Another Heat Exchanger Thread

[Jip]

Pelicans. I need help. I am removing and storing the original engine and transmission from a 1969 911T. Then installing a 1979 3.0 CIS with a 915 transmission.
Question. Exactly which SSI heat exchangers would I purchase from PP and retain the original heating system in the 911T? Phone conversations and Emails haven't answered my question.

Thanks to all.

Jip

[darrin]

wouldn't the Heat Exchangers and exhaust from the '69's original engine work in this situation?

[bgyglfr]

I don't see any reason the original 69 HEs wouldn't work unless you want to store them with engine or they're rusted out.

[Jip]

Hello, Darrin. A local boy said Heat Exchangers up to 1974 would work. My main concern is there an issue with 3.0 liter exhaust port flanges being larger than 2.0 liter exhaust ports? The Heat Exchangers I removed from the 3.0 is a thin flange version, or about 9mm or 3/8''. Does that matter? I posted this question so people who actually know for sure which part to order and even sell the exact product.

Thank You, Darrin.

Jip

[bgyglfr]

Thin flange will bolt right up to both thick and thin engines. You just have to deal with the longer studs on the thick flange engines. The thick HEs will not bolt to a thin flange motor though. The exhaust you just stripped from your 3.0 would be way more constructive that the exhaust from the 69. SSI have the same inside diameter as original Porsche HEs.

[Jip]

OK, OK, OK. Finally, Finally, Finally. Please understand, fellow Pelicans. Most of this whole issue revolves around my 'widow bwain' not accepting the fact that a 3 liter engine has the same size exhaust ports as a 2 liter. Therefore, the thick/thin flange issue and, yes I installed a front oil cooler, became more issues I wasn't ready for. A different Heat Exchanger then before. Muffler inlet/exhaust diameter. MFI, CIS, Carburetors. Items that are difficult to address when using the 'Ask a Question' feature on this fine website. But with the help of Ken and Bruce in the tech dept. the finer points of this, I hope once in a lifetime purchase of a set of gold plated SSI's goes as smoothly as possible. So now the correct HE's are in the mail along with a boat load of gaskets for a general top-end inspection and clean-up of this well used '79 3.0 liter going into a '69 911, now with a front mounted oil cooler and original heating system. Oh, yeah. And with CIS.
Thanks for all the helpful feedback, bgyglfr and Darrin. And to anyone else who actually spent some brain power on this one.

'Cheers' Jip

[Jip]

Ok, fellers. Back again. More than a week ago I ordered all of the correct parts to install SSI heat exchangers on a '79 3.0 liter that is being installed in a 1969 911, with the intentions of retaining the original '69 heating system. After a few phone calls to various vendors and knowledgable people it was decided the thin flange ~pre-1974 Heat Exchangers are the correct fit. Upon receiving the SSi's, the first Heat Exchanger sat right on the engine. Please understand the engine is turned upside down in the engine stand, therefore the above photograph is of #4 cylinder head with the HE placed on the studs on the exhaust ports. Notice the corner of the head hits the bend in the HE and won't allow the thin exhaust flanges to fully rest on the #4,5,6 exhaust ports. The HE flanges are ~3/8'' from the exhaust port on the heads.










This would be a closer look at the corner of #4 cylinder head hitting the inside corner of the HE. Remember, the engine is upside down.







The mark in the corner of the bend is where the corner of the head is hitting the HE. This will not allow the HE to fully rest on the exhaust ports by ~1/4 to 3/8''.





With a couple of Emails and phone conversations it was decided an updated post on this thread asking the question, 'what the heck is going on here'? The part numbers all seem correct, and in agreement with the fine members who originally posted replies. Has anybody run into to this situation? I really don't think the proper cure for this is to take a hammer to my new ~$2000.00 SSI's,,,,is it? Or is the cure something like, 'you just need to use a Pre-1974 HE on one side and a 1976 HE on the other? After about 50 years of 'fixing' cars, boat and motorcycles, I've run into this before. Mixing and matching different parts to make it fit. Is this one of those instances or is there a simple fix one of our members may know about. As you may guess this normally simple task is making me weird in the head. No pun intended.

Please Help.

Please.


Jip

[ClickClickBoom]

Ball peen hammer, I have installed 2 sets on 2 different cars and had to "tune" them both to fit.
Its a hard pill to choke down, that expensive parts need to be "fitted" but that's what it takes, after the first hit you will be over it.

[Jip]

Oh, Man! Don't say that. I was thinking my torch and ball peen hammer would solve the problem, but it just has to be something I'm overlooking. But, if you say so,,,,,,


Thanks for the info, ClickClickBoom.

Jip

[tharbert]

Yup, hold your nose and fold that seam over with a mallet. While it may hurt your feelings a little, it won't hurt the HE.

[john walker's workshop]

Dansk must have tossed the original patterns and did it their way. Never had any issues with real SSIs.

[ClickClickBoom]

Mine were original SSIs, I did buy both sets used. I believe on the first set I searched and found the same advise. Remember these are stainless steel, as such they might relax or move when heated. If I remember correctly I had to clearance both sets in similar spots, for a 2.7 and a 3.2. Castings might have been slightly changed over the years. The other option would be, die grinder, carbide burr bit and contour the offending casting, if there is enough meat to remove.

[Jip]

OK, so back at it. After 5 days of gazing at the new SSI Heat Exchangers while postponing the day when I get out the torch and sledge hammer, I came across this thread.


Heat Exchanger flange difficulties

A fella' whose three exhaust flanges didn't line up. That got me to thinking do mine line up?
Well, yes. They do line up.





Not only that but they are 2'' high.




So after checking the Heat Exchanger in question, not only do they line up with the straight edge but they are a whopping 1 5/8'' high. Hhhmmm...could it be?



So somewhat following the suggestion made in the other thread I placed the Heat Exchanger in question in the vice. With shoulder under the HE shell and standing on ones' tip-toes the three flanges could be bent what would be upwards about 1/4''. They needed to be twice that.



So Now,,,,,,,,,,not only is the HE shell resting on the #4 cyl. head but is also resting on the 1'' aluminium line located on the bottom of the oil cooler plus the back side of the oil cooler. I won't bother to tell you what happens when stainless steel chews a hole in the oil cooler.



Oh, and the exhaust flanges are still ~1/4'' away from the exhaust ports on the heads. My guess is during shipment from Denmark to the Best Coast of North America the Heat Exchangers may have been stacked in such a way as to bend the 3 exhaust flanges downward and into the HE shell. I guess.


Jip

[tharbert]

I think you have two choices...adjust the sheet metal or return them to the vendor. The problem appears to be the sheet metal surround, not the headers inside. If I understand what you're saying, you were simply deforming the sheet metal surround by .25" rather than moving the headers. I'm guessing you'd have to crush the whole air box for it to work. Reshaping the area next the #4 seems to be the ticket. If worried about it, find a body shop guy.

BTW, lets hope the moderators ignore the nice posters in the background.

[eastbay]

I think I would have ordered the HE to fit the engine, not the chassis. The heat system is just flex tube from engine to chassis.

The real test is to try the new Dansk HEs on the old engine, if they still don't fit there then you have the choice of bending or returning.

As you can see, the engineering of these systems is of Model A technology. There is quite a bit of bending and tweaking possible on the heat box of the stock systems. Disappointing for sure on a new piece, but as you said that is the old car thing.

My idea would be to mount up the offending HE to the motor and then try to lever from the motor with a couple of wide wood pieces to force bend the entire heat box portion down and away to get your 2". Very carefully of course (and possibly on the spare motor). BTDT on the stock system.

[Jip]

Back for a moment while I continue to plot and scheme. In the link I posted to the thread about Heat Exchanger installation is what got me going on this approach. Allow me to C&P the first 2 posts in the thread.

'Registered User

Join Date: Mar 2009
Location: Edmonton, AB
Posts: 525


Heat Exchanger flange difficulties


I'm trying to install my '71E MFI heat exchangers on my newly rebuilt engine. Its upside down on an engine stand. I can see that the first cylinder flange I install the nuts on is not pulling all the way down as I can still get a feeler gauge in. A flat edge across the heat exchanger flange mating faces tells me that these flanges are no where near parallel. Some of the ears on the flanges seem bent too. Is this all par for the course? Any suggestions as I'm sure its not going to seal the way it is now. I think I can heat and straighten the the flanges but getting the mating faces aligned may be difficult.
__________________
__________________________

'70 911E coupe, a project
Old 11-29-2015, 10:16 PM

Registered User

Join Date: Oct 2008
Location: Nash County, NC
Posts: 5,457


Different scenarios at different application.

The 3 pipes are individual inside the heat box until the connection pipe so they will pull tight.
Work all three so they all pull down together. I have seen double gaskets used to close leaking exhaust.
Bruce
Old 11-29-2015, 11:19 PM

Jip, again.

In the photo above with the HE upside down in the vice is how I pulled the exhaust pipes out of the heater shell about 1/4''. I could pull them out the required 1/2'' but settle back to ~1/4''. As in the photos above the flanges need to be 2'' from the heat exchanger shell. However, fret not, Pelicans. I'll just have to move on to Plan C. Scheduled for early 'nex veek'.

Jip

[KevinB_NJ]

Subscribed as I'm leaning toward SSI's on my 3.0 as well.

[Jip]

Stick around, KevinB_NJ. Maybe we'll all learn something.

eastbay. I didn't want to use the stock exhaust with it's extra 50lbs. of Cats and hoses and tubes and elbows going every which away. The pre-74 HE's 'will' bolt right onto the '79 3 liter. The problem is after ordering, returning and re-ordering a fresh set the exact same problem arises with the right hand side Heat Exchanger. For whatever reason the exhaust flanges are ~1 1/2'' high.

See?



They need to be 2'' high like the left one.



Placing the right side HE on the engine, the heater box rests on the #4 cyl. head. The oil line on the oil cooler and the forward end of the heater box hits the oil cooler. This leaves about a 1/2'' gap between the exhaust flange and the exhaust ports on the heads. If I tighten down on the flange nuts it will draw the heater box onto the oil line, oil cooler and #4cyl. head with such force that it will chew a hole in the oil line and probably damage the cooler. ''At which point oil pours all over the engine. Engine fries itself. Oil burst into flames. Million dollar car burns up. I die. What else would you like? The other HE is a perfect fit with 2'' flanges.
Yes, me and the boys at Pelican had a chat, for a month or two and Plan B is to be re-visited. Which is to place the offending Heat Exchanger in the vice. Push up on the heater box while an assistant(wife) tightens a cool set of designer hose clamps around the exhaust tubing holding the flange at the 2'' mark. Ingenious? Quite. Cheap and easy? Indeed. I had that done yesterday at the local HotRod Car and Turbo-Anything Shop.

[Jip]

tharbert. The sheetmetal becomes the problem because the headers are 'too far' inside.
So,,,whilst at the HotRod Shop, Kid Turbo and I mounted the HE upside down in the vise. I push up on the heater box. Kid Turbo measures the flange when it comes out at 2'' high and tightens the T-Bolt Hose Clamp. Sweet. Then with all of the flanges 2'' high like the other HE, Kid Turbo then tack welds a bead on the hose clamp on the two outer flanges leaving the center flange to find it's plane with the other two when tightened down.


I mentioned all this bullshorts I had up my sleeve to Glenn at PP who, along with Bruce Stone have stayed up to the minute on this circus. I say circus in jest as this whole SheBang has been rather enjoyable. Little Ol' Me doing another Rube Goldberg hack job on a part to make it work that was designed by Rocket Scientists. A lot of self doubt can raise its' head. Plus post all this crap? I could be laughed out of the country.

Anyway, note the tack welds. Flange is 2'' high. Tighten hose clamp holding it firmly in place. Tack weld hose clamp in a couple of spots. Same with the center flange except don't weld it. It will find its' own plane with the other two tightened down.



Best,,,or better of all is the heater box has a good 3/8'' clearance now from the oil line on the cooler. And a little wrap with a mallet will knock a little clearance where the heater box touches the oil cooler.




Jip

[universeman]

Clever. Did you think about installing some kind of temporary collar, so you could remove those hose clamps with the collar holding the "spread" (or perhaps 3 studs of the proper length), then tack weld the flange inner to the outer shell itself (removing the clamps from the equation)?