problem fitting Spectra CU730 radiator

[kikkegek]

he guys,

My radiator just kept on leaking on one of the hose connections. So I decided to buy a replacement.

A local store here supplied me with what should have been a "bolt-in-replacement"...the Spectra Prenium CU730

link to rockauto with specs
http://www.rockauto.com/catalog/moreinfo.php?pk=272029

I now encountered a couple of problems:

1. the radiator core is about 2cm ('0.8") higher and thicker

2. also the part that rests in rubbers at the bottom and top holding the radiator in place is 8cm wide in stead of 6 cm in my case. 3.15" in stead of 2,36".

Otherwise the radiator is fine. All connections are in the right place and fit fine.

But this means I had to cut my rubbers on top and bottom that support the radiator and modify my top brackets that hold the radiator in place.

We double checked and we are 100% sure this is the correct radiator for my K20 Suburban.

I cant find any mounting materials or new rubbers that do fit this radiators.

Can you guys help me? do you know where I can get mounting materials for this rad?

[kikkegek]

ttt help?

I have lready emailed Spectra, but aint gettin any replies! so much for customer support

[jblaven]

I would think that if your aftermarket radiator manufacturer didn't provide or doesn't have the brackets you need, then you might be on your own.

When I bought my new radiator from Summit Racing here in GA, I was shocked at the number of models that were available.

You may need to get creative with a trip to a hardware store. I know I can buy metal in short pieces to make brackets and such (I had to make a small piece to reattach the throttle bracket to the new Vortec intake manifold. The bolt holes were different.

Anyway, since it is an aftermarket radiator, you may have a hard time finding brackets from anyone else other than Spectra. Good luck with it.

[thirdstreettito]

Jochen, you may need to make your own brackets, shouldn't be too hard, a few pieces of steel from the hardware store should do fine. And for some "cushion" you can use a few pieces of truck mudflap.

[kikkegek]

pretty dissapointed in customer support from Spectra...

I ask them this:

Hi Spectra,

I recently replaced the stock radiator from my '86 Chevy Suburban K20. It has a three row thick standard radiator, and the CuU730 showed up as a bolt-in-replacement.

I bought it from a local shop (in the Netherlands) and had a hard time fitting it into my car.

I have added pictures for you. I had to cut, bent and adjust my mounting brackets and rubbers to be able to fit the CU730...

problem I found is:
- core is 2 cm (0.8 inch) higher...my rad is 52 cm high, the CU730 is 54 cm high
- core thickness is 2 cm (0.8 inch) thicker....my core is 4 cm thick and the CU730 is 6 cm thick
- where the core meets the plastic sides it is also 2 cm (0.8 inch) thicker...my radiator is 6 cm thick while the CU730 is 8 cm thick at that point...

since the CU730 is mentioned as "fits my car..." on several websites like JCWHITNEY, AUTOPARTSWAREHOUSE, etc...and your website too...I thought I bring this info to you...

I have been looking for mounting hardware, but cant find any...

you can see in the picture I have sent along that the CU730 now sits higher then the stock radiator and I can only just close the hood..because it just doesnt touch the radiatorcap...

I thought this feedback would be valuable to you and that is why I have sent it.

what would like to know:
- is there mounting hardware available? because right now my radiator is sitting on cut-up rubbers and in cut-and-bent radiator supports....

the radiator self is perfect. cools very good and connections were all in the perfect place...just the dimensions are off...

with kind regards,


Jochen Schilperoort
The Netherlands...

and add thse two pics:





at first they dont reply.

then I resent my message to all departments and Nicolas kicks in:

Good day Sir,

I have reviewed the measurements you sent us and I believe the radiator you should have used was CU716 to have a trouble free install however installing the CU730 in your truck will give you more cooling capacity as it is more efficient.

Let me know if you have more question it will be a pleasure to answer them.

Thank you.

Nicolas Vallières

and he doenst reply to any of the stuff I mention....ja, you need to by a differrent one???? why???? this one says "fits your car" on all websites...

I resent my message:

hello Nicolas,

thank you for the swift reply.

I am not looking for a different radiator. I already bought this one and I am having problems mounting it.

Also, all the shops I have visited offer the CU730 as a perfect fit for my car, which it isnt..

that is why I contacted you...

the CU716 has exactly the same width and height...which means it will also not fit. It is just thinner, meaning it will not give me the cooling I need for my truck.

I was meaning to help you guys, because the CU730 and thus the CU716 do not fit "bolt-in", although this is stated on the websites.

you did now answer my question in my previous email: since the radiator is not a perfect fit (although stated on all website it is!):

what would like to know:
- is there mounting hardware available? because right now my radiator is sitting on cut-up rubbers and in cut-and-bent radiator supports....

I hope you can help me, because right now the radiator is not perfectly mounted...it sits on cut-up rubbers...wich will not last.

Jochen

and get this one:

Sir,

I have verified with my engineering and the appropriate radiator you need would be a CU1599 as the CU730 you have ordered is wider than your OEM unit.

We do offer multiple radiators for your application and if you want an OEM fit you will need to buy another unit as we do not sell a conversion kit from a 32mm OEM unit to a 57mm Aluminum radiator.

with this picture:


this rad is just as high...so again wont "bolt in" just like that...

and he is basically saying...replace your three row thick copper radiator with a single row radiator...the core is 1 cm (0.4") less thick...


SO:
1. this will never be a "bolt in replacement" and will never just like that fit your car.
2. we do not offer brackets, your on your own...

3. is a aluminium rad soo much better in cooling that you can go from three copper rows to one aluminium row?

[kikkegek]

finally got this answer today.

The Cu1599 will fit as the header are not as wide and the cooling capacity of a 32mm Aluminum core will match your 40mm Oem without problem.

Any other question, do not hesitate to ask.

[thirdstreettito]

Jeez, that sucks. But maybe it will be worth the wait.

About the 1 row aluminum being better than a 3 row copper/brass. I've heard that is true, see the problem with copper/brass is that it holds heat longer than aluminum, and is more likely to leak because it is copper and brass soldered together with aluminum solder, 3 different metals all trying to do the same job, not good. I hope that the 1 core does better than the stock radiator. Good luck Jochen

[TheApocalyptican]

Just to answer the question about whether the 1 row alu can match the 3 row brass.... as thirdstreettito said....the aluminum ones are supposed to cool better. However, if I was in your situation, I would keep the rad you have now, and do the mods necessary to make the brackets fit correctly. I'd love to give you a hand in modding them, but the computer screen isn't a very good workshop. However, I would use the stock brackets and mod them, and attempt to mod the rubber pieces as well, but if the rubber pieces didn't work, I would find something rubber to cut up and fit to the brackets.

[TheApocalyptican]

Wanted to come back to this with info for anyone with this problem in the future. Obviously the best would be to measure what you have that fits, and not believe the websites. This goes for more than radiators too. There's just too many different options available for parts....so it's best to get all the info on what you need vs what is being sold.

As far as these radiators themselves....the 730 is a 2 row rad. The others they list for our trucks are only 1 row. This makes the core size thicker, and makes the header size bigger too. The header is the actual area that is used for mounting in our trucks, which makes the header size VERY important. Looks to me like all the 1 row 19" headers are very close in size to where you can interchange them without doing anything to the mounts. Also the same for the 1 row 17". Which only leaves the 2 row 19", which is the 730, which kikkegek has. The solution for his radiator, and I apologize for not noticing this before kikkegek, is that this rad is meant to go in place of the thicker stock rads that are available. Basically, you need the bigger rad mounting bracket that is a single piece that goes over the support and the rad.

[kikkegek]

Originally Posted by TheApocalyptican

Wanted to come back to this with info for anyone with this problem in the future. Obviously the best would be to measure what you have that fits, and not believe the websites. This goes for more than radiators too. There's just too many different options available for parts....so it's best to get all the info on what you need vs what is being sold.

As far as these radiators themselves....the 730 is a 2 row rad. The others they list for our trucks are only 1 row. This makes the core size thicker, and makes the header size bigger too. The header is the actual area that is used for mounting in our trucks, which makes the header size VERY important. Looks to me like all the 1 row 19" headers are very close in size to where you can interchange them without doing anything to the mounts. Also the same for the 1 row 17". Which only leaves the 2 row 19", which is the 730, which kikkegek has. The solution for his radiator, and I apologize for not noticing this before kikkegek, is that this rad is meant to go in place of the thicker stock rads that are available. Basically, you need the bigger rad mounting bracket that is a single piece that goes over the support and the rad.

dont worry man!

thanks for getting back to me and letting me know.

the modded (not pretty) supports and rubbers have been holding up for over a year now and doing fine. problem is that a rather inexpensive part becomes expensive by the time it reaches the Netherlands where I live.

So I'll keep it in mind and maybe upgrade in the future...

thanks man!

this solves my question on the top part....but which supports/rubbers should I use on the bottom?

[motornut]

I've used cut bits of heater hose in a pinch
say 3 inches with a half inch or so cut out in the length
you end up with a "c" open down for the top or up for the bottom

[Axle]

Dragging this oldie back up since I was looking for something else, but Just fyi, a cu730 IS a bolt in, IF you buy the correct rubbers and top brackets.
isolators: GM p/n 06264100
top brackets (for the individual style brackets as on the 1983 models) GM p/n 14039949 and 14039950 (left and a right).
You can modify your stock radiator shroud, or find one in a wrecking yard out of a truck with the tall 3 row rad that'll need minimal modifications. Good luck finding an original app shroud for the cu730 though.

Original radiator applications are all over the map, one year it'll be with heavy duty cooling, other years the 3 row will be spec'd for heavy duty cooling. Ditto for a/c applications, sometimes yes, sometimes no. Been used with everything from the 305+ to the diesels, and even though it has an transmission cooler, its also used in manual transmission applications.

Alex.