Cylinder Head

[bucfan1234]

I would like to upgrade down the line with a cam cylinder head combo. I have read just baout all of the tech and stickies here, and I know by now that I cant afford the aluminum product for my ride.

I'd like a low end power cam, and I think the most I would want to rev would be 5000 or 5500. The car is not a daily driver, but still street, so it can be fairly aggressive. I have a C-4 (would consider a T-5, but keeping the C-4 for now)

So? Here are the two questions that I have for my budget.

What is the best late model large log cylinder head for me to be on the lookout for to use in this project? Year, vehicle, from a 200 or 250?

I also was planning to upgrade to 302 springs, adjustable 1.6 rockers and a cam.

Second question? What cam should be focused on for my goal. I'd like a good all round maybe something from 500 - 5000? Don't know new to this. I gather from the tech that with my auto I need to stay away from 109, but can I run 110?

Basically I need a plan, then a list, then to save up to make it happen on the cheap. Can you guys help me by clearing the muddy water of all the choices to narrow down to the best way for me to go?

Thanks in advance.

 

[rbohm]

8) any of the later large log heads will do just fine. pick one from like 1972 on. if you want a decent performance head without spending a lot of money, when you get the head you want ship it here and have mike's people go through the head for you;

http://classicinlines.com/HeadWork.asp

as for cam selection, check out that same site for a line of cams ground by clay smith. when you pick a cam, pick one that works in the rpm range where the engine will spend about 80% of its time. for a street six that means between 1500-5000 rpm. lobe separation choice will depend on what compression ratio you are wanting to use, lower compression use a wider lobe separation.

 

[bucfan1234]

Thanks. I am still learning and confused but that helps. I am planning to run near stock 1967 CR which around 9:1 right? This would let me continue to run 89 or 93 right?

What kind of gains could I expect with a modified late model log, direct 2v, 1.6 rockers and say:

264/264 112?

How would that compare to 264/264 110 and 264/274 112 ans 110.

Those all seem like they are in that rpm range, but I gather from what I have read that the 110 LC would bring in the power earlier in the rpm range. Is that right?

 

[JackFish]

Just to clarify, the 200 and 250 share the same head.
I have the 264/274 with a 112 lobe center. The 112 is recommended if you are using an automatic transmission.
I have it installed straight up, and I wouldn't describe it as a great street cam installed that way.
If the cam was advanced that would bring the torque curve down somewhat, but I can't speak from personal experience on how it performs there.
I can say that this cam doesn't really even start to turn on until you're already going about 60mph, and all the way up over 100mph. 8)
And since you want 1.6 rollers you can probably go to a more torquey cam and still get it to breathe.
I'd recommend going with a cam package that includes dual valve springs and retainers.
And get the double roller chain.

Oh and I have a 3.08 rear with a C4. It will NOT burn rubber!

 

[falcon1963]

Install a cylinder head later than a 78, mill it .070" to get the chamber cc's down to close the 50-52 cc's install a direct mounted carb on the log & install an Isky 262 camshaft with valve springs at least 100# seat pressure.
The stock 302 springs are too weak for a performance camshaft.
For a direct mount at least use a holley 350 2bbl or a autolite 2bbl in the same flow rating. Falcon Man

 

[AzCoupe]

JackFish,
You definitely need to pull your timing cover and degree your cam. If you installed it straight up, dot to dot, it could be retarded several degrees. Based on what your saying, I think you'd see a huge improvement in low end power. I'll even lend you my cam degree kit and a video that shows you how to do it. All you need to supply is the labor and gaskets.

Bucfan1234,
If your on a tight budget, go with a late model head (72 on), a 2V conversion, oversized valves, and do as much port work as possible. You'll be suprised by the increase in performance, especially with a good street cam and headers. Don't forget to upgrade the ignition as well.

As for valve springs for street use, we now carry a 302-HP spring that has 100lbs of seat pressure and 270lbs open (stock 302 springs are 80lbs/200lbs). However I also prefer the dual springs, which are 110lbs/260lbs.

As for rocker arms, were pretty close to releasing our own line of high ratio, roller tipped, rocker arms. The first batch will be 1.65, but we're also going to offer them in 1.6 and 1.73 ratios. We plan to offer the rockers in kit, which includes the rocker arms and a new shaft, or as a complete assembly. Price for the kit will be around $300-350, while the completed assembly will be around $375-425, we're just not sure yet. This is quite a bit cheaper than the current price of $565 for a complete assembly, which we can't even get anymore. The manufacturer just doesn't want to make them anymore, so we decided to make our own.

Here's a pic of the first samples

 

[bucfan1234]

Thanks everyone. I think a plan is developing.

AZ Coupe:

I will be on the lookout for a head to have worked on, and I am interested in your new product at the lower price. Any idea when they will be available? Will I need to wait for the 1.6 or will the 1.65 work? Do I need to change the valve springs to use the rockers or can I wait and just use the new spring on the new head?

Sorry if these are dumb questions, but like I said, I am learning. Also what cam would you recommend AZCoupe. My stang is not a daily driver so economy isn't that big of a concern.

And one unrelated question? Can the gears be changed in the 7.25? or will I need to find an 8" rear end to replace it if I wanted to go to 3.55?

By the way that yellow 69 is awesome!! Makes me wish I still had my 1970.

 

[rbohm]

8) how lobe separation works. take a cam, any cam it doesnt matter, lets say the lobe separation angle is 110 degrees, typical street cam. if you narrow the lobe centers to 108 degrees, you lose cylinder pressure as valve overlap increases. this lowers the dynamic compression ratio, without changing the static ratio. static compression ratio is set based on what the total cylinder volume is with the piston at bottom dead center divided by the total cylinder volume at top dead center. dynamic compression ratio it more complex as it takes in a number of variables. when you lower the dynamic compression ratio, it tricks the engine into thinking it has less compression ratio than it really does at lower rpms. when you widen the lobe separation angle the opposite is true, go from 110 degrees to 112 degrees, and you increase the dynamic compression ratio, especially at lower rpms, thus tricking the engine into thinking it has more compression ratio than it really has.

the end result is this, lets say you build an engine, and you calculate the static compression ratio at 9:1. you decide that you want more low end power but you dont want to raise the compression ratio, so what you do is select a cam that has wider lobe centers.

i realize that cam selection is a mystical science, and even the pros make the wrong call from time to time even using a computer to help them. in your case i would recommend using a dual pattern cam with 264in/274ex duration, and .450 valve lift. if you are running an automatic, use the 112 lobe separation angle, a manual trans can use the 110 lobe centers.

here is an excellent article on this subject;

http://classicinlines.com/CompressionR.asp

 

[JackFish]

AZCoupe - I did degree the cam and it spec'ed out OK.
The lack of bottom end power can be related to the fact I still have only a 1bbl Holley 1946 on it, and the 3.08 rear. And when I say "lack of" I mean it in a relative sense, compared to my previous engine which was stock, but had the cam advanced 4 degrees. So it has a "slower" response to the throttle off the line, but the real power and difference in this cam is on the top end for sure. My old engine used to top out at about 85-90mph and 4000rpm. I buried the speedo at about 120mph the other night and it was still asking for more. I'm ok with it because I wanted a strong highway car, not a street car.

 

[falcon1963]

8) how lobe separation works. take a cam, any cam it doesnt matter, lets say the lobe separation angle is 110 degrees, typical street cam. if you narrow the lobe centers to 108 degrees, you lose cylinder pressure as valve overlap increases. this lowers the dynamic compression ratio, without changing the static ratio. static compression ratio is set based on what the total cylinder volume is with the piston at bottom dead center divided by the total cylinder volume at top dead center. dynamic compression ratio it more complex as it takes in a number of variables. when you lower the dynamic compression ratio, it tricks the engine into thinking it has less compression ratio than it really does at lower rpms. when you widen the lobe separation angle the opposite is true, go from 110 degrees to 112 degrees, and you increase the dynamic compression ratio, especially at lower rpms, thus tricking the engine into thinking it has more compression ratio than it really has.

the end result is this, lets say you build an engine, and you calculate the static compression ratio at 9:1. you decide that you want more low end power but you dont want to raise the compression ratio, so what you do is select a cam that has wider lobe centers.

i realize that cam selection is a mystical science, and even the pros make the wrong call from time to time even using a computer to help them. in your case i would recommend using a dual pattern cam with 264in/274ex duration, and .450 valve lift. if you are running an automatic, use the 112 lobe separation angle, a manual trans can use the 110 lobe centers.

here is an excellent article on this subject;

http://classicinlines.com/CompressionR.asp

Wrong, looking at the events on a 110 L/C camshaft on a 274 camshaft, according to Mikes website comparing the 224 cam using a 112 L/C the 110 camshaft intake closing is at 67 degrees after bottom dead center & the 112 L/C camshaft has the intake closing at 69 degrees after bottom dead center.
Using Mike dymanic compression formula the later closing of the intake of the the 112 L/C camshaft would produce a lower dynamic compression cause the intake valve closes later.

The 110 L/C camshaft will produce more lowend, but at the price of a rougher idle cause of valve overlap.

The intake closing is the main focus on more low end or more top end.

I do agree on the smaller intake for more low end.

If you have a manual trans the more overlap of the 110 L/C cam will not strangle the engine compared to an auto trans vehicle, unless you install a larger stall converter.

If i am wrong tell me. Falcon Man

 

[lorwood]

bucfan
Good luck finding the head, It took me a while. One of the members sent me this link http://www.car-part.com/ Helped me find a large log D7 I believe Mike should have received it by now. Can't wait until I get it back. Good luck

 

[Lazy JW]

......

The 110 L/C camshaft will produce more lowend, but at the price of a rougher idle cause of valve overlap.....

Good luck getting both of those to happen; rough idle does not lug well.

 

[rbohm]

8) how lobe separation works. take a cam, any cam it doesnt matter, lets say the lobe separation angle is 110 degrees, typical street cam. if you narrow the lobe centers to 108 degrees, you lose cylinder pressure as valve overlap increases. this lowers the dynamic compression ratio, without changing the static ratio. static compression ratio is set based on what the total cylinder volume is with the piston at bottom dead center divided by the total cylinder volume at top dead center. dynamic compression ratio it more complex as it takes in a number of variables. when you lower the dynamic compression ratio, it tricks the engine into thinking it has less compression ratio than it really does at lower rpms. when you widen the lobe separation angle the opposite is true, go from 110 degrees to 112 degrees, and you increase the dynamic compression ratio, especially at lower rpms, thus tricking the engine into thinking it has more compression ratio than it really has.

the end result is this, lets say you build an engine, and you calculate the static compression ratio at 9:1. you decide that you want more low end power but you dont want to raise the compression ratio, so what you do is select a cam that has wider lobe centers.

i realize that cam selection is a mystical science, and even the pros make the wrong call from time to time even using a computer to help them. in your case i would recommend using a dual pattern cam with 264in/274ex duration, and .450 valve lift. if you are running an automatic, use the 112 lobe separation angle, a manual trans can use the 110 lobe centers.

here is an excellent article on this subject;

http://classicinlines.com/CompressionR.asp

Wrong, looking at the events on a 110 L/C camshaft on a 274 camshaft, according to Mikes website comparing the 224 cam using a 112 L/C the 110 camshaft intake closing is at 67 degrees after bottom dead center & the 112 L/C camshaft has the intake closing at 69 degrees after bottom dead center.
Using Mike dymanic compression formula the later closing of the intake of the the 112 L/C camshaft would produce a lower dynamic compression cause the intake valve closes later.

The 110 L/C camshaft will produce more lowend, but at the price of a rougher idle cause of valve overlap.

The intake closing is the main focus on more low end or more top end.

I do agree on the smaller intake for more low end.

If you have a manual trans the more overlap of the 110 L/C cam will not strangle the engine compared to an auto trans vehicle, unless you install a larger stall converter.

If i am wrong tell me. Falcon Man

you are wrong, and right in a way. wrong in that less overlap traps more cylinder pressure raising the dynamic compression ratio, which increases the low end power. increase the overlap, and you lose cylinder pressure at low speeds, lowering the dynamic compression ratio. you gain it back at higher speeds though. smokey yunich found that later intake valve closing actually increased power across the board, with in reason. go too far though and you lose power. a wider lobe center will also smooth out the idle. all in all the difference is minimal on a street cam, but it is used as a tuning option on race engines.

 

[AzCoupe]

AZCoupe - I did degree the cam and it spec'ed out OK.
The lack of bottom end power can be related to the fact I still have only a 1bbl Holley 1946 on it, and the 3.08 rear. And when I say "lack of" I mean it in a relative sense, compared to my previous engine which was stock, but had the cam advanced 4 degrees. So it has a "slower" response to the throttle off the line, but the real power and difference in this cam is on the top end for sure. My old engine used to top out at about 85-90mph and 4000rpm. I buried the speedo at about 120mph the other night and it was still asking for more. I'm ok with it because I wanted a strong highway car, not a street car.

Gotcha.... Just curious, what's your C/R?

bucfan
Good luck finding the head, It took me a while. One of the members sent me this link http://www.car-part.com/ Helped me find a large log D7 I believe Mike should have received it by now. Can't wait until I get it back. Good luck

Yep, it's here. Showed up Wed afternoon.

Any idea when they will be available? Will I need to wait for the 1.6 or will the 1.65 work? Do I need to change the valve springs to use the rockers or can I wait and just use the new spring on the new head?

We're hoping to get the 1.65 rockers in 4-6 weeks. The 1.6 and 1.73 should follow in three to four weeks. I'm not sure if the 1.65 or 1.6 will work with stock springs, I still need to check that out. My main concern is coil bind. I posted a pic above.

 

[JackFish]

Gotcha.... Just curious, what's your C/R?

I was shooting for 9:1, with .050 milled and a steel head gasket.
Did not deck the block.

 

[AzCoupe]

9-1 should be OK. Did you happen to CC the combustion chambers?

 

[JackFish]

9-1 should be OK. Did you happen to CC the combustion chambers?

I made an amateur attempt and they were in the 54cc range.