We're bringin' back the Flat Tops!

[jayhawk]

4 hours ago, motorman7 said:

Being an engineer, I have to say that the carb heat shields inherently have a heat transfer issue.  There are black insulators between the heat shield and carb float bowl, but the securing bolts on the opposite side directly contact the heat shield and screw directly into the float bowl base.  This means that all of the heat that the heat shield is absorbing is transferred through the bolt assembly into the base of the float bowl., which means the shield is not helping very much and the float bowl is acting like a heat sink.  So, I added two gray fiber washers on the opposite side of the heat shield (from the insulators) so that the bolts do not directly contact the heat shield.  This way the heat shield is isolated and not channeling as much heat into the float bowl.  This is pretty much the only mod that i have made to the carbs and hopefully it reduces the susceptibility to vapor lock.

@Zup
@Captain Obvious

 

 

Pardon the ignorance of a Flat Top owner (actually they are also SU carbs. SU HIF designs)  but did the round top carbs have any heat shields?

[w3wilkes]

 

20 minutes ago, jayhawk said:

Pardon the ignorance of a Flat Top owner (actually they are also SU carbs. SU HIF designs)  but did the round top carbs have any heat shields?

Yes, the round tops have a heat shield between the exhaust manifold and the carbs. You can see the heat shield in this shot

[siteunseen]

Here's a shot of mine.  Disregard the circle up top, that was another paint file.  It's the arrow pointing to it.

[siteunseen]

Here's a great shot thanks @240260280

I'm flogging a dead horse I know but that's what I do.

Edited May 25, 2019 by siteunseen

[Captain Obvious]

What everyone else said.

That's added value right there, isn't it?      

[motorman7]

Put the exhaust in this weekend.  Need to go the store and get some muffler clamps, used the hose clamps since they were available.   Parts to finish out the carbs should be coming in this week.  Will need to get those plated, then will install hose.

 

Also, need a little help finding the rear bumperette rubber. You can see it is missing in the last pic. They are different for the '73 than the earlier models and don't seem to be readily available.  These ones on eBay seem to be the right ones, but not sure, no part number.

https://www.ebay.com/itm/REAR-BUMPER-BAR-RUBBER-OVERRIDER-RUBBER-INSERTS-for-DATSUN-NISSAN-240Z-260Z/132883410645

 

 

Edited May 28, 2019 by motorman7

[Captain Obvious]

Beautiful.

One question though... Are you sure you got the T/C rod bar washers in the correct direction?  Could be an optical illusion caused by all the shiny bling, but they look backwards to me. It looks like you have them convex side out:

 

[motorman7]

Thanks @Captain Obvious...got those washers inverted.  Thanks also @Zup and @Terrapin Z for the parts.  Things are coming together here.  Will get those non-brass/copper parts plated.

[Captain Obvious]

Much better on the washers. Back side washers too, right? 

Hey... Someone has to ask.     

[motorman7]

50 minutes ago, Captain Obvious said:

Much better on the washers. Back side washers too, right? 

Hey... Someone has to ask.     

 

Yes, backside washer too...of course.  Interesting though, I went through all of my manuals and really could not find a clear picture or verbage of how the washers are supposed to go and unfortunately, my '70 is not available for verification.  The only information I could find was to ensure that the rounded part of the rubber was toward the frame.  Will have to double check on the source.....may have been a Chilton's.   It does seem odd to me that the convex side is toward the rubber.  I would think that water would/could accumulate at the interface.  Seems like convex side out would reduce water intrusion.

[Captain Obvious]

The washer orientation seemed odd to me too at first, but I accepted it when I likened it to shock absorbers and sway bar bushing washers. They use the bushings and washers as a kind of spherical bearing because you want the shaft to be able to move in all directions. Putting the convex domed side inward helps facilitate that and makes it operate spherically.

Oh, and I believe the rounded side of the rubber bushings should be outboard too... Sounds like you may have yours backwards. That one also seems counter-intuitive, and the pics in the manuals are not good enough to be definitive, but I've been into a couple cars now where I was pretty sure the bushings were original and they were installed with the smaller section towards the body and the thicker rounded section towards the washers.

When I get a chance, I will dig up some pics of crusty cracked (but original) T/C rod bushings.

The pic I posted above is (what I believe to be) the proper orientation of everything. If you're running rubber on both sides, just mirror the rear rubber bushing to the front.

[motorman7]

Yes, will double check the source on the rubber when I get home.  I actually had the rubber as shown in your picture above but switched it after reading the manual.