Blue Jeep build

[gt1guy]

Just get one of these machines that turns a tube into a noodle. Should be ezpz

That is so cool. There's no limit to the retarded things I would make with something like that.

 

[csutton7]

Wow. Header lego's. Good work. Now I'm guessing you will have to number each piece so you know where the corresponding cut tube will go, so that you can get it all welded up correctly. Will it stay together as you remove the whole thing?

 

[Kreep]

They are going to be a TRI-Y design. 1.875" into 2.125" into 3.00"

I made the same mistake on my headers. You are going to lose velocity when it transitions from 1.875" to 2.125". Instead you should keep it 1.875" all the way to the 3" collector. Now, if you were doing it the easy way and connecting 1-3 and 5-7 then you would want the larger secondary section due to the exhaust pulse overlap.

I know it's not what you wanted to hear. But I'm thinking of redoing my headers next year...

 

[gt1guy]

Wow. Header lego's. Good work. Now I'm guessing you will have to number each piece so you know where the corresponding cut tube will go, so that you can get it all welded up correctly. Will it stay together as you remove the whole thing?

Yes, number, and mark each block where it connects to the next block to keep the orientation. Hopefully I'll be able to tack the flange and collector on the bench in the correct orientation and add some stoppers at the bends. Basically a jig that only the correct shape would fit in.
The blocks themselves are marked on the outside of the bend. So if you have 4 blocks with the marks lined up, you know 4" of that size and radius elbow will fit. Bad part is I have a bunch of bends that none of the marks line up, so I'll have to measure the amount of rotation.

I made the same mistake on my headers. You are going to lose velocity when it transitions from 1.875" to 2.125". Instead you should keep it 1.875" all the way to the 3" collector. Now, if you were doing it the easy way and connecting 1-3 and 5-7 then you would want the larger secondary section due to the exhaust pulse overlap.

I know it's not what you wanted to hear. But I'm thinking of redoing my headers next year...

That's not what the header builders I talked to recommended. Every single one of them recommended the step from 1.875 to 2.125. I sent them all the specs on my engine, trans, gears, tire size, weight, and emphasized it was a Jeep. I said I wanted a focus on low- mid range.
All of them said those sizes and lengths would improve the low-mid without affecting the top end.

In the end, I'm gonna stick with what was recommended to me to start with.

Hell, I've never even fired this engine yet, I wont know if the headers are off a bit

 

[gt1guy]

Damn I'm slipping.

Kreep how could you tell your headers were off?

What engine?

 

[Kreep]

Damn I'm slipping.

Kreep how could you tell your headers were off?

What engine?

Short answer:
Rethinking my answer, I take it back. The problem I have is unique to the way I built them. As long as you keep the primaries fairly long you'll be fine.

Long answer:
Ran back to back pulls on the dyno comparing them with a set of long tube headers. Both had 1.75" primaries and mine made a little more midrange and gave up some top and bottom end even though my length to the collector was longer and should have had more low end. Like you I did a Tri-Y. keeping 1-5 and 3-7 together and followed the common advice of using a larger secondary. I have 1.75" into 2" into a single 3.5" 4-1 collector. But let's ignore that oddity and talk about the acoustics/fluid dynamics.

Exhaust pulses create an "echo" when there is a change in cross sectional area. If this echo hits the exhaust valve while it's opening it rebounds and gives a little push helping the cylinder empty quicker. So I get two reflections, one when it hits the 2-1 collector and jumps to 2" and another when it hits the 4-1 collector and jumps to 3.5". The issue I have is that half of my primaries are so short I'd have to be turning 10,000 rpm. Plus, I'm much more interested in low end torque so I think I'd be better off running 1.75" all the way back to the collector.

Engine is an AMC 401 bored and stroked to 418. RV roller cam, LS valves, springs and rockers. 11.3:1 compression running E85. Best pull measured 472 HP at 5,200 rpm and 508 ft-lb at 4,300 rpm (457 HP and 492 ft-lb corrected).

My headers are pretty long which should have boosted low end torque, the length from exhaust valve to collector is 41.6" for the shortest, 46" for the longest and the rest are 45.25". The length of the secondaries ranges from 24" to 29".

I certainly don't have your skills, so forgive me posting these pics in your thread...
Here are the offending primaries, 2-4 and 6-8:

And this is the snake's next required to keep the lengths equal:

Black is best pull. Blue is last pull with the long tube headers. Green is first and only pull with my headers. As luck would have it we forgot to turn on the fan and the air was hot and full of smoke from oil burning off the headers. On the other hand the engine was cool so it probably helped the numbers a little.

 

[gt1guy]

Well that wasn't as hard as I thought.

Easy way to keep the blocks from moving is by using a lot of this around the blocks.

Wish I could say it was my brilliant idea.......but I can't..........saw it in a YT video last night.

Sucks that it turns out I don't have a lot of connections that look like this. Par for the course on this build...

 

[csutton7]

Pretty good idea with the tape. Gotta love youtube when things work like you just watched.

 

[gt1guy]

Pretty good idea with the tape. Gotta love youtube when things work like you just watched.

Totally agree. The tape is a stupid simple solution and ends up making everything solid. The blocks rotate freely when just snapped together, which is a good thing.............until you're done and need to remove it.

 

[gt1guy]

So today I decided to go for the mold of the hood.

3 coats of parting wax......... went on great.

3 coats of PVA sprayed on...........went on great.

25mil of tooling gelcoat sprayed on in 4 coats............went on great.

2 layers of CSM................had a really hard time keeping it from bridging around the edges. But I felt that I got it.

1st layer of woven fiberglass..................was a complete disaster. I had cut it to be one complete piece...............that was a mistake. Kept getting folds I couldn't work out. So I ripped that layer off.......and walked the fuck away.

Having never done anything like this before, what I was expecting, and reality, were way different. Once I hit the woven stuff, I realized I need to reevaluate how I have cut all the other layers. They're all one piece.

My only saving grace is that the top surface wont completely cure, the resin in contact with the air. You have to add styrene to the last mix of resin you use to get it to completely cure. The styrene will float to the top and seal out the air. So I "should" be able to pick up where I left off.


This shit is way harder than I thought it would be.

 

[csutton7]

Live and learn is still a mantra that does not go away! I can understand trying to use one sheet, but now that you bring that up I don't believe I've ever seen anyone do it that way. So maybe there's the ol' "method to the madness" that needs to happen with many smaller sheets. Of course it's not like I've watched a ton of fiberglass work, so I can only go with what I've watched over the years.

Hopefully you can start back up with where you left off, cuz then you have the double suck on your hands.

 

[Kowboy]

The Million Dollar Hood.

 

[gt1guy]

Live and learn is still a mantra that does not go away! I can understand trying to use one sheet, but now that you bring that up I don't believe I've ever seen anyone do it that way. So maybe there's the ol' "method to the madness" that needs to happen with many smaller sheets. Of course it's not like I've watched a ton of fiberglass work, so I can only go with what I've watched over the years.

Hopefully you can start back up with where you left off, cuz then you have the double suck on your hands.

Took a closer look at it today. Not as bad as I thought. The last layer that I pulled back off yesterday sure looked like a sack of buttholes though. Glad I took it off.
I did find a few bubbled that I ground out "slowly" with a bur bit in a drill. They went all the way to the gelcoat, so I'm glad I took care of those. Also ran over the whole thing with the DA to smooth out all the little sticky things that would want to make my life suck.

The Million Dollar Hood.

I'm about 2k into tools and supplies to make a hood nobody would be willing to pay $28.95 for.

And that's not even close to being the dumbest thing I've ever done.

 

[SLOWPOKE693]

I detest fiberglass work. One of my best friends back home owns a race car body business and deals with that stuff daily. We made a mold of a TJ-esq grill and hood and then some parts with those molds and calling it a miserable experience is being polite. Some things in life are just worth paying other people to do.

The only time I ever saw him use single sheets of mat to make body panels was when he did late model circle track doors. They were basically flat with a 90° curved radius at the top and super simple to lay out in single sheets. Everything else including the hoods were done in sections to keep the wrinkles out.

 

[gt1guy]

Got all my suspension links yesterday. HT 4130 from BentFab. 2.5"x.500" lowers , 1.75"x .120" uppers.

Also got the mold done for the most part. I'm at 20 layers now. Everything went fine after the first day. I guess that was my learning curve. Ended up with what felt like a pretty good system of knocking out the layers. Even doing full layers in one piece. The trick (for me anyway) was to let the last layer start to get tacky before setting the next on it. That let me smooth the next layer out (dry) with a bondo spreader and the tacky shit underneath would hold it in place. Worked really good, maybe that's how it's supposed to be done, I got no clue.

Next up is to laminate some 2x4's on it to give it more strength and have something to screw into if i need to add legs when it;s upside down. Right now it will only sit on the scoop.

 

[1Sinner]

Looking much better!

 

[gt1guy]

Looking much better

Thank you Sir,

I'm happy with the side that doesn't matter. I'll hold off making a prediction as to what the other side will look like.

It's done now. Got the wood 2x4's stuck on and did a final coat of resin with the styrene/wax in it over the whole thing. I'll give it a good 24hrs to cure completely, before I find out if I can get the mold off the hood.

 

[csutton7]

Cool to see you do this and kudos, cuz you are right it's a shit ton of work, and I'm only going off what you post on here. But then again if you need something unique you are just going to have to bite the bullet!!

 

[gt1guy]

Cool to see you do this and kudos, cuz you are right it's a shit ton of work, and I'm only going off what you post on here. But then again if you need something unique you are just going to have to bite the bullet!!

Thank you.

I wasn't thinking about doing this when I modified the stock hood. It wasn't until I finished with the stock hood that I realized all I had was a shape and it wasn't something that could be used. That's when I bit the bullet. There's been times now that I thought the bullet went off in my mouth.

But, I'm learning how to do this kind of stuff now and that knowledge lasts forever.

 

[gt1guy]

It's certainly cured 100% now. No tackyness at all and you can definitely see the dull looking wax that floated to the surface to seal off the air.

Damn thing is dangerous to rub your hand on right now. No shortage of little needles sticking up.
Going to hit with the DA before anything else.

 

[gt1guy]

Here we go

Kinda afraid

 

[gt1guy]

Not as afraid now

Flange material came right off. Still has the PVA all the way around and the gelcoat looks good. Can also see the fillet clay all the way around.

PVA peels right off like it should. It's also water soluble.

 

[gt1guy]

Hood popped out of the mold like a champ..........

Then I thought I was going to have a panic attack.......

Turns out that gigantic missing piece was just the Bondo that let go as the hood popped free.

Looks like all the PVA stayed with the gelcoat on the mold.

At first glance the mold looks great. Need to clean it up to take a closer look. But so far I'm really happy and surprised.

 

[gt1guy]

So cleaned up it looks great.

There are 5 tiny little spots that will need attention. One just needs a bit of sanding, the other four are bubbles that need to be filled.
Only the spot that needs sanding is in the hood part of the mold. The others are in the edges.

I absolutely can't believe it came out this good for having zero clue and watching a few YT videos. I'm happy as fuck right now.

All cleaned up.

 

[1Sinner]

Damn! Looks amazing.

 

[SLOWPOKE693]

Nice job!

 

[gt1guy]

Damn! Looks amazing.

Nice job!

Thanks guys. It's as much of a surprise to me as I'm sure it was to you.

I'm happy it came out usable. It's a relief to be confident now, that I can make a usable hood in it.

From what I've heard, I need to let it sit for at least a few weeks before doing anything with it.

So I guess it's back to headers now.

 

[gt1guy]

Passenger side primaries layed out. Interesting side note........the passenger side ended up exactly the same as the driver side......one collector 4" in front of the other. Like exactly the same distance even though it's a different cylinder combination being tied together.

I just found it strange and wasn't expecting it to play out that way.


Pass side

Driver side

Just like the driver side, I have to pull the header studs to get them on/off. While kind of a pain, I already have the studs and don't feel like buying bolts. It's not like you're touching the headers after it's running. So fuck it.


Next up is pulling them off and getting a count of bends and straight tube I need to buy. Finding a place that sells 1.875" bent on a 2"CLR and 2.5"CLR wasn't exactly easy. SPD Exhaust sells u-bends in those radius's.
The secondaries part of the headers will be easy. Just one simple bend to turn it flat under the tub. After that, the rest of the exhaust is a straight shot back.


Realized I was missing the fuel cell vent on my list of shit to do. Figured it would be smarter to just bend up some tube, rather than adding it to the list. I also had to order the fittings I need to connect the tube together because I didn't have a single piece long enough..................again

Vent ends at the bottom of the cell.

 

[Wisconsinite]

This build is so badass. I can't wait to see how the finished hood turns out. Do you ever watch a Youtube channel called easy composites? They do a lot of carbon fiber work.......... cough cough carbon fiber hood cough cough.

 

[gt1guy]

This build is so badass. I can't wait to see how the finished hood turns out. Do you ever watch a Youtube channel called easy composites? They do a lot of carbon fiber work.......... cough cough carbon fiber hood cough cough.

Thank you Sir

I have not seen anything from Easy Composites, but after checking them out right now I will.

I'd really like to do the hood AND the grill in carbon fiber but.................. Just the price of the materials alone is brutal. I did price out doing the hood. That would cost me around 3k.

I do plan to buy a good vacuum pump and try my hand at vacuum infusion when I do make the hood. First hood will be fiberglass.