I just thought I'd put some confusion to rest.

I've been running without the liner for a while now, and the paint on the hood is beginning to craze a bit.

So, if you've ever wondered how accurate the idea of that liner protecting the paint is, wonder no more. It's accurate.

It's one of those things I kept putting off, as I didn't feel like removing the hood.

 

I put a 1" liner under mine and did it with the hood in place.

 

This is reasonably priced and looks much better that the factory. Look back at my post. https://www.jaguarforums.com/forum/x...ertible-84877/

This is the same one they're having a drawing for right now.

 

Yeah, I saw that. I even entered the contest.

That's a good product. He's chosen a good material for the application and the suggested installation procedure is effective. The fact that it's cut for the application is a nice bonus, and the price is sure right.

I'd intended to run some Dynamat Dynaliner under there. I like the look of exposed supports around liners. All I've got laying around is the extreme, though, which looks tacky as heck under a hood.

I thought I might run it all the way up to the front, as well. I'll call him to see if he can provide a sheet I can cut to fit, as I don't think what I was after comes in sheets wide enough for that humungous hood.

 

I think the length stops at the radiator shroud. I did have to trim it because it was slightly too wide at the top corner and partially down the side. You definitely have to remove the grill and hood which is easy. Also drill out the pop rivets for the old liner brackets and bar then clean the hood and dry fit the liner. You can reattach the brackets and bar with 1/8' pop rivets when you are done or leave them off. The glue holds the liner in. It looks cool.

 

Yeah, on my '96, the supports are welded in several unfortunate places. If they were riveted in, those buggers would have been gone long ago.

 

You could always dynamat and then install the hoodliner over that.

 

I've got a couple of Dynamat Xtreme bulk packs, but you can never get the wrinkles out of that stuff no matter how much heat you use, and it would look stupid under there with all the foil.

As for going over it, I think a hood liner alone will be enough. It shouldn't take much to kick enough heat off the underside of the hood. That thing is heavy as it is. I don't want to add too much more weight, in the event that it falls on my head one day.

That stupid up-down-up-down crap on the pistons is just asking for trouble in windy conditions. I narrowly escaped the other day, before using a stick to hold it up.

I can't get it to work half the time anyway, and as a result, the lower mount on the locking piston looks to fail in the future.

 

I could not agree more. Eventually I found a brillant firm in the UK, called SGS, who will make new gas struts to order, I am sure there is an equivalent in the US. I got a pair made for me and ordered them uprated by 20%. Absolutely brilliant; no more problems winter or summer.

Going too hard risks bending the bonnet (hood); but 20% extra presure has caused no problems at all.

Greg

 

How do we explain the decades of cars that had no hood liners fitted by the OEM and no paint issues? The first cars that appeared with them installed had the fan/radiator area covered only- strictly for noise suppression.

There's still many cars in production today with no liners, again with no paint issues.

 

The heat output from the V12 surpasses any other engine I have ever encountered in a road car, and it is much closer to the bonnet (hood) than any other too; and the engine bay is very poorly ventilated by the air draught as the car moves. If you open the hood on a train carrying cars where the train has fire sensors (such as the train carrying cars under the English Channel), the heat will set off the fire sensors. Ask me how I know!

Greg

 

C'mon over and we'll compare your V12 to some '60s and 70s big block Corvettes for heat and cramped engine compartments.

 

Bet you had fun trying to explain THAT one!

Marty.....................

 

Easy.

Different paint and differences in engine bays, as well as the engines within them.

 

Okay

 

And addition, since mention was made of decades ... petroleum based paints, generally single stage ... and lower temperature thermostats both of which were widely used until the advent of environmental considerations.

 

touche.

 

Interesting comparison- I'm far more familiar with the 427 and 454 cu. in. engine Corvettes which (from my world) create more underhood heat than any other car I've dealt with. Both the '63-'67 and '68-'82 body styles are famous for having virtually zero cooling system margin which causes the driver to spend more time looking at the temp gauge than the road. This, accompanied by a roasting hot cabin can make the cars unpleasant to drive on hot summer's days.

Getting back to the crazing paint you've observed. If original to the car, the spider webbing is something the plastic car crowd is accustomed to seeing on older cars, first appearing on horizontal surfaces exposed to the sun, then gradually spreading to all surfaces. The OEM paint was single stage nitrocellulose lacquer up to about 1981, then urethane base/clear coat after that. What did Jag use when your car was built?

 

Clearly the first picture which is of a 63-67 generation Corvette tri-power big block engine compartment is much less cramped than the XJS V12 engine compartment shown in the second picture. Trivia note, the big block is either a 396 or a 427 as the 454 was never available as an option in 63-67. The 68-82 generation, after 1971 were more cramped as delivered from the factory, but not to the degree of the V-12.

The air intake of those generations, and most generations of Corvette is limited by the body design. BTW, the factory recommended summer thermostat in those years was definitely not the year round 185*C/83*C that you advocate in other threads.

Nitrocellulose? You have your decades mixed up. Try this summary iinstead:


Corvette Paint
Restoration and Judging

NCRS Guidelines to

Typical Corvette Factory Paint Finish and Body preparation

Brief History of Corvette Paint

1953 – 1957: Nitro-saleous Lacquer Paint
1955: Start of the use of Metallic paint

1958+: Acrylic Lacquer Paint
1985+: Clearcoat Paint process

C5’s: Waterborn Paint


source: http://www.ncrs.org/heartland/Corvet...esentation.ppt as published by National Corvette Restorers Society

Urethane is not mentioned in the paint process history. At best, it may have been a change to catalyzed acrylic clearcoat which was introduced to market at about that time. Any paint rep will tell you that acrylic with hardener is not two part urethane.

In any event, whether a fiberglass bodied car crazes paint or not, has more or less underhood heat than a metal bodied car, still does not refute that a hood liner is needed or not in a XJS V-12.

Indeed, highlighting the paint failures on Corvettes and claiming that they run hot is more supportive of a hood liner being a sensible precaution rather than the other way around.

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