What gains/benefits have people seen running ported heads and bigger valves? Either factory ported heads like socal stage 1 and stage 2, eldelbrock, Wagler, ect... The question is more based toward a big single turbo truck for mostly competition. Do they seem to help spool up? Has anyone done back to back dyno testing with the heads being the only change? What about running the largest valves in the stock bore vs. going say .020 over or .040 over and getting the biggest valves. I probably have more questions but this may get a conversation started.
Ported heads and bigger valves
- Thread starter buick455
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engine is an air pump. more you can move in and out, more power you are going to make. More boost is a way around a low flowing heads/cam. you can also lower the turbos pressure ratio. making it move the same amount of air with less boost and thus reducing heat induced into the air charge. makes more power just from reduction in heat and increases longevity of the turbo. again, all depends on where you currently on in the turbos map to where things are after.
higher flowing heads and cam will decrease spool up time on a big single vs a stock setup on a big turbo. converter can play a roll in either case as well if running an auto
big valves depends on the heads. aftermarket heads with larger valves move the valves closer to the cyl center to keep from shrouding happening in a stock bore. thats the better way to go.
higher flowing heads and cam will decrease spool up time on a big single vs a stock setup on a big turbo. converter can play a roll in either case as well if running an auto
big valves depends on the heads. aftermarket heads with larger valves move the valves closer to the cyl center to keep from shrouding happening in a stock bore. thats the better way to go.
What type of competing are you going to be doing? Also, please fill out your signature so we know what vehicle you are talking about :thumb:
It is an LB7 with an Allison and it is 99% strictly a sled puller with a very large single and a lot of fuel. It already runs very strong and is very competitive. I'm basically looking to see what people have actually found on their trucks when putting "bigger" heads on. I totally understand all the theory, just curious what people have noticed that actually have "bigger" heads. Thanks for the responses so far.
all i stated is exactly what ive found from a 1000hp engine on up to a 2200hp engine. 2200hp engine was a cummins though
depends on the head you use. thats kind of an open ended question
.040 bored block can have cracked cyl wall issues if you are pushing high power through it.
I lost about 7 pounds of boost going with ii race heads. That's not even big boy heads. Lost more when I went to 3.5 inch piping. A lot of variables to it. One thing I see is no one port matches exhaust manifold to head. Witch is huge.
Stock heads will make big power but just need help.
Stock heads will make big power but just need help.
I dropped 5 PSI of boost going from SoCal Stage 1 heads to the Wagler aluminum as-cast (which I guess they don't make anymore?). Didn't notice much change in spool, saw a much bigger improvement changing out the converter.
I also noticed how far off the ports were from the heads vs the exhaust manifolds as ne-max stated. I have had our machine shop match the manifolds up. Last season we went from 3" charge piping to 3.5" although I don't have any data to compare. We had some very unfortunate issues with tuning and aftermarket heads otherwise I could give an engine dyno comparison of before and after of 3" to 3.5" piping, a different custom cam, and head changes. Unfortunately the before and after results are very skewed.
You don't gain much by Over boring cylinders. all things equal in the gas world its shown like 5-10hp gain on the dyno.
Like James Said your engine is an Air pump.
This is the closest thing I can show you to a stock head Vs. a modified head straight up comparison and how it affects the overall performance.
Edelbrock changed the valve angle 1 degree and went with an oversized valve on there castings. The results would be similar with CNC ported factory casting Vs. just an OEM casting.
https://www.youtube.com/watch?v=HSFfvNsdno0
Like James Said your engine is an Air pump.
This is the closest thing I can show you to a stock head Vs. a modified head straight up comparison and how it affects the overall performance.
Edelbrock changed the valve angle 1 degree and went with an oversized valve on there castings. The results would be similar with CNC ported factory casting Vs. just an OEM casting.
https://www.youtube.com/watch?v=HSFfvNsdno0
The other thing that isn't mentioned is how much meat is left on the Edelbrock to support porting. Right now the SoCal stage 2 is the most proven head we have available to us but I think once a good porting house gets their hands on these and develops a good porting profile for these they may be the hot ticket item.
Good info. I've seen that video and it was decent. I do wish they would swapped the valve springs to test their theory but it makes sense. I agree Brad, I'm sure Guy already has some they are porting/working on but it'll be interesting to see the results vs the factory castings heavily ported.
Supposedly there is a Shop I believe in Texas that has done some porting on the Edlebrocks. I wasn't able to find anything But I am also not on social Media either...
Oh BTW. That Complete Gasket kit seems to be the way to go!
It looks like it contains the oil cooler seals in it
Fill the block and put a set of solid iron heads on it. Leave the bore as small as you can. Done deal.
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Fill the block and put a set of solid iron heads on it. Leave the bore as small as you can. Done deal.
Have you had or seen a decent amount of blocks crack?
A few at limited pro level, yes.Fill the block and put a set of solid iron heads on it. Leave the bore as small as you can. Done deal.
Have you had or seen a decent amount of blocks crack?
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In the class I'm in I can't have a filled block. Obviously in the 6.7 Cummins world it is highly recommended to sleeve the cylinders anything over 1000hp really. I don't hear to much about this in the duramax world, some but not a lot. What are your thoughts on that or does the block still seem to give too much?
Wagler's big money engines that use stock blocks are filled, sleeved, and deck plated. Strengthens block but also allows for quick piston replacement. In these applications the thought is the piston is now your weakest point but the couple guys I know haven't hurt pistons, they've broken billet cranks!
The non sleeved filled block that I know that cracked had 70 hooks and 90 dyno runs, or vise versa. Either way, lots of beating.
Our last engine was filled, .040 overbore. 40 hooks, 25 dyno runs. Ran fine when sold. Wasn't cracked visibly yet, but they can be cracking without signs when its filled. We also ran ours half the time in a different class at 15 to 1600 hp. Dot tires required. Which is a saving grace imo. Put cuts on at that power level and make it work, parts are going to fail quicker.
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The non sleeved filled block that I know that cracked had 70 hooks and 90 dyno runs, or vise versa. Either way, lots of beating.
Our last engine was filled, .040 overbore. 40 hooks, 25 dyno runs. Ran fine when sold. Wasn't cracked visibly yet, but they can be cracking without signs when its filled. We also ran ours half the time in a different class at 15 to 1600 hp. Dot tires required. Which is a saving grace imo. Put cuts on at that power level and make it work, parts are going to fail quicker.
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I hear ya. We run DOT tires and no duals and are in the 1200hp range, probably on the higher side of that. Our engine builder did not think we needed to sleeve it but we are at .040 over which kinda worries me. He's seen probably over a hand full of these crack but they were all 3.0 grooved and 3.6 trucks but he seems comfortable with ours. We'll see.