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2.4 "T" Performance Potential

I'm just kind of daydreaming here (slow day at work), so I was wondering what can reasonably be extracted from a street going 2.4 T engine. I have a '72 T that I picked up earlier this year that has a very strong running, recently rebuilt, all original engine. It still has MFI, which is well tuned and runs quite well. It seems like higher compression through the use of 2.2 "S" pistons and more aggressive cam timing from some "E" cams are popular improvements on these engines. How much of an increase in power are these changes worth? Can I run higher compression than the "S" pistons without twin plugging? How high could I go if I were willing to twin plug, and would that provide a worthwhile increase over the "S" pistons? Do the iron cylinders present some kind of limit related to their ability to dissipate heat? Maybe a better, more all-inclusive question would be just what is possible without changing any of the major castings?
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Jeff
'72 911T 3.0 MFI
At the track: http://www.youtube.com/watch?v=_YjzSZmGXZ8
'93 Ducati 900 Super Sport
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Old 11-05-2004, 09:37 AM
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dtw dtw is offline
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Do a search. This has been exhaustively covered by me, Tyson Schmidt, Tim Walsh, and many others.
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Old 11-05-2004, 01:27 PM
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Warren Hall Student
 
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If the car is for "street going" then the only thing I would consider would be higher compression pistons. I think that the T cams and ports are the ideal choice for a 2.4L street motor. I believe it was Road & Track that felt the same when they tested the T,E & S way back in 72' or so.

I personally wouldn't go for the bigger cams and ports unless they were accompanied with a displacement increase to offset the peakiness of the bigger cams.

You've got a great motor, I know because I have the same one in my 72'T. I love it.

Have you considered suspension, wheels and tires as a means of getting better performance? That might be the way to go for now.
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Old 11-06-2004, 12:54 AM
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I have a '72T motor I just rebuilt, and the only upgrade I have are 2.2L T pistons. I really have no clue if it's a noticeable increase since my car had a blown engine when I bought it.

That aside, I'm happy with the performance. It's a very light, tossable car that has excellent throttle response.
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Old 11-06-2004, 02:51 PM
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Set the compression around 9.5-1 and use a set of my Solex with 102 lobe center cams. The engine will have a nice wide powerband without being "peaky" like a 911 S
Unless you have the worst fuel in the world, twin plugging would not be required.
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Old 11-06-2004, 04:35 PM
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John, (camgrinder) I am just beginning a 73T rebuild and also considering some options

- would these solex cams work with standard compression ie. 7.5 ? don't know if I'm going to need pistons or not yet
- will the MFI pump need to be recalibrated?

Thanks, Joe
Old 11-07-2004, 04:58 PM
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Hi Joe,
The wide lobe center solex cams like compression. I would like to see a minimum of 8.5-1.
Yes the MFI pump would need to be recalibrated.
The E cam is the best choice for a T style engine with normal compression.
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Old 11-07-2004, 05:03 PM
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Dave, could you find your thread and post a link? I did a search before I posted originally and I didn't find it. I did read the Road and Track review from '72 that some one posted here some time ago. It was interesting to read the comments on how the three models compared. Anyway, my engine only has about 15,000 miles on it right now. I will be going through the suspension before the engine, but I am kind of getting some sort of a long range plan together. I'm just wondering if I should budget for any major engine components, like new cylinders and heads. I've seen a lot of positive comments on using 2.2 "S" pistons in 2.4's, the good results obtained with "E" cams in street 2.4's, and such. Most of it seems geared to aluminum cylinders and the larger ported "E" heads. If I can stick with my original castings and run this combination, that would be great. Would the iron cylinders present any issues?
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Jeff
'72 911T 3.0 MFI
At the track: http://www.youtube.com/watch?v=_YjzSZmGXZ8
'93 Ducati 900 Super Sport
"God invented whiskey so the Irish wouldn't rule the world"
Old 11-07-2004, 07:17 PM
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Another possibility to consider is having the T cylinders bored to 85mm for the 9.5 J&E pistons. This combined with E cams was recommended to me by EBS and others, and I already had a set of Webers. Should be running by spring.
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Old 11-08-2004, 05:55 PM
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David, that's pretty much what I have been leaning towards on mine. That is the combination that I see recommended the most for the "T" engine. It certainly sounds like the easiest way to go. I was just kind of wondering what the advantages or dissadvantages may be in going with even higher compression, and what the upper limit is before the need for running twin plugs. If I were willing to twin plug it, would a "T" engine run well with significantly higher compression, say in the 11:1 to 12:1 range? Would I just be opening a whole can of (expensive) worms, or would such a combination be workable?
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Jeff
'72 911T 3.0 MFI
At the track: http://www.youtube.com/watch?v=_YjzSZmGXZ8
'93 Ducati 900 Super Sport
"God invented whiskey so the Irish wouldn't rule the world"
Old 11-09-2004, 05:07 AM
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Send a message via AIM to Tim Walsh
Do a search on 2.4T and partial name Walsh and you'll find alot of threads that came up in the last year or so about my new motor, and Dtw's new motor.
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Tim
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Old 11-09-2004, 05:27 AM
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Thanks Tim. It looks like you have this topic pretty well covered. I tried all kinds of searches on every combination I could think of concerning this, and either came up with way too much unrelated information to sift through or not much at all. Adding your name to the search sure helped. It looks like I've got some reading to do. Thanks again.
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Jeff
'72 911T 3.0 MFI
At the track: http://www.youtube.com/watch?v=_YjzSZmGXZ8
'93 Ducati 900 Super Sport
"God invented whiskey so the Irish wouldn't rule the world"
Old 11-09-2004, 12:26 PM
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