Tamiya 1/32 F-4J marines Phantom kit no 08 correct exhausts.

[Ayovan]

On 2/28/2021 at 6:18 AM, Gary Needham said:

Bob.

 

IF you can get hold of a set from someone with a junked or 'for parts only' kit, then the Revell 1/32 F4 kit exhausts were an almost perfect fit to the Tamiya fuselage. The detail is somewhat basic granted, but you can always add more detail with with an Eduard etch set for the liners or add some scratch details yourself.

 

Either way, it looks MUCH better that a gap equating to about a scale foot all way around the exhaust area (what on earth were Tamiya thinking?) If you look online, then you will rarely, if ever, see built versions of this kit showing close-up detail shots in that area of the model for that very reason I suspect.

 

Gary

With that being said, then would the after market cans for Revell also be a good fit for the Tamiya kits?  I have both, A Revell F-4G, and 2 Tamiya kits, an F-4J, and an F-4C/D.

Edited April 2, 2021 by Ayovan

[Anders_Isaksson]

I´m pretty sure I have seen a new set of exhausts announced from Res/Kit, but can now only find this picture of the set.

Nothing on the Res/Kit website. Strange.

 

Res/Kit do some great stuff so a few sets of proper F-4 exhausts may fit the bill for the Tamiya kit.

[Derek B]

On 3/2/2021 at 2:56 AM, cmayer said:

I don't have measurements for the -8/-15 short cans (those used on the F-4B/N, C/D, RF-4C and early RF-4B); but I was able to measure the diameters of some -17s (USAF F-4E), both while mounted on the aircraft, and while stored on the engine trolley; and both a fully closed nozzle (as it would be in mil power while in flight), and fully open, as they were most often while shut down/parked.

 

EDIT: To clarify, these measurements from a J79-GE-17 apply to the -10, as well, so the data is good for the entire F-4E/EJ/F/USAF G as well as the J/S and late RF-4B (with -10 motors) and RF-4E series of airframes.

 

Straight measurements in inches:

Length of the -17 augmenter petal (turkey feathers), from the edge of silver mounting trim to the end of the petal (fully open nozzle*): 26" [1/32 scale = 13/16" or 20.65mm]

Base of the Augmenter (diameter): 38" [1/32 scale = 1 3/16" or 30.18mm]

Diameter of the fully open augmenter (straight across the open petals at the aft end of the can): 37" [1/32 scale = 1 5/32" or 29.35mm]

Diameter of fully closed nozzle (engine resting on maintenance trolley): 29.75" [1/32 scale = .9297" or 23.50mm]

Diameter of metal mounting trim (thin metal ring around the augmenter nozzle): 38.25" (basically a 1/8" gap around the augmenter) [1/32 scale = 1.195" or 30.36mm]

Width of the metal trim midway down the augmenter: 2 5/8" (from the camouflage skin to the augmenter); note: this applies to -10/-17 type aircraft only [1/32 scale = .082" or 2.08mm]

Length of the engine bay vent (4x metal vents at the top of the engine mounting trim): 4 7/8" [1/32 scale = .152" or 3.87mm]

 

Measurement accuracy: with an assistant to manage all the tools, I used sections of 2x4 and a level to extend the baselines from the top/bottom of the mounted engines to get a straight diameter for the base of the augmenter; could be off a 1/4' here or there. But the measurements for the open-end of the augmenter are accurate within 1/32 of an inch, as I was able to pull the tape measure directly across the open augmenter petals (outside to outside measurement), without any contortions or obstructions. Even so, I wish I had a 6-foot caliper micrometer...

 

I also took measurements of the intake along with the fixed and variable ramps; but the values I got are the same or very close to the measurements I've seen posted by Derek and Ian from their work on the F-4J (UK), so I haven't added those to the forum (all J-79 Phantom intakes and fuselages should have the same measurements and contours).

 

* - Also a word about the length of the augmenter petal: I didn't measure the "length" of an open vs. closed augmenter (I wish I had); I merely measured the length of an individual petal (26") which will be the same length whether the augmenter is open or closed...what would also be useful, would be the distance from the metal trim, to the end of the augmenter when it is fully open, and fully closed...I imagine the fully open dimension would be just a hair under 26", since the petals are not quite perpendicular to the mounting ring when fully open, and the closed distance would probably be somewhere close to 23"-24", as the nozzle closes into a tight, conical shape.

 

Hope this helps. I don't have a Tamiya F-4 to measure...and I've always read, "the Tamiya Nozzles are horribly undersized...." But looking at photos of the great builds I've seen on this site and elsewhere, I've also wondered if the Tamiya nozzles were actually too small in diameter, or if their aft fuselage was too fat. Over time, however, I'm now convinced both are true: their nozzles are too small and the aft fuselage is also too large.

 

Good Hunting!
Chris

 

Barry Chandler measured the open nozzle diameter of the J79 engine for me, so I can confirm Chris' finding of 37" diameter, making it 29.35 mm in 1/32 scale (thanks for all your dimensions Chris  ).

 

Derek

[Gary Needham]

5 hours ago, Ayovan said:

With that being said, then would the after market cans for Revell also be a good fit for the Tamiya kits?  I have both, A Revell F-4-G, and 2 Tamiya kits, an F-4-J, and an F-4-C/D.

 

No idea and the problem with (any) resin AM is the potential for shrinkage in individual batches / packages. Short of testing it or hearing from someone who has them to hand, I would treat any purchase with caution. If resin can be incorrectly sized for the Tamiya kit; then why not Revell kits as well.

 

Gary

[thierry laurent]

1 hour ago, Gary Needham said:

 

No idea and the problem with (any) resin AM is the potential for shrinkage in individual batches / packages. Short of testing it or hearing from someone who has them to hand, I would treat any purchase with caution. If resin can be incorrectly sized for the Tamiya kit; then why not Revell kits as well.

 

Gary

The difference lies in the fact the dimensions of the original parts are wrong in the first case whereas they are correct in the second one. So, any aftermarket set not based on actual dimensions or the Revell parts but on the Tamiya ones is automatically wrong. On the opposite, the other parts 'should' be correct if there is no casting issue.

[Derek B]

Just a little insight into resin cast parts and some of the reasons for size variations.

 

If a kit component is upgraded or improved in detail using that kit part as the basis for a master pattern, then due to both resin and RTV shrinkage (no matter how little that may be in percentage terms), the cast resin copies will always be slightly undersize compared to the original kit part.

 

Add to this that some AM manufacturers - to protect what could be a delicate master pattern part or parts - sometimes use 'good' first casts as 'sub-master patterns', and make new RTV moulds of this for production; this 'second generation' cast and mould increase the shrinkage even more, resulting in what can sometimes be considerably undersized final production castings.

 

Therefore, detailing a kit part in order to use as a master pattern can cause undersize issues in its final production condition, and is difficult to overcome unless that part can be enlarged slightly (which can be done - I normally do this). Completely scratch built master pattern parts (whether created by hand or, these days, 3D printing) can, of course, be made oversized from the start to allow for material shrinkage (I allow typically 1% to 1.5% for this, depending upon the size of the pattern, but this is only my rule of thumb from years of experience doing it). 

 

Regards

 

Derek

 

 

[Ayovan]

1 hour ago, thierry laurent said:

The difference lies in the fact the dimensions of the original parts are wrong in the first case whereas they are correct in the second one. So, any aftermarket set not based on actual dimensions or the Revell parts but on the Tamiya ones is automatically wrong. On the opposite, the other parts 'should' be correct if there is no casting issue.

I might give it a try. I guess someone has to be the guinea pig.

[Gary Needham]

Derek B .

 

You make some good points.

 

My frustration lies with those who simply take (known incorrect) sized kit parts and then simply 'super detail' them to sell them at a premium price. I simply do not understand this logic and surely the purpose of buying AM stuff like this is to correct a kit fault; not compound it AND pay for the privilege of doing so.

 

Gary

[thierry laurent]

4 minutes ago, Gary Needham said:

Derek B .

 

You make some good points.

 

My frustration lies with those who simply take (known incorrect) sized kit parts and then simply 'super detail' them to sell them at a premium price. I simply do not understand this logic and surely the purpose of buying AM stuff like this is to correct a kit fault; not compound it AND pay for the privilege of doing so.

 

Gary

You would be surprised knowing how many times excellent modellers are adding beautiful details to incorrectly sized items! This also encompasses people making masters. Sometimes, this is deliberate to ensure compatibility with the kit, sometimes this is not...!

[Ayovan]

8 hours ago, Gary Needham said:

 

No idea and the problem with (any) resin AM is the potential for shrinkage in individual batches / packages. Short of testing it or hearing from someone who has them to hand, I would treat any purchase with caution. If resin can be incorrectly sized for the Tamiya kit; then why not Revell kits as well.

 

Gary

Being I have both Revell and Tamiya kits, I will pick up a set of Revell  AM cans and see how well they fit the Tamiya kits. I mean I will use them either way, and if they fit I will have an extra set of oem Revell cans I can use.

[Ayovan]

1 hour ago, Ayovan said:

Being I have both Revell and Tamiya kits, I will pick up a set of Revell  AM cans and see how well they fit the Tamiya kits. I mean I will use them either way, and if they fit I will have an extra set of oem Revell cans I can use.

I bought the GT resin exhaust nozzle set for the Revell, and a wolfpack  exhaust nozzle set for one of my Tamiya kits from Sprue Bros. We shall see in a few days whether or not the the Revell Am cans work on Tamiya kits. I need to check the OEM Revell cans and see how well they match up to Tamiya

[Anders_Isaksson]

On 4/1/2021 at 11:41 AM, Anders_Isaksson said:

I´m pretty sure I have seen a new set of exhausts announced from Res/Kit, but can now only find this picture of the set.

Nothing on the Res/Kit website. Strange.

 

Res/Kit do some great stuff so a few sets of proper F-4 exhausts may fit the bill for the Tamiya kit.

I emailed Res/Kit yesterday and got a reply that the F-4 (E/J/F/G/S) exhaust set will be available in the next couple of days. Great!

Edited April 2, 2021 by Anders_Isaksson

[Mark P]

Yes, but will they be appropriately sized? Time will tell...

 

Mark Proulx

[allbann]

Anyone bought the Reskit exhaust?

 

How is the size compared to the kit parts?

[Tony T]

Another vote for the Q-M-T exhausts designed for the Revell E/F but which fit the Tamiya E/EJ/J kits and look the part.

 

I haven't test-fitted the ResKit ones but they look nice "in the catalogue"

 

Tony