951 Engine Rebuild Project
01-28-2011, 03:58 PM
#16
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John there are plenty of people who have questioned the stock intake and blame the design for mismatched flow which inturn can/have possibly caused problems...however this may also be anecdotal or bench racing. Not too many have flowed the stock one and I don't think I've seen any hard data showing comparisons between them, modified stock, and aftermarket. This would be nice to see but it's highly unlikely to happen publicly for all the obvious reasons. The one on my 3L is extruded honed and has had some mods done to equalise flow. The builder of that Yellow aussie racecar saw a picture of it and suggested that no matter what you do to the stock intake it would cause failure somewhere along the line...in a racecar application. He said that they had flowed all the components and this was his conclusion. He also said that the stock TB would flow something like 1130cfm which contradicts current beliefs. Perhaps flow benches are like dynos. You can get all sorts of reads?
And yes flow benches are much like Dynos... A LOT of the outcome is the operator / setup...
I'm not one to say the stock intake is the be all end all, but it is VERY good for street use! Can it be improved, yes, but the AM intakes available you have to give something up to gain, and in this case I believe what he will be giving up is not in line with his intended use...
But that is just my oppinion.. were it a race car, sure short runner large plenum, geared to WOT... but on a street car?
01-29-2011, 08:26 AM
#17
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I have never figured out what the fixation is to modify the stock intake. The stock intake does a pretty good job for the RPM range it was designed for - and that is the rpm range that 99.5% of all 944 turbo engines should operate. The gains of the highly modified intakes are pretty minimal. The main reason I use them is on the 16v turbo project which require a modified intake to work.
I have run quite a few stock intake 8v engines with 4 channel EGT and full sequential tuning – I don’t find the need to tweak any single cylinder. Contrary to some theories the failure of the head gasket at #4 cylinder is not because of a lean condition.
I am not sure what the target is for the intake manifold pictured earlier in this thread – I am guessing that it is just more plenum volume? That’s a lot of work for a small gain. Turbo cars are nowhere near as fussy about intakes as NA cars. In NA cars this would make a noticeable difference. It would be interesting to see a direct comparison – if Dr. D. were just a little closer (!) I would offer up a dyno test session where we could swap the intake right on the dyno.
If you want to read the ‘ultimate’ thread on intake manifolds take a look here – be forewarded that you will give up at least an hour of your life (its worth it – no skipping ahead!)….. http://forums.hybridz.org/index.php?showtopic=61549
I have run quite a few stock intake 8v engines with 4 channel EGT and full sequential tuning – I don’t find the need to tweak any single cylinder. Contrary to some theories the failure of the head gasket at #4 cylinder is not because of a lean condition.
I am not sure what the target is for the intake manifold pictured earlier in this thread – I am guessing that it is just more plenum volume? That’s a lot of work for a small gain. Turbo cars are nowhere near as fussy about intakes as NA cars. In NA cars this would make a noticeable difference. It would be interesting to see a direct comparison – if Dr. D. were just a little closer (!) I would offer up a dyno test session where we could swap the intake right on the dyno.
If you want to read the ‘ultimate’ thread on intake manifolds take a look here – be forewarded that you will give up at least an hour of your life (its worth it – no skipping ahead!)….. http://forums.hybridz.org/index.php?showtopic=61549
01-29-2011, 02:48 PM
#18
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Hmm, it looks like the resonance length of the runners on that custom intake manifold corresponds to ~9000 rpm.
Many people here talk about the unequal runner length on the stock manifold. To them: Please take the effort to actually measure/estimate the center lengths for example with a tape measure, string or bendable wire) and post here the estimated mean and percent differences. I think you’ll be surprised.
Laust
Many people here talk about the unequal runner length on the stock manifold. To them: Please take the effort to actually measure/estimate the center lengths for example with a tape measure, string or bendable wire) and post here the estimated mean and percent differences. I think you’ll be surprised.
Laust
01-29-2011, 05:31 PM
#19
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See, there we go. We have strong support for the stock intake and yet this guy that built the Aussie thing was dead against it and claims to have had it all tested. I spoke to him at length about all sorts of subjects on these motors. His concern was more #1 than #4. I'm not saying that any of this is gospel. I wasn't there at the tests so can't claim this to be 100% set in stone. I think for a road car the stock one is fine 100% of the time. For a high powered track car, not so sure...probably fine if you can watch and tune each cylinder.
01-30-2011, 12:01 AM
#20
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It is made for high revs. Not purposely I suppose,but the preferred sport by most local mechanics is drag racing and their thoughts are biased towered high revs and high dyno numbers. Im an engineer so i do agree with John and Chris. I'm working towards efficiency and purpose.
What about the data Lindsey states in his site about the intakes?
I am willing to negotiate donate or trade the intake to somebody wnho may have the time and commitment to the forum to post results and data.
What about the data Lindsey states in his site about the intakes?
I am willing to negotiate donate or trade the intake to somebody wnho may have the time and commitment to the forum to post results and data.
07-25-2011, 11:54 PM
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Any updates on your rebuild?
i did get my engine back from the machine shop...(get some pics soon), got the engine rebuild kit since the machine shop guy verified the crank and it was fine, just a little cleaning (THANK GOD).
Well I decided to try out the cometic head gasket. So the following was done:
- Resurfaced block gasket surface
- Stayed with stock studs (bought new)
- Reconditioned head (Resurfaced since it had some small spots that needed welding), cleaned valves seats, the std stuff.
- Lindsey steam kit hole
- Lightened stock flywheel slightly
- Balanced engine components
I still have to send in the cam to see if it's ok.
10-30-2012, 06:44 PM
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OK...I am real lazy for documenting this stuff but here are some pics of the rebuild and updates. Here's the reason why I've taken so long... "Baby steps"...literaly!
-You can see the oil tube support purchased from Paragon.
-I also received my rebuilt and upgraded clutch from clutchmaster. VERY NICE!
-Percks of the job and playing around at our powder line...
-You can see the oil tube support purchased from Paragon.
-I also received my rebuilt and upgraded clutch from clutchmaster. VERY NICE!
-Percks of the job and playing around at our powder line...
02-17-2017, 12:48 PM
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Sorry for leaving this all behind....I found a second one!! LOL! I gotta stop working on these cars...a second one popped out 
Anyhow, the cars running pretty great... let me take a break and I'll upload the pics and update!!
Anyhow, the cars running pretty great... let me take a break and I'll upload the pics and update!!
Last edited by Dr. Dynamics; 02-17-2017 at 12:49 PM. Reason: fix pic link
