1974 Camaro Z28
Discussion
SturdyHSV said:
That's made a big difference to the front end, nice one 
What's behind the bumpers, could they go altogether?
They're crash bumpers, so behind them are two small pneumatic rams and then a chunk of leaf springs. If I remember rightly there's something like 40kg of weight saving to be had my taking them out front and rear. It's a common mod to tuck the bumpers and I fully intended to do it when I first bought the car, but the big bumper look has grown on me. I do think the front bumper could do with raising an inch or so though and I'll probably lose the leaf springs too as they're only rated to low speeds. What's behind the bumpers, could they go altogether?
Edited by Rogue86 on Monday 28th June 12:35
Thought I'd head out while the football was on and the roads were quiet, but I only made it as far as the drive when I noticed a significant leak underneath the car. After a bit of digging, it turned out to be coming from the steering gear box, dripping fluid out of the end cap.
I've got a pretty good workflow down now when something goes wrong with the car. Being mechanically handicapped, my first step is to find out what it actually is that seems to be broken - usually with the help of casting numbers. In this case, it turned out to be the steering gear box - a Saginaw 800 which was common OE equipment in the 70s. Google is great for diagrams so after a bit of research it seems fairly likely to be one of the many seals that makes the thing up.
Next is the dreaded RockAuto search - usually where I find out how much something is going to cost me, before tax and shipping are added. It wasn't good news for a replacement box! So I started searching for rebuild kits instead. Better in terms of price, but getting hold of one was proving tricky. As it turns out though, reliable Steve had one laying in his garage from his '68!
So out with the old...
Not a bad job actually, again thanks to Steve lending me the right puller for the Pitman arm (which did need swapping).
While I was making a day of it, I decided to have a closer look at the diff. Other than it being a "posi" as stated when I bought the car, I had no idea what it actually was. So using the casting numbers, I decoded them and found that its also original with the car (being built in the same month as the engine). A 10-bolt positraction LSD with a 3.73 ratio. By then using that in combination with the gear ratios, max rpm of the engine and tyre circumference, I could work out some theoretical gear/speeds which might outline what it was the car was really built for.
1st gear - 49.57mph
2nd gear - 74.82mph
3rd gear - 97.93mph
4th gear - 120.45mph
That about marries up with the actual driving experience. It's a very snappy car to drive, with gobs of power low down. The cam feels like it drops off around 5k, so real-world that probably knocks 10mph off each of those speeds.With that in mind I'd say this was probably intended to be a traffic-light car or 1/8th mile racer. It's definitely fast enough to trap at what would be over its max speed on a full quarter mile sprint. As you can imagine, it's really not built for a UK motorway where most people are doing 80mph! But it's happy cruising at 55mph.
I've got a pretty good workflow down now when something goes wrong with the car. Being mechanically handicapped, my first step is to find out what it actually is that seems to be broken - usually with the help of casting numbers. In this case, it turned out to be the steering gear box - a Saginaw 800 which was common OE equipment in the 70s. Google is great for diagrams so after a bit of research it seems fairly likely to be one of the many seals that makes the thing up.
Next is the dreaded RockAuto search - usually where I find out how much something is going to cost me, before tax and shipping are added. It wasn't good news for a replacement box! So I started searching for rebuild kits instead. Better in terms of price, but getting hold of one was proving tricky. As it turns out though, reliable Steve had one laying in his garage from his '68!
So out with the old...
Not a bad job actually, again thanks to Steve lending me the right puller for the Pitman arm (which did need swapping).
While I was making a day of it, I decided to have a closer look at the diff. Other than it being a "posi" as stated when I bought the car, I had no idea what it actually was. So using the casting numbers, I decoded them and found that its also original with the car (being built in the same month as the engine). A 10-bolt positraction LSD with a 3.73 ratio. By then using that in combination with the gear ratios, max rpm of the engine and tyre circumference, I could work out some theoretical gear/speeds which might outline what it was the car was really built for.
1st gear - 49.57mph
2nd gear - 74.82mph
3rd gear - 97.93mph
4th gear - 120.45mph
That about marries up with the actual driving experience. It's a very snappy car to drive, with gobs of power low down. The cam feels like it drops off around 5k, so real-world that probably knocks 10mph off each of those speeds.With that in mind I'd say this was probably intended to be a traffic-light car or 1/8th mile racer. It's definitely fast enough to trap at what would be over its max speed on a full quarter mile sprint. As you can imagine, it's really not built for a UK motorway where most people are doing 80mph! But it's happy cruising at 55mph.
We've had a local powder-coaters open up recently and one of the things they're hoping to specialise in is ceramic-coating. My engine bay is looking a bit worse for wear, so I thought I'd head down to see if I could get my headers redone. Unfortunately they're not quite ready to offer it as a service, so I headed back home and decided, for the first time since I was 18, to give wrapping them a go.
Partly its cosmetic, but largely the exhaust is blowing its guts off. So I got new ARP bolts, some new flanges and some new gaskets to go on too.
There really is no room to wiggle them out through the top, so on one of the hottest days we've had this year I figured I'd put trust in my new-build quality tarmac drive and go in underneath.
With the exhaust dropped off, it was easy to see that the flanges didn't quite match up and were the biggest cause for the blowing. Ten minutes of gentle persuasion with a hammer and they lined up perfectly.
After some swearing, the manifold eventually came out and the old gasket came off.
The wrapping itself wasn't so bad, except as soon as I'd finished it I realised I should have wrapped them upside down so that the overlaps faced the other way. I also would have needed two packs of wrap per header, so my only real goal was to wrap the bits you can see with the bonnet open. But as this is only intended to be a temporary solution until I can get them ceramic coated, I wrapped the other side to match and worked to get them back on.
It's done the trick.
Remember the foreshadowing about the tarmac and the hot day?
Well, there's a reason for that. Although until my new oil sump gets here I don't think I'm ready to talk about it.
I've also taken the opportunity to order some new gaskets, oil filter and rocker covers to get on with tidying the engine bay.
Partly its cosmetic, but largely the exhaust is blowing its guts off. So I got new ARP bolts, some new flanges and some new gaskets to go on too.
There really is no room to wiggle them out through the top, so on one of the hottest days we've had this year I figured I'd put trust in my new-build quality tarmac drive and go in underneath.
With the exhaust dropped off, it was easy to see that the flanges didn't quite match up and were the biggest cause for the blowing. Ten minutes of gentle persuasion with a hammer and they lined up perfectly.
After some swearing, the manifold eventually came out and the old gasket came off.
The wrapping itself wasn't so bad, except as soon as I'd finished it I realised I should have wrapped them upside down so that the overlaps faced the other way. I also would have needed two packs of wrap per header, so my only real goal was to wrap the bits you can see with the bonnet open. But as this is only intended to be a temporary solution until I can get them ceramic coated, I wrapped the other side to match and worked to get them back on.
It's done the trick.
Remember the foreshadowing about the tarmac and the hot day?
Well, there's a reason for that. Although until my new oil sump gets here I don't think I'm ready to talk about it.
I've also taken the opportunity to order some new gaskets, oil filter and rocker covers to get on with tidying the engine bay. 
Ben Lowden said:
Great work! And still have the Iggy I see?
Sorry if I've missed them, but have you got any videos of what this sounds like?
Yes, still got (and absolutely love!) the Iggy. I've tried tarting it up a bit in recent months to make it look like somebody cares about it. It's just ticking over to 130k miles now but it still loves being driven to death everywhere. Recently put on some RS*R springs too.Sorry if I've missed them, but have you got any videos of what this sounds like?
I don't really have any video of the black car, so I've just uploaded a really brief/old video a friend took as we joined the motorway. It's not terribly exciting (I didn't actually know he was filming at the time) and it's shot on a phone, but it does at least do the noise some justice. I really need to get out with and film something on the camera, especially now the exhaust isn't blowing.
https://www.youtube.com/watch?v=naBDV3jWHBo
In other news, my sump hasn't turned up yet but all the other parts have so I'm almost ready to go. Lots of gaskets, including one for the spare fuel pump to try it out. But mainly, these.
I ordered the push-in breather too to match. It does mean I'll lose a dedicated oil fill hole but I should be able to pull out the breather or PCV easy enough for top ups.
With the chrome water neck on and the intake painted it should go a long way in tidying up the engine bay.
Phwoar the Iggy looks so good in that pic, glad to hear it’s still going well! What are the odds of you posting that and me seeing one in the exact same spec locally in Kent on the same day? Must be a sign that I need to buy one...
And thanks for posting that video too, sounds amazing!
And thanks for posting that video too, sounds amazing!
Ben Lowden said:
Phwoar the Iggy looks so good in that pic, glad to hear it’s still going well! What are the odds of you posting that and me seeing one in the exact same spec locally in Kent on the same day? Must be a sign that I need to buy one...
And thanks for posting that video too, sounds amazing!
They are absolutely brilliant cars. This is my second and I'm worried they're going to keep slowly creeping up in price so I might not have a third!And thanks for posting that video too, sounds amazing!
Turn7 said:
Loving the Black look....
Rogue, was it you that did an RX7 a few years back ?
It was, the first car I ever really fell in love with. I'd have another in a heartbeat. Although it's got to be said, now I'm used to how over engineered (or built) the Camaro is, the last RX7 I drove felt like a cheap toy by comparison and it was tiny inside. God it was pretty though. Rogue, was it you that did an RX7 a few years back ?
Rogue86 said:
Turn7 said:
Loving the Black look....
Rogue, was it you that did an RX7 a few years back ?
It was, the first car I ever really fell in love with. I'd have another in a heartbeat. Although it's got to be said, now I'm used to how over engineered (or built) the Camaro is, the last RX7 I drove felt like a cheap toy by comparison and it was tiny inside. God it was pretty though. Rogue, was it you that did an RX7 a few years back ?
Lovely car that, and if they werent all so old now, Id consider one.
Turn7 said:
Thanks, I thought I was right....
Lovely car that, and if they werent all so old now, Id consider one.
Yeah, last ones produced in 2002 if I remember rightly so they're all quite old now. There are still some really well-looked after cars appearing on the market though!Lovely car that, and if they werent all so old now, Id consider one.
Right, so back to it. I'm finally ready to talk about the sump. As you've probably guessed, the short version of this story is that the jack slipped off the subframe, dropping the car onto it which smashed straight into the sump creating a natural disaster on my driveway. The long version is much funnier and explains why there were no stands to stop this from happening, but it's better in person and over a beer!
Obviously having never done this job before, we jacked the car up and tried to figure out the best way to get the sump off. What we did come away thinking was that this would be a straightforward job.
We figured it would slide back, over the subframe and drop down. Easy.
We were wrong. There aren't enough expletives in the world to describe this job. It turns out you need to rotate the crank, unbolt the engine from the mounts (and therefore the fan shroud) and jack the engine up in order to create the space required to drop the sump out. But after several hours, we got it off.
You can see just how bad that hole really is!
We checked over everything above the sump to make sure the jack hadn't started a fight with anything else. Luckily everything looked good!
The new sump looks considerably more substantial and most crucially, doesn't have a massive gaping hole in it.
Getting it back on was even more of a job than getting the old one off and it very nearly finished off the pair of us. The sump ended up coming back off four times in total with the four-piece gaskets moving all over the place even with sealant holding it in place. We also had to reuse a piece of the old gasket which was much, much thicker.
Its 0130hrs. We both need a short break from the sump and an easy win would boost both of us. I take the Z28 finned valve covers off in order to identify the heads and get the new Edelbrock covers on.
From the casting on the heads, it looks like they're 333882 GM - original 1974 smog heads. Most importantly what I discovered was that the bolts holding the valve cover in place were now too long. Of course they are. After 20mins of trying to find some shiny bolts to replace them that were the right size, we came up empty and took a dremel to the original bolts instead.
Perfect. We then went back to the sump and walked out of the garage at 0315hrs feeling a lot older than we did 6 hours earlier with the job complete and a new filter in place. Now all we need to do is fill the oil up and make sure it doesnt leak.
Also on the agenda tonight is to whip the intake off, paint it black, get the chrome water neck on and replace/flush the coolant. If we get time, we'll also (finally) get the door handles on.
Edited by Rogue86 on Saturday 7th August 12:02
Bobberoo said:
WOW that's a nasty gash!!!
Last night was the night to crack the intake and coolant. We started to flush the system and debated what to do with the intake. I think we both wanted to paint it, but with it raining sideways outside the garage we figured we'd just polish it with the dremel.
Unfortunately we just couldn't get the finish we wanted and it was taking hours, so we did what we both actually wanted to do which was to take the intake off and get an early (0100hrs) night!
It did end up being a late one because we had to clear all the sealant out!
Fortunately, Josh had some spare indoors space to take the intake home with the paint and give it a go himself. We both had a good sleep and re-attacked it this afternoon. I've got to say, he'd done a bloody good job of tidying it up.
It didn't take long to get back on, although because the distributor goes through the back of it we knew we would have to look at the timing again once it was all back together. Also put the chrome neck on, which unfortunately took a bit of adjustment with the alternator bracket to get back on.
Next step was reassembly and a coolant flush/change. To see why this was important, this was the state of the old water neck...
We used Wynns flush to clean it all up, then flushed the system with water around 8 times before it started coming out clear.
It was time to take the car out and sort out the timing. We did it on the road, and after lots of pulling over and slight tweaks of moving the distributor, I think we finally cracked it. The car now pulls really smoothly even from low-down, and the moments of slight hesitation there are in the power band I'm confident are either the fault of the carb or the fuel pump. That said, they are very intermittent and the car was lighting the back wheels up with barely any input. It's weird now that the exhaust now has no blows, the exhaust note is still insane but its more refined. As a driver, the sound is now (finally) behind me where it should be which is taking some getting used to!
I'm now sat having a well earned beer. The car looks brilliant, sounds incredible and drives amazingly. For the first time since I bought the car, I'm starting to feel like I'm driving a proper car and not that I'm rolling round in a project.
skyrover said:
Great update. Good camerawork as well.
At least the car did not fall while someone was under it.
Do you have plans to fit better heads at some point?
Thank you! Yes luckily at the time he was in front of the car trying to lower it on the jack so not underneath it. Apparently it made a hell of a bang and most of the neighbours came running out to see if he was alright!At least the car did not fall while someone was under it.
Do you have plans to fit better heads at some point?
With what I've read, the heads are 'alright'. Apparently they're the best of the rubbish ones that were put on to choke the cars output from 74 onwards to meet California emissions rules. That said, the ultimate plan (maybe next year) is to whip the engine out and rebuild everything. At that point I'll probably upgrade the heads too. Early reading suggests Vortec heads are a good match but I'll look more into it.
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