FE Power Forums
FE Power Forums => FE Technical Forum => Topic started by: 677litre on February 23, 2016, 06:25:12 PM
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I picked up a set of 14 bolt C6AE-R today that need rebuilding but overall in good shape. Yes I'm aware money is better spent on some Edelbrocks but lets for a moment disregard that, partly because I want to stay true to the stock look for the year I'm restoring and second I like the challenge of getting what I can out of old iron within reason, it's a street car not a drag racer.
Looking for links to porting these specific heads, pictures are always nice. I know about the exhaust lip to be removed.
With a 30 over 428, dual quad low riser intake, what are the largest and/or most beneficial valves I can install? With stock piston? Aftermarket pistons required for larger valve relief for largest valves installable? Note: I may still go the stroker kit route for the extra cubes.
I'm going with a roller cam, haven't decided specs yet, open to suggestion on that as well. Pump gas friendly.
Thanks.
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The set that I got have a 2.09 intake and a 1.75 exhaust
There close but they don't touch ;D
Just some "cleanup" in the ports. There on a 4.250 bore motor and make good power
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I have run 2.15/1.67 in iron heads and they work well. Bigger exhaust valves will get real close to the bore and can hit with a lot of lift. Bigger intakes will fit, but there is debate on whether it helps as it gets closer to the bore. In a 428, I'd likely go 2.15/1.67 and then focus on the valve job and the rest of the bowl to make a nice smooth path to the new valves.
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Recommendations on where to buy decently priced complete valves, guides etc etc? The local machine shop will just be buying and marking up the same stuff so they told me they don't mind me buying all the parts myself.
Refresh me on the thermactor port bumps in the exhaust, they can be ground smooth correct?
With regards to the R heads specifically - how large can you take the exhaust before it is an issue. I know there is not much meat on the one side of the valve seats. It also sounds debatable whether installing new exhaust seats is necessary if not needed with so little there to hold the seat in place.
The links in this old thread are long gone dead and I was wondering if anyone has any old the old pics and info discussed?
http://www.network54.com/Forum/74182/thread/1156317484/C6AE-R+exhaust+hump+removal
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I think Barry R sells the valves you want. A lot of people just go up to CJ sized valves, which are 2.09/1.65, and that's a pretty good improvement. Not sure how big you can go with the exhausts on those heads...
Yes, you can grind the thermactor bumps out of the exhaust ports, and that would be one of the first things I'd do if I were you.
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Thanks Jay, just to be clear on the thermactor bumps, they are just solid as part of the castings and not hollow on these right? That is, they can be completely ground down to port size without worrying about breaking through correct?
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You can also try www.alexparts.com for what you need. I've ran a few sets of his valves, retainers, seals and locks with good results. Cheap prices with quick turnaround.
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You can also try www.alexparts.com for what you need. I've ran a few sets of his valves, retainers, seals and locks with good results. Cheap prices with quick turnaround.
The Link seems to be broken. :(
Edit: I found the right link. Thanks. :)
http://www.alexsparts.com/
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Is it worth going with 11/32" guides and valves?
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If your going to do a nice valve job/upgrade go with a 45* seat on the intake.
A stock CJ intake seat is 30* and not the best starting point for serious upgrades.
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Thanks Jay, just to be clear on the thermactor bumps, they are just solid as part of the castings and not hollow on these right? That is, they can be completely ground down to port size without worrying about breaking through correct?
Mine were solid , gone now ;D I don't think any were hollow but I could be wrong
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Just for reference, here is a C8AE-H with 2.15/1.67s in a 4.05 uncut 390 block. You can see there is a ton of room for the intake valve even in the small bore, but you can also see the exhaust gets tight, and gets tighter with lift.
I like the Alex's parts CJ valves for a budget build, but I am not sure they have 2.15 intakes. If going that route, and it assuming it isn't a big power maker or racer, I'd likely go with their CJ valves, my hunch is the money would be better spent on the valve job and bowl work.
If it's a hotter/higher RPM motor, I'd likely spend the money for Ferrea or some other higher end component. FWIW I run Ferrea in my Mustang, but I did try the Alex's parts stuff in my 445 truck motor, it never sees north of 5000-ish. Have had heard only good things about Alex's cheap valves from others too
(http://i528.photobucket.com/albums/dd329/My427stang/1.jpg)
(http://i528.photobucket.com/albums/dd329/My427stang/Room2.jpg)
(http://i528.photobucket.com/albums/dd329/My427stang/Room3.jpg)
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2.15/1.67s look like they might be perfect for a 4.160 bore 428 though? i could see going bigger but there doesn't appear to be much more without the valves touching? I'll contact Andy's but it looks like they only sell certain sizes. If I go the Ferrea route is there a supplier you guy recommend?
With regards to the factory cast but not machined thermactor ports on these, I'm still not sure if they are solid or actually open on these castings.
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When you say roller cam, are you talking hydraulic or solid? If you are going to use a large exhaust valve, then you may consider notching the bore of the cylinder just under the exhaust valve in each corresponding bore. The 427 MR did this from the factory. It will help unshroud the exhaust valve at lift. Also it will be beneficial if you are going lift numbers near or over .600" on the exhaust. Just don't cut into the ring sealing area. Joe-JDC
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Interesting photo showing just how offset the valves are in the bore. Next time mine is down I'am going to have to see how tight it is around the exhaust on the larger bore
I do agree port and bowl work probably better spent money
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When you say roller cam, are you talking hydraulic or solid? If you are going to use a large exhaust valve, then you may consider notching the bore of the cylinder just under the exhaust valve in each corresponding bore. The 427 MR did this from the factory. It will help unshroud the exhaust valve at lift. Also it will be beneficial if you are going lift numbers near or over .600" on the exhaust. Just don't cut into the ring sealing area. Joe-JDC
Trying to decide. I have a set of new hydraulic roller lifters on the shelf here but no cam yet and since it's a weekend cruiser probably not seeing more than 6000rpm the benefits of a solid roller may not be seen. But I'm open to suggestions. :)
Is it possible to install the 427 valve size 2.19/1.71 into these heads? I thought the 427 valves were space a little wider to achieve this?
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With regards to the factory cast but not machined thermactor ports on these, I'm still not sure if they are solid or actually open on these castings.
Pretty sure they are solid, but if not you would see a hole on the top of the head casting, over each exhaust port. And if that hole is there, it can be threaded and plugged.
I've put 2.19/1.71 valves into a 4.09 bore before, with Edelbrock heads, and they barely fit. 390 and 428 spacing on the valves is 2.0", and 427 spacing is 2.1"; if I recall correctly Edelbrock split the difference on their 428CJ heads, and they measure 2.05" spacing.
Unless you are going all out with the porting, I think the standard CJ valves will be fine. And you really won't pick up much from the 11/32" valves in terms of flow, but you will get a weight reduction. If you are not going to run the engine past 6000 RPM, probably not worth the switch.
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With regards to the factory cast but not machined thermactor ports on these, I'm still not sure if they are solid or actually open on these castings.
Pretty sure they are solid, but if not you would see a hole on the top of the head casting, over each exhaust port. And if that hole is there, it can be threaded and plugged.
I've put 2.19/1.71 valves into a 4.09 bore before, with Edelbrock heads, and they barely fit. 390 and 428 spacing on the valves is 2.0", and 427 spacing is 2.1"; if I recall correctly Edelbrock split the difference on their 428CJ heads, and they measure 2.05" spacing.
Unless you are going all out with the porting, I think the standard CJ valves will be fine. And you really won't pick up much from the 11/32" valves in terms of flow, but you will get a weight reduction. If you are not going to run the engine past 6000 RPM, probably not worth the switch.
Thanks jay. Yeah I'm mostly playing around with a bunch of "what ifs" for these heads, why not. Even if I won't see any gain with the intended use of the motor I'm still interested in seeing what can be done, within reason.
On an FE is there more benefit from going bigger exhaust valves and only modest larger intake valves on the intake? Weird combos like 2.15/1.71? Just playing with ideas. Chris.
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Usually the intake path is more critical than the exhaust path, so if you are going to be pushing the envelope with one or the other, make it with the intake.
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2.15/1.67s look like they might be perfect for a 4.160 bore 428 though? i could see going bigger but there doesn't appear to be much more without the valves touching? I'll contact Andy's but it looks like they only sell certain sizes. If I go the Ferrea route is there a supplier you guy recommend?
With regards to the factory cast but not machined thermactor ports on these, I'm still not sure if they are solid or actually open on these castings.
I do think the 2.15/1.67 combo is good for a 428, but there are a few more options for undercut stem 2.09 valves compared to 2.09, so you can save a little dough. I do not think there would be a measurable difference in power, unless you had a very talented porter that can match the port to the slightly bigger valve.
Some things to think about, although guys all have their techniques, and porting is certainly not as simple as a cross section match, think about the port like a gradual funnel, reducing by about 1- 1.25% in size as it approaches the valve. If the port is matched to a 2.09, you won't gain much if any with a bigger valve. Add to that, you are probably starting from a med riser port location on the intake manifold, so high and "more square" as it enters the head, it's not like you want, or even can, use the whole low riser port in function.
2.09 or 2.15 really doesn't matter at your desired performance level IMHO, 2.15 is certainly a good enough option as is 2.09, but I'd consider thinking more about the entire intake port efficiency instead of maximizing valve size at your RPM. Valve design/shape, modern valve job (which not as many people do as they claim), bowl transition, bowl shape, size and guide area cleanup, width of the port, some work on the short side, transition at the roof of the intake at the carb, etc. The valve size is going to be a one small part of it (at your RPM/power level)
That being said, like Jay said, if you are going to go big, go big on the intake side.
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2.15/1.67s look like they might be perfect for a 4.160 bore 428 though? i could see going bigger but there doesn't appear to be much more without the valves touching? I'll contact Andy's but it looks like they only sell certain sizes. If I go the Ferrea route is there a supplier you guy recommend?
With regards to the factory cast but not machined thermactor ports on these, I'm still not sure if they are solid or actually open on these castings.
I do think the 2.15/1.67 combo is good for a 428, but there are a few more options for undercut stem 2.09 valves compared to 2.09, so you can save a little dough. I do not think there would be a measurable difference in power, unless you had a very talented porter that can match the port to the slightly bigger valve.
Some things to think about, although guys all have their techniques, and porting is certainly not as simple as a cross section match, think about the port like a gradual funnel, reducing by about 1- 1.25% in size as it approaches the valve. If the port is matched to a 2.09, you won't gain much if any with a bigger valve. Add to that, you are probably starting from a med riser port location on the intake manifold, so high and "more square" as it enters the head, it's not like you want, or even can, use the whole low riser port in function.
2.09 or 2.15 really doesn't matter at your desired performance level IMHO, 2.15 is certainly a good enough option as is 2.09, but I'd consider thinking more about the entire intake port efficiency instead of maximizing valve size at your RPM. Valve design/shape, modern valve job (which not as many people do as they claim), bowl transition, bowl shape, size and guide area cleanup, width of the port, some work on the short side, transition at the roof of the intake at the carb, etc. The valve size is going to be a one small part of it (at your RPM/power level)
That being said, like Jay said, if you are going to go big, go big on the intake side.
Thanks for the info. I'm mostly playing around with ideas rightnow, this will be a slow build as I have other things on the go but I like to gain knowledge from people like yourself that have experience with FEs so I don't go blind into a machine shop and have someone butcher a decent set of heads because he's a Chevy guy or something. ;)
So theoretically you can technically stuff a set of 2.19/1.71 valves in these heads but there is almost zero tolerance left between them. What is the recommended minimum distance between valves?
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Some of you may have responded to this question on another site but I need input.
C6AE-Rs - I'm being told that 2.19 intake valves will be too big for these heads and be very shrouded and have the same issue as the 2.15 and spark plug ports. 2.15 with 45deg seats would be better but are extremely close to the spark plug ports and prone to cracking in that area as a result. Thoughts?
I'm pretty sure CJ sized exhaust valves are the way to go but are hardened exhaust seats required?? For street and cruising with the occasional strip run?
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I think if you're not going to do any porting, the 2.19 valves are definitely too big, and the CJ valves would be better. As far as hardened seats go, they are always a good idea if you are running unleaded fuel, but unless you put 50K miles on the engine with unleaded fuel, you'll probably never have an issue with the stock seats.
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Another approach: depending on RPM and power goals, a complete 'stock' rebuild with larger chromed replacement stock valve stems and reamed stock guides (no inserts), hard exhaust seats, new Ford GT springs, stock seals (i have never had smoking issues like some), cut the exhaust flange face and clean-up cut on heads cost me $800. I think that is a good value for a reliable set of heads.
Sure, they will not flow like edelbrocks. Normally i would have taken the time to do some hand porting my self bid way along in this process, but this time, i did not bother. They are going on a stock 428. I considered CJ valves, but in reality, the stock .490.499 lift cam, the stock rod bolts, etc. dont want to rev over 5000, so i decided not to bother with CJ size valves. I have upgraded before with good results, but in this case, i just had him work the stock size (replacements are 2.03 1.66 i think.) I think CJ valves would have cost another $100 to $150 in labor to cut and blend the larger intake seats.
http://i140.photobucket.com/albums/r19/TorinoBP88/RebuiltC6AE-Rheads04_zpsa1a6b7ca.jpg
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(not sure why i can not edit my previous post)
To be clear: I installed 0.017 larger valve stems so i did not have to put valve guides in. The stock replacement valve heads were only 0.001 bigger. n/m
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To answer the question about the thermactor bump, they are solid and can be ground completely down with no issues.
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With regards to the factory cast but not machined thermactor ports on these, I'm still not sure if they are solid or actually open on these castings.
Pretty sure they are solid, but if not you would see a hole on the top of the head casting, over each exhaust port. And if that hole is there, it can be threaded and plugged.
I've put 2.19/1.71 valves into a 4.09 bore before, with Edelbrock heads, and they barely fit. 390 and 428 spacing on the valves is 2.0", and 427 spacing is 2.1"; if I recall correctly Edelbrock split the difference on their 428CJ heads, and they measure 2.05" spacing.
Unless you are going all out with the porting, I think the standard CJ valves will be fine. And you really won't pick up much from the 11/32" valves in terms of flow, but you will get a weight reduction. If you are not going to run the engine past 6000 RPM, probably not worth the switch.
Jay, so I think I'm shooting for 2.15 / 1.65 both 45 deg seats, a good valve job and as much porting as possible. The motor should have enough down low being a stroker (462) and I'm probably going to install one of BBMs new tunnel wedge intakes when they come out the end of June. I'm still on the fence with regards to installing hardened exhaust seats, there is not a lot of meat in that area on the Rs to install them and at the same time go to the valve sizes I'm after. The car will be a weekend toy but I like to go for lone cruises come weekends.
Can anyone post or point me to some good pictures of porting work on these heads??
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I did some quick porting on my heads. BUT they are 2.03 and 1.55. If I would have spent more time on them.... But in 2 hrs time.
Won't let me post pics from my phone for some reason
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Here are a few pictures for you
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Jays intake adapter installed with those heads
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Maybe these will help?
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Hi, new here but very interested in these questions.
If one was going to sleeve their 428 block in a bore & stroke package, is there a bore size maximum at which these heads would not see any further gain with accurate porting and 2.15/1.71 valves?
My goals are very similar with 6,000 being the absolute ceiling and a 2x4 OEM PI intake manifold.