Improved sleeper
10-31-2012, 06:30 PM
#21
Le Mans Master
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383
72 Stingray,
I appreciate your comments. I do need to build the engine for the RPM that I will drive. and that is what I want to do. I keep looking at cam specs and dyno charts to find the best torque under 5000, and more importantly the best torque at 1500-3500 RPM where I see the majority of my shifting. You are correct, that I may be better off getting a good iron head rather than paying to rebuild mine. The Performer RPM claims to be designed for 1500-6000 RPM, maybe I should go with Performer thats advertised from idle to 5000. Of course, the cam has to match the heads on RPM range.
I still am baffled at what seems to be the idea that people routinely operate C3 Corvettes at 5000 plus RPM. Unless you are on a race track, running out to 5000 in each gear will result in major speeds on the way to 4th gear. What am I missing? Cause it sounds more like bragging rights than practical driving. I have a 4.2 liter V6 in my Ford F150, and even with that engine, If I were to go to 5000 RPM in each gear, I would be at highway speeds by 3rd gear! And all I did was flog the engine for nothing.
I appreciate your comments. I do need to build the engine for the RPM that I will drive. and that is what I want to do. I keep looking at cam specs and dyno charts to find the best torque under 5000, and more importantly the best torque at 1500-3500 RPM where I see the majority of my shifting. You are correct, that I may be better off getting a good iron head rather than paying to rebuild mine. The Performer RPM claims to be designed for 1500-6000 RPM, maybe I should go with Performer thats advertised from idle to 5000. Of course, the cam has to match the heads on RPM range.
I still am baffled at what seems to be the idea that people routinely operate C3 Corvettes at 5000 plus RPM. Unless you are on a race track, running out to 5000 in each gear will result in major speeds on the way to 4th gear. What am I missing? Cause it sounds more like bragging rights than practical driving. I have a 4.2 liter V6 in my Ford F150, and even with that engine, If I were to go to 5000 RPM in each gear, I would be at highway speeds by 3rd gear! And all I did was flog the engine for nothing.
10-31-2012, 08:39 PM
#22
Le Mans Master
my suggestion is pocket port your stock heads, shave them a little and install with a thinner gasket. then get something close to the L-82 cam with about a 110 degree lsa a performer intake and port a set of ram horns. you really don't need the torque of a stroker for what you want. you would be amazed how that would run.
11-01-2012, 01:56 AM
#24
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The part that people miss is that all that talk about TQ at lower RPM is always discussed as WOT. At part throttle it doesn't matter. You select parts for part throttle driveability is that is what you want. Driveability is in the tune as much as anything.
When you go WOT at low RPM...some parts will make more power at lower rpm...and then choke up as RPM climbs. If only being used from zero to the speed limit....I wouldn't touch it. I'd just tune a stock engine very well and be done. For me...I like the ability to go past the speed limit...in 1st gear!!
JIM
When you go WOT at low RPM...some parts will make more power at lower rpm...and then choke up as RPM climbs. If only being used from zero to the speed limit....I wouldn't touch it. I'd just tune a stock engine very well and be done. For me...I like the ability to go past the speed limit...in 1st gear!!
JIM
11-01-2012, 07:42 AM
#25
Le Mans Master
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Wot
427,
I am not following you completely about the WOT comment, but here is what I look at it. If I push the gas pedal down and the tach reads 2500 RPM and on my stock engine I have X amount of torque, I will be accelerating at some rate. If I then compare that to an engine with 2X amount of torque, ie.twice the torque at 2500 RPM, then I should be accelerating quite a bit quicker. Maybe not twice as much as I think there is other physics issues going on. And that is what I am looking for, as much torque at the RPM's that I drive as I can get. I could care less what is happenning at 5000 RPM.
I see it as the same thing as how a big block moves the car at lower RPM. So, the 383 idea seems to serve that purpose if not going to go big block.
But in the end, I am just not sure I need to go as far as a 383. WHile I have heard it is just as cheap to build a 383, I don't find it adding up to be cheap because I also want quality and reliability, so I am not going for the cheapest stuff out there just to have 383. Ideally I would like to start with a GMPP 383 Short block, but it is a good $1200 more than a ZZ4 short block. As for using my L-48 engine, my biggest problem is that I don't know any good machine shops in the Pittsburgh area, and not interested in experimenting. I see my heads as being really a liability, the block may be good, but it is a 2 - piece seal, and I was hoping to NOT have leak problems. Who knows what work will need done on the crank? And all of that would cost has to be compared with buying a ZZ4 short block for $2300. Problem with the ZZ4 short block is that it is NOT a 383. IF I could get a good short block with quality parts for $2300 invested, I would consider that.
And I think I may be very satisfied with a decently built 350 that focuses on low end (2500-4000 RPM) torque versus 383. That is really the question that I am still pondering.
Thanks for all the comments, it is helpful, .....and interesting.
I am not following you completely about the WOT comment, but here is what I look at it. If I push the gas pedal down and the tach reads 2500 RPM and on my stock engine I have X amount of torque, I will be accelerating at some rate. If I then compare that to an engine with 2X amount of torque, ie.twice the torque at 2500 RPM, then I should be accelerating quite a bit quicker. Maybe not twice as much as I think there is other physics issues going on. And that is what I am looking for, as much torque at the RPM's that I drive as I can get. I could care less what is happenning at 5000 RPM.
I see it as the same thing as how a big block moves the car at lower RPM. So, the 383 idea seems to serve that purpose if not going to go big block.
But in the end, I am just not sure I need to go as far as a 383. WHile I have heard it is just as cheap to build a 383, I don't find it adding up to be cheap because I also want quality and reliability, so I am not going for the cheapest stuff out there just to have 383. Ideally I would like to start with a GMPP 383 Short block, but it is a good $1200 more than a ZZ4 short block. As for using my L-48 engine, my biggest problem is that I don't know any good machine shops in the Pittsburgh area, and not interested in experimenting. I see my heads as being really a liability, the block may be good, but it is a 2 - piece seal, and I was hoping to NOT have leak problems. Who knows what work will need done on the crank? And all of that would cost has to be compared with buying a ZZ4 short block for $2300. Problem with the ZZ4 short block is that it is NOT a 383. IF I could get a good short block with quality parts for $2300 invested, I would consider that.
And I think I may be very satisfied with a decently built 350 that focuses on low end (2500-4000 RPM) torque versus 383. That is really the question that I am still pondering.
Thanks for all the comments, it is helpful, .....and interesting.
11-01-2012, 10:08 AM
#26
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St. Jude Donor '05
Dont fool yourself from reading your posts youre a cubes type guy
Youll only get X amount from a 350, 383 406 etc without moving the powerband higher. Youve had BBC before so youre ruined lol.....Do the stroker. Get the best set of heads you can afford then youll need less cam to acheive your goals.
No 350 on teh planet given similar parts will make the same tq as a motor with a larger stroke. Sliced and diced a 350 every which way there is wasnt til cubes were added the smiling began.
Youll only get X amount from a 350, 383 406 etc without moving the powerband higher. Youve had BBC before so youre ruined lol.....Do the stroker. Get the best set of heads you can afford then youll need less cam to acheive your goals.
No 350 on teh planet given similar parts will make the same tq as a motor with a larger stroke. Sliced and diced a 350 every which way there is wasnt til cubes were added the smiling began.
11-01-2012, 01:10 PM
#27
Melting Slicks
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St. Jude Donor '09
72 Stingray,
I still am baffled at what seems to be the idea that people routinely operate C3 Corvettes at 5000 plus RPM. Unless you are on a race track, running out to 5000 in each gear will result in major speeds on the way to 4th gear. What am I missing? Cause it sounds more like bragging rights than practical driving. I have a 4.2 liter V6 in my Ford F150, and even with that engine, If I were to go to 5000 RPM in each gear, I would be at highway speeds by 3rd gear! And all I did was flog the engine for nothing.
I still am baffled at what seems to be the idea that people routinely operate C3 Corvettes at 5000 plus RPM. Unless you are on a race track, running out to 5000 in each gear will result in major speeds on the way to 4th gear. What am I missing? Cause it sounds more like bragging rights than practical driving. I have a 4.2 liter V6 in my Ford F150, and even with that engine, If I were to go to 5000 RPM in each gear, I would be at highway speeds by 3rd gear! And all I did was flog the engine for nothing.
Check the specs on RPM intakes. I have Performer RPM Q-Jet and stock air cleaner does not work. I beleive the standard Performer will fit, but I went to RPM to get better alignment with head ports.
11-02-2012, 06:20 AM
#28
A well tuned qjet will easily feed a 383. I think the rams horns will be a restriction for you with a 383, but others with more knowledge will probably weigh in here.
A stock motor with free flowing exhaust (i.e. no cat converter) and a more aggressive distributor and timing curve will produce noticeably better "seat of the pants" feel. New headers/exhaust more so, but you would lose some of the "stock look".
A stock motor with free flowing exhaust (i.e. no cat converter) and a more aggressive distributor and timing curve will produce noticeably better "seat of the pants" feel. New headers/exhaust more so, but you would lose some of the "stock look".
I had rams horns on the 383 I built a year ago and put headers on this summer. I also upgraded the 2" exhaust (no cat) to 2.5" duals with an x-pipe. Instant improvement in the "seat of the pants" acceleration. Now I can break the tires loose from a rolling start with wide rear tires. Couldn't really do that at all with the old exhaust. I do have Vortec heads on the 383 and they fit my budget at the time but many perimeter bolt heads flow much better.
Last edited by myko; 11-02-2012 at 06:23 AM.