OK , Im re-building a 225 for daily driving.
The camshaft that was in the engine originally was cactus ,thats why the re-build.
Any how ,I got the block and head machined , .100" off the block
.060" off the head, is what I asked for ,which would bring the static compression up to about 9.5:1.
looks like the machinist took off .068-9" off the head.
No problem this should bring SCR up to 10:1.

I worked out the dynamic compression of the engine with the following camshaft specs, which is a camshaft I recently purchased.

The specs are
Here

Using the advertised duration specs I calculated a intake closing of 63*ABDC (@ .006")
Putting this figure into the wallace racing DCR calculator gave a DCR of 8.11:1. Beautiful . (Should be a little lower than this using seat to seat)
Should be good using 98 or 95 RON (about 93 -90 in US)

So ,this afternoon I put the cam in ,crankshaft and No1 with no rings.
Heres what the cam measured.

Intake duration at 0.006" =336* !!!
Intake duration @ 0.050" =201*
Lobe center line 103.5*ATDC

Intake open@ 0.006" =60* BTDC
Intake closing @ 0.006" = 96*ABDC

Intake opening @ 0.050" = 3* ATDC
Intake closing @ 0.050" = 24* ABDC

Exhaust duration @ 0.050" was 216*
Opening @ 0.050"= 44* BBDC
Closing @ 0.050" = 8 * BTDC
Lobe center line 116*BTDC
(LSA in crankshaft degrees=219.5*)
LSA 109.75*
Advance = about 6.5*

Using the intake closing @ 0.006 " 96* ABDC
gives the 10:1 SCR a DCR of 5.73:1 !!!!
Not happy!:evil:
I am going to measure it all again tomorrow,with a fresh start,
but Its not looking to good.
This thing looks like it will idle like an asthmatic pig.
I dont mind a little lope at idle .
I think this cam would be all ok except the Intake closing point?


Now what to do?:roll:
I have a few options ,and would welcome any suggestions.
I could bump up the SCR to about 13:1 (dont think so)
I could Send the cam back (maybe)
i could get the intake lobe re-ground to close at 63*(to give DCR 8:1 or there abouts (looking like the best bet)
I could pull the stock cam out of my S series and transfer it ,if it looks ok(PITA)

Sorry about the ramble ,I just had to vent it somewhere!

Brendan.

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1963 AP5 Valiant 225 PB 904 Stock except extractors & 2 1/4 inch exhaust.


1962 S series valiant 225 PB auto. factory every thing. Full restoration job.
Currently on hold till AP5 is on the road.

Hi there, is that the replacement for the first cam? I can't really comment on the figures, I'm reading it on my iPhone and .... Well eyes just aren't what they used to be! I do have a crane cam here that has advertised duration taken at .014" lift... What duration/ timing do you get at recommended lash settings? If you get stuck and the cam gurus think its no good for your application just let me know, I have a mild regrind that's had minimal use that your welcome to try, it's been sitting a while but only mild surface rust on journals that would polish out ok. Can't remember exact specs but basically a 20/60 grind, ran well in a stocker, if you want it let me know and I will mail it up to you. I also have a new crane, specs are in a previous post. Hope it helps, cheers

Gday Steve.
This is the replacement for the incorrect cam which was delivered.
this is the camshaft I originally asked for when ordering.
It is the mild replacement cam.

The measured specs for this cam are all reasonably close to those on the link I posted,except the inlet opening and closing points.
Duration at .050" is 200* very close to their spec of 198.
My main concern is the intake closing point.
Lash is to be at 0.010" on intake.
the inlet lobe closing measures @ 0.006" 97* ABDC.
allowing for rocker ratio of 1.5:1 should have the rocker tip at .009"lift .
This is .001 off the valve stem and the valve would be on the seat .

Putting 97* ABDC into the DCR calculator gives DCR of 5.65:1 !!(10:1 SCR)

Before ordering the cam
I worked out the Intake closing point from the specs on the website I linked before, (272* advertised duration. I assume @. 006")
This give a closing point at about 63* ABDC which in turn would give me a DCR of 8.1:1

As you can see, the difference between actual and advertised Intake closing points (34*) makes a huge difference to DCR
Unfortunately I have modified the oil holes on the cam at the rear journal to improve oil flow to the rockers, so a return may not be possible.
Tomorrow i will call the supplier and see what they say.
I may go with a re grind on this cam ,as the cam is close to what it needs to be.
If all else fails I may take you up on your offer.
I will let you know how I get on.
Thanks very much Steve.
Brendan.

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1963 AP5 Valiant 225 PB 904 Stock except extractors & 2 1/4 inch exhaust.


1962 S series valiant 225 PB auto. factory every thing. Full restoration job.
Currently on hold till AP5 is on the road.

It appears to me you haven't found the correct intake closing point. Using advertised duration on a mechanical cam without knowing the checking clearance is going to be near worthless. The KB Pistons calculators says for the intake closing point: "Intake Closing Point (Degrees)ABDC @ 0.050 lift +15 degrees"

http://kb-silvolite.com/calc.php?action=comp2

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Joshua

Hey Brendan, IF you decide the cam needs regrinding it may be worth taking it for a drive to Alstonville. Waggotts are up there these days, I emailed him the rv10 specs but haven't chased him up yet. They know their stuff but not sure how long it takes to get a job done these days, I think they are in a semi retirement mode. The site you linked seemed a little vague saying that specs may change with suppliers.... I hope you have a win there, it's been years since I have dealt with hemi bill but I never had a prob, but I only ever bought new parts from him. I have found Graham at blue star to be really good, but not sure if he's still around? Anyways good luck with it, I'm sure you will get it sorted. The other thing that springs to mind is how far you will need to back those tappett adjuster off with .160" removed, are they still tight? Maybe the reduced base circle on a regrind cam would work better? If you get a refund on your cam just get my old cam and get it reground... The offer is always there. Cheers, stay dry up there !

Post deleted due to me being an IDIOT!

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1963 AP5 Valiant 225 PB 904 Stock except extractors & 2 1/4 inch exhaust.


1962 S series valiant 225 PB auto. factory every thing. Full restoration job.
Currently on hold till AP5 is on the road.

Joshua wrote . You are entirely correct.
Now the cam looks ok.

I went out and measured the valve lift with the head on the engine .
put head on and put dial indicator on retainer.
.001 " valve lift opening @ 5*BTDC
.001" valve lift closing @40 ABDC
total duration 225*


max lift was .354" at about 107*
Im glad i worked this out now!
could have been more embarrasing i suppose
Now i have to work out where I went wrong.
Thanks for the help guys.

_________________
1963 AP5 Valiant 225 PB 904 Stock except extractors & 2 1/4 inch exhaust.


1962 S series valiant 225 PB auto. factory every thing. Full restoration job.
Currently on hold till AP5 is on the road.