum 2 barrel intake & 350CFM Holley carburetor are not included. Just the motor. Thanks!

>>>>>>>>>>>>>& oregan cam grinders could re grind the cam- maybe offer money on the cam itself?

 

[greymouser7]

maybe this is interesting & close enou??
http://dothan.craigslist.org/pts/4858554906.html

REBUILT SLANT 6 ENGINE, 4 TRANS & PARTS, MOPAR 440's - $300 (dothan, al)

Here is an excellent mopar slant 6 motor that i pulled from my dads car a couple of years ago when i replaced it with a 440. Motor was rebuilt and only had around 600-700 miles on it when pulled. It is a 225 one barrel. Comes complete with motor mounts, hoses, fan, fan belt, kickdown linkage, air cleaner, etc. everything minus starter. Have 2 good automatic transmissions and 2 core trans. Also have some extra parts shown including NOS mopar plug wires and electronic distributor. I planned to put this in my dart but sold car recently so i don't need now. Engine has been stored in my shop since so it is dusty. Will sell slant 6, 4 trans and other S-6 parts together for first $300 or trade. Have (2) cast crank 440's for sale as well as big and small block 727's, 3 and 4 speed trans and more. one 440 is complete minus exhaust manifolds (locked up) for $225 and one is just the block with crank and a few other items for $100. Many other mopar parts and a few project cars also. I DON'T HAVE TEXT ON MY PHONE, SO CALLS ONLY. If no answer please leave message. Thanks, Steve. 334-seven 01-four 1 six 7.

am still looking for a cam for you

 

[greymouser7]

http://www.ebay.com/itm/COMP-Cams-H...Parts_Accessories&hash=item5b0890ee14&vxp=mtr

COMP Cams Camshaft, Hydraulic Flat Tappet, Advertised Duration 252/252, Lift .425/.425, Mopar, 225, Slant Six, Each


Please hover mouse to enlarge image






•Advertised Duration
252 int./252 exh.
•Advertised Exhaust Duration
252
•Advertised Intake Duration
252
•Basic Operating RPM Range
800-4,500
•Cam Style
Hydraulic flat tappet
•Camshaft Manufacturers Description
Good stock replacement for mileage and power increase. Low rpm torque. Smooth idle.
•Computer-Controlled Compatible
No
•Duration at 050 inch Lift
206 int./206 exh.
•Exhaust Duration at 050 inch Lift
206
•Exhaust Valve Lift with Factory Rocker Arm Ratio
0.425 in.
•Grind Number
252H
•Intake Duration at 050 inch Lift
206
•Intake Valve Lift with Factory Rocker Arm Ratio
0.425 in.
•Lobe Separation (degrees)
110
•Quantity
Sold individually.
•Valve Lift with Factory Rocker Arm Ratio
0.425 int./0.425 exh.
•Valve Springs Required
No


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http://www.ebay.com/itm/COMP-Cams-H...Parts_Accessories&hash=item5b0ab875c0&vxp=mtr

COMP Cams 64-240-4 Camshaft, Mechanical Flat Tappet, Advertised Duration 252/252, Lift .435/.435, Mopar, 225, Slant Six, Each


Please hover mouse to enlarge image






•Advertised Duration
252 int./252 exh.
•Advertised Exhaust Duration
252
•Advertised Intake Duration
252
•Basic Operating RPM Range
800-4,500
•Cam Style
Mechanical flat tappet
•Computer-Controlled Compatible
No
•Duration at 050 inch Lift
215 int./215 exh.
•Exhaust Duration at 050 inch Lift
215
•Exhaust Valve Lash
0.012 in.
•Exhaust Valve Lift with Factory Rocker Arm Ratio
0.435 in.
•Grind Number
CR6 252S-10
•Intake Duration at 050 inch Lift
215
•Intake Valve Lash
0.010 in.
•Intake Valve Lift with Factory Rocker Arm Ratio
0.435 in.
•Lobe Separation (degrees)
110
•Quantity
Sold individually.
•Valve Lift with Factory Rocker Arm Ratio
0.435 int./0.435 exh.
•Valve Springs Required
Yes

 

[Blackbirdsrt78]

I think that I am going to have to get a custom cam ground. Those all the the same duration for the intake and exhaust. Or I could use one of these cams and it should work just fine as long as the intake duration is not to high. I would feel better if the cam was custom ground.

 

[greymouser7]

summitracing: Howards Cams 759991 $155.97

Brand:Howards Cams

Manufacturer's Part Number:759991

Part Type:Camshafts, Custom Grind

Summit Racing Part Number:HRS-759991

http://www.summitracing.com/parts/hrs-759991

 

[Blackbirdsrt78]

Thanks thats what I was figuring I would have to go with. ok so lets see what the actual numbers should be for the custom grind.

 

[kkritsilas]

You should talk to the cam manufacturer's techs. Let them know what you want to do, and they can probably figure out the right cam, whether it be off the shelf or custom.

BTW. The Eaton M90 is a Roots style supercharger.

Kostas

 

[MiradaMegacab]

Search FABO forced indiction section.
Bill Dedman has some great tech threads as does 805MoparKid
MoparKid had alot of supercharged/ 6 threads

 

[greymouser7]

http://www.foundationpc.com/press/press66d.html


I. Street Use

A. Carburetion

1. Single Barrels
Any 170 cu. in. slant six having a small BBS carburetor (1-1/4" dia. venturi) will produce about 5% more power when the 225 cu. in. BBS carburetor (1-11/32" dia. venturi) is installed. These two carburetors can be identified by measuring their throttle bore diameter. The larger carburetor has a 1-11/16" dia. throttle bore and the smaller carburetor has a 1-9/16" dia. throttle bore. All 170 manual transmission jobs and the 1960 and 1961 170 with automatic transmission have the smaller carburetor.
2. Two Barrels

a. Two Barrel Conversion Available from MoPar
A two barrel set up (as used on the 225 cu. in. marine engine) is available from MoPar as follows: •1 - 2463849 carburetor
•1 - E8467 manifold
•1 - 2465310 air cleaner

b. Do-It-Yourself Two Barrel
The two-barrel carburetor from any 318 V-8 engine (without CAP Package) can be used as shown in Fig. 1 attached. [Ed: This figure is a crude hand drawing of an overhead view of the engine block, manifold, and carburetor plate. There is an arrow to the carburetor plate saying, "Plate shaped like 2 bbl. gasket welded on std. manifold." There is an arrow pointing from the carburetor toward the slant six block saying. "Carburetor float bowl points this way." Finally, there is a dimension from the center line of the carburetor plate bores to the cylinder head face (where the manifold meets the head) marked 7 3/8" inches.]
c. "B" Engine Two Barrel
The larger two barrel from a 361 or 383 can be installed as in item b. above. However, low speed driveability in cold weather may be unsatisfactory on the street.
d. Four Barrel for the Street
The AFB from the 273 power pack can be adapted to the 225 six cylinder. The four barrel bores must be centered upon the standard six cylinder inlet manifold's plenum chamber.
B. Compression Ratio
Up to .090" can be removed from the slant six cylinder head. The slant six cylinder head has an especially thick lower deck surface.
For example, removal of .090" will raise the compression ratio of a 225 engine from 8 to 1 up to 9.5 to 1. Removal of .090" will raise the compression ratio of a 170 engine from 8 to 1 up to 10 to 1.

NOTE: It is advisable to used the stainless steel head gasket from the 225 marine engine after milling the cylinder head. Also, the valve-to-piston clearance should be checked if the milled head is used in conjunction with a high lift camshaft.

C. Spark Advance
For street use, the total spark advance at engine speeds over 3000 rpm should be 30 to 32 degrees (check with the vacuum advance disconnected).
D. Valve Gear

1. All-around Street Cam
Marine engine camshaft #E7885M is the best all-around street cam. It is a 244-degree duration with .405" lift and 26-degree overlap. Standard slant six cam is 232-degree duration with only 8-degree overlap.
2. Super Street Cam
Hyper Pack Cam #2205620 (276-degree duration) is borderline for driveability even when used with a manual transmission and a high numerical axle ratio. The Hyper Pack cam should never be used with an automatic transmission.
3. Valve Springs
Heavy duty valve spring #1944554 should be used with the marine cam E7885M and must be used with Hyper Pack Cam #2205620 because of the valve lift involved.
Heavy duty valve spring retainers #2202546 must be used any time engine speeds of over 5000 rpm are attempted. BOth cam E7885M and cam 2205620 use standard tappets.

E. Exhaust System

1. Hyper Pipe
Exhaust pipe and muffler assembly #2208350 fits the Lancer through and including the 1961 model. This is a 2 1/2" dia. exhaust pipe and a "B" engine size muffler and offers several percent gain in output over the standard system.
On the '62 and later 170 slant six the rear pipe must be modified for clearance to back geared starter. 2208350 will clear the starter on all 225's.

2. Exhaust Manifolds
The best street exhaust manifold combination includes the front three cylinders from the standard manifold combined with the rear Hyper Pack header manifold. This allows the front three cylinders to provide carburetor heat which is necessary below 50 F ambient temperature. The back three cylinders exhaust through the Hyper Pack Header #2129900; and the Hyper Pack Exhaust Pipe and Muffler #2208350 can easily be modified to fit this combination.
II. Drag Strip

A. Stock Class
A MoPar Hyper Pack #2205573 (see list attached) was available for the 1961 Lancer. This kit can be raced in NHRA stock with the standard 8 to 1 compression ratio only. NHRA allows a combustion chamber minimum CCs of 53.8 CC. NHRA minimum piston top to block deck measurements are .141" for the 225 and .000" for the 170.
B. Modified
Based on experience gained since 1960, the basic Hyper Pack can be improved upon for modified drag racing as follows:
1. Carburetor
Three Weber dual carburetors 48 IDA will improve engine output nicely compared to Hyper Pack inlet manifold and carburetor on the slant six. Obviously a hand-fabricated inlet manifold would be required; one cylinder per Weber throttle bore.
2. Compression Ratio
Using 1965 - 1966 vintage gasoline quality, compression ratios between 12 and 13 to 1 should perform satisfactorily on the drag strip. "West Coast" pistons would be required to attain ratios this high. Step seal "Dykes" top piston rings should also be used because they lower engine friction at high speeds. "Slug" pistons should be fitted at .008" to .010" clearance.
3. Valve Gear
It appears that either the Racer Brown ST12 or the Iskenderian 1012B should perform well in fully modified engines. Obviously Iskenderian or Racer Brown push rods, retainers, springs and so on should be used. No slant six dynamometer work has been done at Dodge with these cams, but these cams have produced power very well in the Dodge Wedge Head V-8's.
4. Exhaust System
Cylinders 1, 2 & 3 should exhaust through 1-5/8" or 1-3/4" O.D. pipes about forty inches long into a cloverleaf collector and then through a 2-1/2" O.D. outlet pipe much like current factory-sponsored Super Stock practice. Cylinders 4, 5 & 6 should have a duplicate system.
5. Big Valves
The standard 6 cylinder valves are 1.62" dia. inlet and 1.36" dia. exhaust. Bigger valves can be installed as follows:
a. Exhaust Valve (Oversize)
The 1957 Dodge V-8 exhaust valve #1827958 makes a very convenient oversize valve for the slant six. The head diameter is 1.5" or .140" oversize and the length is satisfactory. It is necessary to provide a clearance notch at the top of the bore.
b. Inlet Valve (Oversize)
The 1-3/4" dia. 163744 exhaust valve from the 1957 or 1958 Chrysler 392 V-8 can be made into a .130" oversize inlet valve. However, it is necessary to reduce its length by .270" and cut three more lock grooves down the stem. No bore notch is required for clearance for this oversize inlet valve.
6. Engine Oiling
For high-speed, fully modified engines provision must be made for more oil flow through the main bearings to the rod bearings. One way to achieve this is to groove the crankshaft (which unfortunately may result in crank breakage). A better way is to use upper main bearing shells in the main caps. (It will be necessary to file down the locating tabs to allow the grooves to align.) These tabs merely locate the bearings. The tabs do not prevent rotation; the inserts are "crushed" by the cap to prevent rotation.
The oil sump should be greatly enlarged so that the oil level is at least six inches below the crankshaft's path. At least six quarts capacity is necessary.

7. Durability
The truck 225 crankshaft (shot peened and not cold straightened) should be used for fully modified 225 slant sixes.
MoPar Hyper Pack Major Components


ITEM

PART NO.

NAME

1. 2205620 Assy. - Camshaft
3. 1944554 Assy. - Valve Spring & Damper
4. 2129619 Assy. - Valve Push Rod
7. 2129898 Manifold - Intake
17. 2129899 Manifold - Exhaust - Front
18. 2129900 Manifold - Exhaust - Rear
20. 2129881 Assy. - Carburetor
21. 2121952 Gasket - Carburetor Flange
25. 2129992 Assy. - Air Cleaner
26. 1821170 Gasket - Air Cleaner
54. 2201223 Assy. - Clutch Cover & Pressure Plate
55. 2201219 Assy. - Clutch Driving Disc
60. 1636570 Gasket - Exhaust Pipe Flange
61. 2298350 Assy. - Muffler & Exhaust Pipe

Four Barrel Carburetor For All Slant-Six Engines
A carburetor that gives proper fuel mixture and distribution characteristics for the six-cylinder engine using a Hyper-Pak intake manifold or a modified standard intake manifold can be made from a Carter model 3854-S carburetor. This carburetor is used on the 1965 and later 273 cubic inch high performance engine. The modifications are as follows: 1.Replace the metering rods with No. 16-177 rods. (.067 - .065 - .055" dia.)
2.Replace the throttle side secondary jets with No. 120-181 jets. (.049" dia.)
3.Replace the choke side secondary jets with No. 120-226 jets. (.065" dia.)
4.Replace the primary venturi clusters with clutch No. 48-264S.
The throttle linkage will have to be fabricated to match the installation.