Just got some numbers back from my heads which are 2.0 914 heads 44x38, but have some questions about them to be sure they are accurate. A local shop did it and he doesnt usually work on vw heads. He flowed the heads not usung the manifolds on them and the ehaust was flowed without a pipe. Is this pretty standard way of flowing these heads
Software is flow kwik 28" H20 and numbers are as follows :
Int Exh
.100 66.7 52.6
.200 123.5 96.4
.300 165.6 121.5
.400 196.6 131.1
.500 211.3 127.6
.550 214.1 126.1
do these sound about right. I was told that not using a manifold on the head while flowing gives you higher Intake flow and if I had used a pipe on exhaust side it will usually increase flow about five percent.?? Does anyone know if this is true?/
Any opinions on these numbers i know nothing about what they mean.
Head floow
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MASSIVE TYPE IV
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He shoukld have known better than that...
You need tests done with the manifold and with some sort of exhaust, preferably the one that will be getting used for the engine when its in the car..
Len can go into more detail, but I'll say the intake looks elevated and the exhaust looks like its hurting a bit- totally typical if tested without manifolds attached..
You need tests done with the manifold and with some sort of exhaust, preferably the one that will be getting used for the engine when its in the car..
Len can go into more detail, but I'll say the intake looks elevated and the exhaust looks like its hurting a bit- totally typical if tested without manifolds attached..
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HAM Inc
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Testing without manifolds (in & ex) will draw the #'s down. On the intake side it generally only effects the #'s after .400" lift and on the exhaust it will effect it after around .200. The increase varies from port shape to port shape. Typically the intake flow will pick up around 3-4% the exhaust will see a slightly larger increase with the use of a stub pipe.
The intake #'s you listed are easily achieved with 44 mm valves, though it requires hogging the port. For the street I only recommend peak #'s that high on large displacement (over 2300cc's) engines, and even then it depends on the induction and cam set-up and may not be required in a lot of cases.
At low speeds the loss of velocity in the large ports will yield a sluggish engine at lower speeds that can be difficult if not impossible to tune away. It is very rare that any street engine requires more than 200peak CFM to perform extremely well. If your only concern is peak HP then more is better. Otherwise you may end up with a power plant that has a lot of power up high where you can't use it much.
The exhaust #'s are actually lower than the stock 2.0 914's I've tested. Lower than the correction factor for not testing with a stub. I also use FlowQuik software and hardware, so as long as they keep there system calibrated I would expect our #'s to be pretty darn close.
The intake #'s you listed are easily achieved with 44 mm valves, though it requires hogging the port. For the street I only recommend peak #'s that high on large displacement (over 2300cc's) engines, and even then it depends on the induction and cam set-up and may not be required in a lot of cases.
At low speeds the loss of velocity in the large ports will yield a sluggish engine at lower speeds that can be difficult if not impossible to tune away. It is very rare that any street engine requires more than 200peak CFM to perform extremely well. If your only concern is peak HP then more is better. Otherwise you may end up with a power plant that has a lot of power up high where you can't use it much.
The exhaust #'s are actually lower than the stock 2.0 914's I've tested. Lower than the correction factor for not testing with a stub. I also use FlowQuik software and hardware, so as long as they keep there system calibrated I would expect our #'s to be pretty darn close.
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MASSIVE TYPE IV
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- Joined: Fri Jul 07, 2000 12:01 am
Numbers that aren't accurate are of no use at all..
Having the intake manifold and exhaust in place for flow work is not specific only to the TIV engine, its true with ANY cylinder head..
Len goes so far as testing with the intended carb/ T/B in place and even the air filter!
If the person that flowed your heads didn't mention these things to you- I'd find someone else thats not going to waste your money and their effort.
As for how they'll rspond on the 2056- Who knows because we lack empirical data as to their characteristics, therfore everything is speculation!
Having the intake manifold and exhaust in place for flow work is not specific only to the TIV engine, its true with ANY cylinder head..
Len goes so far as testing with the intended carb/ T/B in place and even the air filter!
If the person that flowed your heads didn't mention these things to you- I'd find someone else thats not going to waste your money and their effort.
As for how they'll rspond on the 2056- Who knows because we lack empirical data as to their characteristics, therfore everything is speculation!
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HAM Inc
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Sixty4Vdub you may be making your engine build a little more complicated than it has to be. Even though I own a flow bench and offer the service to any who want to pay for it, I usually recommend most folks don't bother with it unless they are wading uncharted territory where the data becomes essential to cam, exhaust and induction selection. Most D.I.Yers already have at least 2 out of 3 of those components picked out before they have any head work done. An experienced head tech will dial you in based on the intended use of the street vehicle, and the components you have or plan to purchase, no flow work required here.
Unless you are heavily involved in R & D (like Jake or myself) or build enough engines that you want to keep a record of the performance of various combo's, flow data is, for the most part, useless, other than to satisfy your curiousity.
If you plan to use the flow data to select a cam, then let Jake pull something off the shelf that mates up with what you want out of the vehicle, based on his experience. Jake has poured over reams of flow data over the years and even though your heads may not be optimized for your needs, I'm sure he can come up with something that will offer a suitable compromise. Even if the flow data you have is off a by a few % you won't end-up in left field.
There is no need to reflow your heads unless you plan to use them for competition (in this case cam selection will be more critical and therefore accurate flow data is more important), or are willing to spend money to make changes to the heads if you are not happy with the resulting findings.
Unless you are heavily involved in R & D (like Jake or myself) or build enough engines that you want to keep a record of the performance of various combo's, flow data is, for the most part, useless, other than to satisfy your curiousity.
If you plan to use the flow data to select a cam, then let Jake pull something off the shelf that mates up with what you want out of the vehicle, based on his experience. Jake has poured over reams of flow data over the years and even though your heads may not be optimized for your needs, I'm sure he can come up with something that will offer a suitable compromise. Even if the flow data you have is off a by a few % you won't end-up in left field.
There is no need to reflow your heads unless you plan to use them for competition (in this case cam selection will be more critical and therefore accurate flow data is more important), or are willing to spend money to make changes to the heads if you are not happy with the resulting findings.
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sixt4vdub
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Len, I have a 2056 that im trying to get maximum performance out of prior to installation, It seems I have too much head for the car so I m thinking accurate flow data wll enable me to select a perfect cam too optimize hp??? I read its all in the combo..Is the money and work worth my hp gains?? I dont know. I was hoping to get that answered by some one who has experience in this field . What is the most hp one can get from a 2056 and what does it take to get there?? It would be a no brainer if I had $5k a 2316 comes to mind but that is quite pricey for my budget. Maybe in a few years . All these questions I ask are to learn more about what avenues i will finally end up routing my build. The car is just a toy that i want to have a good bit of power. The more the better. Hopefully i will figure it out soon. Thanks for all your replies.
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MASSIVE TYPE IV
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Without making an undrivable engine the limit on a 2056 is about 135 HP and about 140 on torque..
I can get you 220 ponies out of the combo, but it will be useless on the street because the cam comes on at 5,500 RPM!
If you want bigger usable power- stroke it!
Undoubtedly if you get the heads flowed I can pick one of my cams for you.
I can get you 220 ponies out of the combo, but it will be useless on the street because the cam comes on at 5,500 RPM!
If you want bigger usable power- stroke it!
Undoubtedly if you get the heads flowed I can pick one of my cams for you.
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HAM Inc
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- Joined: Wed Jan 14, 2004 7:33 am
Sixt4vdub it looks like you essentially have two options. You can ask Jake to select a cam based on the flow data you have and hope that it is fairly accurate, or you can have the heads reflowed on a trustworthy bench and let Jake select your cam based on the new data.
An accurate measurement of chamber volume is also critical to the proper selection of a cam as well.
An accurate measurement of chamber volume is also critical to the proper selection of a cam as well.