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V-8 Engine Tech

Non starting MK1 383

Mopar Big Block Talk

by Roh » Tue Jun 02, 2020 1:10 pm

Those old school camshafts are okay, but there are much better ones that are now available that feature faster ramp rates. This gives more area under the curve for a given duration, which basically means more power for a given level of drivability. The important thing is that the camshaft is appropriate for the compression ratio, inlet and exhaust flow, the stall speed, diff ratio, the weight of the car etc.

The first thing to do is to completely dismantle the engine and to then inspect for damage and measure everything for wear. If you are lucky you may get away with just a hone and new bearings.
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by lukey » Tue Jun 02, 2020 5:39 pm

Ah right.. well as much as I’d love to go to town on the internals of the engine and get it running sweet, it’s purely down to cost at the moment.. I know it’ll be much better to replace everything but the block, start with fresh new bits. But it’s going to have to be broken things first... When we get the engine out I’ll strip it down and go over everything very carefully and see what’s what.. I think we’ve established it’s something bottom end, maybe failed bearings or something.. just can’t see how a 11 stone male, hanging off the end of a 6ft long pole, on the end of an Already long socket Didn’t even loosen something up...

the car / engine has only done 12000 Odd miles Since 1968 ( if you believe the TAC and paperwork ).. it had Engine issues at the start of its life, constantly in work at Jensen and even had a replacement gearbox and torque converter from Jensen in 1971... we loose track of the cars info in 1973. Until my granddad found it in the late 80s... why the car was dumped in a muddy field with the engine completely in bits we don’t know.. it had been there a while from what he was told.. maybe now I’m find out why it was taken off the road... hopefully it’s not an expensive fix otherwise it’ll be sat for quite a bit longer. Though I suppose it would give me chance to sort the rest of the car out and leave the engine until last if that’s the case.
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by johnw » Fri Jun 05, 2020 8:09 am

Sorry to hear about the starter. Looks like the advice we gave you to go aftermarket for that was a red herring.

Roh's advice is very good there.

Grant wrote:Mopar purple Cam is the one you want Lukey, plenty of low down power and vacuum.. don't be tempted to go aggressive on that.. and put a manual gearbox in the goose!! :P

I would say keep it all stock, get it all running first. The Mk1 383 is pretty much perfect and given the budget of £1000 you mention and timescale, stick to project minimum for now. Just a timing chain and steel sprocket kit for tops £50, to replace the old plastic coated aluminium cam sprocket which has a 20 year lifespan. If you are lucky you have a new kit fitted already. That was the attraction back in the day to young kids, the Mk1's were little rockets as is, and petrol was cheap.

Lap the valves, get some black VHT paint from Halfords, make the heads and inlet and exhaust manifolds look great. Always a good bonding session that between man and machine. Check when done with the head upside down on a bench and with fuel poured in the combustion chamber, I am pretty sure you know that, but always worth doing after a stuck valve.

I would stick to Chrysler parts and Felpro gasket kits for main items. A lot of repro parts are simply not as good as the originals quality wise, but they can be marked up to the price of genuine and sold as upgrades. Importing garbage with markups then customs on top is so disheartening. The Purple Shaft cam is made by Chrysler, and comes in a kit with new tappits, which opens another debate. Oil debates, zinc content debates, and should you switch to roller tappets and not buy that Purple Shaft, but a roller version. I would side step that whole topic and get it running nicely, sort the brakes, then some gentle testing. Once the motor is running right, and you have stuck your foot firmly to the floor and held it there through all the gears :D , I think you will agree Jensen did a good job in 1968.

Grant is also right, but if possible it is worth experiencing the car as is first. Get it on the road for now, then you can pull the engine again (would be rude to only use the engine hoist once), detail the engine bay, fit the manual gearbox, purple shaft cam, and obligatory carb upgrade: six pack carb or dual quad setup? More questions! Oh, and a Keith Black block could be a good option if you are still looking to save weight. They come in various sizes these days, including 383, which were at one time sold by Chrysler under their Mopar brand, so a factory part in that sense. Brakes, new seal kits and EBC pads if the old pistons are OK. Then on to wheels. Wolfrace wheels or Mk3 alloys? Another topic! Alternatively keep the car completely stock?
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by lukey » Sat Jun 06, 2020 4:21 pm

I’ve found some photos of the engine when my granddad bought the car.. some photos of when he had it rebuilt in 1990-91, and how the engine sits now, well before I started dismantling it...
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by lukey » Sat Jun 06, 2020 4:22 pm

When he bought it and got it home
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by lukey » Sat Jun 06, 2020 5:30 pm

Now
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