Sourcing ignition leads HEI

[GreigM]

Hoping for some more advice. I've had suspicion my car hasn't been running correctly since I picked it up. The left bank smokes and produces significantly more "puff" than the right. The plugs in the car were obviously old/mixed and replacing them hasn't improved the situation entirely. When driving it feels rough at speed and I'm not convinced I'm hearing that V8 sound I expected.

On trying to disconnect the leads to determine if the cylinders are firing I've been shocked several times, leading me to thing the leads are old/broken down. I've got a blue HEI-style ignition system fitted, however one of the leads plugged into it is missing the metal "cap" inside the rubber boot. I guess this will be enough to ensure this plug doesn't fire (and possible source of the shocks).

Can anyone recommend where I can get the correct cable with correct ends quickly in the UK?

 

[Chuffer]

Hoping for some more advice. I've had suspicion my car hasn't been running correctly since I picked it up. The left bank smokes and produces significantly more "puff" than the right. The plugs in the car were obviously old/mixed and replacing them hasn't improved the situation entirely. When driving it feels rough at speed and I'm not convinced I'm hearing that V8 sound I expected.

On trying to disconnect the leads to determine if the cylinders are firing I've been shocked several times, leading me to thing the leads are old/broken down. I've got a blue HEI-style ignition system fitted, however one of the leads plugged into it is missing the metal "cap" inside the rubber boot. I guess this will be enough to ensure this plug doesn't fire (and possible source of the shocks).

Can anyone recommend where I can get the correct cable with correct ends quickly in the UK?

Presumably you plan to replace the full set of leads not just the broken one ? There are the Vette specialists like Corvette Kingdom that supply and deliver as well as American car parts dealers such as US Automotive - Bedford , Frosts - Wellingborough . As you have a `smoker` , does it use a lot of oil ? Is it in the correct state of tune ? Timing etc ? There could be a number of issues but plugs and leads is always a good place to start as it the first easy option to rule out . Make sure the plugs are the correct heat rating too .

 

[GreigM]

Presumably you plan to replace the full set of leads not just the broken one ? There are the Vette specialists like Corvette Kingdom that supply and deliver as well as American car parts dealers such as US Automotive - Bedford , Frosts - Wellingborough . As you have a `smoker` , does it use a lot of oil ? Is it in the correct state of tune ? Timing etc ? There could be a number of issues but plugs and leads is always a good place to start as it the first easy option to rule out . Make sure the plugs are the correct heat rating too .

To be honest I'm taking a little smoke on startup of a 50yr old car as to not be the end of the earth, it was more the lack of "puff" from the right exhaust that drew my attention. Will replace the full set if I can, but want to make sure I get the correct thing - not afraid of cost, want it to be right.

 

[teamzr1]

To be honest I'm taking a little smoke on startup of a 50yr old car as to not be the end of the earth, it was more the lack of "puff" from the right exhaust that drew my attention. Will replace the full set if I can, but want to make sure I get the correct thing - not afraid of cost, want it to be right.

What type and viscosity engine oil are you using ?

 

[Roscobbc]

Best first tell us year/generation and where in UK you are based

 

[GreigM]

What type and viscosity engine oil are you using ?

Not known at this point - the car came to me from a well-known reputable source in the corvette world after extensive restoration and haven't asked the question. Have owned/driven a lot of cars in my time, a little puff on startup especially when doing low miles doesn't worry so long as its clearing.

 

[GreigM]

So looking around, Corvette Kingdom look to be able to sort me out, but can anyone double-check this is the correct lead set for a HEI distributor and NGK BPR6FS plugs?

75-77 SPARK PLUG WIRE SET - CORRECT HEI :: Corvette Kingdom

www.corvettekingdom.co.uk

Distributor looks like this:

 

[Roscobbc]

Spark plug wires can deterioate with age........if its unknown when they were last replaced by a previous owner it does no harm (more likely the reverse) replacing them......as long as the replacements are from a good quality brand. A 'puff' of blue oil smoke out of one exhaust pipe (or both) on startup (the clears) could simply be valve stem oil seals deterioated or missing........as you say no big deal. Spark plug is a mid heat range resistor plug........run the number through an 'on-line' sat+park plug makers comparison chart and compare with OEM plug suggested for your year/model vehicle.

 

[Chuffer]

Not known at this point - the car came to me from a well-known reputable source in the corvette world after extensive restoration and haven't asked the question. Have owned/driven a lot of cars in my time, a little puff on startup especially when doing low miles doesn't worry so long as its clearing.

As Roscobbc said , a bit more info about you car would be useful for guys to give more advice . Also how long have you owned it and did you purchase it from the " well known reputable dealer " ? if so , ask some questions to gain more knowledge and history . The dealer should be able to tell what oil he uses in the Corvettes he restores .
Your footnote says you have a 1972 C3 small block 350 . Most of us C3 owners swear by Valvolene VR1 20/ 50 as it has high zinc content .

 

[teamzr1]

Not known at this point - the car came to me from a well-known reputable source in the corvette world after extensive restoration and haven't asked the question. Have owned/driven a lot of cars in my time, a little puff on startup especially when doing low miles doesn't worry so long as its clearing.

If 5w30 is in there now, too light and can sneak past the piston rings and become blow by

Next time try like 10w30

Also like Mobil I sell a true synthetic that is for older engines that is made up differently to reduce oil usage

 

[johng]

I fitted a set of these last year to my 78 with what looks like the same blue distributor cap, they fit and work just fine.
More Information for UNITED MOTOR PRODUCTS 8840

 

[Chuffer]

I have Mallory 8mm Silicon leads with a Street/ Strip HEI dizzie .

 

[Mr. Cricket]

To be honest I'm taking a little smoke on startup of a 50yr old car as to not be the end of the earth, it was more the lack of "puff" from the right exhaust that drew my attention. Will replace the full set if I can, but want to make sure I get the correct thing - not afraid of cost, want it to be right.

You may have a heat riser on the RHS exhaust between the manifold and exhaust which directs heat to the base of the carb meaning the RHS tailpipe will show less emissions than the LHS on start up which is a good thing to have. Aside from the lead issue of course..

 

[Mr. Cricket]

from the net:

The exhaust heat riser valve on a C3 Corvette is designed to help the engine warm up more quickly by directing hot exhaust gases under the carburetor. This is achieved by partially restricting the right exhaust pipe, which forces the exhaust gas up through and across the intake manifold, heating the carb choke. The valve has a bi-metallic spring or a vacuum-activated valve that allows it to open up once the engine warms up, ensuring normal exhaust flow

A pic of the doo dad. I have one on my C3

 

[GreigM]

As Roscobbc said , a bit more info about you car would be useful for guys to give more advice . Also how long have you owned it and did you purchase it from the " well known reputable dealer " ? if so , ask some questions to gain more knowledge and history . The dealer should be able to tell what oil he uses in the Corvettes he restores .
Your footnote says you have a 1972 C3 small block 350 . Most of us C3 owners swear by Valvolene VR1 20/ 50 as it has high zinc content .

I've had it around 6 weeks now. Bought from Gavin@emc so would be confident the oil is correct. I'm working through a couple of teething issues, which is not unexpected for a big restoration on a very old car, but has been taking an annoyingly long time to rectify.

So an update, new leads arrived, replaced the damaged one and immediately a more balanced v8 sound and no more shocks from the leads!

I also managed to get my wipers to work, which haven't worked correctly since receiving the car (and being in Scotland is fairly essential). So I can now drive and wipe, might finally get a decent length drive in the car!

Thanks for the advice on the heat riser valve Mr Cricket - this is definitely what is happening as after some time idling the right exhaust blew the vapour (I'm going to call it that as now I observe a bit more I'm sure its a bit of moisture buring off from short runs) for a minute then cleared, it certainly doesn't smell overly like burnt oil.

My last 2 issues if anyone can help - the fan belt squeals very loudly with any sort of revs above 3000rpm. Is this a sign I need a new fan belt or just common on these cars? If a new belt where is best to replace and how to tell what I need - my car as an air con car, but the air con pump is not in the belt routing and isn't being turned, so does that mean just a standard belt?

Finally I had to short the wiper bypass switch to get the wipers to work - its rusty at the back and obviously not functioning. Can anyone recommend where I can get a replacement for a 72. It looks like this:

 

[antijam]

Finally I had to short the wiper bypass switch to get the wipers to work - its rusty at the back and obviously not functioning. Can anyone recommend where I can get a replacement for a 72.

There are several available on eBay - all from the States; shipping tends to be prohibitive.
Corvette Kingdom can get you one but they don't have it in stock so you'll have to wait for it to be imported - usually 2 or 3 weeks.
Best bet might be this used one from Claremont. It's significantly cheaper than new and their parts are pretty reliable.

 

[MilkyNoSugar]

I would contact Gavin at EMC if you need some advice or guidance. Always very helpful in my experience and I am sure he could get the correct belts for you. However, if you are more of a DIYer and enjoy the research and tracking down your own parts there are options. For your v belt layout, and the part numbers have a look at this website. It is a good resource to understand what the original belt layout should have been, and what the part numbers are. Not the cheapest though.

1968-1982 C3 Corvette Fans, Fan Clutches, Fan Belts and Hardware

Mid America Motorworks - Shop for Corvette Parts, Accesories, Interiors for restoration, and gifts.

www.mamotorworks.com

I have just replaced all my belts on my 1972 big block after the short crank to the water pump belt snapped following a brief period of belt noise at startup. Relatively easy to do and took an hour or two at most. Most of the time was wasted tidying up the alternator wiring and cleaning while parts were removed. You may as well replace them all as the costs are not too bad. If you still have the original viscous coupling type fan, keep it upright when removed. There is no tensioner on the crank to water pump belt, so you need to remove the bolts on the top water pump pulley, fit the belt over the crank pulley and top pulley, then bolt the pulley back in place.

Two out of the three belts on my car were not the correct length nor routed correctly according to the images I found for the routing.

I got Gates brand belts from Rock Auto and this is the link you need I think. 1972 CHEVROLET CORVETTE 5.7L 350cid V8 Belt | RockAuto
Rock Auto delivered the belts in 3 days, all postage and duty clearly detailed in the shopping basket and paid so no hold-up at customs or anything extra to pay. All in it was £50.

 

[GreigM]

There are several available on eBay - all from the States; shipping tends to be prohibitive.
Corvette Kingdom can get you one but they don't have it in stock so you'll have to wait for it to be imported - usually 2 or 3 weeks.
Best bet might be this used one from Claremont. It's significantly cheaper than new and their parts are pretty reliable.

It's odd, I see the same on corvette kingdom for a 72 but it looks slightly different to mine. When working on it last night the knob came out and it has a long pole with knurled end. I'm now thinking the "pole" has come away with the knob and it is this:

70-72 WINDSHIELD WIPER OVER RIDE SWITCH :: Corvette Kingdom

www.corvettekingdom.co.uk

I do travel to the states regularly (where my love for an old stingray comes from) so can pick up the odd spare part there....when I come to it I may even try to get an exhaust with a bit more of that good v8 noise in my suitcase(s)

 

[GreigM]

I would contact Gavin at EMC if you need some advice or guidance. Always very helpful in my experience and I am sure he could get the correct belts for you. However, if you are more of a DIYer and enjoy the research and tracking down your own parts there are options. For your v belt layout, and the part numbers have a look at this website. It is a good resource to understand what the original belt layout should have been, and what the part numbers are. Not the cheapest though.

1968-1982 C3 Corvette Fans, Fan Clutches, Fan Belts and Hardware

Mid America Motorworks - Shop for Corvette Parts, Accesories, Interiors for restoration, and gifts.

www.mamotorworks.com

I have just replaced all my belts on my 1972 big block after the short crank to the water pump belt snapped following a brief period of belt noise at startup. Relatively easy to do and took an hour or two at most. Most of the time was wasted tidying up the alternator wiring and cleaning while parts were removed. You may as well replace them all as the costs are not too bad. If you still have the original viscous coupling type fan, keep it upright when removed. There is no tensioner on the crank to water pump belt, so you need to remove the bolts on the top water pump pulley, fit the belt over the crank pulley and top pulley, then bolt the pulley back in place.

Two out of the three belts on my car were not the correct length nor routed correctly according to the images I found for the routing.

I got Gates brand belts from Rock Auto and this is the link you need I think. 1972 CHEVROLET CORVETTE 5.7L 350cid V8 Belt | RockAuto
Rock Auto delivered the belts in 3 days, all postage and duty clearly detailed in the shopping basket and paid so no hold-up at customs or anything extra to pay. All in it was £50.

It's a bit of both - happy to DIY and its one of the attractions of an older car, but want the basics running quickly. I'm not worried about cost here, and happy to pay premium to make the car just right. I also race in my spare time and nothing could compare to the cost of that so the old vette is cheap in comparison....

Great info on the belts, very much appreciated.

 

[Roscobbc]

Remember there are two water pump types used on earlier (perhaps even later) C3's. Certainly applicable to big block cars (perhaps SBC's) - 'short' and 'long' type water pumps.
If you have 'short' style water pump its possible the belts won't align correctly. More importantly the rear of the respective pulley can interfere with the water pump fixings.......there is a spacer lit kit available which most people seem to use.......spacer kit is basically several 2" or so diameter alluminium discs.......simply use enough of them (usually all that are supplied in the kit) to clear water pump behind and assure correct pulley alignment.