Radically altered yank and the dreaded IVA

Radically altered yank and the dreaded IVA

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Rustykipper

Original Poster:

10 posts

80 months

Wednesday 30th May 2018
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Morning chaps, this is for any IVA experts out there, no idea where to post this but as it’s a yank this would be a good starting point.

Ok, I’ve got an 1984 S10 blazer 4x4 that’s been in the family for over 20 years and over this time has gained a 5.7L V8 in the place of the tired old 2.8l V6 together with a matching 700R4 auto, it’s not so much a daily driver but gets used every weekend all year round. With regards to the V8 my interpretation is that this makes it ‘substantially changed’ (I think it might be 15% more powerful than original), as there are no body or chassis modifications I understand this just means I don’t get free road tax when the vehicle hits 40 and have to carry on having MOT’s, I’d rather enjoy the V8 and forgo the free tax and would prefer to have the yearly MOT as I put spanners to it myself. I have a Chrysler 8.25 rear axle going in soon to give me rear discs and more strength but this will still keep me above 8 points unless I’m misunderstanding something.

Now here’s the thing, I plan to carry out a solid axle conversion which involves removing all the front suspension and replacing it with a Jeep XJ front axle hung off a pair of leaf springs (coilover shocks in the future) and 32 inch tyres, this will take me well below 8 points not to mention modifying the chassis, this definitely makes it radically altered. I could just do it and keep quite but don’t want to spend the rest of my days looking over my shoulder anyhow it seems the DVLA are now actively looking into modified vehicles so would only be a matter of time.
This will then mean re-registering the truck and going for a (B)IVA. I’ve read through the IVA manual a few times but I can see a few issues I’m not 100% sure about.

1. Engine. I don’t have either a receipt or proof of age for the engine, I know from the date stamped on the main bearings it’s a 1986 lump. I guess worst case it has to be tested to 1996 standards? Not a biggie as the last emission test it passed with 0.01% CO and 350ppm HC, a bit of carb and timing tweaking should get it through, I believe Q plate motors don’t require an MOT emission test thereafter.

2. Glass, windscreen is not a problem as it was replaced about 20 years ago and is E43R marked, side glass could be a big issue, its matked DOT and tempered but the IVA will only accept E marked glass. I could probably get the two side windows made by Pilkington but the rear side windows are HUGE. I’m kind of thinking about panelling over them kind of turning the truck into a van just for the test. If I knew they would come out in one piece I could substitute some sheet steel and then refit them or possibly sell them on and replace with E marked Perspex / polycarbonate.

3. Rear 3 point seatbelts, the current bench seat has built-in retracing lap belts (2 point). The only way I can see to fit retracting 3 point belts is to fit a rear roll cage similar to a mk2 Frontera and mount the mechanism to it. I’m thinking a 2.5 inch CDS steel hoop bolted to the wheel arches with load spreading plates and gussets and then a couple of triangulation legs bolted to the load space floor behind, it would be way strong enough (I’m well known for over engineering everything!) any thoughts? Can I retain the 2 other mounts built into the seat? I think a roll cage in the back would look pretty awesome!
Probably easier to permanently remove the rear seat but I really don’t want to do that.
I believe I’m likely to require rear head rests also.

4. The floorline cone thing test, my front spring mounts will be directly under the bumper, these will definitely get fouled by the cone, I guess the only thing to do is to temporarily move the front bumper forward.

Sorry for the long post.


p.s. I did post some more pictures but as yet can't get them to show.

Edited by Rustykipper on Wednesday 30th May 12:39

Cardinal Hips

323 posts

72 months

Wednesday 30th May 2018
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Rustykipper said:
With regards to the V8 my interpretation is that this makes it ‘substantially changed’ (I think it might be 15% more powerful than original),
The +15% power clause was dropped from the final MOT legislation, 6 years before you will be using that one though...

Here is the actual blurb from DVLA:

"Alternative cubic capacities of the same basic engine and alternative original equipment engines do not count as a substantial change.

If the number of cylinders in an engine is different from the original, it’s likely to be, but not necessarily, the case that the current engine is not alternative original equipment."

I'd argue that the v8 was available in that year blazer so not substantially changed. Only points removed are for engine trans if you are looking at points system.

As for the rest, good luck.

As soon as you start welding / modifying the chassis, all bets are off technically, if you're going IVA Real Steel UK can help with certification of engines I believe.



Moose of Death

26 posts

140 months

Wednesday 30th May 2018
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Hi. I've got a few odd notes, they may or may not help in any way.

1. Concerning what year the block itself is, this might help:
http://www.nastyz28.com/sbchevy/sblock.html
1A. That 2.8 V6 might have made 110hp, at best. 115% of 110 is 126.5 hp, which even the crummiest of 5.7's had no problem trouncing.

2. Concerning the conversion to a straight axle, if this is being done to generate some extra lift in order to create clearance for taller tires, I'd almost suggest keeping the stock front suspension, and simply go with a body lift...if that's legal. You also (typically) get more ground clearance than with a stick axle anyway.

3. I've got a question about the side glass, in that if it's marked 'DOT', it's legal for the American market...and is probably the original glass for that vehicle. Why would there be a mandate that requires you to update to a Britain-legal glass that was never manufactured for that vehicle? And having had to get custom glass made for various custom vehicles over the years, yes, it's ridiculously expensive, and possibly more expensive than the vehicle is worth. I might contact a referee if there is one available in order to receive clarification, as what I'm seeing from you almost sounds like the requirements that one would see for a brand-new 'kit' or custom-made vehicle, not a mass-produced truck like what that Blazer is.
3A. The long side windows should be easy to remove by any competent glass shop.
3B. Replacing the side windows with steel sheets isn't a bad idea, but creates some hellacious blind spots, especially on the passenger side of the vehicle.

4. Ditto with the rear seat belt arrangement, I'd seek clarification, unless I'm mistaken, it again almost sounds like 'custom-vehicle' territory, as you'll have to do quite a bit of work in order to get a 3-point belt set in the back, and if I've got to that level of work, I'd just add a 5-point harness to each seat and call it a day.
4A. I'd simply remove the rear seat and make a van out of it.

Rustykipper

Original Poster:

10 posts

80 months

Thursday 31st May 2018
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Thanks guys.

The rear glass is bonded and probably structural, I can’t believe it will come out without a fight.

The reason for the suspension change is kind of threefold.

1. The standard independent suspension is absolute pants off road due to minimal travel and small tyres, and the aluminium front diff is not up to the power of the V8.

2. The truck drives like a dream on the road, the handling is really tight for a truck and the V8 makes it a pleasure to drive but driving around the broken, rutted and cobbled streets of Sheffield is literally like falling down the stairs, by half way down the fun as gone out of it and you just want it to stop. I’ve had bulbs shake out of the dashboard, glass falling out, lights falling off and once I had the dog in the back, oh lordy, think pinball machine……he was not happy, he runs away and hides now every time I open the garage door! I’ve had new rear springs made since which has softened the rear a bit.

3. I want to fit some bigger rubber but 28 inch is about as big as I can go without a hugely expensive lift kit or a body lift which in either case I’ve still got the limited travel of the IFS suspension, also the torsion bars seem to be almost impossible to find so once one of those snap its game over.
What our American cousins do is simply hack off the existing suspension and fit an axle and springs usually from a grand waggoneer then Bobs your uncle Fanny’s your aunt. Not so easy over here.
Also the solid axle has the benefit of 12 inch discs and 2 pot callipers to counter the bigger rubber.

The glass is purely tick box bureaucracy. The IVA manual lists American, Canadian and Japanese comparable standards for glass, in the case of American its ‘FMVSS 205 (U1)’ however it goes on to state the glass must have the marking ‘E 43R’ from the original manufacture and then states there is also a mandatory marking to be shown indicating the type of safety glass (l,ll,lll,lV). So temped to engrave something on the glass but might end up doing 5 years porridge! The glass is original and perfectly safe, the only difference from UK glass is the missing markings.

We had a similar problem at work when we built some plant for the US, the UL inspector refused to sign the unit off as it didn’t have ‘UL’ printed on the cable (big inch and a half thick cables), we had all the certificates for the cable showing the certifications but we had to pull all the cables out and ship new cables over from the States, Then the CSA inspector (Canadian) turned up and went against just about everything the American inspector specified…….. thick end of million quid lost through bureaucracy and 5 years on the plant still sits in a corner of the car park and the project manager retired due to nervous breakdown!

I had a quick look at Rockauto last night to see if my 1st gen S10 had the same part number for the front side windows as the later Blazers that were sold in Europe but they look to be different.
I have both axles prepped and laying on the garage floor, if this was a land rover or something easily replicable I would maybe take the risk but I’ve had this truck well over 20 years so kind of attached to it. Someone sensible might cut their losses and go with a body lift…..
Probably worth ringing one of the local test stations and asking the question but don’t want to flag anything up.


Edit. I've just noticed the IVA test manual states "Non-European and Other Acceptable Standards" yet the glass must be E marked...... a bit of a contradiction going on here....confused!?

https://assets.publishing.service.gov.uk/governmen...page 25


Edited by Rustykipper on Thursday 31st May 15:19


Edited by Rustykipper on Thursday 31st May 15:21

Moose of Death

26 posts

140 months

Thursday 31st May 2018
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1. You mentioned the Jeep XJ front axle, and then mentioned 12" rotors and two-piston calipers. Over here, the 'XJ' a Jeep Cherokee, which, at best, got an 11" rotor and single-piston calipers (I've owned three, and sell a hell of a lot of parts for others).

I only mention this because you wanted something to run with the power of the V8, and those are typically thrown away here in favor of something stronger as well. You then mentioned the Bland Wagoneer...

1A. There are typically piles of Blazers and S10/S15's in wrecking yards here, and I could have sworn that there were aftermarket versions available, concerning replacement torsion bars. I've never been too disappointed in a torsion bar front suspension (they ride really well), but once again, the differential is the limiting factor here, so yeah, I agree, it's time that it went. They do drive really nice, however. I've not been terribly impressed with any solid-axle-front vehicle that I've ever driven (although I've considered making a autocross track toy out of a Cherokee), but suspension compliance is an issue on rougher roads and streets, so while I'd mourn the loss of a slightly better daily-driver suspension in the factory torsion bar setup, it's really not an off-road-friendly arrangement.

2. Concerning the side glass, I'm a bit vague on details (the last one I worked on in that regard was...two decades ago?), but I seem to recall that it was either bolted and glued in, or simply glued in. This is General Morons that we're talking about here...and a 1980's GM product as well...and structural rigidity isn't one of their noted hallmarks.

3. Having worked on several of these rigs, and performed a couple of the V8 swaps you're talking about, I know that there is some attachment to the vehicle, but I'd seriously consider tossing the Chevy V8 into a Land Rover and calling it a day, lol.

I'm surprised that the interior is as intact as it appears in the picture or two above, as the Blazer/S10 has been something of a build quality nightmare from day one, with drives typically enhanced by various plastic interior pieces breaking off while you drive...or the side windows falling out of their tracks...
I have a 1990 Chevy C3500 with a 454 sitting in the driveway right now, so I reserve the right to talk badly about GM products.

Rustykipper

Original Poster:

10 posts

80 months

Thursday 31st May 2018
quotequote all
Hey Moose, any idea if the torsion bars are still available new over there? These trucks are like hens teeth in UK wrecking yards. I think part of my problem is the bars are just plain tired and the weight of the V8 is compounding the issue, if I jack the front of the vehicle I'm getting almost no down travel on the suspension.

Oh, for the 12 inch discs I've done a WJ knuckle conversion, this gives me full crossover steering as well as huge brakes, I had to ship the knuckles from Germany as they need to be left hand drive. The rear axle is from a Jeep liberty and that has even bigger rotors.

The interiors not bad, the rear seat area is like new, the driver and passenger area are a bit tired and cracked, the top of the dash is quite bad, these trucks are a celebration of man made materials! The quality of plastic quite laughable but the mechanics are crude and easy to fix and the chassis will last a thousand years, its over thirty years old and almost like new

I have considered fitting an iron front diff from a Bravada but would have to get it shipped over, if I went that route I would swap in a full time transfer box and go AWD, it might limit all the embarrassing wheelspin!

A better bet for rough roads might be to keep the IFS but go with coilovers, essentially a pre-runner setup but again I will run out of points and have to submit for the IVA test.

Moose of Death

26 posts

140 months

Friday 1st June 2018
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Rustykipper said:
Hey Moose, any idea if the torsion bars are still available new over there? These trucks are like hens teeth in UK wrecking yards. I think part of my problem is the bars are just plain tired and the weight of the V8 is compounding the issue, if I jack the front of the vehicle I'm getting almost no down travel on the suspension.

Oh, for the 12 inch discs I've done a WJ knuckle conversion, this gives me full crossover steering as well as huge brakes, I had to ship the knuckles from Germany as they need to be left hand drive. The rear axle is from a Jeep liberty and that has even bigger rotors.

The interiors not bad, the rear seat area is like new, the driver and passenger area are a bit tired and cracked, the top of the dash is quite bad, these trucks are a celebration of man made materials! The quality of plastic quite laughable but the mechanics are crude and easy to fix and the chassis will last a thousand years, its over thirty years old and almost like new

I have considered fitting an iron front diff from a Bravada but would have to get it shipped over, if I went that route I would swap in a full time transfer box and go AWD, it might limit all the embarrassing wheelspin!

A better bet for rough roads might be to keep the IFS but go with coilovers, essentially a pre-runner setup but again I will run out of points and have to submit for the IVA test.
1. I seem to recall that 2nd-gen torsion bars fit into the 1st-gen trucks, but you have to grind a lip off of one end. This isn't a bad thing, as I've got the part number list (I think) saved from a previous project:

LH 15956501 26.63mm 1052 RH 15956502 26.63mm 1052 LH 15956503 27.94mm 1276 RH 15956504 27.94mm 1276 LH 15956505 29.36mm 1450 RH 15956506 29.36mm 1646 LH 15956509 30.69mm 1883 RH 15956510 30.69mm 1883 LH 15956511 32.51mm 2305 RH 15956512 32.51mm 2305

I seem to recall the MM number to be the torque values. I think the two strongest ones are from a ZR2 truck...but don't quote me. It might be easier to find the 2nd-gen torsion bars over there across the pond.

I'm also curious if the Chevy Astro/GMC Safari AWD torsion bars might not be made to work, or might be compatible. More on the DisAstro and Safari in a moment.

2. I'd strongly suggest the Bravada bits and pieces, as you can run it full-time AWD, which sounds like what you're needing anyway. I seem to recall the Bravada being a little...binding in sharp corners (parking lots, etc), but beyond that, that's an idea I'd pursue, unless you're turning this into a mud buggy or something.

I'm also curious if you couldn't run a Chevrolet Astro/GMC Safari mini-van diff and transfer case (might be easier to find), but I can guarantee that those definitely bind up a bit in close-quarters maneuvering, but they work really well in inclement conditions. I've owned two AWD Chevy Astros.

3. I'd be pleasantly surprised if your existing torsion bars were up to the task of holding up a cast-iron 5.7, I seem to recall that those weigh something like an additional 150-200 pounds over the tiny 2.8.

4. Concerning the state of the interior, I'm not surprised to hear that, I've owned a lot of 1980's and 1990's GM products, and I've not owned one yet that the interior didn't fall apart on. That makes owning one really difficult, as I absolutely love the 3rd-generation Camaro and Firebird/Trans Am, and I'd love to own one each (A last-year Z28 and 1989 Trans Am GTA)...if they weren't a disaster in almost every aspect but the body design, absolutely sexy cars.

Rustykipper

Original Poster:

10 posts

80 months

Tuesday 5th June 2018
quotequote all
Thanks again Moose.

It looks like all the torsion bars have been discontinued, summit racing have a single GMC Safari bar so might have a search for yard that has a second gen being broken, they were sold over here in small numbers, failing that I’ll try to get a pair shipped from a US breakers. I’m sure the second gens are significantly heavier than mine and they come with the 4.3L which must be getting on for the weight of the 5.7. I’ve offset some of the weight, battery relocated to load space, gear reduction starter and aluminium intake replacing the heavy cast iron original.

I’m kind of thinking about an IFS suspension lift (if still available), if its 100% bolt on and I’m just relocating the front suspension then I think I should scrape through on points. This will have to be a second gen lift kit that may need modifying for the 1st gen torsion bar mount, I think they stopped making the earlier kits donkeys years ago.

Failing that it will have to be a body lift, this should allow me to fit some 31 inch rubber. I might look at some softer riding shocks to take some of the harshness out of the ride, I’m sure 20 years back this truck was quite bouncy it seems to crash over potholes now.

I now need to try to find someone who wants a Dana30 front axle with WJ knuckles and all mounting hardware removed ready for leaf springs, I’ve lost a small fortune but at least still have the truck!