1990 Yugo GV+ aka Yugo From Hell

Things fell apart tonight....

Hadn't intended to go quite so far but sometimes it's best to jump in with both feet. The factory harness is gone, engine harness salvaged with plans to put MS on this puppy. I think I left 200-400 lbs on the table when I was doing weight reduction last time so Im trying to find it now :)

And for the folks waiting on the suspension bits I didnt forget you, I only had a few hours tonight and I was trying to chase wires so I could make sure I knew what the state of thing was so I can design the electrical during the day.

Wow, that engine looks positively tiny in that bay...

peter wrote: Wow, that engine looks positively tiny in that bay...

Kinda what I was thinking...seems like something bigger should go in there

I've always wanted to drop an Alfa V6 from a 164 in a Yugo but honestly I'd rather put the engine in the rear and drop a fuel cell in the engine bay when I do that....someday

Acetone wipe to remove tree sap, wash, 220, 320, 600, 1000, Rubbing compound, polishing compound, first coat (of 10) of carnuba wax applied, hour wait between coats. Noone said this would be quick. Waiting on a shipment of filleting clay anyway so I can't get beyond the waxing stage until it gets here.

It's mold making time :)

5 day weekend starts tonight and at least 2 of those days are all mine so there will be lots of parts prep for fiberglassing and I'm going to toss the best of the spare motors up on the engine stand and see what it holds. Also going to try to strip off the suspension for the folks who are waiting on the old bits.

Started tearing down a spare motor to see what I need for it. Hmmm, I don't remember that being there on a stock motor.....

Looks like this one may have had a little love at one point.

After 10 coats of wax are applied its time to get the hood ready to be a mold. First step is to create flanges for the mold edges. I used cut up coroplast signs with some hot melt glue to hold them in place.

After the flanges are applied the gap must be filled and smoothed with filleting clay. This prevents an undercut in the mold which would make it impossible to release.

Now that it's flanged and fillited can you guess the next step? If you said wax some more you are correct. If you said anything else you will cry when it comes time to release the mold. One final waxing of everything. Once its had a few hours for the wax to harden I'll be spraying on mold release.

And now in gelcoat. Time to start laying up glass :) If anything goes wrong it will be this stage as I bought some expired gelcoat because it was 1/10th the price, but so far it seems to be laying up correctly.

Just out of curiosity, how are you handling the vents in the hood there?

Thanks for doing the step-by-step, very interesting.

Are you brushing on the gel-coat?

Fingers crossed.

(...and thanks for the detailed step by step description so we can learn more about your process)

peter wrote: Just out of curiosity, how are you handling the vents in the hood there? Thanks for doing the step-by-step, very interesting.

I taped over them but the imprint will remain in the mold so it can be dremeled out afterward or, in my case, filled in. The vent is there to feed fresh air to the heater and I have no hvac so I'll just fill it and smooth it. The impression is only about an 1/8th of an inch so easy enough to skim with some filler. I molded this so I can offer it to other Yugo geeks as well, if I had been doing it just for me I'd have smoothed out the vent before taking the mold.

oldtin wrote: Are you brushing on the gel-coat?

Yes, and I'm fully aware its the wrong way to go. But I'm too cheap to spend $150 for a gelcoat gun. I've seen lots of folks get decent results brushing it on so I'm crossing my fingers :)

A bit more about the process while I wait. The gelcoat needs to set up, usually 45 minutes to an hour. It should still be tacky but not wet. This is one of the reasons brushing is bad because you end up with variances in thickness which set up differently. If its too "wet" it will get moved around by the next layer of fiberglass. Too "dry" and the resin wont bond to it. As it starts to set it looses its gloss a bit, it's just about that point when you are ready to start laying glass. About 10 more minutes here.

For a mold you want to lay up the glass 3 to 4 times the thickness of the final part. I'll be doing 4 layers of 1.5 oz mat for the mold and one layer of 4oz fabric backed by 1 layer of 1.5oz mat for the actual part. Despite the weight differences the 1.5 mat is much thicker than the 4oz cloth.

Another note with brushing on gelcoat. With all the wax and release agents you are bound to get separations in the coat from the brustrokes, or thin areas where you can see the substrate. You must build up the coats (allowing a little cure time between) to a thickness of approx 20mil and you have to ensure all the separations are sealed and to a uniform thickness. If you dont then the resin can get under the gelcoat and cause bubbling, wrinkling and other things you dont really want to see.

All laid up, 4 layers of 1.5 oz matting and about a gallon of resin. Now to wait....24 hours cure time before we can see if it worked. The extra hot temps should help with the cure. One other note not showing in the photo. I trimmed all the edges with a razor knife before it cures, after it cures you'd need a dremel or grinder to get through it but while it's still curing a razor will slice through it pretty easy.

Well sadly there are some voids in the gelcoat. I chalk this up purely to my inexperience with using gelcoat. All is not lost though, the voids are easily filled and smoothed and overall the mold should be a good one with a little extra effort. It has just a touch more flex than I'd like so I'm going to pop it back on the hood and mold some reinforcements into the back.

Thanks for documenting this. I'll be doing someting similar on my RX-7 to be rid of the incredibly heavy steel hood.

DaveEstey wrote: Thanks for documenting this. I'll be doing someting similar on my RX-7 to be rid of the incredibly heavy steel hood.

Well since you are following along.....

About filling those issues. Here's how it's gonna go.

First I have to wash everything with a good wax remover to get all the release compounds and mold release off of it, scrubbing the voided areas well with a brush.

Although theoretically body filler could be used it wont hold up well long term and there's a better solution.

I can mix up some gelcoat with some styrene wax and use that to slowly build up the damaged areas. The styrene wax floats to the surface of the gelcoat and blocks air which would otherwise inhibit a full cure. However because of the wax if I have to build up coats then I will have to sand/clean the wax layer between coats. Once it is correctly built up and cured then it can be sanded (400,600,1000....etc) then polished.

It's going to require a little more effort but in the end I should have a good mold.

Optionally I could just pull parts off it as is with the knowledge I'd have to sand out any imperfections once it is out of the mold.

Ok, making some progress in fixing the mold. Adding in layers of gelcoat to the damaged areas, 24 hours to cure then knock it down and fill the low spots again. On the 3rd coat now and just about there I think. It's a lot of work but if you are making more than one part from your mold it's a time saver in the long run. If I was just making one part then I could do the same work to get the finished part smoothed off when it came out of the mold. I will probably not get a "class A" surface with these repairs, that's a surface which is good enough to just buff the gelcoat when the part comes out of the mold and it's done. But as I intend to paint the parts and not have gelcoat as the final finish this will be ok.

At these fill stages I'm just knocking everything flat with 120, after the final fill I will work my way up through the numbers to at least 1000 grit to get it all smooth again.

A picture of where its at and some "tools of the trade"

Still prepping the mold. Some of the tools in use

1) Wax and grease remover, first used to clean all the release agents from the mold and now used in between the repair gelcoat layers because the gelcoat has wax in it to help it cure in the open air.

2) Durablocks, one of the greatest things for sanding, sadly I cannot locate the rest of my set which are hiding somewhere in the garage right now. They require a special sandpaper which comes on a roll and is adhesive backed. Costs a little more but it's great stuff, and even without the durablocks I'd use it.

3) a small block of wood with some sandpaper around it, good for edges and tight spaces. I have something similar in my durablock set but as mentioned I can't find it. But it goes to prove you dont need fancy tools and you can make due with what is on hand.

4) More making due withe what is on hand, a paint cap with sandpaper around it, good for round edges. This is where the sticky backed sandpaper is great for making almost anything into a sanding block :)

Requesting a bump on over to the build threads section please :)

Yes, finally getting back to this. Still smoothing out imperfections in the hood mold. Many lovely new (to me) parts have been arriving and waiting for me to get some time to get to work.

Lemons NJ has been announced for Aug next year, gives me more time than anticipated (its usually in April) but I still doubt I will be done by then, I've gone a bit deeper in my plans and goals and I've added the Colony Park to play with too and plenty of other non car projects going on so we'll just have to see how it progresses. But if I keep the build thread active then all you enablers can push me to get off my butt ;)

Ok, so my garage has been...well to put it nicely, a complete wreck. Too many quick projects and working on other peoples things with no cleanup time and no help so it just got worse and worse.

Exhibit A

So with the first fully free weekend I've had in months I got it back to a workable state which put me in a much better frame of mind for some project work. Technically the YFH is still for sale but what the heck, noone is biting I'll keep building. I really didn't want to get into fiberglass work again right now so I went back to the motor Im building. I loaned my engine hoist to a friend of the wifes earlier this year and when he brought it back he brought his new engine stand he had bought for the project and gave it to me with the words "I'll never build a motor again" This allowed me to take the junk 1300 Yugo EFI spare and put it on a stand to start transferring bits over to the 1500 Fiat motor.

First up oil pump. The X1/9 mounts the motor at a different angle than the 128 and Yugo so you need to use the Yugo oil pump and pan on the motor. Here you can see some of the differences (Yugo on left)

I also cleaned up the oil pan and gave it a fresh coat of paint. I really wish I could use the X1/9 pans as they are nice finned aluminum jobs that look pretty instead of the stamped steel piece the Yugo uses.

I also pulled the front crank seal plate. The Yugo one is on the bottom, you can see on the left the little mount for the crank sensor for the EFI, its a 60-1 wheel so megasquirt compatible. Sure I could have just fabbed a little bracket for the sensor but the pieces were here so why not use the factory bits.

The Yugo piece also provides a little more protection to the timing belt which is a good thing.

So I'll keep tinkering away at this until it runs or one of you nutters finally buys it. Right now its a zero cost project because I have all the parts here so its just time and effort.

bump

Thanks for the move Joey!

So a bit more on the conversion of Fiat motor to fit in Yugo. The oil drain tube has a different curvature and the Fiat one will not allow the Yugo oil pan to seat so time to switch those out. Yugo one on top

Of course that means the hole in the windage tray needed enlarged, quick work with an auto body saw.

Yep, that fits now.

Tested refurbed oil pan, nothing is fouling any more, yea! On to the next steps.

The big valve head has one valve seat that is suspect. For those of you familiar with such is this something I can go to any machine shop and they'll have a seat to fit and cut? None of the fiat parts vendors list valve seats specifically so I'm thinking this is probably just a generic machine shop type thing. Of course I could send it out to one of the fiat head specialists but if I do that I'm not going to stop at just a valve seat install ;)

Glad to see you're still plugging away on YFH, top notch as always. Keep at it!