Taken from a port right under the throttle body I can check for vacuum tomorrow under that throttle load and see. If I’m remembering correctly I think it’s close to 0. Will update with the number the Holley puts out with the internal 1 bar map
Taken from a port right under the throttle body I can check for vacuum tomorrow under that throttle load and see. If I’m remembering correctly I think it’s close to 0. Will update with the number the Holley puts out with the internal 1 bar mapAbsolutely!! I bet that body wasnt even flowing 750CFM at that setting. When the blades are cocked over like that, the disruption in the laminar flows are giant. You've probably got some power on the table too. It'd be worth testing a 1 and 2" spacer beneath the TB. @5700rpm, the engine (357ci) is pulling roughly 500-520cfm @ 85% efficiency, and I'd gotta think you're better than that. As flat as that graph is, it's running out of air, which is why I was thinking it wanted more over lap or something.
Did you guys have a vacuum sensor connected?
At full throttle, top of the RPM range, you only want about .8-1" of vacuum. With that throttle position, I bet you were closer to 5-7" of vacuum.
Taken from a port right under the throttle body Vacuum reads 100kpa which translates to 0” of vacuum at 83% throttle which means there is no restriction at the intake. Just took the car for a driveAbsolutely!! I bet that body wasnt even flowing 750CFM at that setting. When the blades are cocked over like that, the disruption in the laminar flows are giant. You've probably got some power on the table too. It'd be worth testing a 1 and 2" spacer beneath the TB. @5700rpm, the engine (357ci) is pulling roughly 500-520cfm @ 85% efficiency, and I'd gotta think you're better than that. As flat as that graph is, it's running out of air, which is why I was thinking it wanted more over lap or something.
Did you guys have a vacuum sensor connected?
At full throttle, top of the RPM range, you only want about .8-1" of vacuum. With that throttle position, I bet you were closer to 5-7" of vacuum.
Cam was designed with the intake in mind. Custom grind from Ed Curtis so I can’t really speak for why he chose the specs he did. The intake was brand new and compression test if I remember was 175-180 between each cylinder so that came up fine. Haven’t done a leak down test yet but I’m thinking I should just to rule out every possibility. Gonna try to rent a bore scope to take a good look at the port alignment on the heads/intakeFinally got to sit down and read through your first post again and subsequent posts since I originally read your post on my phone, while sitting on the beach drinking a couple beers......
Before I would go chasing anything else at this point, I'm with @revhead347 and I would check the engine over for mechanical issues. The coolant and oil would be a concern of mine and would need to be addressed before going any further. Do a compression and leak down test to first to check head gasket/ect. You need to find the cause of these issues before you go chasing more power. These issues alone can cause power and tuning issues.
I'm also still fairly confident that cam is just not working well with your intake and head combo after looking at the specs closer. You have a large runner intake that is ideally suited for 351+ cubic inch engines running from 4000-8000rpm. You have a 205cc 66cc head running 10.1 compression. That head/intake combo is not ideal for a N/A 6700 RPM 357 cubic inch engine. Now, the Super Vic does put out some surprisingly good low end torque numbers for it's size and the 11r 205 heads are great street/strip heads with great port velocity and flow numbers across the board, so I think you could work with those parts if you get an appropriate cam and spin it to 7K.
If I had looked at your engine specs with no other information, I would have thought this engine was built for boost with those parts. Was that that intake new when you put it on the car?
Just my 2 cents
Car was meant to be a daily driver but still try to make 400 to the tire. Can cruise around at 1300 rpm and it feels stock aside from the loud exhaust. I checked port alignment with the first go around but I had the intake off to fix a vacuum leak at the runners so I’m just gonna be safe and double check it. Might be able to get away with taking the throttle body off and having a look in there with my phone. Compression test was done after putting it back together having the intake off so about a month backWhen did you do your comp test? After you started to see the coolant weeping? Not that it's definitive, just checking.
Def. check your port alignment, I thought you said you had checked that already. Being a new intake, it should have been straight and ground at the right angle. You can get different size intake gaskets to help with port alignment when you have the intake/heads/deck ground. Ed sells some nice ones, I just used his .200 gasket to get my alignment correct.
As long as Ed new everything about your combo and intentions, then I'd be hard pressed to fault him on his cam design. He def. knows tons more then I do about cam design, though that cam just seems odd for the combo from anything I've ever used.....
It was me, it’s my first build and I wanted it to be a good learning experience. Left the cam choice to be custom and Ed never objected to the selected parts. Was between a super vic and the tfs single plane but that was on back order for several months and needed an intake ASAPWho spec'd your engine combo for those goals if I can ask?
Yeah, def want to get that throttle to open all the way, but personally I'd still want to find and fix the leak issues first and work my way down my list.Your first order of business is getting that throttle WIDE open. It matters.
One thing I would like to know, those heads , straight from TFS are supposed to be good to .600 lift. And you were saying your cam was 600ish... Did you check clearances? 40+ years ago, I learned the hard way, you gotta check everything. Coil bind, guide to keeper/retainer clearance (which was where my first machine shop nightmare started).
As far as the grind goes, its a relatively short duration cam with a bunch of lift. Im not sure your getting what you could out of those heads like that, but, I agree that it should probably make a little more power IF THE THROTTLE OPENED UP ALL THE WAY...
I was comparing some of my parts to a build article on hot rod magazine where they pumped out 505 hp with 357 cubes and 11r heads. Cam was around 228@ 50 with around 570 lift if I’m remembering correctly. 108 Lsa and had 10.7:1 comp with 19011r headsHis cam screams supercharger to me. I think he could do himself some good by setting that ILC at 105, if the intakes dont get into the pistons.
With that wide LSA, the cam will still carry the top end. The later IC setting work ok with super chargers because you use the charger to fill the cylinder and build low speed cylinder pressure.
Stretching those LCs out is a way of stretching the peak power out without losing the bottom and middle, but there's a point of diminishing returns and I think he's about 2-3 degrees beyond that in an NA application.
I use DynoSim6 a LOT. And the accuracy there is pretty amazing. The last engine I did was a 501ci Dart, with Dart Pro1 345cc intakes, 13.2:1 compression with a .747 lift mech roller and a 1050 BLP Carb. It's a Circle track boat engine. I took the time to enter all the flow numbers from the heads, imported the cam, and duplicated the rest to the actual engine and I was within 6hp of what the Sym predicted. I made 775hp at 6800 and 635ft lbs at 5500 with an acceptable curve (ya gotta be able to drive a circle boat). The engine accordin to the sym is a cam and intake manifold from 1000hp, but it has to run WFO for 7 miles at a time.
If I can get a full cam card, and actual flow numbers from those heads, I'll take the time to enter all that data into the Sym (probably take an hour and a half or so) and tell you where you can really hope to land, hp and tq wise.
The most bizarre thing with the Sym, it even predicted the ignition timing. With those giant 119cc Chambers, I had a 48.5cc dome. With that giant dome, you have to advance the timing to get the flame front started to get hatched out over the dome. Sym predicted 41. I ended up at 40.
In the end, I agree with fixing any leaks. You can check the port alignment with a bore scope, but I doubt it's enough to kill 50hp. As long as the head is bigger than the manifold, it's fine. The heads and manifold are good parts. You've got plenty of TB on it (if its open) that's going to leave cam and cam timing.
If I was going to guess, the cam he has is +/- a degree or two to a Comp XFI236HR-14, with a little more lift. And that signs off at 6300. Almost exactly what he's got going on.
Ptv was .250 intake and .375 exhaustYeah, def want to get that throttle to open all the way, but personally I'd still want to find and fix the leak issues first and work my way down my list.
TFS lists them as .600, but they are technically good to .650 lift. They use PAC valve springs. He should already have pistons with the correct valve reliefs already to run that lift, not that PTV clearance shouldn't be checked. You don't gain much in static flow going over .600 lift mark on those heads since they are still a standard intake port height SBF with shallow valve angles, so the short side turn radius is fairly sharp and limits high lift flow. They are excellent in the low to mid lift flow though and have a very efficient chamber, which is why you can run such low timing (usually 28-30 total). Most street/strip cams I see ground for the 11r don't go above .600 lift and usually stay in the .58-.59 range and have more duration.
Just for comparison, here is the cam I am running in the TFS 205 11R headed 363 I am building. This is built for a supercharger and has 9.3 to 1 static comp ratio.
And @Cclaro, I wasn't knocking your head and intake choices, they are great parts in their own right. Knowing what your goals are now, I personally would have went with a 190 11r and a slightly smaller intake. Reason being, to keep port velocity up for better low to mid range power while still being able to support your max rpm effort. I think I might see what Ed did here now, he decreased duration and increased lift to compensate for the large port size to help with low to mid power..... I've seen that done on circle track engines when the port size was too large. Though the 114 LSA still throws me off, usually that's tightened up a little as well.
That LSA from 108 to 114 is HUGE.I was comparing some of my parts to a build article on hot rod magazine where they pumped out 505 hp with 357 cubes and 11r heads. Cam was around 228@ 50 with around 570 lift if I’m remembering correctly. 108 Lsa and had 10.7:1 comp with 19011r heads-
Yep, that was my first thought when I saw his specs. Then was a little surprised when I saw it was N/A, and even more surprised when he stated his goals.His cam screams supercharger to me. I think he could do himself some good by setting that ILC at 105, if the intakes dont get into the pistons.
With that wide LSA, the cam will still carry the top end. The later IC setting work ok with super chargers because you use the charger to fill the cylinder and build low speed cylinder pressure.
Stretching those LCs out is a way of stretching the peak power out without losing the bottom and middle, but there's a point of diminishing returns and I think he's about 2-3 degrees beyond that in an NA application.
I use DynoSim6 a LOT. And the accuracy there is pretty amazing. The last engine I did was a 501ci Dart, with Dart Pro1 345cc intakes, 13.2:1 compression with a .747 lift mech roller and a 1050 BLP Carb. It's a Circle track boat engine. I took the time to enter all the flow numbers from the heads, imported the cam, and duplicated the rest to the actual engine and I was within 6hp of what the Sym predicted. I made 775hp at 6800 and 635ft lbs at 5500 with an acceptable curve (ya gotta be able to drive a circle boat). The engine accordin to the sym is a cam and intake manifold from 1000hp, but it has to run WFO for 7 miles at a time.
If I can get a full cam card, and actual flow numbers from those heads, I'll take the time to enter all that data into the Sym (probably take an hour and a half or so) and tell you where you can really hope to land, hp and tq wise.
The most bizarre thing with the Sym, it even predicted the ignition timing. With those giant 119cc Chambers, I had a 48.5cc dome. With that giant dome, you have to advance the timing to get the flame front started to get hatched out over the dome. Sym predicted 41. I ended up at 40.
In the end, I agree with fixing any leaks. You can check the port alignment with a bore scope, but I doubt it's enough to kill 50hp. As long as the head is bigger than the manifold, it's fine. The heads and manifold are good parts. You've got plenty of TB on it (if its open) that's going to leave cam and cam timing.
If I was going to guess, the cam he has is +/- a degree or two to a Comp XFI236HR-14, with a little more lift. And that signs off at 6300. Almost exactly what he's got going on.
I was comparing some of my parts to a build article on hot rod magazine where they pumped out 505 hp with 357 cubes and 11r heads. Cam was around 228@ 50 with around 570 lift if I’m remembering correctly. 108 Lsa and had 10.7:1 comp with 19011r heads
I’d trade the power over drive ability, if I wanna step things up in the future I might go ahead and look for a more aggressive grind. Just wanna try to get it into the 11s in the quarterYep, that was my first thought when I saw his specs. Then was a little surprised when I saw it was N/A, and even more surprised when he stated his goals.
I think once you put his combo into DynoSim you'll see the camshaft is a compromise to keep that combo as streetable as possible, as was his goal. That compromise is killing top end power. I agree with everything you are saying concerning typical camshaft design btw, I just don't think he is going to see his numbers with that cam no matter what he does. With that intake and heads, he should be planning to pull 7000 RPM and have a 3500 RPM+ powerband, or be boosted. He wanted a more street friendly engine, and it looks like Ed delivered.
And DynoSim is a great tool. I've been using 5 for awhile and should look into upgrading, but it does what I need. Most anything in an Engine is quantifiable, so it's just knowing how to calculate all the variables together to be able to predict engine output and needs. I just tend do the math by hand still for general calculations since I have a cache of formulas from Vizard, Smokey, ect that seem to get you really close. I'd be curious to see what Dynosim has to say about his combo. TFS publishing their flow data on their heads, so you can find the 11r 205 numbers here: https://static.trickflow.com/global/images/chartsguides/t/tfs airflow tw 11r 205cc 2014c.pdf
Yeah, that's what I would expect to see out of a well matched combo. You figure, that 505 is without accessories and on an engine dyno. Put engine accessories on it and a transmission behind it, and that's where the 410-430 RWHP number comes from that I would expect to see. And yep, there is the tighter LSA I would expect.
There's almost 80hp in just the drive line (trans, u joints, differential, brake drag on the drums/discs etc). I've seen alternators cost 22hp alone. Throw a power steering pump, water pump, and whatever else...it's easy to see a parasitic loss down to 380ish at the tire from 505.Yep, that was my first thought when I saw his specs. Then was a little surprised when I saw it was N/A, and even more surprised when he stated his goals.
I think once you put his combo into DynoSim you'll see the camshaft is a compromise to keep that combo as streetable as possible, as was his goal. That compromise is killing top end power. I agree with everything you are saying concerning typical camshaft design btw, I just don't think he is going to see his numbers with that cam no matter what he does. With that intake and heads, he should be planning to pull 7000 RPM and have a 3500 RPM+ powerband, or be boosted. He wanted a more street friendly engine, and it looks like Ed delivered.
And DynoSim is a great tool. I've been using 5 for awhile and should look into upgrading, but it does what I need. Most anything in an Engine is quantifiable, so it's just knowing how to calculate all the variables together to be able to predict engine output and needs. I just tend do the math by hand still for general calculations since I have a cache of formulas from Vizard, Smokey, ect that seem to get you really close. I'd be curious to see what Dynosim has to say about his combo. TFS publishing their flow data on their heads, so you can find the 11r 205 numbers here: https://static.trickflow.com/global/images/chartsguides/t/tfs airflow tw 11r 205cc 2014c.pdf
Yeah, that's what I would expect to see out of a well matched combo. You figure, that 505 is without accessories and on an engine dyno. Put engine accessories on it and a transmission behind it, and that's where the 410-430 RWHP number comes from that I would expect to see. And yep, there is the tighter LSA I would expect.
ProCharger. Done. With that manifold and heads, at 6 pounds of boost, Im telling you, youre knocking on the door of 700hp. Push 10 psi in there...youve got axle problems.I’d trade the power over drive ability, if I wanna step things up in the future I might go ahead and look for a more aggressive grind. Just wanna try to get it into the 11s in the quarter
Not that these tests are universal by any means but I’ve seen that the biggest power difference is made between the water pump and alternator. I think engine power had a total loss of like 24 horseThere's almost 80hp in just the drive line (trans, u joints, differential, brake drag on the drums/discs etc). I've seen alternators cost 22hp alone. Throw a power steering pump, water pump, and whatever else...it's easy to see a parasitic loss down to 380ish at the tire from 505.
10:1 compression seems a little bit high for boost dont you think? I’d hate to restrict the car to just race gas or e85ProCharger. Done. With that manifold and heads, at 6 pounds of boost, Im telling you, youre knocking on the door of 700hp. Push 10 psi in there...youve got axle problems.
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