Quench height of standard 500 engine

[dnb]

What is the usual quench height of a standard 500 engine? If it makes any difference I'd prefer MY1996. Just trying to sanity check something. I'd measure mine, but it's not exactly standard any more...

Thanks

[EGB]

Quench ht "???????????????????????????????

[spend]

piston-head clearance, but Dave's obviously been reading Yanky articles / catalogues

[dnb]

Got it in one. And squish is a silly word...

[Aussie John]

"If the pistons are hitting the head then just rev it! I'm sure some clearance will appear from somewhere!!! [How is the rebuild going then?]

[dnb]

LOL. The rebuild is going reasonably well. It's been a bit difficult to find time to spend on it, but then that's normal. The bottom end is back together. (only a little non-standard now ) Just waiting on head work now.

I wanted to compare the quench heights of the old and new builds for the sake of sanity, but I lost the scrap of paper I wrote the old measurement down on.

[carsy]

Come on whats none standard about this bottom end.

Have you got some of these beauties in it.

http://www.v8tuner.co.uk/product.php?id=874

[dnb]

I might have

Edited by dnb on Monday 17th March 18:49

[spend]

Where should the valve reliefs go?

[carsy]

Good work Dave. What do you reckon CR wise using these then. Slightly more or slightly less. All things being equal.

Edited by carsy on Monday 17th March 19:55

[ctsdave]

If it helps, the pistons on the racer (wildcat 6" rods and kb pistons using modded 4.6 crank) sit flush with the top of the block. Wildcat supplied the hg (cant remember its thickness) and we run about 11.5:1 comp ratio.

Dave

[spitfire4v8]

crikey did you use a 1200 grit honing stone ?

[dnb]

spend said:

Where should the valve reliefs go?

I'd have thought they were best put in the pistons.

TVR Power say the top in case you were asking if I'd put them in upside down... (Yes, I did put one in upside down )
http://www.tvrpower.co.uk/machining/slug/rover-v8-...

[dnb]

carsy said:

Good work Dave. What do you reckon CR wise using these then. Slightly more or slightly less. All things being equal.

The block has been skimmed along with the bananas (I hope they'll turn back in to heads) so CR will be up on last time. Depending on head gasket choice, CR will be 11:1 dead or 10.85 So a bit more than I had last time with the tin HG & standard pistons.

spitfire4v8 said:

crikey did you use a 1200 grit honing stone ?

It's going to be bling on the inside too It's amazing how different things look to a camera under LED lights.

[spend]

dnb said:

spend said:

Where should the valve reliefs go?

I'd have thought they were best put in the pistons.

TVR Power say the top in case you were asking if I'd put them in upside down... (Yes, I did put one in upside down )
http://www.tvrpower.co.uk/machining/slug/rover-v8-...

No they're the right way up, but just don't look right for your valves, can't make out whether too small or angles wrong or camera/perspective...

Blue a valve & check with bare heads slotted on. A lot of pistons seem to be tight on valve relief size for the TVR valve sizes.

You also have to go round with cam & valves installed to check valve piston clearance, when decking / raising CR. If you have time its also worth making a spreadsheet of how much clearance you have vs crank angle for if you ever want a custom cam IMHO (& if you want to shave any margins close cross checking all 8 just for safety).

[TVR Beaver]

spitfire4v8 said:

crikey did you use a 1200 grit honing stone ?

are you saying it looks too rough or too light?.. it looks very smooth to me .. who did it?

[dnb]

I checked the valves and they are fine for size. Not measured depth with a head on yet but it's fine for my current cam. Rest assured all the checks you suggest have either been done or are on the list!

The block work was V8 Developments

[dnb]

Looks like the shininess of the photo is making it difficult to see the details.

[dnb]

Answering the original question yields an interesting result (rather than getting distracted by shiny things )

The original pistons sat 30 thou down the bore, so the squish clearance on a standard head would be huge at approx 80 thou using a standard TVR head gasket. So when I changed the cam last time (6 years ago ) and put in a thin gasket, the squish clearance moved to 48 thou (1.2mm) - a much more sane number, but still larger than one might like...

[carsy]

Any update on this re build Dave.