Isky 3/4 Max 1 Camshaft

Ronnieroadster said:
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
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A lot to be said for press-on timing gears.
 
Thanks again and speaking of stock heads and compression, this is most likely how Ford obtained a 7.5 CR on the 52-54 and the higher horsepower as well. The 6.8 on my Mercury is quite low and of course is best suited for a blown engine ;-). I have a degree wheel and this was required to time and modify the rotory intake valve plate on 2 stroke Rotax engines. The core with the EAB is possibly a 255, a Ford Reman engine from years ago but is riddled with cracks including through the valve train but it has a good crank and many other items including manifolds that fit my Merc.
 
Pete said:
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.
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How much does one dare mill the heads? Not as concerned as much about the thickness of the head and what is left but the valve flow passages or is it to the point of measuring the depth of these before and matching after milling by machining these out or is this actually not that critical compared to reducing the squish area directly above the piston? How about milling the top of the block down as well or is this a waste of time and only required for a warped or damaged surface?
 
Pete said:
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.
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Thanks for the Tilden info! Lots of reading and a great source of info!
https://www.tildentechnologies.com/Cams/FlatheadPerformance.html

It will be interesting seeing the comparison of the OEM and the Isky specs I found and posted.
 
56markII said:
How much does one dare mill the heads? Not as concerned as much about the thickness of the head and what is left but the valve flow passages or is it to the point of measuring the depth of these before and matching after milling by machining these out or is this actually not that critical compared to reducing the squish area directly above the piston? How about milling the top of the block down as well or is this a waste of time and only required for a warped or damaged surface?
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Before you go re-working a set of stock heads, you better check with your machine shop and see if they can even do them. It may be cheaper to buy a set of new Edelbrock or Sharp's.

Most shops can mill the heads now days but VERY few have the cutters to flycut the domes and over the valves and this will have to be done if you mill .080 which is the most I recommend.
This work is quite expensive even if they can do them. You will probably be over half the cost of new heads.

Even if you just take a minimum off to clean up, you will have to clay the pistons and valves on all cylinders for proper clearance.

Do not mill the block unless it is warped or damaged.
 
After more searching I found this thread and OlRon uses foil for checking for a .040-.050 cylinder head/piston clearance. Actually the engine rebuilder machine shops around here mill heads and my old C8MC heads were milled .010 back in the 80's when I first purchased the Merc and rebuilt the flattie. It was amazing how good it ran for how rough it was! Pulled the pan to find skirts laying in the pan. A typical Ford Flathead, they run forever and don't die! Been a loooooong time since I looked at milling heads on a Flathead and other than that remember hearing a local old timer mention he had one car with stacked head gaskets because the piston hit the head. Perhaps somebody by mistake put 239 Pistons in a 255?

https://www.fordbarn.com/forum/showthread.php?t=137982&showall=1

Of course a forum called Fordbarn would be a good source!
 
The cost of milling the heads here would be less than purchasing from the United States so this is most likely the most logical option! Living in the Snow Mexican republic of Canuckastan means I'm dealing with (if I'm lucky) a $0.74 dollar plus exchange surcharges and this applies to both the item and shipping! Can somebody tell me what the real difference is between the 8CM and perhaps EAB heads? The newest of the flatties had a reported CR of 7.5 compared to my aniemic 6.8 which in reality is probably lower as others have mentioned. The C8CM heads are still on my Mercury and in the future I'm forced to pull them to adjust my valve clearance!! Adjustable $h!t lifters can be adjusted by removing the intake but this will be a TOTAL waste of time due to creeping so I'm forced to remove the lifters, remove the adjuster bolt and compress it in a vice to increase thread resistance and there is not enough room to lift them out unless I remove the heads, remove the valve guide retainer and lift the valves. I will NEVER use these again! Other than a degree wheel and figuring out the duration of the cam, did Ford ever stamp an ID number on their camshafts? I have an EAB core heavily infested with cracks and it was one of those Ford authorized rebuilds so there is no guarantee the camshaft is an original EAB cam.
 
56markII said:
The cost of milling the heads here would be less than purchasing from the United States so this is most likely the most logical option! Living in the Snow Mexican republic of Canuckastan means I'm dealing with (if I'm lucky) a $0.74 dollar plus exchange surcharges and this applies to both the item and shipping! Can somebody tell me what the real difference is between the 8CM and perhaps EAB heads? The newest of the flatties had a reported CR of 7.5 compared to my aniemic 6.8 which in reality is probably lower as others have mentioned. The C8CM heads are still on my Mercury and in the future I'm forced to pull them to adjust my valve clearance!! Adjustable $h!t lifters can be adjusted by removing the intake but this will be a TOTAL waste of time due to creeping so I'm forced to remove the lifters, remove the adjuster bolt and compress it in a vice to increase thread resistance and there is not enough room to lift them out unless I remove the heads, remove the valve guide retainer and lift the valves. I will NEVER use these again! Other than a degree wheel and figuring out the duration of the cam, did Ford ever stamp an ID number on their camshafts? I have an EAB core heavily infested with cracks and it was one of those Ford authorized rebuilds so there is no guarantee the camshaft is an original EAB cam.
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To help you solve the loss adjuster thread issues when i run into that problem i simply clean the threads with brake cleaner to get rid of any oils i then use red Locktite placing a drop of Locktite on the adjuster thread at the location of the lower and upper thread and then reinstall the adjuster. Now after you have your clearance set the Locktite will hold the adjuster perfectly. It will take some effort in the future to move the adjuster for future adjustments when needed but its not difficult and you will find it will solve your problem.
Ronnieroadster
 
Every cam regardless of brand/mfr should at least be degree-checked at a minimum. Most will be "nominally" correct, if you find it way off it needs to be addressed.

We check every one we install and go as far as modifying the cam AND the cam gears to accept a SBC/BBC cam "pill", this allows the cam to be moved a fair amount! These pills come in 0*, 2*, 4*, 6*, and 8*.

Thanks, Gary in N.Y.

P.S. Here's a shot (again) of a finished cam/cam gear, not really all that difficult to do!
 

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We milled the block back in the day when our race car was torn down at the end of a race to be sure it was stock !! Just saying.
 
Kerk said:
We milled the block back in the day when our race car was torn down at the end of a race to be sure it was stock !! Just saying.
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Problem with that method is the flathead blocks have a fairly thin deck to begin with.
 
One thing you should be aware of is: The compression ratio charts should be taken with a grand of sand. They vary all over the place. Measure them.
 
philipswanson said:
Don't you mean a grain of salt???
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No, he meant what he said. The old saying goes as you mention but he means a whole beach full of sand. In other words, charts are meaningless except for bench racing. They give a lot of micro info that is useless in the real world.
The only way to really know is to measure the chamber with a burette tube and some juice WITH THE HEAD ON and if you are going to this extent, you have to have measured the stroke with a dial indicator to get it to .001 TIR.

On a street engine if you are off chamber to chamber by 1/2 cc, you won't feel it in the seat of the pants but on an all out engine it could be the difference between 1st and 2nd place.
 
I have a method for measuring the compression out to several decimal places. I posted it here but nobody waz interested. It only works when the engine is on a stand , so you can level it. The process goes like this: accurately measure the size of the combustion chamber. Place a used gasket on the block and install the head tighten it down. Make sure the piston was on the compression stroke and a quarter inch from the top. Now screw the measuring gauge into the spark plug hole. Now for the results. Pore into the new gauge the amount of fluid for the volumn of the chamber. Now move the piston up to TDC. no fliud in the gauge, yet. Now add fluid into the new gauge untill to regesters on the gauge. By rocking the piston you can find TDC and the amount of fluid you had to add to the chamber to get the exact size of the combustion chamber. This usual requires about 15 more cc's.
For gustamating the CR I just add 15 cc's to the chamber volume and use it/ So If you have a 65cc Edelbrock head, then the chamber is aprox 80 CC and the CR is much lower than you thought. When I waz younger I did allot of "Stuff" like this.
 
Ol' Ron said:
I have a method for measuring the compression out to several decimal places. I posted it here but nobody waz interested. It only works when the engine is on a stand , so you can level it. The process goes like this: accurately measure the size of the combustion chamber. Place a used gasket on the block and install the head tighten it down. Make sure the piston was on the compression stroke and a quarter inch from the top. Now screw the measuring gauge into the spark plug hole. Now for the results. Pore into the new gauge the amount of fluid for the volumn of the chamber. Now move the piston up to TDC. no fliud in the gauge, yet. Now add fluid into the new gauge untill to regesters on the gauge. By rocking the piston you can find TDC and the amount of fluid you had to add to the chamber to get the exact size of the combustion chamber. This usual requires about 15 more cc's.
For gustamating the CR I just add 15 cc's to the chamber volume and use it/ So If you have a 65cc Edelbrock head, then the chamber is aprox 80 CC and the CR is much lower than you thought. When I waz younger I did allot of "Stuff" like this.
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Then in reality with such a large variation in cylinder head combustion chamber size one might as well place a piece of plexiglass over the head, carefully fill and measure the volume to "try" to determine size after all if the engine is still in the vehicle you would be SOL using the installed head method. One thing I find totally annoying is when the question is asked about results, the response is disappointing to say the least. "It made a slight difference" or "it made quite a large difference" quite simply just doesn't cut it!! Difference to what?? "My car went X miles per hour before and now does X miles per hour after" would most certainly make more sense!! How about zero to 60 in X amounts of seconds before and after as well. It is as rediculous as the specs I posted earlier from Speedway of the Isky camshafts stating good idle blah blah or idle with hot rod sound is TOTALLY meaningless to me. Throw a blue bottle or glass pack on and run the idle rich and you will have the same hot rod sound! In reality if they are manufacturing camshafts to fit a 1949-54 239 or 255 take a 239 or 255 in new stock condition which is most certainly not hard to do, place it on a dyno and measure torque and horse power. NOW take the same engine and install an Isky 450-811100 and go through the same procedure again. Next since these companies sell performance heads and intakes intall these and again place on the dyno. THESE are "real" numbers and facts and in reality are just tooooooo much to ask for instead of wasting unnecessary time and money. As mentioned before numerous people over cam or carburete their engines resulting in a total street unfriendly vehicle. Now as for cylinder heads, what about compression before and after? Slap a compression tester on a good or rebuilt engine and measure. Next remove the head and unless the chamber volumn is accurately known CC the head. CC the head to be replacing the stock OEM head, install. And again also measure the compression using a compression gauge. Now as advertised Isky mentions the 450-811100 and the 450-817700 are designed to work with OEM stock Carburetion so their story goes and if one wants to warm up a flathead mildly or moderately this shouldn't be that hard to provide more usable information, should it? BTW I am still looking for a source of Ron's book as I have purchased 3 books already and out of the 3, two of them provided the same information as just purchasing a good shop manual, whether it be a Motors manual or OEM and other than this also provided some porting info. The third was TOTAL radical specs of full drag strip too the point of shoveling thousands of $ into an engine which many most certainly cannot afford. This is my rant for today for good reason because if one is on a bit of a budget taking small steps would be a good idea hopefully in the right direction.
 
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