Isky 3/4 Max 1 Camshaft
- Thread starter 40larry
- Start date
Pete
BANNED
From an Isky catalog.
MAX #1 Good Low Speed Power Cam in conjunction with stock carb. And intake manifold. Good idle. Type (3/4) Valve Lift (.364 .364) Valve Lash hot (.014 .014) ADV Duration (249 249) .050 Duration (226 226) LC 111.
Ol' Ron
Well-known member
This is a very good cam for a stock or near stock displacement engine. Built many 258 engines with this cam. These engines were the stock type rebuilds of the late 40's early 50's 20 cubes and a point in compression. Dual 94 made them hard to beat back in the day. When reading JWL's book the Max #1 put the stock flathead over the 100 hp mark. Unfortunately, in today's market, it's an expensive proposition, any cam is!!!
Is the following exactly what is given in the Isky catalog? What does it mean?
"Duration (249 249) .050 Duration (226 226) LC111"
Pete
BANNED
249 is at running clearance.
226 is at .050 lift.
"LC" is "lobe center" which in this case also happens to be the lobe separation or the degrees between the ex and in lobes.
zzlegend
Well-known member
Good question Larry. I am running that cam in my 27 roadster and now in the process of rebuilding my son's 47 coupe Flathead and he wants to run the same cam.
Thanks Pete for the info.
Automotive Stud
Well-known member
I have a max 1 cam in my '47 with dual '97's, aluminum heads, and headers. It's a nice running combination.
Do the intake and exhaust valves have identical duration specs? Some MFRs list intake duration and exhaust duration specs separately.
Ol' Ron
Well-known member
Some day we should have a thread on camshafts that are not too technical. If that's passable. For me the duration and lift at .050" gives me the peek torque rpm, also lift rate. However, that doesn't always work out the way you might think. Take the L-100, When I first saw that cam I said it wouldn't work in a 5500 lb Ambulance. And it worked great, I still don't know why???
glennpm
Well-known member
Yes JSeery, much easier with a larger clearance to find and measure. I used this great article when I set and "degreed" my cam in one of my bikes, a 1979 Yamaha XS650 that has a revised firing order.
"Check Your Lobe Centers, Ma'am?"
Same thing here verbatim and probably "borrowed" or vice versa from Muzzys.
https://store.schnitzracing.com/cam-lobe-centers-explained/
Glenn
"Check Your Lobe Centers, Ma'am?"
Same thing here verbatim and probably "borrowed" or vice versa from Muzzys.
https://store.schnitzracing.com/cam-lobe-centers-explained/
Glenn
Pete
BANNED
On most common vintage street cams the PROFILE on each lobe is the same.
The timing numbers can be different due to advancing or retarding the cam in relation to the crank.
No matter how much you advance or retard it, the lobe separation angle will remain the same.
56markII
Member
Ron that would be quite simply fantastic having a thread on camshafts in simpler terms and what they do and do not do
After searching around for information which isn't always easy to find at least for me it is hard
I stumbled upon a pair of Isky450-811100 and
450-817700
https://static.speedwaymotors.com/images/charts/ISKY.gif
https://static.speedwaymotors.com/images/charts/ISKY.gif
https://www.speedwaymotors.com/Isky...7-B-1949-53-Flathead-Ford-Camshaft,25445.html
They mention both of these will work with a stock carburetor with good idle and low to midrange RPM and the 811100 will work good with multiple carbs as well.
They also mention the 811100 will give good "hot rod sound" which puzzles me.
Does this "Hotrod sound" also mean the car will be shaking and bobbing like a Mexican Jumping Bean or will it be totally civilized?
What is my application?
A very stock 1950 Mercury Sport Sedan with a stock 255ci and on it is the larger OEM Holley 885FF that is larger than the wee little 97's and was also used on the much larger Lincoln 337 and numerous much larger truck applications throughout the 50's.
My differential ratio is (unfortunately?) the 4.27:1 mountain (description from OEM parts manual) differential and luckily for me I have the Borg Warner 3 speed/OD otherwise I would be roaring at high revs at 50-60MPH.
My heads are stock but in my hoard I have other more desirable OEM Mercury heads as per claims on the Internet.
My occupation has been a mechanic for almost 40 years but in my case I have always been rebuilding in totally stock form and am considering warming up my Mercury that I have owned since the early 80's.
Hopefully somebody can tell me what I can expect using stock carburation and heads with these Isky's? No I don't want something radical, just warmed up a bit kind of like Ford getting 125HP out of them in the later 255 used up to 1954(we used them in 1954 up here in Canuckastan)
Pete
BANNED
Ron that would be quite simply fantastic having a thread on camshafts in simpler terms and what they do and do not do
After searching around for information which isn't always easy to find at least for me it is hard
450-811100 and
450-817700
https://static.speedwaymotors.com/images/charts/ISKY.gif
https://static.speedwaymotors.com/images/charts/ISKY.gif
https://www.speedwaymotors.com/Isky...7-B-1949-53-Flathead-Ford-Camshaft,25445.html
They mention both of these will work with a stock carburetor with good idle and low to midrange RPM and the 811100 will work good with multiple carbs as well.
They also mention the 811100 will give good "hot rod sound" which puzzles me.
Does this "Hotrod sound" also mean the car will be shaking and bobbing like a Mexican Jumping Bean or will it be totally civilized?
What is my application?
A very stock 1950 Mercury Sport Sedan with a stock 255ci and on it is the larger OEM Holley 885FF that is larger than the wee little 97's and was also used on the much larger Lincoln 337 and numerous much larger truck applications throughout the 50's.
My differential ratio is (unfortunately?) the 4.27:1 mountain (description from OEM parts manual) differential and luckily for me I have the Borg Warner 3 speed/OD otherwise I would be roaring at high revs at 50-60MPH.
My heads are stock but in my hoard I have other more desirable OEM Mercury heads as per claims on the Internet.
My occupation has been a mechanic for almost 40 years but in my case I have always been rebuilding in totally stock form and am considering warming up my Mercury that I have owned since the early 80's.
Hopefully somebody can tell me what I can expect using stock carburation and heads with these Isky's? No I don't want something radical, just warmed up a bit kind of like Ford getting 125HP out of them in the later 255 used up to 1954(we used them in 1954 up here in Canuckastan)
Larry at: https://www.tildentechnologies.com/
probably has the best website for the beginner to get cam design and use info.
From what you say, I gather you do not want the "hot rod sound", which simply means a rough lopey idle. Several cams available will give you a stock smooth idle and SLIGHTLY improved performance. With what you have for an engine (basically stock) you may not notice any improvement in the seat of pants though.
The stock 53 Ford EA or EAA was the hottest stock cam that came out in the flathead engine. The 77B Isky will be very slightly better while retaining stock idle. Any cam with specs above this will likely be getting into the lopey idle range and will have reduced low rpm performance.
I have been in the cam and racing business for 68 years and have seen that people tend to choose a cam that is too big for their application the first time around.
56markII
Member
Hi Pete and thanks for reply!! Yes I see that all the time and they are TOTALLY unsuitable for street and at times the vacuum accessories don't work as well. A slight Lopey idle I can live with and my guess is the slightly more aggressive version I listed is perhaps that kind that will have a slight gallop of the idle perhaps not making the car shake?? Nope I'm most certainly not looking for massive increase but just a bit of a warming up
This would be indicated by having this car since the early 80's and using 110 hp for all those years. By some chance do you know the specs of that better Ford OEM cam and how does it compare to those Isly's? They also increased the compression to 7.5 in the latest and HP was 125 HP OEM as well and I should check my heads to be sure what I got but I'm sure I have a pair like you mentioned. 25-35+ HP shouldn't be that difficult to achieve on these and as it is I have been digging around for info on popup pistons as well. OlRon mentioned he has used 239 Pistons in the 255 as well after I was always thinking about this. He never went into much detail about using them and my future experiment that I hope to do is drag one of my cores into the shop and place a 255 crank into it with a 239 piston without rings and place a head on it doing a crush test to measure the clearance. One fellow at Isky I talked to mentioned compression is a very big factor for how the cam behaves and what it can do as well. Then there is the argument of reducing the stoke with a 239 piston but in reality the bottom of the stroke is reduced but the end result is the chamber is also reduced at TDC of compression. This is probably a bigger win win situation than worrying about a 1/4 inch reduction of BDC anyway! I have also read this is a factor for milling heads as well because yes you reduce the "squish" area on top of the piston but you also reduce the flow area above the valves as well. I have a pair of 239's and a pair of 255's laying around so I have test parts available to do simple rotational tests for seeing what goes on. Also being a higher lift cam for the slightly more aggressive Isky they mention checking valve to head clearance as well. Hopefully somebody can chime in on their experiences with popup Pistons and how high the compression is raised. Different HP heads? Well such heads and intakes are not very common up here in Canada and perhaps more can be accomplished using popup Pistons whether they be special high performance or just a stock 239 stuck in to be used, that and a better civilized camshaft.
This would be indicated by having this car since the early 80's and using 110 hp for all those years. By some chance do you know the specs of that better Ford OEM cam and how does it compare to those Isly's? They also increased the compression to 7.5 in the latest and HP was 125 HP OEM as well and I should check my heads to be sure what I got but I'm sure I have a pair like you mentioned. 25-35+ HP shouldn't be that difficult to achieve on these and as it is I have been digging around for info on popup pistons as well. OlRon mentioned he has used 239 Pistons in the 255 as well after I was always thinking about this. He never went into much detail about using them and my future experiment that I hope to do is drag one of my cores into the shop and place a 255 crank into it with a 239 piston without rings and place a head on it doing a crush test to measure the clearance. One fellow at Isky I talked to mentioned compression is a very big factor for how the cam behaves and what it can do as well. Then there is the argument of reducing the stoke with a 239 piston but in reality the bottom of the stroke is reduced but the end result is the chamber is also reduced at TDC of compression. This is probably a bigger win win situation than worrying about a 1/4 inch reduction of BDC anyway! I have also read this is a factor for milling heads as well because yes you reduce the "squish" area on top of the piston but you also reduce the flow area above the valves as well. I have a pair of 239's and a pair of 255's laying around so I have test parts available to do simple rotational tests for seeing what goes on. Also being a higher lift cam for the slightly more aggressive Isky they mention checking valve to head clearance as well. Hopefully somebody can chime in on their experiences with popup Pistons and how high the compression is raised. Different HP heads? Well such heads and intakes are not very common up here in Canada and perhaps more can be accomplished using popup Pistons whether they be special high performance or just a stock 239 stuck in to be used, that and a better civilized camshaft.
Pete
BANNED
Hi Pete and thanks for reply!! Yes I see that all the time and they are TOTALLY unsuitable for street and at times the vacuum accessories don't work as well. A slight Lopey idle I can live with and my guess is the slightly more aggressive version I listed is perhaps that kind that will have a slight gallop of the idle perhaps not making the car shake?? Nope I'm most certainly not looking for massive increase but just a bit of a warming up
For cam comparison specs go to the Tilden website.
As far as pop up pistons, forget it. You can get way more compression than you need on the street by just milling and matching the dome to the pistons, with stock heads.
Ronnieroadster
Well-known member
All of the above information is great BUT unless you check the cam timing as advertised on the timing card the true events will never be known. I have found as an example on an Isky cam advertised at a 111 C/L it was actually at 115. To determine if there was possibly an issue with the new cam gear bolt holes being in a different location causing the problem I put an original Ford cam gear on after doing this the results were the same a 115 C/L.
Since its not a simple task to alter the cam timing events on the Flathead with bolt on gears few will ever check their cam to the manufacturers timing information most just take the cam from the box and slide it into their Flathead. When I run into this issue with a cam I do correct it by altering the bolt holes and bushing each hole to the correct position. Not a simple task but one thats worth the effort.
Ronnieroadster
Since its not a simple task to alter the cam timing events on the Flathead with bolt on gears few will ever check their cam to the manufacturers timing information most just take the cam from the box and slide it into their Flathead. When I run into this issue with a cam I do correct it by altering the bolt holes and bushing each hole to the correct position. Not a simple task but one thats worth the effort.
Ronnieroadster