83 Triumph Acclaim Sprint

Small update, all the bolts are here and look promising, I've fitted the new 5V reg and fixed a broken wire on the crank sensor plug, taken some data logs and everything looks good. Next up pulling the head off. But first I've got to get the jazz ready to collect a pile of spitfire engine parts tomorrow.
Dan

My plan, such that it is, is to cut a slot at 90 degrees to the CROWN of the short side radius with a hacksaw blade that has been marked at 2mm depth of cut so i don't go too deep. Take the top of CROWN off with a burr, then blend that back in.

If the short side radius was a 90 I'd be taking the tip into 2 to 45, then cutting them into 4 22.5s thoughts?

What have you taken the seat ID out to? No good doing any work in a port because the restriction is always the seat ID

Measure first then

Seat
Valve
Throat
Port

Typically in that order - page 10 of this thread has some notes, with a few more on page 6 and 7 of the flowbench thread.

Just remember you still need a transition from the seat to the throat.


Trying to explain it writing it is a PITA so this may not be easy to follow. As the seat is on an angle of 45 degrees a 1.5 wide seat takes up just over a 1 mm of seat diameter so if you then have 1.2mm of 60 degree that takes up even less diameter - 0.6mm

So from the 36mm diameter of valve - you take 0.5 x 2 1.2 x 2 and 0.6 x 2 - and that gives you a dimension for the inner diameter of the seat.

36 - 4.5 = 31.5 you could take the seat ID to 32 and still get the 45 and the 60 transition on there - but it will need care and accuracy.

As its the same width of seat for a small valve or big valve the bigger the valve the better the benefit.

On a small valve you could use 1.2mm for the 45 width and 1.0 for the 60 to tray and maximise what you can take the ID to.

Do all the work on one that can be sacrificed unless fully confident in your abilities.

Something just isn't right with that tool, so I think ill have to scratch build one, I've ordered a set of boring bars, hopefully the smallest one will be the correct size to build a better tool, hopefully my I might get my lathe working and get the tool made.

I'm really missing this car, but I don't want to put the engine back together till I have at least tried to make some improvements to its breathing,

A couple of weeks an ago YouTube randomly shows me a video of a K swapped Honda Jazz, (same model as my daily), and I started missing Frank more and more, which somehow brought me to a car I've had a hankering for, for several years, a Honda Del Sol, oh what a spiral I've gone down............... B16VTECtargatopedcoupegoodness. It's a sickness, I tell you, a sickness.

Must Fix Frank, Must Fix Frank, Must Fix Frank, Must Fix Frank, Must Fix Frank, Must Fix Frank, Must Fix Frank, Must Fix Frank.

It's Alive

I did make the tool, but it broke the first time I used it, so that's something to look at another time.

Pulling the last stud out was remarkably stiff, so it was a good job I had bought a tap especially for chasing the threads out, it's a fine metric thread don't you know, the face of the block cleaned up well.



The Kia Picanto head bolts worked a treat, they came with their own washers which was lucky, the one under the oil pump drive gear just clears.



I knew the 2 rear outside corner bolts were considerably shorter as they had to pass under the fuel pump and distributor, I had bought some 12 grade bolts to suit and used the old head bolt washers under them, but the bolt that goes above the water pump is 7mm shorter than the longer ones, this was a surprise to me and nearly stopped play, until I came up with a plan, a very cunning plan, one which you have probably worked out by now.



Yes a large stack of washers, there is nothing above it except the rocker cover so it will probably stay like it, unless there is a good reason not too.

I gave the rocker shafts a quick once over and spotted the cap for the oil pump drive has stripped threads, there was 2 of them and both were partially stripped, and I have almost exactly a 50% failure rate at fitting Helicoils, and guess what, the first one went in perfectly, the second went in perfectly on the third attempt.



I always forget the 2 middle supports on the rocker shafts have shorter bolts.

I set the timing, did the valve clearances hooked up the speeduino to the laptop, and we have a crank trigger signal, the plugs were firing but nothing, turns out the tank was dry, after a splash and dash for some of Tesco's finest E5, Frank limped in to life, I got the static timing set at 12 degrees, but he kept backfiring. I stopped and rechecked everything, finding nothing i tried to restart and nothing no sparks and crank trigger, so I stuck 2 fingers up at the speeduino and fitted the dizzy, well, I was about to when I had an idea, the last time the dizzy was in I couldn't get the timing set where I wanted it, because the swing is limited, by a slot in the baseplate, a quick trip to see the nice Mr slitty disk and that problem went away forever. With the dizzy refitted, I could get the engine up to temp and drain the oil, nice bit of NOS filter there.



By this time it was 10 pm and getting dark so tomorrow I recheck the valve clearances, and ignition timing and go for a spin, I can't wait.

Having been out for another drive, I can confirm Frank is driving just about as well as he ever has, two things have struck me, 1 the exhaust note is far less harsh and raspy, 2 the cam doesn't seem to come on anywhere in the rev range.

I picked up a copy of how to build and power tune distributors, after rereading it, it estimates with a hemi head the max advance should be between 38 and 44 deg, I went and checked the specs for the acclaim dizzy, auto vac advance unit static 12deg, + 27 to 31 deg at 4000 rpm which puts it right in the ballpark, I'll have to pull the dizzy to check it but its looking good.

I also got the WB O2 sensor connected to the laptop and the AFR looks good on power and rather lean at idle (this engine was designed as a lean-burn engine), but I think ill go over it again and check for leaks before I stand by those numbers though.

Which just leaves the cam timing, now this is a subject I've never really understood so last night I ordered a copy of the selecting and setting up camshaft book from the same series, I've not finished reading it, but as this is the only upgraded cam available I will have to try making the best of it.
I think it is currently set up at approximately 12 (crankshaft) degrees advanced, But I've got to get my head around the whole crank vs cam degree thing, but as far as I can see I have 3 choice to set it up.

1 the cam pulley that's currently fitted has 4 keyways cut in to it, which should give me 1/4 tooth adjustability, which equates to 2.8125 deg of cam rotation.

2 Offset woodruff keys, I'm sure they are out there, but I can't seem to find them in 4mm wide to check the rest of the dims.

3 a vernier pulley, of course none of the available ones that I can find have the same pulley dims, I need a 32 tooth pulley 94mm across by 24mm thick, with a 20mm hole in the centre, and a 4mm wide keyway.
as there is as much chance of me finding one as me winning the lotto, I'm going for a DIY solution, if I can get it centred in the lathe properly it's defiantly doable.
heres some pics from my archive.




















Right my brain hurts.
Night
D

A much cleverer person than me will soon be along, I'm sure - but I read your last two posts and wondered the following:-
- What's the standard full ignition advance figure? 38-44 degrees is a lot of advance (usually required in pretty poor heads like Ford crossflows with long flame paths so that the fire is started early enough, rather than efficient high-squish multi-valve heads). Your 27-32degrees at 4000RPM sounds reasonable - I'm not sure what the mention of the vac advance unit was for, though, as the vac advance unit will add timing at part throttle, it has no effect at what. It doesn't add 12 degrees to any timing figure anywhere.

- Running the cam advanced would be trying to make the engine stronger lower in the rev range - perhaps why you commented that the engine doesn't seem to come "on the cam". 12 degrees is an awful lot of timing advance. Standard timing or perhaps a few degrees retarded would aim for better power at high RPM (all else being equal and the engine able to make use of the different breathing).

And completely agree that an adjustable pulley is the best way to get the timing exactly where you want it without offset keys/dowels being available.