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I am trying to get my winter projects in line here and exhaust for the 1971 Cutlass is the main one. Is there any big sound differences between long tube and short headers? Ease of install? Clearance issues between them? I know on my Mustang the long tubes sound better but due to the lack of room underneath as well as low ground clearance they are known to scrape the ground. I doubt this would be an issue with the Cutlass having much more ground clearance and just more room overall. If I was going to use one of those header back system kits, are they designed to work with both (long enough to work with short headers) or are they more intended for the long tubes?
I was also wondering what you guys might suggest to stay on the cheaper side of things. It is not a performance car so something more basic or maybe not as robust would be fine for this car.
I've read your post a few times, and now trying to gauge your expectations. Comparing an olds to mustang is like chinese to english. The parts cataloges have pages of mustang parts. The Olds has...a foot note if anything.
Both exhaust is low hanging. Sooner or later you'll scrape one.
There is always clearance issues with headers. In an olds its the dipstick, oil filter housing, transmission lines and the brake valve on drivers side, that can be an issue. These are important to understanding going into this. It can be overcome and a lot of folks have done it.
If you can't do long tube headers, don't do headers at all. I just don't see the point in a street car unless the engine is modified to make use of them.
With the header back systems, your on your own. They'll fit or they won't. You might need to visit a muffler shop or do the welding in your driveway to finish it up.
Yea, I know this sounds negative, just don't go into this thinking it will be easy. You can do anything you want, just know there are pit falls and ask your self what is your time worth versus your expectations?
I wasn't comparing the Cutlass to a Mustang, just using it as an example of possible concerns because it is the other car I have that will be doing similar work to and have done more research into at this time.
Thanks for the heads up on likely clearance issues and trouble spots with the oldsmobiles. That is what I am looking for. I would prefer long tube so if that is the general preference and there will be clearance issues whether short or long is used, long tube it is. I just thought on these there might be one that fits great and one that doesn't.
From what I could find, I would probably be able to get the headers and exhaust kit on at home, and then have the kit welded up to the collectors at a shop, possibly even doing a temporary flex pipe setup to get it there.
There are many pros and cons for short or long tubes. I've seen a lot of long tube headers beaten with hammers to fit. I've also seen a lot of long tube headers flattened on the bottom from speed bumps and other obstacles which can't be good for performance. Dyno tests may show a little gain with long tubes, but with the right cam you won't give up much using shorties. My next choice is short tubes.
Good points. I also get the opinion of why do a full dual exhaust on a stock car in the first place, and that a muffler change will get the sound, but to me there is a big difference between a small single exhaust with a loud muffler and a full larger dual exhaust system. I have also had it suggested that I should just use the stock manifolds to make things easier up front, but I know I will regret going 95% of the way instead of just doing it all. I have also heard that these engines really do benefit from a system like this rather than the small single system mine came with.
Thanks for the information and opinions. I will shop around a bit and see what I can come up with that I think will work well. I had one of those pre-designed kits picked out, but then had it suggested to me to check out a performance exhaust shop because they thought for the same price I could have a custom made system done. Based on their rough estimate I think it will be a lot more, but I will realistically price both out today and see where the numbers land.
I have Sanderson Shorties that have seen better days. I am planning on the Thornton stainless shorties which can bolt right in place of manifolds with dual exhaust. Ram Air Restorations or Rocket Racing carry 2.5" manderel bent down pipes. Don't buy the Pypes stainless 2.5" down pipes, their quality control has been horrible, a lot of their products don't fit without modifications. Flowmaster makes tail pipes in aluminized and stainless.
Last edited by olds 307 and 403; September 28th, 2018 at 06:32 AM.
Here's the fundamental issue. Correctly designed headers are tuned to a specific length to help scavenge the exhaust pulses from the cylinders and thus increase HP. "Shorty" headers can't do that, they are just slightly less restrictive versions of exhaust manifolds. Your call if you want real headers or not and are willing to put up with the ground clearance issues to get the gains.
I have a set of Hedman headers on my car (had the same on my '70 Supreme as well) and the only time they scraped the ground was in school when we had 7 people in the car and went airborne over a railroad crossing at speed. Lotsa sparks flying on that landing, I tells ya! But other than that incident in the late '80s, no scraping issues with the headers.
The first thing I did to my ‘72 was headers and dual exhaust, night and day. The second thing I do was change the rear gear, again night and day.
Look on here, I did a header/manifold comparison. 30 hp and tq better with the headers throughout the rpm range. They’re one of the few things you can change the helps power AND mileage.
71OldsCut, Look at BBO board for recent headers thread, good info there.
Originally Posted by joe_padavano
Here's the fundamental issue. Correctly designed headers are tuned to a specific length to help scavenge the exhaust pulses from the cylinders and thus increase HP. "Shorty" headers can't do that, they are just slightly less restrictive versions of exhaust manifolds. Your call if you want real headers or not and are willing to put up with the ground clearance issues to get the gains.
Joe, Your feedback and other research has me considering long tubes now. If I stay cost conscientious (a.k.a. cheapo ), isn't going long tube headers still significantly better for power gain & better than Shortys ..... even if NOT tuned for the application ??? chances of no gain or decrease not plausible ?
cutlassefi, Great info / suggestion on a logical approach to gain performance
Guy I work with runs a Camaro with SBC at the track and had such a hard time changing his oil filter with long tube headers he changed to shorties. He says it had zero effect on his performance. 60 ft., ET, and trap speeds are all still identical to previous times. He is extremely consistent. And he can now change the oil filter without pulling the engine. Dunno at what point the long tubes make a difference, but for street performance it might just be in sex appeal.
OR, I have heard that there is a piece that connects the exhaust manifolds to make it single exhaust and it can be removed. Is that true and if so, can a piece be bolted up to the manifolds to connect the new dual exhaust system to them? I think I would still prefer the headers, but it is sounding like even with them, there might be clearance issues resulting in a different oil filter, having to get a mini starter and even with all that still having to jack the engine up slightly in some cases. I want to look into it a little more, but being that the car is just a stock cruiser and the common opinion that shortys are only marginally better than the stock manifolds, I am questioning if I want to go down the road of snapping off manifold bolts, and then after than all the fitment issues. Maybe it is better to just stick with the manifolds. I could always change them out later if I was really unhappy with the result.
Thanks to all for the information and opinions. It has really helped me narrow things down and figure things out.
Unless you have an LS engine in your Cutlass those headers won't work, read the application. There are no ground clearance issues with long tubes unless your car is lowered. Short tubes provide no real gain in HP as Joe and Cutlassefi explained above.
I have heard that there is a piece that connects the exhaust manifolds to make it single exhaust and it can be removed. Is that true and if so, can a piece be bolted up to the manifolds to connect the new dual exhaust system to them?
Yes, factory dual exhaust cars had the crossover port capped and a separate head pipe, muffler, and tail pipe connected where the crossover pipe would have been.
being that the car is just a stock cruiser and the common opinion that shortys are only marginally better than the stock manifolds, I am questioning if I want to go down the road of snapping off manifold bolts, and then after than all the fitment issues. Maybe it is better to just stick with the manifolds. I could always change them out later if I was really unhappy with the result.
I myself and several members here, have installed hedmann shorty hedders on our 350 SBO. I have them on my 76 and love them. No fitment issues , no dings ,no dents, no scraps on the ceramic coating.
They installed very nice , tucked the pipes up nice and high as well.
You will notice a difference, long tube... perhaps more noticeable. However.. if you want a header that goes in nice and slick , and sound good.. I wouldn't under estimate what can come from short hedders.
Jus' sayin'
Best of luck with your decision!
Thanks, good catch with the LS. My phone views websites differently than an actual computer and I didn't see that. I see it on the laptop though.
76olds - Do you have a link to the headers you are referring to? They sound like they would be worth a try. If they fit great like you say all I would have to contend with is getting the bolts out without snapping them off. I did a search but all I could find on the website were for LS swaps.
I had hedman send mine out for ceramic coating , forget the cost ,but well worth it . They still look great . I installed them with Remflex graphite gaskets . Never a leak ! Worth the effort IMO.
Hope this helps
Eric
Perfect, thanks! These look and sound like they will do the job. One of the reviews says it fits a 1971 perfectly and all they had to do was take the starter off. I think I will give these a shot and just hope I can get the old rusty bolts off without any issues.
They will fit your 71' with no issues, you will need a custom bent pipe to come off the drivers hedder, but other than that, its all good .
I think you will be happy with them ! I would recommend the Remflex hedder exhaust gaskets as well , they crush nicely initially, then a heat cycle re-torque and your good . The best hedder gasket on the market IMO.
Looks like you are a year behind me. I was pondering the same exhaust mod last year. I used Hooker longtube Comps and the Summit header back 2.5 inch exhaust. Everything fit real well. No issues that required bending or modifying the headers. They tuck up nicely and are higher than my deep sump transmission pan therefore no ground clearance issues. There was an issue with the Summitt exhaust flanges matching up to the header flanges. I am please with performance increase and sound. Here is a link to a thread I did on the swap and pics. https://classicoldsmobile.com/forums...r-install.html
Geez,
I forgot about your Hooker Long Tube Comps thread Sampson! Good to see you chiming in here with such an awesome install. This is a great option for 71oldsCut if he's looking for a bit more performance over the short .
Thanks, I will look into that. I also read that acetone and ATF mix make the best penetrating fluid so I will probably try soaking the bolts in that for a while. It is a winter project, and we get long winters here so I got nothing but time, lol.
Hi Sampson, just read your thread, they look great and have more ground clearance than I would have thought. By the sounds of your thread and what I have read in general, it sounds like I should make sure there are no children's ears present while I am doing this, lol.
Thanks, I will look into that. I also read that acetone and ATF mix make the best penetrating fluid so I will probably try soaking the bolts in that for a while. It is a winter project, and we get long winters here so I got nothing but time, lol.
Hi Sampson, just read your thread, they look great and have more ground clearance than I would have thought. By the sounds of your thread and what I have read in general, it sounds like I should make sure there are no children's ears present while I am doing this, lol.
exactly!
The Hooker Comps fit and went in place great. My issues related to the difference between the flange sizing between the 2.5" Summitt Exhaust and the Hooker 2.5" Flanges. I have been driving the car all year and every time I take off from a stop light I forget all about any frustration I may have had last winter.😎
I am getting things done and have a question about possible issues with connecting the exhaust to the headers. As mentioned above I have gone with these:
After they are attached to the engine, they basically point straight down. Is it OK to come off them with a 90 degree elbow? I don't see any other way with the amount of clearance there is to work with. I think for flow a 45 degree would be best, but I just don't see how there will be room for anything other than a fairly tight 90 degree bend based on measurements. Perhaps there will be more room than expected after they are actually installed but I don't think so.
I recall seeing 90 degree elbows right after headers before, just wondering if this is fairly common and works fine.
I am getting things done and have a question about possible issues with connecting the exhaust to the headers. As mentioned above I have gone with these:
After they are attached to the engine, they basically point straight down. Is it OK to come off them with a 90 degree elbow? I don't see any other way with the amount of clearance there is to work with. I think for flow a 45 degree would be best, but I just don't see how there will be room for anything other than a fairly tight 90 degree bend based on measurements. Perhaps there will be more room than expected after they are actually installed but I don't think so.
I recall seeing 90 degree elbows right after headers before, just wondering if this is fairly common and works fine.
Thanks!
You will need to install similar to the photo below, I had the same problem with the same short headers going into my 76 Olds . I wanted them tucked up nice. Easy to fab up and weld thou.
Hope this helps!
I was thinking something like that. So basically you just welded a tight radius elbow (4" is as tight as I can find) up close to the reducer? How do you find the ground clearance after doing this?
Other than this one issue, I am surprised at how easy the passenger side went on. I wanted to see exactly what I was dealing with rather than just trying to get close with a measuring tape so I took the passenger side out for a test fit. It dropped right in from the top and was bolted up in about 10 minutes! I didn't torque anything down but with the remflex in place and it snug enough to be held in place it went really easy. I don't think the driver's side will be quite as easy, but the starter is already off and there shouldn't be too much of a fight sliding it in from the bottom I think.
Both sides set really nice in my 76' 350 actually, no issues at all .
The back header bolt on the drivers side didn't get torqued, just no room to get in with the torque wrench. Just snugged it up to where I thought was good, I haven't had any issues with leaks with the Remflex gaskets. Did one cruise for head soak test and re-tightened. Perfect !
The front drivers side pipe,
An exhaust shop with a bender with the form accessories would be ideal . Or you would need to fabricate a cone, heat the pipe, hit until it forms to the cone shape, the cut off the excess.
I know the guy that owns the exhaust shop in my area so that certainly helped. First, was the cross member.
I didn't have the dual hump cross member, so I had to torch my cross member out a bit, then welded a plate in place for strength. I took the measurement from the cut out's. I have the 2 1/4 pipe running about 3/4 " under the cut-outs.
We Made a cone in the above post with a piece of 2 1/4 pipe. Mandrel bent the front pipe from the muffler to the cone, cutting to fit before welding.
Hope this helps!
Another member Macadoo installed the same short headers on his 71 or 72 olds with the 350 . He know has a 455 in the car but you may look for his thread under small blocks and have a look at what he done. His thread is back several years now.
His ran a little lower than he would have liked if I remember correctly.
I don't know how to add other posts here so someone many help out in finding his thread here.
Search Macadoo and pull up his "Pulling the motor Thread" I the header install will be in it that thread.
Eric
Last edited by 76olds; January 5th, 2019 at 04:01 PM.
Reason: Macadoo- Pulling the motor thread
I do have the dual hump cross member on mine so at least it shouldn't be an issue there. Now that I have one header on the car I will get under there tomorrow and start measuring things out. I have a 'plan A' in mind that I am really hoping keeps everything high enough, but the information you have provided above should work if that plan gets shot down.
I will see if I can find that other thread and see if there is anything there that I can apply as well.
Your welcome, were all Happy to help!
I think you find something useful in Mac's thread, he tried it a couple different ways as well , with off the shelf pieces initially.
Post some pics as you go if you get a chance. That will certainly help others here one day .
Thanks for the link. Lots of useful stuff there, especially if I end up taking the motor out in the next year or two.
One thing I noticed after getting the starter off was that there appears to be oil leaking from where the dipstick tube meets the engine - is it common or even possible for a leak to occur there? To get that out, I can just gently pull/wigle it out right? I was thinking when I reinstall it I should just put a small amount of RVT near where it bottoms out into the engine.
I think if that is leaking, and while everything is exposed better around the pan, I will snug the pan bolts up again and between the two perhaps I can get the leak mostly taken care of. Snugging the bolts up the first time really helped, but I really went easy on them because I was really worried about damaging the old gasket. They were all really loose, some finger tight, same for the valve covers... and transmission pan bolts.
I drew up the exhaust elbow to scale I was thinking of going with so I could get under the car and get a good idea of how low it will be. It looks like going with a custom welded setup like the picture above will put the bottom of the exhaust about 1-2" below the cross member. Does this sound about right to what you have on your 76? It is hard to tell with the car up in the air exactly how close to the ground this will be...
I also see a potential issue on the passenger side - it looks like with this setup it will pass under the oil filter with about 1", maybe 1.5" clear. I think that would be enough to get the filter on and off, but will have to measure it as it sit now and then measure it all the way unscrewed to confirm. The other concern is about heat, should I be concerned about too much heat being transferred to the oil or the heat possibly damaging the filter? I think it heat is a concern some of that fabric wrap might help just in that area. The clearance to do oil changes I think might be the bigger issue.
My Sanderson's have 3" shorter collector's than the Hedman's, I have a lot of ground clearance, even with the crossmember, maybe slightly above. I actually got it custom bent for my G body, it could have been bent even tighter on my 70S. I can fit the full size 51528 Wix filter and still have enough clearance from the exhaust. I am putting the system back on the G body, so I will go with Thornton stainless shorties, Pypes or Ram Air Restorations down pipes, H pipe and Jones mufflers with my horribly over priced tail pipes.
The full length headers on my car are close to the oil filter. Been that way since 1982 and it hasn't been an issue. And I use the larger Wix 51049 oil filter.
Ok, that is good to know. So I just have to make sure I have enough clearance to get the filter on and off. I didn't think heat was too big of a deal, but would rather figure it out now than after an exhaust system has been designed close to it.
The full length headers on my car are close to the oil filter. Been that way since 1982 and it hasn't been an issue. And I use the larger Wix 51049 oil filter.
Beat me to it.
In any case, insulation only delays heat transfer, it doesn't prevent it. No insulation is perfect. Depending on how long you drive your car at one time, the heat will eventually get past the insulation. This is the fundamental problem with starter insulation or heat shields as well.
[QUOTE=71OldsCut;1146155] Does this sound about right to what you have on your 76? It is hard to tell with the car up in the air exactly how close to the ground this will be...
My 2 1/4 front pipes sit about 1.5 " below the cross member on each side
I also see a potential issue on the passenger side - it looks like with this setup it will pass under the oil filter with about 1", maybe 1.5" clear.
The passenger side on my 76 didn't require a cone to get an nice bend. I have about 1 7/8 clearance. A little tight but I only use the short oil filter, the longer style would never go.
I didn't take any pics of the passenger side, mainly because it didn't cause any issues at all.
The other concern is about heat, should I be concerned about too much heat being transferred to the oil or the heat possibly damaging the filter? I think it heat is a concern some of that fabric wrap might help just in that area. The clearance to do oil changes I think might be the bigger issue
As for heat concerns with the filter, I haven't noticed any issues with the oil filters that I have changed over the years. I'm sure the heat does transfer into the filter , however I don't see anything that would lead to concern.
I do oil changes at the end of our summer season before storage , then another oil change after a few cruises in the spring. No issues doing oil changes with a short filter.
Good to see,
Olds 307and403 chime in , I know he runs short headers as well . Maybe he can share a few pics as well .
I think you will be fine once you have your design and measurements completed. We did several measurements throughout the bending/trimming and welding process. Mainly because I wanted things to look neat , tucked up nicely, with decent clearance's before welding up the entire system.
September 27th, 2018, 06:33 PM
