I'm back! ( cylinder head questions about my 200)

[Sedanman]

Hi guys!

It's been a long time - and a long and winding road. But I'll skip all that and get down to business; If I ask something that's been covered since I was here a few years ago, sorry - I have a pinched nerve and can't spend a lot of time on the computer searching the archives. Hopefully my good Ford Six karma from 4 or so years ago of helping others will come around to help me this time

In the time since I was last here, I installed a low mileage '68 200 with a '69 head in my '64 Sedan (C-4 trans, 3.0 8-inch rearend). My guess is it has about 6-8k miles on it, but mileage with my 170 carb is a dismal 14mpg. The engine had a 170 carb on it when I bought it, and I used the better one off my previous 170. Better is a relative term here! After trying several parts store rebuilt Carters that made great power but ran way too lean, I ordered and now have a new 1101 for a 250 from Pony Carbs to match my larger intake log and carb hole.

I had a shop test it last week, and here's the stats; 13%,17%,15%,4%,5%,10% on the leakdown, 155,160160,160,150,155 on the comp. test. He said even if all cyl were 17%, that would be good. In a sick way I was hoping he'd find something wrong so I could fix it - burnt valves or something.....

Anyway, I'll be pulling the head off as some manifold bolts are broken and need to be extracted. The goal is to have it back on before Aug. 30th for a car show. I want to improve mileage and torque, so here's the questions;

1) Milling:If the motor has already been rebuilt at least once, what is a "safe" amount to mill the head? Ford six guide says " Heads can be milled as much as .090;060 leaves room for error/thin casting or increased lift/dur. cam". My cam is stock for now, but am considering the 1.6 rocker assembly later when I can afford it. Is there a standard amount most heads get milled during standard re-surfacing?

2) Rocker assembly: Since I'm milling the head, I know I need to go to adjustable rockers. I have two sets - one from my old 170 ( adjuster nuts never stayed tight even after replacing), and one from my '65 200 that has a lot of miles on it. How to tell if they need rebuilding/replacement?

3) Valves: If I'm running a stock cam and an 1101 one barrel (with the big venturi), single 2 inch exhaust with stock manifold, how much am I going to gain by putting in the larger valves I've heard so much talk about in the past? This is the medium sized log intake - not the early 80's head. Trying to figure out if the cost is justifiable. I'd rather save money if it's not going to make a huge difference and put it into my suspension.

4) Porting/polishing: I have the original first edition of the FSP guide by Schjeldahls which makes several suggestions; Since I don't have a lot of time for grinding (maybe 2 weeks) and doing everything, if I did do some porting/polishing where should I focus my time; In the exhaust manifold and ports, opening up the carb hole for better flow, unshrouding valves, or polishing the combustion chambers? Unless I go with the bigger valves (only if current ones are burnt), I won't be pulling them and working in the intake ports.

Polishing the combustion chamber lowers comp. ratio, so with not knowing how many times the head has been milled this is all an inexact science. Which is more important in a mild engine, compression or polished chambers? The ford six guide does not give combustion chamber sizes for the or compression ratios with the '69 head. I'm not sure if my head is a 200 or 250 - Casting #s are 0J24 C9DE 6090 M

5) Port divider - I've seen several debates on this in the past, but it's been a few years and would like to know the latest opinions on this topic; Is the small (if any) gain in power on a very mild engine worth all the grinding that's needed? I've heard it takes hours to get them to fit. And what is the best method of holding it in place; I've heard of welding it, epoxy, or some just using the manifold to hold it in place.

6) 1.6 Ratio rockers: Is this worthwhile given the cost and mild carb/exhaust combo I'm running? Will it hurt mileage? Will it be too "radical" for a turbo later? I'm not puting a header on - car is very low, and I may eventually go to a turbo so don't want to wast my $ there.

7) Carb heat shield. It was 103 degrees here the other day (unusual for Seattle), and within ten minutes of driving the car was running rough and stalling - the temp guage was not pegged, but I could tell this was carburetor boiling. I've already re-routed the heater hoses from away under the carb, but the issue of heat from he exhaust rising to the carb concerns me here. Has anyone made any kind of heat shield that reduces manifold heat raising up under the carb?

I don't have a lot of money to spend, so my focus is on trying to improve driveability/torque, and hopefully gas mileage. Down the road if I strike it rich, then I'll go for a 2-V head and turbo I've already done the carb and ignition tuning and she's running as lean and clean as can be, but will probably have the dist. re-curved at some point.

Thanks!

 

[Lazy JW]

I don't have a lot of money to spend......

Keeping this in mind:

Your compression is good; this indicates that the valves are good also. Leave 'em alone.

If you really, really want to, go ahead and mill the head. With those compression numbers, I wouldn't even pull the head were it mine.

Polishing the chambers is cheap if you do it yourself and have LOTS of time to spend on something that will give oh-so-very little benefit in a basically stock engine. As mentioned above, I wouldn't even spend the money for a new gasket on an engine with compression numbers that good.

Same goes for the port divider. Lots of work, relatively small gain and you can't do it without pulling the head. You already have a good engine there Bro, and you did mention not having bundles of cash.

1.6 ratio rockers: This is one thing I would consider doing; reason being it will transfer to a new head later on and will give some improvement now. Not as much gain as if you pulled the head did EVERYTHING to it (which is the best way to get maximum benefit).

Carb shield: definitely do it.

I also question your distributor advance curve; 14 mpg is pretty poor for an engine in that condition with a good carb.

Have fun,
Joe

 

[powerband]

[quote="Sedanman"]Hi guys!
....

I'll be pulling the head off as some manifold bolts are broken and need to be extracted. The goal is to have it back on before Aug. 30th for a car show. I want to improve mileage and torque...I don't have a lot of money to spend, so my focus is on trying to improve driveability/torque, and hopefully gas mileage. Down the road if I strike it rich, then I'll go for a 2-V head and turbo I've already done the carb and ignition tuning and she's running as lean and clean as can be, but will probably have the dist. re-curved at some point.

Thanks![/quote]



My .02 :

> If your primary goal is fix the manifold bolts and back together in time for a show , you are in good shape. The stats on your engine and modest goals should get you back on road within the abilities of the critical remove/install person. Taking head off is best for manifold fastener repairs and will reveal latent defects and give an opportunity to measure for additional modifications to be considered. Careful application of CR Calulator formula will add to predictable results.

When you take head off try to determine (pics please if possible) if an original steel shim gasket is in place or replacement. This critical gasket thickness effects overall performance warrants addressing . AFter removal and inspection you'll have info, machine shops typically can inexpensively fix manifold flanges, mill to planned CR spec , related head work.. A set of rocker arms you can have confidence i is good thinking. Port divider is cheap and ready to install while head is accessible.



start simple, have fun ...

 

[JackFish]

My thought s on #2.
You do not need an adjustable rocker set because you've milled the head.
You can use shorter pushrods or washers under the rocker bolts.
The 1.6 roller arms are what, like $450, for about 2hp. at the most. Total cool factor though!

 

[rbohm]

Hi guys!

It's been a long time - and a long and winding road. But I'll skip all that and get down to business; If I ask something that's been covered since I was here a few years ago, sorry - I have a pinched nerve and can't spend a lot of time on the computer searching the archives. Hopefully my good Ford Six karma from 4 or so years ago of helping others will come around to help me this time

welcome back.

I had a shop test it last week, and here's the stats; 13%,17%,15%,4%,5%,10% on the leakdown, 155,160160,160,150,155 on the comp. test. He said even if all cyl were 17%, that would be good. In a sick way I was hoping he'd find something wrong so I could fix it - burnt valves or something.....

your compression numbers are just fine, its your leak down numbers that concern me. i agree that anything under 20% is fine, but the variance is quite strange. usually leak down numbers are consistent with compression numbers as far as the variance goes. i suspect that the guy made some mistakes doing the leak down test.

1) Milling:If the motor has already been rebuilt at least once, what is a "safe" amount to mill the head? Ford six guide says " Heads can be milled as much as .090;060 leaves room for error/thin casting or increased lift/dur. cam". My cam is stock for now, but am considering the 1.6 rocker assembly later when I can afford it. Is there a standard amount most heads get milled during standard re-surfacing?

as i recall most heads get a cut of about .010" just to flatten out the gasket surface. i would mill the head .050" to compensate for the thickness of the composite gasket and call it done.

3) Valves: If I'm running a stock cam and an 1101 one barrel (with the big venturi), single 2 inch exhaust with stock manifold, how much am I going to gain by putting in the larger valves I've heard so much talk about in the past? This is the medium sized log intake - not the early 80's head. Trying to figure out if the cost is justifiable. I'd rather save money if it's not going to make a huge difference and put it into my suspension.

there is a gain when installing larger valves in any engine. in these engine any increase in airflow to the cylinders is always good, just dont go too large on the valves as you will hurt low end torque. a 1.75in/1.50ex is as big as you want to go unless you are going to the classic inlines aluminum head, then the 1.88in valve wont hurt anything.

4) Porting/polishing: I have the original first edition of the FSP guide by Schjeldahls which makes several suggestions; Since I don't have a lot of time for grinding (maybe 2 weeks) and doing everything, if I did do some porting/polishing where should I focus my time; In the exhaust manifold and ports, opening up the carb hole for better flow, unshrouding valves, or polishing the combustion chambers? Unless I go with the bigger valves (only if current ones are burnt), I won't be pulling them and working in the intake ports.

put your time in the exhaust side porting. you want to enlarge the runners to fit the gasket, but you also want to avoid breaking through to the water jacket in the ports, so blend the opening back into the port as smoothly as possible. you only need enlarge the first(last?) 3/4" of the port itself. you also want to smooth out the valve bowls, and thin out the valve guide, while shaping it for minimum restriction. you also want to remove all the sharp edges in the bowls by blending them as smoothly as possible.

Polishing the combustion chamber lowers comp. ratio, so with not knowing how many times the head has been milled this is all an inexact science. Which is more important in a mild engine, compression or polished chambers? The ford six guide does not give combustion chamber sizes for the or compression ratios with the '69 head. I'm not sure if my head is a 200 or 250 - Casting #s are 0J24 C9DE 6090 M

dont worry about polishing the chambers to a mirror like finish, they will just carbon up as the engine gets time on it. you can however smooth out the casting bumps to where they feel smooth to the touch. this actually helps combustion even though you might lose as much as .01 points of compression.

5) Port divider - I've seen several debates on this in the past, but it's been a few years and would like to know the latest opinions on this topic; Is the small (if any) gain in power on a very mild engine worth all the grinding that's needed? I've heard it takes hours to get them to fit. And what is the best method of holding it in place; I've heard of welding it, epoxy, or some just using the manifold to hold it in place.

install the port divider, then port the center ports to make them even with the other ports. as for how to install it, weld it in place. tha tis the most secure way to go.

6) 1.6 Ratio rockers: Is this worthwhile given the cost and mild carb/exhaust combo I'm running? Will it hurt mileage? Will it be too "radical" for a turbo later? I'm not puting a header on - car is very low, and I may eventually go to a turbo so don't want to wast my $ there.

1.6 rockers are a cheap way to pick up about 8% more lift, and about 3 degrees more duration. again with these engine anything you can do to improve airflow into the cylinders is always good. the other advantage is that you dont have to install a cam with longer duration that may make the car less drivable to get the same lift. you can even go one step further and put a 1.6 rocker on the exhaust side, and a 1.5 rocker on the intake side and make your own dual pattern style cam, or augment a dual pattern cam.

7) Carb heat shield. It was 103 degrees here the other day (unusual for Seattle), and within ten minutes of driving the car was running rough and stalling - the temp guage was not pegged, but I could tell this was carburetor boiling. I've already re-routed the heater hoses from away under the carb, but the issue of heat from he exhaust rising to the carb concerns me here. Has anyone made any kind of heat shield that reduces manifold heat raising up under the carb?

install a heat shield. the problem is the carb is located right over the 3 and 4 exhaust ports, and that heat is what causes fuel boiling in the carb. headers will hel aleviate the problem as well.

I don't have a lot of money to spend, so my focus is on trying to improve driveability/torque, and hopefully gas mileage. Down the road if I strike it rich, then I'll go for a 2-V head and turbo I've already done the carb and ignition tuning and she's running as lean and clean as can be, but will probably have the dist. re-curved at some point.

Thanks!

save your money until you can afford the classic inlines aluminum head. the cost is going to be about the same when you factor in rebuilding a used aussie head.

 

['68falconohio]

This pic isn't of your casting code, but there aren't any pics of the exhaust side in the porting sticky.

 

[Lazy JW]

.......

Anyway, I'll be pulling the head off as some manifold bolts are broken and need to be extracted.....

Somehow I overlooked that statement
I am still loathe to pull the head off a good engine. I prefer to buy some left-hand drill bits and have at it rather than pull the head, but that's just me.
Joe

 

[Sedanman]

Thanks for the quick responses, guys. As usual there are some different opinions shared and that's okay.

JackFish - Regarding the 1.6 rocker assem. and price, I think it's listed at $325 including $50 core charge, so that would come out to $275, not a bad deal for bolt on performance. I just don't want my mileage getting worse. Regarding the shorter pushrods, the six manual said they were hard to find, and since I have two adjustable assemblies in my garage...

rbohm -

put your time in the exhaust side porting. you want to enlarge the runners to fit the gasket, but you also want to avoid breaking through to the water jacket in the ports, so blend the opening back into the port as smoothly as possible. you only need enlarge the first(last?) 3/4" of the port itself. you also want to smooth out the valve bowls, and thin out the valve guide, while shaping it for minimum restriction. you also want to remove all the sharp edges in the bowls by blending them as smoothly as possible

Thanks, the exhaust porting was my next question, as far as how far to go back inside. Should I go staight back, or taper from the opening? Six guide to says to open the exhaust manifold openings slightly larger than gasket size. The valve bowls and guides is probably something I'll skip, due to time constraints and lack of experience as well as the tools to remove the valves.


Joe - I've dealt with trying to extract broken exhaust bolts before. I'd rather pull the head and get it milled than try that again

your compression numbers are just fine, its your leak down numbers that concern me. i agree that anything under 20% is fine, but the variance is quite strange. usually leak down numbers are consistent with compression numbers as far as the variance goes. i suspect that the guy made some mistakes doing the leak down test.

I noticed that too after getting home and looking at the paperwork - he was in a hurry to close when I got there. I'll give him a call. But unless the rings are really bad, I'll go ahead with this stage 1 head project as the noisy exhaust manifold leak is just getting embarrassing.

install a heat shield. the problem is the carb is located right over the 3 and 4 exhaust ports, and that heat is what causes fuel boiling in the carb. headers will hel aleviate the problem as well.

Anybody have any photos of such a thing? I'm really not much of a fabricator so it would be pretty crude...

dont worry about polishing the chambers to a mirror like finish, they will just carbon up as the engine gets time on it. you can however smooth out the casting bumps to where they feel smooth to the touch. this actually helps combustion even though you might lose as much as .01 points of compression.

It's been awhile since I've looked at the bottom side of a head - specifically what casting bumps are you referring to? I did see mention in the Ford six guide about unshroudling valves enlarging the combustion chamber volume/lowering compression - would that be more than the .01 stated above?

As for the exhaust port divider debate, it appears to be continuing. It's cheap to buy, but how many hours of grinding does it take to get a good fit? Last I heard it was more than a few, but maybe the casting has improved recently...

 

[powerband]

From an old post...

The factory info that came with my Hooker Super-Comps installation kit included header bolts, gaskets and the port divider. Hooker has a detailed installation guide to install Port DIvider: Grind it carefully to match your engine and be sure to leave a few thousandths projecting past the block for the headers to lock it in with an interference fit.

The benefits of the divider aside, while you have the head handy ( :| ) , You may take minutes with chalk and a grinder then you can install or save for later mods...

Have Fun,

thumb:

 

[rbohm]

Thanks, the exhaust porting was my next question, as far as how far to go back inside. Should I go staight back, or taper from the opening? Six guide to says to open the exhaust manifold openings slightly larger than gasket size. The valve bowls and guides is probably something I'll skip, due to time constraints and lack of experience as well as the tools to remove the valves.

you want to blend it back in a taper. unless you take the time to cut up a few junk heads, you wont have an yidea how thick the port walls are going back to the valve bowls. they are generally thickest near the port opening.

I noticed that too after getting home and looking at the paperwork - he was in a hurry to close when I got there. I'll give him a call. But unless the rings are really bad, I'll go ahead with this stage 1 head project as the noisy exhaust manifold leak is just getting embarrassing.

with the compression numbers you engine put up, i doubt there is any issue in the short block.

Anybody have any photos of such a thing? I'm really not much of a fabricator so it would be pretty crude...

usually a heat shield is a simple metal plate that blocks heat from getting to the carb. check on summit racings website as they show pictures on heat shields used on 4bbl carbs. something similar can be used on out engines.

It's been awhile since I've looked at the bottom side of a head - specifically what casting bumps are you referring to? I did see mention in the Ford six guide about unshroudling valves enlarging the combustion chamber volume/lowering compression - would that be more than the .01 stated above?

when you look at an as cast part, it is loaded with peaks and valleys that mimick the casting sand used in the casting process. you want to smooth that out, but dont worry about a mirror finish.

As for the exhaust port divider debate, it appears to be continuing. It's cheap to buy, but how many hours of grinding does it take to get a good fit? Last I heard it was more than a few, but maybe the casting has improved recently...

it will take a couple of hours to get the fit and finish right. but when porting the heads, dont be in a hurry.

 

[Sedanman]

So the finned part goes inside? I would think that would cause leaking between the two sides. Getting ready to inhale lots of metal... :0)

rbohm - what about the ends of the log where the freeze plugs are - can you fit a grinder in there to do any good? I haven't looked down my carb hole recently, but if I recall correctly the casting was rough on the front and rear ends of the manifold going to the end cylinders.

 

[rbohm]

So the finned part goes inside? I would think that would cause leaking between the two sides. Getting ready to inhale lots of metal... :0)

blend it as smoothly as you can. as for leaking from one side to another, like water and electricity, air will follow the path of least resistance.

rbohm - what about the ends of the log where the freeze plugs are - can you fit a grinder in there to do any good? I haven't looked down my carb hole recently, but if I recall correctly the casting was rough on the front and rear ends of the manifold going to the end cylinders.

you can remove the plugs at the end of the log and use a long sanding roll to smooth out the inside of the log.

as for getting ready to inhale a lot of metal, you dont know the half of it. do yourself a big favor and wear a surgeons mask while working on the head, that way you will avoid inhaling the metal particles.

 

[BIGREDRASA]

As much as my poll on the divider failed to convince me one way or the other, I'm planning to install one with my "new" D7 head. I'm actually more concerned about hot exhaust gasses eroding the header's flange between 3 & 4 tubes.

Powerband, do you have a direct link to the Port Divider on the Holley/Hooker site?

 

[Anonymous]

Jackfish said

The 1.6 roller arms are what, like $450, for about 2hp. at the most.

From what i've have run & had dyno tested, and read about its more like a 10 HP gain.
You should check out the dyno tests on classic inlines websites.
Yes they are costly, but they are a good investment also preventing valve guide wear & less valve train friction.
You can run what you want, but if you want to run with the big dogs you need to get off the porch. Outlaw

 

[JackFish]

This topic has been debated here before:
viewtopic.php?f=1&t=23499&p=164461&hilit=+roller+rockers#p164461

and on a stock motor there is very little hp increase.

This is certainly an interesting topic with a wide view of opinions.

First, it is a proven fact that upgrading from stock 1.5 rockers to 1.6 roller tipped rockers, on a relatively stock motor, will add approximately 2HP (not 10-12) and 2-3lbs of torque across the entire RPM range. This is achieved in two ways, the lifter opens a little higher and a little faster (adds approximately 3 degrees to the valve duration), and by reducing friction.

There is no doubt that these increases in HP and torque can be achieved by other means which cost less, but the primary advantage is the reduced friction and wear on the valve train components.

The biggest reasons for rebuilding a motor (or the cylinder head only) is when oil consumption goes beyond a desirable limit. The two main reasons oil consumption goes up, worn rings and/or valve guides, the later being the the most frequent cause. By dramatically reducing the friction on the valve stem and guides, you increase the longevity of the motor, plain and simple. The extra HP and torque is just a side benefit, and not the primary reason for going with roller tips IMO.

Why install a dual roller chain? Not for gains in HP and torque, rather increased strength and longevity. Are they worth the 30-50% extra in cost? I think most would readily agree, they are.

Yet, there are exceptions to the power gains in extreme cases.

This month, we decided to take the valve covers off for the first time and upgrade our factory stamped-steel, 1.5:1-ratio rockers with a set of 1.6:1 roller-tip versions. This will give us a bit more lift and duration and open our valves a bit faster.

Was it worth it? In our case, definitely. Once the work was done, we headed back to the chassis dyno and found almost 20-more horsepower virtually across the entire rpm range. Even with the small increase in camshaft motions provided by the rockers, the enthusiastic little engine took full advantage of its newfound breathing capabilities.

These outstanding results are not typical, however. Remember, our LT1 is motivated by a Vortech centrifugal supercharger, so our engine is much more sensitive to breathing than most. The supercharger serves as an amplifier, and where relatively small changes can have amplified results, minor problems can have a huge effect, too. Such is life with a blower motor. In our case, the 1.6:1 rocker swap was a great move, since we didn't sacrifice anything (like idle quality or driveability) but gained plenty of power. The car is more responsive and certainly more fun!

So, we were able to see a tremendous improvement in both horsepower and torque with the addition of 1.6:1 rockers over our factory 1.5:1 units. Does this mean you can expect a 20-plus-horsepower improvement by doing the same? We seriously doubt it.

 

[Sedanman]

'68falconohio - that looks like one of those human body part models in doctor's offices :rolflmao:

rbohm - just kidding about the dust - I usually go overkill and wear a respirator when doing this kind of stuff.

BIGREDRASA, littlest outlaw, and JackFish; Hmmm, maybe I shouldn't waste the time on the port divider/money on the 1:6 rockers. I was not planning on going to the roller tips, so that would negate any possible savings on of wear on the valvetrain. Sounds like it's not really worthwhile until I go to a turbo setup, in which case I'd be building another motor and probably using a 2-v head. I'd rather get this engine running right, and if I had the money put air ride under my car and paint it before really building an engine....

 

[Anonymous]

Good point jackfish, but maybe the engine that only showed a 2 HP gain only had a 1 bbl carb.

I bet an engine with a 2 bbl direct mount carb such as a 350 holley & some cam & headers would pick up possibly 10 HP using the 1.6 roller tip rockers & better yet the 1.65 full roller rockers.

Less friction also means more power. Outlaw

 

['68falconohio]

'68falconohio - that looks like one of those human body part models in doctor's offices :rolflmao: ....

It's actually sitting under my desk at work, the boss has been on me to 'disgard' it... :x He also told me I should've bought a used Hyundai instead of rebuilding an engine for my car .....He will never understand. :roll: