# e85 ??



## cij911 (Oct 25, 2017)

I am rebuilding my carbs (tri power) and apparently the new rubber is e85 safe. Local stations are now selling e85 (which is very popular with high boosted motors). My question is, would e85 work well in a 400 motor with high compression heads ? Are there other issues I would need to change / address ? With fuel injected cars, you usually need to increase flow ~20%, so I am guessing the jets would need to be changed to a larger size.

Anyone been there / done that and have advice, I would appreciate it. Thanks

Chris


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## WheelHorseman (Oct 15, 2017)

I've been wondering the same thing, cij911. I've got a '68 428 HO with the 670 heads and the original spreadbore Qjet manifold, and 4 bbl E85 carbs are available, but I'd rather run a tri-power setup, if possible. I've never read anything online about anyone doing it...


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## GTOJUNIOR (Aug 7, 2011)

FWIW Recent Engine Masters covers this...


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## bigD (Jul 21, 2016)

It can probably be done, but will be easier & probably even cheaper to use Torco Accelerator octane booster.

There are lots of E85 Holley carbs & kits. 

http://e85carbs.com/

There are big Roch-to-Holley adapters. I suppose this would allow you to use E85 Holley 2-barrels. ???

https://www.ebay.com/itm/Fits-Ponti...chester-2GC-Carb-to-Holley-4412-/263452933662 

There are a few guys who build E-85 Q-jets. So, I assume there are guys who can build E-85 Roch 2-barrels. But, it usually involves more than just a jet size increase. 

e85carbs.com will convert your Roch 2-barrel. This quote is taken from their website, near the bottom of the page.

" Convert your Rochester 2brl to E85 We can convert your 2 barrel carb quickly. This includes normal replacement parts for E85. If your carb needs an overhaul we can get that done for an extra charge. We can convert most 2 barrel performance carbs.

Purchase your conversion here with PayPal or credit card, print out your recipt and Ship a copy with your carb and send it to us at: Rob Mix Services, Inc.*465 North Street * Saint Paul, MN 55130. This overhaul can take 1 week in shop but we try to turn it sooner if possable. Return shipping will be added at checkout about $24.50 "

http://e85carbs.com/

Several carb shops build 2-barrel Rochs for circle track racing. They use high flow needle & seats, small floats, and are drilled for Holley jets, in order to flow more fuel. So, I figure one of these guys could build a good E85 Roch. I'd talk to SMI about it. 

https://www.smicarburetor.com/products/sfID1/7/sfID2/49/productID/60 

Also, the actual ethanol content of E85 can vary greatly, from area to area, and can change from season to season. If you switch to E85, you need an ethanol tester, in order to verify the ethanol content, before using it.


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## cij911 (Oct 25, 2017)

Well Torco Accelerator will get very costly if one drives there car a fair bit.

e85 is an easy upgrade on newer fuel injected cars, but appears to be a bit more of a challenge with the older cars. Given the cheap price of e85 and the effective octane rating of 100 +, it would be great for the original high compression Pontiac motors. That said, I will probably just stick to a low compression tri power ....


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## WheelHorseman (Oct 15, 2017)

That's what I thought, it's no rap on anyone who replied, but I still have seen no one who has actually run E 85 through a '66 tri power. I've seen comparisons between the racing gas and E 85, but I'm not buying 55 gallon drums (at what, $400 or more?) of racing gas to store in my garage! And I do want to drive the car at least 5K miles per year. Changing to open chamber heads, and re-rebuilding the motor with dished pistons to drop down to a 9:1 compression ratio would lead to a huge loss in torque and h.p., right? Even though everyone says watch out for the winter E 70 versus summer E 85, why is that so bad, and how do you fix it? Add gallons of pure ethanol to the tank right away if you're not at 85% at the pump? What happens if you temporarily go from E 85 at 105 octane, to E 70 at about 100 octane in a 10.75 to 1 motor? Retard the timing a couple degrees til you get the ethanol back up? I live in the corn belt so E85 is cheap and readily available at all the local Kwik Trips. bigD, thanks for the links and the advice, but we know that a tri power is more than a two barrel carb in that when the end carbs dump open the mixture is probably not the same as a Holley 4 bbl or a Q jet and I'm wondering if you can get all six barrels to work right with E 85, and I've never heard that tale. If anyone has, please let me know.


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## bigD (Jul 21, 2016)

"...E 70 versus summer E 85, why is that so bad, and how do you fix it?..."


If the carb was built & tuned correctly for E85, and you feed it E70, the mixture would be too rich. Would probably need smaller jets, at least. Don't know exactly how much difference a 15% drop in ethanol content would make. Hey, a guy posted that he knew of a Dodge pickup with a 2 barrel that switched from pump gas to E-85 without changing anything & it ran just fine. But, even if that was true, somehow I don't think I'd try that on a Pontiac.

http://www.superchevy.com/how-to/additional-tech/1110chp-e85-fuel-switch/


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## cij911 (Oct 25, 2017)

I have run e85 with modern fuel injected cars (high boosted performance cars) and it really was relatively easy to get the benefits of a pseudo race gas (e85). Essentially with I swapped the injectors for larger flowing ones and remapped the fuel and timing curves (ECU tune). I would think for our situation (Pontiac GTO) all we would need is to make sure the gaskets and fuel lines were ethanol compatible and run larger jets. 

I am seriously looking into it and will document what I do for others.


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## 1968gto421 (Mar 28, 2014)

WheelHorseman said:


> That's what I thought, it's no rap on anyone who replied, but I still have seen no one who has actually run E 85 through a '66 tri power. I've seen comparisons between the racing gas and E 85, but I'm not buying 55 gallon drums (at what, $400 or more?) of racing gas to store in my garage! And I do want to drive the car at least 5K miles per year. Changing to open chamber heads, *and re-rebuilding the motor with dished pistons to drop down to a 9:1 compression ratio would lead to a huge loss in torque and h.p., right?* Even though everyone says watch out for the winter E 70 versus summer E 85, why is that so bad, and how do you fix it? Add gallons of pure ethanol to the tank right away if you're not at 85% at the pump? What happens if you temporarily go from E 85 at 105 octane, to E 70 at about 100 octane in a 10.75 to 1 motor? Retard the timing a couple degrees til you get the ethanol back up? I live in the corn belt so E85 is cheap and readily available at all the local Kwik Trips. bigD, thanks for the links and the advice, but we know that a tri power is more than a two barrel carb in that when the end carbs dump open the mixture is probably not the same as a Holley 4 bbl or a Q jet and I'm wondering if you can get all six barrels to work right with E 85, and I've never heard that tale. If anyone has, please let me know.


Actually it is not as "huge" a loss as many think. Check out the Wallace Racing Calculator:

Wallace Racing - Calculate New HP From Change In Compression Ratios Calculator

Hope this helps.

("Your old Compression Ratio of 10.5:1 and HP of 350 is now calculated 
as a Compression Ratio of 9.5:1 and 346.29 Horsepower.")


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## WheelHorseman (Oct 15, 2017)

Hmmm- I think that Calculator might need some new batteries in it. You can find online an article I read from Hemmings magazine, Aug 2005, called "Tin Indians." They interviewed "Jim Taylor, the legendary Pontiac engine builder from Phillipsburg, NJ." He said; "One point lost in compression equals 50 lbs ft of torque and 50 hp." If I started at 390 hp, that means I'd lose about 80 going from a 10.75 to 9.00 CR. My experience makes me believe Mr. Taylor is correct, all else being equal. That's why I'm still interested in E85, and interested if anyone has tried it in a tri power motor. (The calculator also said I'd lose about 3 hp, which is fantasy IMO.) I think Jim Taylor Engine Service is still in business; I'm going to contact him directly and see if he's changed his belief since he contributed to that story.


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## bigD (Jul 21, 2016)

"...I think Jim Taylor Engine Service is still in business..."

Sorry, but he passed away in 2016. 

http://forums.maxperformanceinc.com/forums/showthread.php?784779&p=5515220#post5515220


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## cij911 (Oct 25, 2017)

WheelHorseman said:


> Hmmm- I think that Calculator might need some new batteries in it. You can find online an article I read from Hemmings magazine, Aug 2005, called "Tin Indians." They interviewed "Jim Taylor, the legendary Pontiac engine builder from Phillipsburg, NJ." He said; "One point lost in compression equals 50 lbs ft of torque and 50 hp." If I started at 390 hp, that means I'd lose about 80 going from a 10.75 to 9.00 CR. My experience makes me believe Mr. Taylor is correct, all else being equal. That's why I'm still interested in E85, and interested if anyone has tried it in a tri power motor. (The calculator also said I'd lose about 3 hp, which is fantasy IMO.) I think Jim Taylor Engine Service is still in business; I'm going to contact him directly and see if he's changed his belief since he contributed to that story.


That was more inline with my expectations as well....I'm sure the engine builders could confirm what they have seen on their dynos ...From Len Williams' site his lower compression (~9:1) 455 puts out ~425 hp. Interestingly I have seen numerous 10:1 455's posting 470+ hp dyno results, which is more inline with Mr. Taylor's claims.....


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## Pinion head (Jan 3, 2015)

There is plotted curve that's been published that shows the improvement from raising static CR in a Pontiac V8 with cast iron head from 8.0 to 9.0-1, then to 10.0-1, then to 11.0-1. The curve was plotted in 1/10ths of point of compression. The major increase in Torque/HP was in raising static CR at the lower levels. Once the static CR ratio was raised from the low 9's to low 10's, there was only a few very very low percentage point of improvement.

Len's 406-408 milled & non ported 6x-4 headed crate engine makes around 380-385 gross HP. That's with 9.2-9.3-1 static compression & his supplied camshaft/lifter combo, and owners good Qjet & a decent ignition curve. One can take a bone stock 68-70 GT0 with a stock 400 350 horse engine, with a little less than 10-1 true static CR. compare both cars with manifolds & aimilarly flowing turbo mufdlers. The 9.2-1 400 will outrun that stock port flow 350 horse 400. Have had hands on exp with both combo engines several times.

Currently, have a customer with 412 with twice surfaced RAIII heads & good ol TRW pistons  block was not decked. even with a big cam to bleed off some cylinder pressure, his issue is going to be too much CR... been there. Instead of reducing static C/R with a well executed dished piston set, he'll end up pulling timing out most of the time, & if he wants it to run well at all, mixing Sunoco purple or 100 oct LL from the Airport. could have listened, the "perceived" loss of HP & torque could all be regained by other improvements.


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## cij911 (Oct 25, 2017)

Pinion head said:


> There is plotted curve that's been published that shows the improvement from raising static CR in a Pontiac V8 with cast iron head from 8.0 to 9.0-1, then to 10.0-1, then to 11.0-1. The curve was plotted in 1/10ths of point of compression. The major increase in Torque/HP was in raising static CR at the lower levels. Once the static CR ratio was raised from the low 9's to low 10's, there was only a few very very low percentage point of improvement.


Pinion head - What would you think about my setup - 400 with 14 heads (from a 68 catalina) with the tri power. Should be ~8.6 or lower :1 according to everything I have read. Would using the 16 heads I have with a nice cam and compression at ~9.5:1 be significantly better ?

Thanks in advance


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## 1968gto421 (Mar 28, 2014)

WheelHorseman said:


> Hmmm- I think that Calculator might need some new batteries in it. You can find online an article I read from Hemmings magazine, Aug 2005, called "Tin Indians." They interviewed "Jim Taylor, the legendary Pontiac engine builder from Phillipsburg, NJ." He said; "One point lost in compression equals 50 lbs ft of torque and 50 hp." If I started at 390 hp, that means I'd lose about 80 going from a 10.75 to 9.00 CR. My experience makes me believe Mr. Taylor is correct, all else being equal. That's why I'm still interested in E85, and interested if anyone has tried it in a tri power motor. (The calculator also said I'd lose about 3 hp, which is fantasy IMO.) I think Jim Taylor Engine Service is still in business; I'm going to contact him directly and see if he's changed his belief since he contributed to that story.


With all due respect to all who have posted here, I ran the HP/torque loss vs compression ratio subject on another Pontiac forum with some professional engine builders on it as well as racers and serious hobbyists. Here are the responses I've gotten so far; interesting reading. (Thanks to all here who got the discussion going.)

Power losses from reducing compression ratio? - PY Online Forums


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## WheelHorseman (Oct 15, 2017)

Thank you 1968gto421. I followed the link to that MaxPerf forum and it was interesting. From what I could tell, there seems to a fair bit of head swapping, cam shopping, dyno testing and engine blue printing to be done before a person can decide what sort of compression ratio they should shoot for? I think I've seen online that aluminum heads, for example, sell for over $2k/set, so it seems to me that actual drag racers don't care how much money they spend on engine building and fuel, but I do have a budget and I don't want a car that's too expensive to build or drive. Where I live in WI, right now 105 Octane E85 costs $2.20/gal, 87 Octane gas w/10 percent alcohol costs $2.39/gal., and the premium 91 Octane "recreational gasoline w/ no alcohol" costs $3.19/gal. I was hoping to leave my '68 428 HO engine with a mostly factory build, the closed chamber 670 heads with a slightly radical 280 degree Isky cam (with Rhoads lifters to give me a less lopey idle and some vacuum for the power brakes), and the '66 tri-power, modified for E85. But if that wouldn't work, and compression ratio is not that significant in making power, I guess I'd prefer to build a motor that would let me fill up my gas tank with 87 Octane, at a 25% discount over premium at every fill up. Those 670 heads were rebuilt with all new exhaust valves, bronze guides, Teflon seals and new springs, so abandoning them and going to aluminum heads (with the heart shaped chambers) is something I'd like to do only if it was necessary to make power and not ruin the bearings with detonation. Of course I've read in these forums about the other iron castings that have more open chambers but are they a good buy as they don't seem to have the optimum combustion chamber design either, and seeing as some are "small valve" heads? What kind of compression are you running in your 421? And which cylinder heads? Do you use a tri-power, or a 4 bbl.? Do you use the Ram Air manifolds? My donor car, a Catalina "freeway enforcer" had only the log style. I think the ceramic coated repros now run $668/set? Thanks for your advice!


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## cij911 (Oct 25, 2017)

WheelHorseman said:


> I think I've seen online that aluminum heads, for example, sell for over $2k/set, so it seems to me that actual drag racers don't care how much money they spend on engine building and fuel, but I do have a budget and I don't want a car that's too expensive to build or drive.


Aluminum heads + roller cam setup ~$3400, which is why I foolishly bought 16 heads only to learn that I would spend another $1200 - 1600 to rebuild / port them + $1000 for roller cam setup.........And at the end of the day the aluminum heads will still outperform.

So unless you can rebuild your iron heads for a lot less than I have found, I'd suggest getting some nice aluminum heads.


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## WheelHorseman (Oct 15, 2017)

cij911, that is helpful. Which brand of heads did you pick and why? Did you stay with forged flat tops, and what CR? Did you keep the cast rods or buy forged? I'd guess forged, since with a roller cam you might be at higher RPM than factory, and probably higher than a 428 can safely go? How much timing do you run, and with what octane of gas? (If this were on the MaxPerf site we'd probably already know your E.T. and trap speed.)  Thanks.


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## WheelHorseman (Oct 15, 2017)

I'm sorry to read that Mr. Taylor has passed away. As the 60's recede further into the past, we lose those legendary Pontiac engine builders. Thanks for letting me know.


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## PontiacJim (Dec 29, 2012)

You could build for the E85, but I have no experience in that area. My concern would be that E85 is somehow phased out because it won't be used in larger quantities or its price is driven up because it is not used in larger quantities. I see ethanol laced gas being a more stable offered gas in the long run - but my opinion as I've seen the attempt to convert cars to propane, CNG, steam (yes steam was being thrown about), and alcohol conversions to include making your own still to produce it. All good in theory and following the "we are running out of gas" scare which has been around since the late 1940's when this theory first came to light.

My choice on my 455 build is to go with 9:1 compression using iron heads. I can run the lower octane gas, but not sure if I will be able to run 87 or have to run 91. I selected a solid cam that will give me about an 8:1 dynamic compression which according to several sites is about the limit for pump gas. Static Compression and Dynamic Compression are different values.

Now if doing a bunch of research on the subject and their differences, you will find many opinions about the Dynamic Compression from it is a big factor to consider when building your engine to others who say it is a crock of BS. I am of the side that it does make a difference.

I put this topic together and had a little fun doing some comparisons using my Dyno 2000 engine program - which is very basic at best. But still, can provide some general numbers. http://www.gtoforum.com/f170/400-vs-455-cam-comparison-numbers-126785/

There might be something helpful in it, or not.


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## cij911 (Oct 25, 2017)

WheelHorseman said:


> cij911, that is helpful. Which brand of heads did you pick and why? Did you stay with forged flat tops, and what CR? Did you keep the cast rods or buy forged? I'd guess forged, since with a roller cam you might be at higher RPM than factory, and probably higher than a 428 can safely go? How much timing do you run, and with what octane of gas? (If this were on the MaxPerf site we'd probably already know your E.T. and trap speed.)  Thanks.


What I have currently is not what I would "build" - it is a 400 with 14 heads out of a 68 Catalina that the previous owner installed and fitted with the tri power (after he blew the original block). I also have some decent 16 heads (large valve, screw in studs, blah blah blah), but by all accounts I should install new valves, springs, and guides, etc. And on top of that the 16 heads, while great when pump gas was a higher octane, will yield too high of a SCR - ~10.5 - 10.70, and really should go with a ~17cc dished piston to lower compression (which mean built bottom end). 

So, if you are going to build a motor, now there are a lot of variables to consider, but PontiacJim's plan is probably as good as any. I was thinking of a forged bottom end 461 stroker with the 16 heads, tri power carbs, and doug headers (currently on the car). A 455 would likely be easier, cheaper, and yield just as good results (compared to the 461).

All that said, I really want to slap the 16 heads on as is .


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## WheelHorseman (Oct 15, 2017)

Thanks, cij911. And PontiacJim. I've been emailing back and forth with Greg from Butler Performance, and I think he's pretty knowlegeable about what works to make power with today's gas. It seems like my best choices are going to be between running E85 with the EZ FI 2.0, which has a computer that will adjust on the fly for the tank to tank inconsistent alcohol percentage in the fuel. If I go that route, I obviously don't use my tri power but keep the 670 cylinder heads and ought to make good power with that one change. If I decide to go to the Edelbrock aluminum heads with 87 CC combustion chambers, I drop the CR from 10.75 to about 9.5 to 1, and I can keep the tri-power running 91 octane gas. Of course those heads, with a roller cam and roller rocker arms, look to be a bit pricey (Uf da!) Greg seems to think that I ought to keep some compression in the motor if I can; he does not recommend dropping the CR to 8:1, which would rule out a lot of the iron heads. I think because I'd rule out a bunch of cams, or maybe I'd have to run a higher RPM to get back the power, and the stock lower end of a 428 really wasn't built for that? Has anyone run a tri-power with the out of box Edelbrock D port heads? Greg told me that the tri-power intake can be tough to seal with the Edelbrock because the tri-power's 2" by 1" ports are so small. It sounds like you don't get the whole .25 inch sealing surface all the way around. Has anyone tried that combo? Thanks for your help.


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## WheelHorseman (Oct 15, 2017)

Sometimes a person can learn as much from what's not said as what is said. I would say there is a lot of disinterest, skepticism, and maybe even suspicion about the successful prospects of using E85 as a pump gas fuel, esp. using a tri-power. Going with Edelbrock aluminum heads and a Lunati roller cam may be pricey, but it is a proven way to make power with today's 91 octane premium gas. And you can use your tri-power, if you're willing to take the performance hit. Seems like the new heads will flow a lot better than what the old tri-power ports can deliver, so that is the now the power "bottleneck" if you will. I guess it shouldn't be shocking that a 50 year old design would be eclipsed. I'm encouraged by other posts, especially the Jim Taylor track test showing the tri-power making more power than a Q-jet. Gonna go with the alum cylinder heads and tri-power. Just to conclude, thanks everyone for their information, and to pose a speculative question- with the tariffs on aluminum and steel soon to go into effect, I wonder if prices for these parts will take a quick jump? I'll be interested to look back someday and see if that happened...


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## cij911 (Oct 25, 2017)

WheelHorseman said:


> Sometimes a person can learn as much from what's not said as what is said. I would say there is a lot of disinterest, skepticism, and maybe even suspicion about the successful prospects of using E85 as a pump gas fuel, esp. using a tri-power..


I am not a skeptic re e70-85. I ran it in a super high output Evo IX and the stuff was amazing - great for 30 psi. + boosted, high horsepower (600whp+) motors. 

As far as e70 - 85 (winter vs summer blends), as long as you are not tuned on the ragged edge, I never had to make any adjustments. For our setups, one could conservatively tune the car based off the lowest effective octane and run safely. Again, the biggest thing I experienced was worse gas mileage and needing to use larger fuel injectors (so for our cars I would guess larger jetting). My experience with e70-85 has been great and I would REALLY like to set the GTO for e70-85 and keep the iron heads and 10.5:1 compression ratio.


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## 1968gto421 (Mar 28, 2014)

WheelHorseman said:


> Sometimes a person can learn as much from what's not said as what is said. I would say there is a lot of disinterest, skepticism, and maybe even suspicion about the successful prospects of using E85 as a pump gas fuel, esp. using a tri-power. Going with Edelbrock aluminum heads and a Lunati roller cam may be pricey, but it is a proven way to make power with today's 91 octane premium gas. And you can use your tri-power, if you're willing to take the performance hit. Seems like the new heads will flow a lot better than what the old tri-power ports can deliver, so that is the now the power "bottleneck" if you will. I guess it shouldn't be shocking that a 50 year old design would be eclipsed. I'm encouraged by other posts, especially the Jim Taylor track test showing the tri-power making more power than a Q-jet. Gonna go with the alum cylinder heads and tri-power. Just to conclude, thanks everyone for their information, and to pose a speculative question- with the tariffs on aluminum and steel soon to go into effect, I wonder if prices for these parts will take a quick jump? I'll be interested to look back someday and see if that happened...


Q-jets vs Tri-power, I have heard stories about which produces more power, same with heads, carbs, efi, cams, E85 vs gas, etc, etc. My opinion is that *its your car, build it your way*. Nuts on the gear head pundits' opinions.

I go by this: "without data you just have an opinion". Make sure the data is not just a one time thing and is repeatable.

Best of luck with your build, if Butler is assisting you,you're in good hands.


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## Robert1965 (Jan 4, 2020)

Do you need to replace stock fuel pump? will it move enough fuel and will the membrane get dried out by the ethanol. Also I think you have to switch any aluminum lines to stainless steel. Also the rubber hose connectors. From tank to line etc.


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