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Apologies if you already stated this, but I never saw a reply or impressions after the dyno numbers post. What are you impressions? Are you happy with the results?
The engine turned out great, nice piece of hardware!
There is more potential in a combination like this, just not this one as it sits with parts selection I used.
A good rule of thumb for a NA max effort deal is to see 1.5 ft lbs per cube. There is more to be had for certain in this kind of package. 2.2HP per cube could certainly be had, but it isn't easy to get. The parts I used were readily available shelf parts.
The cam/valvetrain has to get ALOT more wild, not just the duration and lift numbers,,,. Some custom designed domes on the pistons, .7mm and 2.0mm rings, lighter valve train parts such as gun-drilled Titanium valves, larger diameter lifters to accommodate crazier lobes, etc. To max it out it needs more RPM, an iron block would likely help also for the best possible ring seal. If it was designed and built like above it could probably do 2.2hp per cube, possibly 2.3. In this one, a little more cam with a more aggressive lobe (same valvetrain) and another point of compression along with a better intake manifold (custom sheet metal with single four top) would probably do 2.0/2.05hp per cube without getting too custom and having 40K in an engine, but that is just a SWAG!
I don't think I got the FULL potential of these heads, however, I do think that for most LS builds using similar hardware as to what was in this one, that an F710 head is not head and shoulders above what else is out there. If so, I think I would have seen at least 830/840 out of this build.
I want to also reiterate the dyno I'm using is dead nuts accurate, (not over inflated like many, or most). This builder/dyno shop I use deals with nothing but high end race engines competing in NHRA Comp and Comp Eliminator. The engines he builds go straight into competition. If they don't run the number there are no excuses that will serve as to why the HP and ET don't line up. The guy doesn't advertise and I am lucky to get in there when I do. He is a NHRA top dragster racer and is either building/refreshing/dynoing or racing. Small shop and is covered up. I don't question his dyno but always see 4 digit NA stuff out there that is nothing short of Pro Stock technology applied to different engines. He doesn't do much with LS's.
If you don't see the correction factor or lbs per hour of fuel and a BSFC number with a dyno sheet posted on the interwebz I would take it with a grain of salt! I hope to post track ET/MPH on this engine in the spring.
Dyno numbers are just a tuning tool, that’s it. Don’t put your faith in dyno numbers, the time slip tells all once car is sorted out. It’s still pulling at 8k, so there’s a little left there. Torque numbers on paper look honest to me.
Was this run on the 1050cfm carb? Did you try a bigger carb? What timing did you wind up at? Fuel? Plugs? I have a 427 AllPro headed motor sitting between the frame rails now getting headers built ready for the first test day here in CA. Any feedback on the 2 to 2-1/8 step headers?
Custom dominator built by RCE using a BLP billet main body with a 2" throttle bore, 1.800" venturi. No need to try a bigger carb, this carb would have supported more power. It was moving 1130 cfm on the 8000 RPM pulls. Same timing as before, 20. No power made with more.
I think the 2" to 2 1/8" are the right size for an engine like this.
Last edited by helicoil; Nov 27, 2021 at 09:28 PM.
Its crazy that your timing is so low. I have a buddy running the same heads on a 427ci and his timing is in the the low/mid 30s. When he first put it together he had about 25 degrees in it and said it felt like a dog. They put it on the dyno and it ended up wanting 3X degrees.
Its crazy that your timing is so low. I have a buddy running the same heads on a 427ci and his timing is in the the low/mid 30s. When he first put it together he had about 25 degrees in it and said it felt like a dog. They put it on the dyno and it ended up wanting 3X degrees.
That's interesting.
20 to 25 yielded no power increase, so I stopped there. Actually at 25 it lost a couple of inches of vacuum through the pull from rattling.
Plugs were happy at 20. I thought other wise so I experimented. No increase in HP or torque up to 25 degrees. It is a 10 degree head, alot of the BBC 9 and 11 degree heads act similar.
That's interesting.
20 to 25 yielded no power increase, so I stopped there. Actually at 25 it lost a couple of inches of vacuum through the pull from rattling.
Plugs were happy at 20. I thought other wise so I experimented. No increase in HP or torque up to 25 degrees. It is a 10 degree head, alot of the BBC 9 and 11 degree heads act similar.
The only thing i could think of that may be contributing to him running some much timing is that he runs E85 and has meth injection. Which would contradict that on his SBE setup, adding the meth actually resulted in running a tad bit less overall for maximum gains.
Same story we got on the phone. Of course its not your fault..... These are a perfectly good Chinese head and valve seat combo. Sorry to see you feel this way? You weren't sorry when you took our money for these heads. Nor anyone else in this thread that has purchased FED products and are having / had issues.
Intake Valve Seats – Ductile Iron
Exhaust Valve Seats – Ductile Iron
^^^^^^^^^^ This was copied straight from FEDs website pertaining to the M311 heads. What brand valve seats are they? Be careful before you say CHE because we called CHE first thinking they were CHE and they told us that these valve seats are NOT CHE. A very well respected individual in the LS world told us that these valve seats came on the heads when they came from china. Care to dispute that? When we sent them to our machine shop to be fixed, the machinist used the words "dog ****" and "worse than factory" to describe the seats.
Casting outsourced overseas. Engineered, Machined and Assembled by FED in the USA. <<<<<< Right off the FED website. Yeah Yeah we missed it. Our mistake. Figured since it was on your website, you wouldn't mind me posting it here. Valve seats look familiar.....
This is a quote from the Alibaba (China) website. Features
1.T6-aluminum castings are T6-heat-treated, low-silica alloy. This makes them similar in strength to 6061-T6 billet and the capability to be machined and welded is also notable.
2.A raised runner design on both intake and exhaust ports is said to allow for more efficient cylinder filling, resulting in better high-rpm operation without sacrificing low- and midrange performance.
3.The exhaust-port exit is on center with the valve, which results in substantially better flow characteristics.
This is a quote from FED. Right off the website. F710 heads specifically.
A357 T6 Aluminum Castings – T6 heat treated, low silica alloy. Similar in strength, machine-ability and weld-ability to 6061-T6 billet.
Raised runner design on both intake and exhaust – Raised runner design allows for more efficient cylinder filling, better high-rpm operation without sacrificing low and mid-range performance.
Exhaust port exit is on center with valve – Substantially better flow characteristics.
Who is copying who here? Just a coincidence?
When we called FED and ordered them, we told FED what the application was, FED spec'd the heads and we even opted for the better inconel exhaust valve. Its not like we told FED that they were going on grandma's Camaro, we told FED it was a turbo car. Everything on this head was bought from FED and for the application as discussed on the phone. FED valve seats, FED valves (inconel exhaust and stainless intake), FED locators, PAC springs, all of it. So if its a valvetrain issue, its still an FED parts problem. Let me be clear here, we don't want anything more from FED. We learned our lesson, we moved on. I just wanted to let readers know and see what exactly is going on here. Every time there is a problem with an FED head, its not FED's fault, it's the customers fault. Then the answer is always "buy the F series head." Apparently when you buy the F series head, its still not their fault. Glad we didn't pull the trigger on that.
The heads made good power. Credit where credit is due. But again, that does us no good if they're broke after about 10 races.
It seems that you're getting two different sets of cylinder heads mixed up.
F710 (or any f-series for that matter) is 100% designed, tooled, and machined in house. These castings are cast in Michigan. These use CHE bronze guides and CHE Ductile Iron seats with the option of CHE Steel Guides w/bronze liners as well as CHE B1 Intake Seats and BX exhaust seats. These are indeed raised runner, 10* valve angle heads.
M311 (which you post a link to) is in fact an offshore casting. We don't hide it and everybody knows this. It is ported and machined by us using the existing bronze guides and ductile iron seats (not by CHE and we've never advertised these to have them). We know the quality of these parts are not THE BEST but they do just fine on a TON of combinations in which the buyer is looking to save some money. Now our new "Boost Monster" M311 comes with CHE Bronze Guides in which we install and are assembled with inconel exhaust valves. These are a STANDARD port location (not raised), 11* LS3 head. The casting is of A319-T6, its similar to what you'd find in a 799, 823, 5364 castings and many cast intake manifolds. It's far from the best casting quality and they're a close copy to the Mast medium bore head (take that as an example of who would be copying who..). Again, we don't sell this head as anything super special nor do we claim it as a "cast in USA" or anything such. It's common knowledge that these are chinese castings. And they're priced accordingly as well. There's a difference between a chinese $2500 cylinder head and a US head starting at $4200...I'm not even sure how anyone could compare M311 heads to the F-Series, CID, Brodix, and many others. They are completely different in price and quality.
You can tell the difference between these two styles of heads simply by the valve cover rail. If it uses a stock style valve cover bolted from the middle, it's an M311. If its got a sb2.2 style perimeter bolt valve cover, that's an F-Series.
I am not saying that. I am saying that its quite the coincidence that alibaba and their sight are so closely aligned. I just did some looking around and thats what I found. I'm just sharing information that is readily available online.
The only thing I am accusing them of is always blaming the customer for a problem that is clearly a head problem and using trash china valve seats in their M311 heads.
Again, the heads on Alibaba are a Mast Medium Bore copy...that should be a good indication of who is copying who on literature. lol.
And just to clarify, you're upset that we used chinese seats in a chinese casting for significantly less money than our F-Series heads with good parts? How much did you purchase these M311 heads for (with what valves) and how much did you purchase your CID heads (with what parts)?
That's like complaining that your Hyundai at a new purchase price of $18,999 didn't have the quality or power of a C7 ZR1 at 100k lol.
Uncle Greg G doesn't need to see this...
FED rep and Greg CID argument on a thread I made. Dirt engine builder comparison using Both heads.
thumbs up to you on the build. But idk, as I'm with you on what you've said and asking How much More cam is needed and that's a nice rpm band and peak. I looked at the updates on cam and springs. I expected more. Someone said it, we just need a head to head with aftermarket ls7 heads. Mast and All Pro included.
Asked Both John/CID and the FED rep the same question. When it goes down the track and makes a number your happy with dyno numbers are out the window. I'm Hoping for 5.40 or better in the 8th mile with a 2900lbs or less vehicle.
Thumbs up to you again.
Oh I remember that post, not your fault BTW but that started a wild fire between us over a silly post IMO.
There was data shared by a mutual customer, sharing his results. That stirred the pot as we were taking shots at certain people and manufactures which we didn't. We just shared a post.
Dove into this a little bit more and am taking a look at the cam again. I think there is some easy, up for grabs HP to be had in increasing the major intensity of the lobe without taxing the valvetrain and getting too far out there on the duration. Its pretty soft right now.
Here is where I left off....
.020" - 309
.050" - 275
.200" - 197.5
Last edited by helicoil; Nov 29, 2021 at 09:38 PM.
Custom dominator built by RCE using a BLP billet main body with a 2" throttle bore, 1.800" venturi. No need to try a bigger carb, this carb would have supported more power. It was moving 1130 cfm on the 8000 RPM pulls. Same timing as before, 20. No power made with more.
I think the 2" to 2 1/8" are the right size for an engine like this.
Only reason I asked that, from what online calculators I have, a 1.800x2.000 carb is a 1130cfm...so you were using all it had. Bet if you had a gauge under the carb she was pulling 1.5in or more of vacuum. Carb guru's I've spoke with say .8iinHg is a good spot to be between booster pull and pumping losses..
Dove into this a little bit more and am taking a look at the cam again. I think there is some easy, up for grabs HP to be had in increasing the major intensity of the lobe without taxing the valvetrain and getting too far out there on the duration. Its pretty soft right now.
Here is where I left off....
.020" - 309
.050" - 275
.200" - 197.5
thanks for that. Interesting
this is what cam motion speced for a similar build but on alchol and 14.2 -1 compression.
I was expecting to see something in the 275/285 at 50
Forgot to add when I ordered the t&d solid rockers they have a 14 week lead time. So if your like me and like to build you own stuff , parts are hard to get right now. 5 weeks lead time on cometic mlx stuff.. getting very frustrated.
Only reason I asked that, from what online calculators I have, a 1.800x2.000 carb is a 1130cfm...so you were using all it had. Bet if you had a gauge under the carb she was pulling 1.5in or more of vacuum. Carb guru's I've spoke with say .8iinHg is a good spot to be between booster pull and pumping losses..
I do have data for the manifold vacuum, there was under .5 in Hg - in the plenum, this carb is using a skirted booster also. This size carb is not a restriction and will support 900HP.
Also, I was not using all it had, the venturi/TB bore size will support more than 1130 cfm. The cfm through the air meter corresponds with what the engine is taking in. The 1128cfm measured was going up linear to the power output, not hampering it.
The carb is not an issue. If you get too big for a dyno number and it won't perform well on the track. It is a balancing act.
Forgot to add when I ordered the t&d solid rockers they have a 14 week lead time. So if your like me and like to build you own stuff , parts are hard to get right now. 5 weeks lead time on cometic mlx stuff.. getting very frustrated.
Absolutely, been that way for awhile and not much change in sight.
thanks for that. Interesting
this is what cam motion speced for a similar build but on alchol and 14.2 -1 compression.
I was expecting to see something in the 275/285 at 50
Looks short to me unless you are keeping it in the low 7000's.
Do you have the .020" and .050" numbers? I am finding Cam Motion is pretty conservative with their solid roller LS profiles.
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