21GT Refurb

[Rick]

I am in the process of refurbing my twin GT. It's a 71' model. What is the original width of the deck stripe, and where can I get the original logo and emblem stickers? Thanks for your help Rick. Refurb will include interior, exterior, and fuel cells as engines and outdrives are fresh.

[Danny]

Rick
I have a 73 GT and to the best of my knowledge the striping on my boat is original, however it may be different than yours because of the colours.
My hull and decks are off white to the beige almost cream colour. My deck stripe is brown and then highlighted on both sides with a thin yellow stripe. The brown is originl gelcoat and it is difficult to tell but but the yellow stipes appear to be in the gelcoat as well. The reason I say this is by the way all three colours responded the same way to buffing. Thr brown stipe is 13.5 inches wide and the yellow stripes are half an inch wide each, for a total of 14.5 inches.
If I remember correctly your baot is white and blue, so I would assume your stripe would be only colour which may make all of what I have said irrelevent.
Richard Weaver can tell you exactly what your boat had originally for decals and also provide them to you. rweaver@javanet.com
I got decals from him for my 16 and was very pleased with the decals and the service.
Good luck with the resoration, a very unique boat especially with the twins.
Danny

[olredalert]

Many 21GTs were made with no racing stripe.Mine was one of them.I copied some others they were building in front of mine
in 71,and put a 3/8 stripe around the edge of the whole deck.The boat sort of took an upscale tone,which is what I think they were after.Not telling you what to do at all,because the racing stripes always look good,but they looked equally as good without the stripe!........just......stripeless........ol red!

[Formula Jr]

Danny, would you have any idea on where to get a glass replacement for the front windshield? And a new set of 350 (LT1) thru the stringers, engine mounts?


Rick, that twin is too wild for words.

[Rick]

Thanks for the input will keep you posted on the progress. Thanks Rick

[Danny]

Rick
Ol Red is right , my neighbour.s 70 GT was originally the light blue with no stripe, he redid his with darker blue hullsides and stripe and dash with a white deck and bottom
I don't know about the motor mounts but I am on the hunt for windshield glass as well, someone replaced mine with plexy and I am mising the glass from one of the side vent windows as well so I am going to replace them all. I was going to start with the local automotive glass guy. I have gotten replace plexy from him in the past for other boats. The original was glass with a light green tint to it and I would prefer the same.
I'll keep you posted as to what I find.
Danny

[Rick]

My windscreen is also plastic. Do you think lexan would be less scratch resistant than plexi? My windscreen is tinted and you can't see through it anyway especially at night. I was considering making a new frame and cutting down the windscreen. Has anyone ever attmpted a frame? Are they screwed to the cap?

[Looped]

Rick,
The only advantage of using Lexan is that it’s bulletproof but only when you get into the thicker ¾ - 1-inch sheets. What Lexan does is it actually lets the object (say a bullet) mold into the Lexan when it hits (kind of like tossing a rock in the water and seeing the water concave itself around the rock before the rock submerges) and then stops it. Because of this, Lexan is a much softer type plastic so it does scratch a lot easier than Plexiglas.

Unfortunately, I worked at a glass company for 6 years (started a couple of years after high school) that dealt with most anything with glass (God I hated that job). We would take some cutoff sheets of Lexan that we would have sitting around and shoot at them in the back of the shop with a 22 and the 1/8 – ¼ inch stuff really was not that strong.

Craig

[MarkGT]

I was wanting to cut down my windshield on my 21GT. I have not been able to find the original weather stripping that holds the Plexigless in. There is two different types rubber strips around the edges that I can not find. The current stuff is severly sun rotted.
DOES ANYONE HAVE A SOURCE? :confused:

I think the boat looks great with about 6"-9" inches removed from the top top of the windshield. To see a fine example check out:
Nates' 21GT (http://www.donzi.net/hull/GTX2100021/PIC00035.jpg)

[olredalert]

21GTs from their inception had a windshield problem.The top part of the frame was only aluminum and had a distinct propensity for bending down and back.I used to have to beg people not to touch the windshield when standing up,or any other time for that matter.The wind would bend it down if the boat went fast enough.As a matter of fact,one 21GT that John Chisholm used to go back and forth to work in for awhile had a little turn-buckle arrangement from the center-top of the windshield to the dash-top.I dont know if that was an actual option or just for him.
Dont know that they ever fixed the problem,as I seem to remember 22s in the early days having a similar problem.Now the 22s seem pretty good though,as is most everything DONZI with the newest regime!.........just.......ol red!

[Jamesbon]

Thanks MarkGT! Go for it Rick...I'm partial to the cut down windshield. Here's a small pic.

Some joint in Ft. Lauderdale made mine. Wish it were stainless...maybe next year...

While we're all at it here, will you guys post more pics of your GT's? PLEASE!! ;)

http://www.donzimarine.com/channel_z/images/mtdora_05.jpg

[Formula Jr]

The brace seen here (http://www.donzi.net/photos/osaffell9001.jpg) is one of the first things I'll add.

This is my newly aquired dash. (http://www.donzi.net/photos/osaffell9002.jpg) I like the cut down idea. These don't look like boats you can run without a windshield of somekind.

When my brother saw the engine compartment on this thing, he went "WOW!" you could put a couple bunks in there and sleep in it!!!

[Formula Jr]

Here's a dumb question. Oddly there's a set of Volvo front Motor Mounts on eBay (What are the odds of that!?) anyway, Is an LT 1 Engine the same as a Chevy 350? What does the LT stand for and when someone says an engine is a four bolt - what are they talking about. I don't anything about engines........
http://www.donzi.net/photos/osaffell9003.jpg
http://www,donzi.net/photos/osaffell9004.jpg (http://www.donzi.net/photos/osaffell9004.jpg)

[Tomahawk]

Rick - a 21 GT with twins! That is very cool. What are the chances of you bringing that rare gem to AOTH II at Lake Cumberland? I know a bunch of guys that love to to see that boat, including me. Hope you can make it. Good luck with your resto.

[Jamesbon]

I'm going to go out on a limb here Owen, an LT1's outside dimensions are the same as any other small block Chevy. I think the LT1's were internally beefier blocks than the standard SBC.

The "4 bolt" part refers to how many bolts hold the three crankshaft center bearing caps down. General duty SBC's usually have 2 bolt main caps or 2 bolts holding each cap down. In a 4 bolt, the two end caps use two bolts and the three center caps have 4 bolts holding them down.

I just picked up a GIL one piece offshore mount for my GT, as the stringers are spaced unusually far apart. This will help keep them there rather than pulling them in.

Nate

[Formula Jr]

Found GIL. (http://www.gilmarine.aa.psiweb.com/index.html) What a weird address???? There's lots of engine mount offerings out there, but all of them so far are thru the top of the stringer lag bolt types - not the thru the stringer types shown. I guess I can just have fabricated an L bracket and backing plate that a standard mount will bolt on to. The more I look at the pics, its pretty clear that the standoffs are custom pieces. I don't like the way they standoff so far. What did your one piece cost?

[Woodsy]

Owen...

You beat me to it. I was just about to post the url for Gil. You used to be able to get there via the www.corsaperf.com (http://www.corsaperf.com) website. As far as the LT-1 question, Depending on the vintage, as some of the newer engines have been called by the LT-1 designation, it will bolt right in. It is dimensionally the same as a standard Chevy 350. No differences at all. The problem arises with the camshaft duration and compression ratio. After already pissing off Looped in trying to describe engine dynamics, I will not get into it. Suffuce to say you will have to examine your camshaft and static compression very carefully so as not to have reversion & detonation. Hope this helps.

Woodsy :D

[Formula Jr]

More stupid questions. Am I right to assume that these single piece engine mounts do not use the trunnions, but bolt directly to the block. Question is, How the heck do you adjust the engine alignment. DO you adjust the engine alignment? And once you have this bolted to the engine, how is it then bolted to the stringers? L-brackets and backing plates? Where is the dampening? I hate seeing parts I can't figure out........

http://www.donzi.net/photos/osaffell9005.gif

[jwright]

I love all of this GT talk!

I replaced the glass in my full windsheild, or should I say plexiglass. I used flat plexiglass from the local glass shop and it fit great, took the curve of the fram no problem. My w/s does not have side vents, so I use flat plexi for the sides too. I do have a source for the people who molded the rubber extrusion that holds it in. I can dig that info up. I can try to get a pic of my boat on here so you can see my w/s. It has survived since 1976 without bending so I guess I am lucky... because I love the look it gives the boat. It also allows me to have full canvas up when I run the boat in the rain.
In regards to the GIL mounts, as far as I know they are not adjustable. I helped set a boat up with them, and we just made sure to have everything right before we bolted them in. I think it is considered a rigid/solid type mount so nothing should move (in theory!) Keep in mind that they may be race oriented so vibration, coupler wear etc.. is not a big concern.

[Looped]

Owen and anyone else curious,

I’m not sure if you were kidding or not but here are a few shots of the differences of 2-bolt mains and 4-bolt mains.

This is a basic 2-bolt mains block with just one bolt holding down each side of the main bearing cap:
http://www.donzi.net/photos/cringer056a.jpg

This is a stronger 4-bolt mains block with two bolts holding down each side of the main bearing cap and all 4 bolts go straight into the main web area of the block:
http://www.donzi.net/photos/cringer057.jpg

These are splayed 4-bolt main bearing caps that are stronger than the stock 4-bolt caps because they have the two center bolts go straight down at 90degs into the web area of the block and the two outer bolts go into both the web area & the side walls of the block at an angle:
http://www.donzi.net/photos/cringer058.gif

PS. Woodsy, You did not tick me off at all, I know what you were saying. It was funny though; I could almost hear your keys slamming when you were typing back to me. I’m sure you will tell me again tomorrow night. :D


Craig

[Formula Jr]

Gils are not adjustable eh? Well, that kills that Idea. I don't like boats that rattle. I'll just have to have something fabricated in Naptown or glass in a parallel set of short stringers I can lag bolt to.

[Looped]

Owen,
You may need to talk to Jamesbon to see what he ended up doing with his GT. I think he said his stringers were around 33” apart from each other so he was going to make some braces or something to narrow the width up. I think he was going to use the same motor mounts that Geoo has that are the Gleenwood adjustable ones that give you a 23” – 26” span to play with and I think they are a stringer thru bolt mount too.

Craig

[oldLenny]

http://www.californiamarine.com/images/catalogue/glenwood/page17.pdf
http://www.stainlessmarine.com/accessory.html

[Voodoocanoe]

Owen, The GIL bracket is a good piece I put one in the raceboat, I used 3" X 3" X 1/2" aluminum L, and milled them to fit, vertically one in front of each side and one in the back of each side thru bolted with 1/2" stainless bolts to sandwich the GIL bracket then thru bolted to the stringer with 1/2" stainless bolts with a 3" X 12" X 1/2" aluminum backing plate on the outside of the stringer, I also applied 3M 5200 on all the aluminum pieces where they contact the stringer. And it is a solid ridgid mount, It takes some careful measuring to get the alignment right, up and down with the engine and check the alignment again over and over until it's perfect, once it's set thats it, permament. I have had the drive off several times and always check the alignment and it has never moved.
I also have not experienced any vibrations with this set up.

[Sam]

Jeff, I have a picture of your boat. You should see it, it's great. Your sitting on the deck with a tow line in your hand that leads to a great looking 16.(broken trim + shallow water = tow) Sorry Jeff I couldn't help myself, I'm sure my day will come, so are you going to AOTH ? I think we should have a strong showing from Mich, and I know everyone would love to see your 21. Give me a shout sometime.

Sam

[Danny]

jwright
If I could get your source for the windshield rubber that would be great.
My 73 has a windshield support in the middle of the dash looks original but I don't know for sure, but it has certainly saved the frame.
Danny

[Rick]

JW if you have the information on the rubber extrusions, it would be helpful. Been gone for a few days taking the 21GT to Destin,Fl from Bolivar, Mo. (about 1000 miles one way, could write a book on this adventure).Red the deck was cream with about a 6" dark blue racing stripe with no outline or pin stripe found a wrap of gelcoat on the aft deck going into the engine compartment. We are going to sand a few sample places but I am beginning to believe that the bottom of the hull was the same dark blue as the side. Where is AOTH and when. I am quite the Donzi Club novice. Thanks Rick

[olredalert]

Rick,

-----I must have been in some twilight zone or something because I just reread your 1st post and realized that weve been talking about the fabled twin 21GT.The only one ever built.I road in this one-of-a-kind GT a couple of times in 71-72 and it was wild.Im glad you decided to keep it,Rick,as it is so very unique.Would have loved to buy it but finances(and wife)wouldnt allow.
-----As I recall your 21 had just abut every option Roy Farmer and the Chisholms could dream up as well.The color Ive seen in some of the pictures doesnt look like the original Sky Blue.Maybe the pictures were lying though.Maybe when you sand it down a bit you will discover the original blue.By the way,I believe you are correct in thinking that the whole hull was blue,with a white boot stripe.Good luck with the project........just.......ol red!

[olredalert]

Rick,

-----Just to put my two cents in about your windshield.With the history behind your particular 21,if it was me,I wouldnt modify it!I think your boat had the vent windows as well,didnt it?They are really a nice option........ol red again!

[Rob]

Rick:

Recent owners of this boat are friends of mine (probably the set just prior to the person you bought it from)if your are interested in some more background. They used it on Lake of the Ozarks.

[Rick]

Red, I probably won't change the windscreen except for putting in a lighter tint, somthing I can see through. The boat currently does not have the vented windows. Right now I am assuming the dark blue hull, because the deck stripe was the darker blue.
Rob, I have owned the boat since 89' the first thing I made payments on when I graduated from college Port Arrowhead at Lake of the Ozarks wouldn't give me the owners name. If you or anyone has any of the boats' lineage it would be greatly appreciated. Thanks Rick

[Rob]

Rick:

A doctor and his wife bought the boat somewhere in FLA and brought it up to Lake of the Ozarks. They ultimately split up and she kept the boat. Both engines were rebuilt, but I understand the rebuilds were much less than satisfactory. I don't think they refinished the boat, but I could ask.

They were not particularly pleased with a number of things about the boat-the way it handled at low speed, hard to plane off, high fuel consumption for a 21 foot boat, lots of problems with the engines, etc. and replaced it with a single big block SuperNova.

I'm sure I can find out more if you are interested.

[BigGrizzly]

If you look in the brochure of the 21GT you will notice the baby blue boat on the front and a yellow on the back which has twins two shifterd two throtles, two tachs and two ignition switches with a brunette modle sitting on the right seat back. threr is a one speedo on the port side of the wheel and two gas tank fillson the starbord side by the modles hand. Ol red there were at least two of these boats. that brochure was 1970, twins not listed in the price list

Randy

[Rick]

Yea, I think the reason Port Arrowhead would not let me know who the previous owners were was because of the marginal rebuilds. I found out when I rebuilt them due to lower than normal oil pressure. I have no grudge because when I bought it I did a compression check and new they were marginal on the top end at least. I did not know the boat came out of Florida. Handling at low speed is tough because there is so much pitch on such a short boat. I am sorting the handling out on the top end with the yaw skulls on the bottom of the outdrives. I got frustrated with the boat and put it in storage for a while, but I now have a fresh wind and a great boat builder on my side. We were thinking about ballasting the front of the boat to try to even out the weight distribution. Grizz, What are your ideas about that. Since I am changing out the fuel tanks I could move the aft tank forward? Does anyone know what the optimal weight distribution for the 21GT Hull? I bought some props from Hill Propellers, they said they had encountered a twin 21GT at Lake Havasoo(spelling) in Arizona, but that was ten years ago. Don't know if it is still alive. As for the fuel consumption give me a break. Ha Ha

[olredalert]

Griz,

-----I dont believe Ive ever seen the catalog with this yellow 21GT twin pictured.Could you or anyone(I guess)post the picture you refer to.Id be really interested to see it as would,probably everyone on the board.Thanks in advance........just.......ol red!

[MarkGT]

jwright
If I could also get your source for the windshield rubber that would be great.

My 74 has a windshield support in the middle may have been added by P.O. it caused the dash to stress crack.

Has anyone upgrade the front their seats?

[Jamesbon]

MarkGT,
Yes, I found a pair of seats from an 18 2+3, you know, the small bucket types. I stripped them down to the fiberglass molds and will recover them as my boat nears completion.

Anyone want my original front seats? They're in great condition. $100 ea., or best offer. See my registry page for pics.

[BigGrizzly]

I would not do the tank move the Hill props woll take care of that. just make they are counter rotating. If there is too much lift just swapp props from left to righr and turn the outdrives in the oppisit direction. this will give more stern lift.

Randy