302 Roller Cam Advice

[1969_Mach1 333]

Yeah we mentioned a VS upgrade earlier... Its always good to get a set of springs that are matched to the proposed camshaft.

And Barnett is right about the wider LSA of 113-114 not hitting as hard, it will have a much smoother sounding idle which will also constitute a much smoother idling motor usually that wont shake the car LOL.

My Hyd roller in my 408 is pretty small and I had it ground on a 113LSA I believe and it is noticeable but not near as noticeable as a lot of smaller cams with tighter LSA. It also has a nice Torque curve.

Yes.  Increasing the LSA without changing duration will reduce valve overlap, thus smoother idle, more vacuum at idle, and a broader smoother power curve.  Obviously, decreasing the LSA without changing duration will increase the valve overlap, create a rougher idle, less vacuum at idle, and create a shorter more abrupt hitting power curve.  Cams with smaller LSA are more common for engines that see only track use and operate within a narrow RPM range.  Cams with a 110 deg to 112 deg LSA seems to be a pretty good compromise for a carbureted street car. 

[MikeStang 247]

Exactly Mach, That is why I had Comp grind my Cam with the wide LSA I did because I wanted

1. Decent Idle because of Auto Trans, and didn't want to run a super high Stall

2. Enough Vac for Power Brakes.

3. Big fat broad power curve

4. running a carb LOL

 

I think a lot of cams that these companies are offering with LSA in the 106/108 Range would be much better served with 110 and up LSA because 99.9% of them are not going into full our race only motors, they are going into something that guys will be cruising on weekends or even DD cars, so why all the hubbub over a cam that just goes chop chop chop and idles like ass and the curve is not near as nice..

[sixt9stang 36]

So much information to process.  Going to start looking at my heads some more when I am home.

 

Edit: not my thumbnails and also why does this happen on this forum?

[MN69Grande 203]

I have to look at the heads that I have more.  They are not the original '69 heads as I got them from a buddy that had put screw in studs and did some other work to them.  I will get some pictures and maybe some measurements so that maybe I can get some help on springs.

 

Pull the valve covers and look at the stamping underneath.  Then use a site like:

http://www.castingnumbers.info/site/main

 

You should be able to get the specs your heads started life with.  Not sure how you would be able to tell what was done to them without pulling them and measuring everything.  What would most concern me is if the heads were milled at some point.  This would change the compression ratio. It could also cause clearance issues if you get too big a cam or change your rockers.

[sixt9stang 36]

Looked at the heads again this morning and got some pictures of the springs that are currently on them and some different measurements.

 

The head casting is C9TE.  There is also the following stamped: 2C28

 

Valve Spring Side:

 

Valve Spring Top:

 

Valve Spring measurements:

Height with retainer: 1.85"

Height without retainer: 1.72"

Diameter: 1.25"

 

I think the guy I got the heads from said they were K-motion springs.  I have no idea of the seat pressure or anything.  The measurements I took were done with a digital caliper and I tried being as accurate as possible.

 

Edit: I think the springs are one of these two:

 

K-700 1.265 diameter single M-200 spring good for camshafts up to .500 lift. 120# @ 1.700, 375# @ 1.150, coil bind at 1.050.

K-750 1.265 diameter single M-300 spring good for camshafts up to .610 lift. 130# @ 1.700, 395# @ 1.150, coil bind at 1.050.

 

 

Also, I had mentioned valve float.  Thinking about it more, that was on the original '69 heads with the original valve springs.  Not these springs.  I did not have these heads on very long before I ended up rounding a lobe on the cam from having a rocker adjusted wrong.  Or maybe these springs are too much pressure for an Edelbrock Performer cam.

[MikeStang 247]

Ah just pop a spring off and run down to the local engine builder and have them check the spring pressure on them at whatever installed height you have now, then check up to about .550-.600 lift... if it falls within the range of the came you wanna run you should be good to go

[MikeStang 247]

On a side note, that is a SHIT LOAD of valve tip sticking up from what im seeing...wonder why its so tall?

[sixt9stang 36]

Ah just pop a spring off and run down to the local engine builder and have them check the spring pressure on them at whatever installed height you have now, then check up to about .550-.600 lift... if it falls within the range of the came you wanna run you should be good to go

 

Sounds like a plan.

 

On a side note, that is a SHIT LOAD of valve tip sticking up from what im seeing...wonder why its so tall?

 

Couldn't tell you on that.  I am still learning a lot of stuff.  I have only rebuilt a few engines and still learning a lot when it comes to the cam and valvetrain.  I would have to look at my old heads and see how they compare.

[1969_Mach1 333]

If they are either of the springs you're thinking about, they should work for a cam up to about 0.560 lift at the valve.  However, I see umbrella valve seals under those springs which are okay but not as good as a viton or rubber material positive type of seal that slightly presses over the valve guide.  On small block Fords, the other limiting factor for valve lift within the cylinder head is the spring retainer contacting the top of the valve guide.  Actually, crushing the valve seal against the top of the valve guide.

 

Those valve tips might be long because they look like valves for stock rail type rockers arms.  Common on 351W of that time period.  Or, somebody could have installed offset keepers or retainers to get the correct spring installed height.  I think it's the first one though.

 

Have a spring checked like MikeStang mentioned.  The setup just looks a little odd for a small block Ford casting cylinder head.  I've seen larger diameter springs on small block Fords to fit over the guide and shoulder that locates the spring at the base of the guide.  After you remove a spring, if you can, upload another picture of a guide, they may have been machined to fit these springs.

 

Look at the bottom of the cylinder head on the intake side for more casting markings.  The markings in the picture don't indicate much. 

[MikeStang 247]

Yeah I pulled a set of stock heads off a 351 a while back and it had rail type rockers and the tips didn't appear that long, but I may be wrong..I tossed the heads but probably should have kept them, just had no use for them LOL.

Be sure to ask the shop what the coil bind in on the springs... you want at least 20% more spring capacity than the max lift of the cam you are using....Example.. Your cam has .550 Max lift, then you want a spring that is capable of at least .660 lift before it hits coil bind...Least that is what I was taught and it hasn't ever steered me wrong yet...

I think I have a set of Hyd Roller springs that may work for you application ill let go cheap...They are brand new and came on my AFR heads, but I needed something a lil more beefy so I sprung for new springs, but they should work well for a small hyd roller like your shooting for....That is if you even need them

[MikeStang 247]

A positive Teflon seal would be a good option to replace the umbrella seals also if that is indeed what's on there now.

[sixt9stang 36]

Thanks Mike.  I will let you know once I have these checked out.  I will have to rent or buy a spring compressor.  It is about the only tool I don't have.

[1969_Mach1 333]

Yeah I pulled a set of stock heads off a 351 a while back and it had rail type rockers and the tips didn't appear that long, but I may be wrong..I tossed the heads but probably should have kept them, just had no use for them LOL.

 

The C9OE and D0OE castings are about the only older small block castings that have any value.  Not a lot because the cost to rebuild them these days.  But if somebody wants a SBF stock casting period correct cylinder head those are the best options. 

[MikeStang 247]

Ah you can always just get some nylon rope and feed it down into the spark plug hole, then loosen off the valves on that cyl and rotate the motor over by hand till it stops, and the rope will support the valve, then just rent ya one of those lil tools from Autozone and pop the retainer and keepers off and voila...check spring, then reinstall and return tool :)

[sixt9stang 36]

The engine is completely disassembled and on the stand.  Got it back from the machine shop a few months ago.

[barnett468 418]

you don't want to run a high lift cam with those heads irregardless of the spring rate

[sixt9stang 36]

Ya.  I am now looking at the cams that you suggested and keeping an eye out for a cheaper used cam.  From what I have been reading the heads are truck heads with a little bit smaller combustion chamber, upping the compression ratio a bit.  But they do not flow that well.

[1969_Mach1 333]

In that case, your initial thought of the E303 or something very similar sounds like a good match for what you have.

[mwye0627 44]

I looked up the C9TE Casting number and it does appear to have been used on 302 Truck engines.

They have the smaller 58 CC Combustion chambers, but they also have the smaller 1.78/1.45 valves.

Source: http://raceabilene.com/kelly/hotrod/engine3.html

[sixt9stang 36]

I looked up the C9TE Casting number and it does appear to have been used on 302 Truck engines.

They have the smaller 58 CC Combustion chambers, but they also have the smaller 1.78/1.45 valves.

Source: http://raceabilene.com/kelly/hotrod/engine3.html

 

Yep. That is what I measured the valves at.

[sixt9stang 36]

Got really busy needing to rebuild my G8's 6.0 which took all the money I was going to use on my 302. :(  Now coming back to this though I brought one of the springs into the machine shop I had do my 6.0 heads but they don't have anything to measure the spring rate.  

My next question is on the valve seals.  Are they supposed to just be loose on 302 heads?

 

[lalojamesliz 56]

I would imagine any decent shop would have a way to measure spring rate..... Try another shop?

Even I thought about getting something for that lol

All this valvetrain learning drove me nuts. 

This is reason and with the suggestions of others is why I just went with a custom cam with Chris Straub. 

If I didn't robb that bank i wouldn't have been able to afford it thought.....j/k

[barnett468 418]

ok, your "machine" shop does not sound like a real machine shop to me and i assure you that i know what i'm talking about because i not only have over 40 years of dealing with machine shops, i used to run the cylinder head department in one, so i would have the heads inspected by someone that knows what the hell they are doing.

the seals you have are called umbrella seals and they are stock on all older engines and are supposed to ride near the top of the valve but they do allow a little oil by the guide which needs lubrication . you can get positive seals that seal against both the guide and the valve if you want . they are cheap and push right on,

.

[sixt9stang 36]

Thanks! I will check with some of the other shops.