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Mopar 340 max rpm? #90593 07/19/08 03:08 AM 07/19/08 03:08 AM
A Anonymous OP Unregistered
Anonymous OP Unregistered A	It's basically all in the title. What is the max RPM of a stock 340? What is it's redline? Thanks

Re: Mopar 340 max rpm? #90594 07/19/08 06:53 AM 07/19/08 06:53 AM
Joined: Jan 2003 Posts: 25,200 Upper Midwest M MoparforLife Too Many Posts
MoparforLife Too Many Posts M Joined: Jan 2003 Posts: 25,200 Upper Midwest	They were really pretty well done in stock form by or before 5800. Sure there are going to guys say well I ran my over and over to 7000 but these should have gotten better tachometer or didn't know/care when the engine was past it's peak. Plus the valves would float long before that/

Re: Mopar 340 max rpm? #90595 07/19/08 10:18 AM 07/19/08 10:18 AM
Joined: Aug 2003 Posts: 4,463 Rome, PA Ryan_340 master
Ryan_340 master Joined: Aug 2003 Posts: 4,463 Rome, PA	I wouldn't turn a stock one much over 6,000 myself. 1972 Power Wagon W100 1973 Power Wagon W200 1971 Duster 1972 Dart Swinger 3-1972 Demons

Re: Mopar 340 max rpm? [Re: Ryan_340] #90596 07/19/08 10:24 AM 07/19/08 10:24 AM
Joined: Jan 2003 Posts: 25,200 Upper Midwest M MoparforLife Too Many Posts
MoparforLife Too Many Posts M Joined: Jan 2003 Posts: 25,200 Upper Midwest	Quote: I wouldn't turn a stock one much over 6,000 myself. You are completely correct. I didn't proof read and hit a 6 instead of a 5. (too early ion the morning) Have edited to the original intent of 5800. After that you ran into point and/or valve float on a lot of them, not to mention the fact you were past the peek power range anyway. Clean it, if it's Dirty. Oil it, if it Squeaks. But: Don't fix it, if it Works!

Re: Mopar 340 max rpm? [Re: MoparforLife] #90597 07/19/08 10:29 AM 07/19/08 10:29 AM
Joined: Jul 2003 Posts: 1,593 USA V VS29H0B pro stock
VS29H0B pro stock V Joined: Jul 2003 Posts: 1,593 USA	+1 There is no point in revving any engine past it's power peak. You won't get any more horsepower, and all you are likely to do is cause damage. 6,000 RPM is about all you should ask out of a stock 1968 - 71 340 with higher compression. Valve train float at any RPMs above peak mean great risk of serious internal engine damage. Like the women I have dated --- Always looking for a better deal ....

Re: Mopar 340 max rpm? #90598 07/19/08 11:24 AM 07/19/08 11:24 AM
A Anonymous OP Unregistered
Anonymous OP Unregistered A	The 73 Duster 340 I used to have (when it wasn't too far from new) was pretty well done at 5200 with the stock exhaust manifolds. Headers raised the shift point to 5800, everything else the same.

Re: Mopar 340 max rpm? #90599 07/19/08 02:37 PM 07/19/08 02:37 PM
Joined: Aug 2004 Posts: 3,333 MARYLAND 69Cuda340S master
69Cuda340S master Joined: Aug 2004 Posts: 3,333 MARYLAND	Here is a good article with some tips on how to deal with valve float: http://www.compcams.com/Community/Articles/Details.asp?ID=-738676943

Re: Mopar 340 max rpm? [Re: 69Cuda340S] #90600 07/19/08 02:49 PM 07/19/08 02:49 PM
Joined: Jan 2003 Posts: 25,200 Upper Midwest M MoparforLife Too Many Posts
MoparforLife Too Many Posts M Joined: Jan 2003 Posts: 25,200 Upper Midwest	He asked about STOCK - not modified. If you will note the power curve still drops off as we mentioned above. Nothing really new there. By the way I have a set of those valve springs here - new in the box. Give someone a good deal on them.

Re: Mopar 340 max rpm? [Re: MoparforLife] #90601 07/19/08 07:50 PM 07/19/08 07:50 PM
Joined: Jan 2003 Posts: 1,481 Outside thedriver pro stock
thedriver pro stock Joined: Jan 2003 Posts: 1,481 Outside	i used to run a pure stock 340 duster. the car would run its best times with the shifter left in drive...it shifted somewhere between 5600-5800. 6000rpm would be the tops i would go. 1973 challenger Dana. 4 speed. Low deck.

Re: Mopar 340 max rpm? [Re: thedriver] #90602 07/20/08 12:05 AM 07/20/08 12:05 AM
A Anonymous OP Unregistered
Anonymous OP Unregistered A	I read an article on the 340 and it said that because of the free flowing heads, it could rev up to like 8000. I was skeptical, and I guess I was right. That seemed pretty high. Thanks Everyone

Re: Mopar 340 max rpm? #90603 07/20/08 01:23 AM 07/20/08 01:23 AM
Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska	Mauisnow13 if you are up for alot of reading(online of course) on this subject you might go to www.moparchat.com & scroll down to & click on circle track chat & read Sanborns oiling mods that are in a sticky at the top. Alot of SB high rpm oiling mods/prep.Excellent material but again a long read. Last edited by RapidRobert; 07/20/08 01:24 AM. live every 24 hour block of time like it's your last day on earth

Re: Mopar 340 max rpm? [Re: MoparforLife] #90604 07/20/08 08:22 AM 07/20/08 08:22 AM
Joined: Jan 2003 Posts: 7,978 Bethel Ct A AdamR master
AdamR master A Joined: Jan 2003 Posts: 7,978 Bethel Ct	Quote: He asked about STOCK - not modified. The first test is a stock rebuild.

Re: Mopar 340 max rpm? [Re: AdamR] #90605 07/20/08 10:32 AM 07/20/08 10:32 AM
Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska	this is an opportunity for me to put into practice my belief that argueing on these message boards is like wrestling with a greased pig, you can't win & sooner or later you figure out that the pig likes it DAMHIK. live every 24 hour block of time like it's your last day on earth

Re: Mopar 340 max rpm? [Re: RapidRobert] #90606 07/20/08 01:43 PM 07/20/08 01:43 PM
Joined: Jan 2003 Posts: 7,978 Bethel Ct A AdamR master
AdamR master A Joined: Jan 2003 Posts: 7,978 Bethel Ct	Seems like every one os agreeing that for a stock 340 theres no need to go over 6000.

Re: Mopar 340 max rpm? [Re: AdamR] #90607 07/20/08 02:21 PM 07/20/08 02:21 PM
Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska	Quote: Seems like every one os agreeing that for a stock 340 theres no need to go over 6000. live every 24 hour block of time like it's your last day on earth

Re: Mopar 340 max rpm? [Re: RapidRobert] #90608 07/20/08 02:59 PM 07/20/08 02:59 PM
Joined: Apr 2005 Posts: 12,271 Overpriced Housing Central RobX4406 I Live Here
RobX4406 I Live Here Joined: Apr 2005 Posts: 12,271 Overpriced Housing Central	I have a really stock build 340 using factory spec valve springs. It will turn 6200. It runs best when shifted at 5600-5700. Max RPM is about 50 rpm short of where it blows up!

Re: Mopar 340 max rpm? [Re: RobX4406] #90609 07/20/08 03:27 PM 07/20/08 03:27 PM
Joined: Oct 2004 Posts: 966 Nebraska 7 71blueduster super street
71blueduster super street 7 Joined: Oct 2004 Posts: 966 Nebraska	When I had my Duster on the dyno, they took my 340 (XE268 Comp Cam with stock X heads) to 6300, but it made peak power around 5700 rpms.

Re: Mopar 340 max rpm? #90610 07/20/08 04:19 PM 07/20/08 04:19 PM
Joined: May 2007 Posts: 209 New Zealand S solidcam enthusiast
solidcam enthusiast S Joined: May 2007 Posts: 209 New Zealand	Everyone has mentioned valve float and after you have experienced it you will look at ways of limiting it.For me I ran a stock 340,with j heads,isky springs and 653 Mopar solid cam to 7k(tacho works fine) with no float(engine did have a few extra mods but stock bottom end)What killed the engine was partly detonation and mostly bearing failure,ie stock sump trying to supply the engine oiling requirement at those revs.If you want to rev the 340 and make it live you will need to look at some aftermarket parts and go into block/valve train prep.

Re: Mopar 340 max rpm? [Re: solidcam] #90611 07/21/08 10:01 AM 07/21/08 10:01 AM
Joined: Feb 2004 Posts: 3,934 Nova Scotia Canada B2Y 1E4 SANDYinNS Canada master
SANDYinNS Canada master Joined: Feb 2004 Posts: 3,934 Nova Scotia Canada B2Y 1E4	Quote: Everyone has mentioned valve float and after you have experienced it you will look at ways of limiting it.For me I ran a stock 340,with j heads,isky springs and 653 Mopar solid cam to 7k(tacho works fine) with no float(engine did have a few extra mods but stock bottom end)What killed the engine was partly detonation and mostly bearing failure,ie stock sump trying to supply the engine oiling requirement at those revs.If you want to rev the 340 and make it live you will need to look at some aftermarket parts and go into block/valve train prep. Add some good springs and a deep pan to rev one higher than 6500. When I was younger and stupid I used to top end race on the highway. scatted 2 of them . The stock pan doesn't hold enough oil for sustained high rpm. If you add a high volume oil pump its even worse. The stock short block on a steel crank 340 is good for atleast 8000 rpm. The limiting factor is the heads. I agree the stock 340 is pretty much done at 6k A buddy has restored (stock looking)340 70 swinger with some mild porting and a bit more cam it will pull till 6500. The extra rpm a 340 is good for comes in handy for missed shifts with a 4 gear! Sandy in Nova Scotia formerly drdodge340 68 coronet wagon, 68 formula s 340 fb barracuda-69 super bee-72 aussie charger-72 aussie vh dodge ute -76 feather duster-76 duster-77 street van - 98 ram 1500 SS/T-99 ram 1500-13 ram red express truck- 2015 hellcat challenger

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