Imported Pistons.

[CastleMGBV8]

Got a letter this morning to inform me that my Chevy Keith Black 305 pistons have cleared customs (5 days) and are ready for delivery, 8 days total from the USA.

Good news, no import duty just VAT and parcel force charge of £13.50

Summit seem to have undercharged me for the pistons and rings only £143.00 they quoted $343.00 including postage at say $1.9 to the pound = £180.00

So total cost including shipping and charges = £186.85 and I get a free hat!

That what I call a great deal, and I can now get on with getting the engine built.

Kevin.

[IainB]

I bought a couple of bits from the US a few days back.
They arrived within 3 days (quicker than a UK supplier I also bought something from) and they also put on the invoice, for evaluation purposes only so I didnt pay anything additional

[350matt]

Thats a good price, I tkae it these pistons are to go in a rover? If so what rods are you using and what bore size are they?
Finally are they strong / good quality so can be used under nitrous etc?
Ta

Matt

[CastleMGBV8]

They are Keith Black Hypereutectic pistons bore size, standard is 3.736" or 94.89mm. they have a .928 pin and require the Chevy rods to match.
I'm using the the Chevy 5.85" rod for my mix and match engine with77mm. stroke but I believe they are available in 5.7" which is only .004 longer than the Rover rod and should be ok subject to where the pistons come to at TDC in the bores. The compression height is 1.561" or 39.649mm.

They are suitable for racing and I believe nitrous use and run with very close tolerance of 2thou so give very good sealing to the cylinders.

You do have to run with a top ring gap of not less than 20thou because of the expansion of the rings, or you will experience seizing and top ring land damage.

If you need any more info just ask. I really need to know which engine you want to base this on to tell whether it can be made to work.

Kevin.

[350matt]

I'm considering rebuilding my TVR 4.3 pre-serp engine at some point so just to keep in the back of my mind what spec I'd need for a strong street engine without costing the earth.

Ta

Matt

[CastleMGBV8]

Matt,

The TVR 4.3 engine is I think basically a Rover 4.2 (4276cc.) with TVR mods and is not far from what I'm currently building.

The engine is really just a 3.9 with a 77mm stroke so you could use those pistons with the same Chevy heavy duty forged 5.85" rods. I got my rods from Paul at V8 tuner for £250.00 which includes ARP bolts which I think is a bargain.

The standard size Chevy 305 flat top piston with 5cc. valve cutouts KB143-8 will give you a capacity of 4355cc which is a useful bonus but with the rover heads you will probably need the dished version or your compression ratio will be too high.

Let me know if you want to do this and I will sort a spec sheet for you.

Kevin.

[350matt]

That would be great thanks, I take it the block would need liners fitting to get out the the 94.8 bore? Or will the std block take it?

Thanks agian

Matt

[CastleMGBV8]

Matt.

What is the car going to be used for?

As you already have virtually a 4.3 engine it may not be cost effective to go the same route I have.

My engine build was to a certain extent controlled by the use of Buick 300 heads which have large combustion chambers 54cc and I had to find a piston that would provide me with a sensible compression ratio.

There may be a more cost effective solution for your requirements.

Do you know what spec the current engine is, I think TVR did the 4.3 with mild or big valve heads, and are you using the Rover EFI as this limits what cam you can use, unless you upgrade the system with an aftermarket ECU.

Kevin.

[350matt]

Hello Kevin

The car will be used for fast road and trackdays. I'm planning to bin the rover Efi off for an Emerald ECU, as far as I'm aware the valve sizes are std SD1 but some porting has already happened.I've not had the heads off yet only manifolds. I'm planning to do some combustion chamber work to de-shroud valves and balance volumes and my current favourite cam would be a V8 Dev 'stealth' grind.
So I'm planning a CR increase to about 10.5:1 / 11:1 ish as I'm assuming it'll be std rover Cr at the moment but as its a TVR god only knows what I'll find when it comes apart....


Ta

Matt

[CastleMGBV8]

Matt,

I collected my pistons from parcel force today to save time and by coincdence the depot was just round the corner from the guy who is going to build my engine so popped in to let him know that we have got the pistons.

He's away for a week, back thurday week and is going to bore the block and do a test build to establish what additional machining is going to be required to make it all fit together properly I should have a full picture early the following week. If your not in a hurry I can come back to you with more accurate information.

The existing liners are fine for the piston I'm using, I checked with Wildcat and V8 Tuner who both confirmed that up to 1mm. was fine as long as the bore is properly centred.

I think you could also talk to V8 developments to see if there is a piston you can use with the standard rods which are perfectly ok even for racing,
this would save you doing all the additional machining work i'm having to do.

I'm also concerned that the Rover version of the engine had a compression ratio of 8.94/1 and I have a feeling that the TVR version must have had a higher compression than that, whether they milled the heads, decks or fitted a different piston I don't know and I dont think there is any one around you can ask at TVR! possibly one of the dealers with good tech knowledge could help.

Kevin.

[CastleMGBV8]

Matt.

Seems TVR Power is still alive, suggest you give them a call and try and get the spec on your engine.

http://www.tvrpower.co.uk/store_misc.php

Kevin.