72 Corvette - Restoration Updates
- Thread starter TimP
- Start date
Mad4slalom
Well-known user
Looking good Tim, removing and re fitting engines is always a thrill for a petrol head diy’erHi Corvette, Many thanks for the technical guidance on this - you have also solved a small mystery that I had forgotten about
When I first got the car home I investigated the CKX engine code - which showed up as being for a Turbo Hydramatic transmission. I had put this down as a question for me to resolve at a later - and then forgot about it. (also possibly explains why the hole in the floor for the gear level has been modded). I have also looked at the serial number P1B16A on the transmission casing (serial # 3925661) which identifies it as a standard M20 gearbox build on the 16 Feb 1971. So someone at some point swapped the original automatic for this manual (see pic below).
Ironically, after I bought the car but before it was delivered I discovered that I have severe arthritis in my knees and I was regretting not buying an automatic - turns out that I did.
So that leaves an interesting dilemma bearing in mind that either option will require some spend: should I rebuild what I have or should I rebuild as it should be?
How light or heavy is a standard clutch on a stock small block in good working order?
View attachment 8041
Handy having a removeable crossmember, often wonder why chevrolet didnt do it on manual cars. The four speed is more engaging than an auto imho and was a pre requisite of cars I considered. Re the clutch, when the car arrived at southampton I was amazed at how heavy the clutch felt after modern cars and vans with hydraulic Ones. But after a few hundred miles I dont even think about it now. The same with my non power brakes, first drive it felt a bit un nerving and before I drove properly on the road I was considering a power brake conversion, the vendor in the USA had told me he had never had a problem stopping the car and I can confirm having about 350 miles under my belt that the brakes are excellent , you just get used to using more force but like the clutch they feel normal now. They brake with good “feel” total confidence and dead straight and even . The handbrake tho , thats another story and is a work in progress. keep up the good work
Many thanks! From my novice perspective having a removable cross member made everything relatively easy to do. I made a trolley (out of an old kitchen worktop) to support and move the gearbox as it was coming out and that really helped too. I had been wondering about clutch effort as my knees are probably going to replaced sometime this year and a heavy clutch won't help. It's interesting to hear your experience with this - although is is perhaps difficult to gauge light and heavy as everyone's experiences and perceptions are different. Thinking about this I realise I haven't driven a manual for a few years now, so that will be refreshing and very welcome especially after using VW group DSG auto boxes for a few years which personally I don't rate very highly. It will be interesting to see what mine is like when everything goes back together.
Be careful what you wish for! I'm not sure anyone has an appetite for another 40 pictures whilst I rebuild the passenger side.
Mad4slalom
Well-known user
Roscobbc
Moderator
Perhaps my experience with manuals will help Tim. I had a lower disc removed about 15 years ago and was left with permanent nerve damage to my left ankle. I can't 'pivot' my foot upwards (so unable to shift-up gears on Jap and late model bikes) The clutches on modern manual gearboxes in typical daily drivers are an issue for me as I can't 'feel' the clutch biting point through my left foot - so choose an auto for preference. My Vette is a manual. I replaced the OEM or pattern original clutch with a Centerforce dual friction assembly when I uprated the engine. This clutch (whilst rated as capable of handling 600+ hp) is actually lighter in operation than the stock type clutch (oddly some of the perfromance versions of the C6 have lighter clutches than the stock version). My C3 has power steering - but with a 12.5" steering wheel the physical effort is increased to (IMHO) a perfect weight, matching the effort of the clutch and the non power assisted brakes. Yes are heavy, very heavy I guess and need a bit of warming-up with the Hawk HP pads - but again the braking weight is a reasonable comparison for the steering and clutch (although admittedly more powerful brakes would be nice)
I find the low seating position in the Vette with my legs stretched horizontally really comfortable - but do have a habit of 'riding' the clutch at times. Don't really have driving issues otherwise even though living in an outer London suburb.
CaptainK
CCCUK Member
Good to see another person who specced only manual gearbox - just like me.
Re: power vs non-power brakes. Can I ask how tall you are? You see, my 68 Vette's brakes were good according to my (much shorter than me) mechanic and he said he had no problems with the brakes. Alas, I'm 6ft and when attempting to apply the (non power at the time) brakes in my Vette was really hard as my leg was 45 degrees out to the side and was quite hard to apply any serious force. As such, the brakes were really bad for me and it put me off driving the Vette as too scary. I promptly put power brakes on it and the feel is much better now, and for me personally I find it much easier to operate the brakes now. I should add that with a 68 Vette, there wasn't the option of "tilt and telescopic" steering wheel, so leg space isn't much for tall people.
That's good to know- thanks! Would you recommend the Centerforce clutch for a stock application? I need to get a new clutch and if this one is lighter than standard that would be a good plus point for me.
I'm really looking forward to getting this car drivable. I got the Corvette out of the garage today - first time in a year or so. Just sitting in the seat and holding the wheel in the sunshine has felt really good. - haven't been able to do that for a while and being able to sit on the repaired seat base and not worry that it will collapse completely requiring something to be surgically removed is very reassuring.
Having got the Corvette out of the garage today and given it a quick clean (very therapeutic) I wanted to follow up with the passenger side rear quarter damage which looked like this.
Removing the damaged material around the hole made it look like this.... Looks horrible but needed to be done.
I decided to use duct tape to act as a former for the new glass fibre due to the complexity of the hole shape.
After three layers of fibre glass mat on the inside and a little trimming it looked like this.
And after a bit of glass fibre reinforced and file filler it (the corner above the bumper line) started to look like it should. I have only done a relatively thin repair on the inside so far - just enough to provide enough strength to repair the outside. I am waiting on a new chassis to bumper bracket (should arrive soon) that I will use to gauge how thick the glass fibre can be without causing fitting issues.
I made a crude template from the drivers side corner which is quite useful in getting the two sides to look the same. The profile is approx symmetrical across the corner and it seems to work upside down on the passenger side quite well.
It's not quite right yet but another day should have it looking how I want it
Whilst the fibre glass was out I repaired one of the kick plates that had snapped - they seem to get pretty fragile in old age. Just some work on the front surface now to tidy up the cracks and it should look fine.
Next week I will continue working on the lifting frame (more soon hopefully), and finish off the repair to the passenger rear corner, particularly the bumper line area and below
Removing the damaged material around the hole made it look like this.... Looks horrible but needed to be done.
I decided to use duct tape to act as a former for the new glass fibre due to the complexity of the hole shape.
After three layers of fibre glass mat on the inside and a little trimming it looked like this.
And after a bit of glass fibre reinforced and file filler it (the corner above the bumper line) started to look like it should. I have only done a relatively thin repair on the inside so far - just enough to provide enough strength to repair the outside. I am waiting on a new chassis to bumper bracket (should arrive soon) that I will use to gauge how thick the glass fibre can be without causing fitting issues.
I made a crude template from the drivers side corner which is quite useful in getting the two sides to look the same. The profile is approx symmetrical across the corner and it seems to work upside down on the passenger side quite well.
It's not quite right yet but another day should have it looking how I want it
Whilst the fibre glass was out I repaired one of the kick plates that had snapped - they seem to get pretty fragile in old age. Just some work on the front surface now to tidy up the cracks and it should look fine.
Next week I will continue working on the lifting frame (more soon hopefully), and finish off the repair to the passenger rear corner, particularly the bumper line area and below
Roscobbc
Moderator
Hi Tim - I also replaced the stock flywheel with a Centerforce item. This was mainly due to uneven wear and 'scorch marks' caused by bell housing and gearbox not tightened-up by previous owner (don't ask) - also used a new release bearing. The other option would be to have the flywheel re-surfaced. The Centerforce fuel friction is a diaphram type clutch and perhaps a little unusual in as each as side of the friction plate is faced with different materials. It also features a whole series of 'bob weights' that apply centrifugal force on the pressure plate at higher rpm, allowing the lighter pedal pressure).I found it lighter in operation than the stock item - not hugely but enough for me. The one thing that is important is the need follow the manufacturers instructions and 'bed' (read 'burn') the new clutch-in much like one does nowadays with new higher performance brake pads and disc pads. I'm running close to 600 hp and over 600 ft/lbs of torque at the flywheel and the clutch copes perfectly with it (its been in the car now for about 10 years). There are some who will advocate the use of a twin plate clutch for lighter operation - I've heard these can be a little tricky to set-up........
The Centerforce clutch sounds like there was a lot of thought/experience gone into it. I know I will have to at least resurface the flywheel although the clutch friction plate that came out was in relatively good condition I think a previous one had been allowed to get a little thin.
I am going to be running close to stock in terms of horse power so it probably won't need much in the way of sophistication to keep it all together. Still trying to contemplate what 600hp in a C3 must be like though. I thought 416hp in my 2017 Mustang (now gone to a new home) was fairly lively even though it probably weighs 7-800lbs more than a C3.
I am going to be running close to stock in terms of horse power so it probably won't need much in the way of sophistication to keep it all together. Still trying to contemplate what 600hp in a C3 must be like though. I thought 416hp in my 2017 Mustang (now gone to a new home) was fairly lively even though it probably weighs 7-800lbs more than a C3.
Just to wrap up this last bodywork item..... here is the passenger rear quarter.
from start...
.....to finish (well nearly). Primer is temporary to help find the lumps and bumps.
I removed the rear lamps for safety whilst finishing the repair.......only to find some a small chunk of missing bodywork where the lamp housing retaining bolt goes. Another little job to do Other items still very much work in progress - more next weekend.
from start...
.....to finish (well nearly). Primer is temporary to help find the lumps and bumps.
I removed the rear lamps for safety whilst finishing the repair.......only to find some a small chunk of missing bodywork where the lamp housing retaining bolt goes. Another little job to do Other items still very much work in progress - more next weekend.
Taking a break from other parts of the rebuild I thought I would have a look at the interior, Not that it is something that I really need to do right now but I try to keep motivated on a long project by doing some random 'fun' bits along the way. Although present, most of the interior is in pretty poor shape. In the long term it will get replaced when time and budgets allow but in the interim I thought I would experiment with some different finishes. I expect to get a mixed view on what I have done but in the spirit of sharing here goes....
Here is the original component - the handbrake cover and arm rest - which is faded and badly scratched. It has a textured finish so can't be sanded without getting a smooth spot where the scratch was. They cost just over £100, so not cheap but they are available new in the right colour so if it does all go pair shaped then I can get a replacement.
First thought was to cover it in a red textured vinyl (see sample) which was similar to the original. The hand brake cover has multiple angles requiring stitching in visible places - well beyond my skill set. This would probably have not turned out well and would have looked a bit pants.
Carbon fibre is all the rage right now - would that work? So I bought a kit from Easy Composites to find out and produced this....
Not perfect - and there is still some finishing to do so plenty of opportunities to make a mess of it yet - but even so I am quite pleased with the way it has turned out as a first attempt. It is a skin using a single layer of carbon fibre weave ( so not a wrap) and multiple coats of clear resin. It's not easy and I've made loads of mistakes along the way but I have learned a lot too so if I decide to do any more I am better placed to do a more professional looking job. If anybody would like a bit more detail on what was required I'd be very happy to post a more detailed explanation of the process.
Here is the original component - the handbrake cover and arm rest - which is faded and badly scratched. It has a textured finish so can't be sanded without getting a smooth spot where the scratch was. They cost just over £100, so not cheap but they are available new in the right colour so if it does all go pair shaped then I can get a replacement.
First thought was to cover it in a red textured vinyl (see sample) which was similar to the original. The hand brake cover has multiple angles requiring stitching in visible places - well beyond my skill set. This would probably have not turned out well and would have looked a bit pants.
Carbon fibre is all the rage right now - would that work? So I bought a kit from Easy Composites to find out and produced this....
Not perfect - and there is still some finishing to do so plenty of opportunities to make a mess of it yet - but even so I am quite pleased with the way it has turned out as a first attempt. It is a skin using a single layer of carbon fibre weave ( so not a wrap) and multiple coats of clear resin. It's not easy and I've made loads of mistakes along the way but I have learned a lot too so if I decide to do any more I am better placed to do a more professional looking job. If anybody would like a bit more detail on what was required I'd be very happy to post a more detailed explanation of the process.
My handbrake cover is made from some sort of plastic and definitely not rigid. You are absolutely correct to be concerned about cracking - what you see here is the third iteration and on the second attempt some cracking did occur in the top resin layer even though the addition of the single CF layer plus three coats of resin have made the cover much more rigid than it was before. If it occurs again I will reinforce the inside of the cover with shaped fibre glass to give the required stiffness (being careful of the required clearances and brackets that go inside) , sand/polish out the cracks on the outside (which I did last time) and give it another coat of resin. It's been fun trying to do this - I could have experimented on a very simple flat shape but I wouldn't have learned half as much as I have trying something more complex.
Sometimes what you will hope will happen triumphs over what you expect to happen. After sanding down (400 grit then 800, 1200, polishing paste, T-cut and then a wax) the top coat that was applied yesterday I had expected some cracking to occur but not this time. So I now have a finished article that - with light switches and hand brake guide fitted - looks like this .....
Still not perfect but the areas that aren't as I would like will be mainly invisible behind the seat base. Turned out better than expected - need to work out if I should keep this finish or buy the replacement as originally planned. Will probably wait until the carpets and seats are installed in the car before deciding - could look quite good contrasted against a red interior.
Any views? Happy to hear both for and against.....
Still not perfect but the areas that aren't as I would like will be mainly invisible behind the seat base. Turned out better than expected - need to work out if I should keep this finish or buy the replacement as originally planned. Will probably wait until the carpets and seats are installed in the car before deciding - could look quite good contrasted against a red interior.
Any views? Happy to hear both for and against.....
sublimemike
Well-known user
Elecy windows aren't they?