4.2 Speed 6 upgrade

[yzf1070]

Just got off the blower with Dave at TVRCraft and he is now offering a 4.2 speed 6 upgrade.
4.2 speed six engine (capacity is exactly 4200cc)
J.E forged pistons
New conrods
New bearings
New oil pump
Engine assembly fully balanced and assembled as a short engine £2920 + vat

Obviously this won't include their head mods.

It should offer an increase in torque and may appeal to those with engines that have suffered piston damage or anyone who is thinking of a bottom end rebuild anyway.

Regards
G

[350matt]

Interesting....

So is it getting possible to build up a speed six without using any of the TVR recipricating or roundy round bits?

Matt

[yzf1070]

For my rebuild they replaced every internal component except the water and scavenge pump and the numerous chain wheels, but yes they can supply all parts independantly and to their spec.

Cheers

G

[the pits]

Wow exciting news! Any word on power and torque figures yet?

Depending on how the tuscan goes after being properly run-in, I'm planning to 'enhance' the car's performance in some way. This could give me another and perhaps better option.

cool.

[_deejay_]

It'll be interesting to see how this performs. Didn't TVR use a 4.2 in the Le Mans cars (they certainly did in the grey t440)?

[dvs_dave]

yzf1070 said:

Just got off the blower with Dave at TVRCraft and he is now offering a 4.2 speed 6 upgrade.
4.2 speed six engine (capacity is exactly 4200cc)
J.E forged pistons
New conrods
New bearings
New oil pump
Engine assembly fully balanced and assembled as a short engine £2920 + vat

Obviously this won't include their head mods.

It should offer an increase in torque and may appeal to those with engines that have suffered piston damage or anyone who is thinking of a bottom end rebuild anyway.

Regards
G

So how much would it be including the head mods? 7k ish?

[yzf1070]

For the full top end rework including new cams as well, I reckon your in the right ball park with that figure.

G

[HarryW]

Is that a billet crank too, at less than £3k fitted it does seem a bargain considering it has forged pistons etc, I would have thought the parts would cost that alone tbh.
As already alluded to I think unless you already have the modified top end then it would be prudent to factor that in too.
If the lot can be done for £7k then it is a way to go, just think a knackered Tuscan is worth what..less than £10k ....add this engine...whey hey a stonkingly strong 4.2 Tuscan with loads of Torque for £17k .

[Steve_T]

I read that differently Harry. To me it reads that your upgrade your engine from 4.0 spec and return it to you as a 4.2 short engine is ~£3k + VAT. For a drive in drive out type approach it would presumably cost some more to uninstall and re-install the engine. Am I wrong? I'm with you that it'd be surprising to find a billet crank installed for that price - after all they must be a four figure sum on their own at retail prices.

Steve.

Edited by Steve_T on Friday 17th November 10:52

[HarryW]

Ah I see thought it was a good price .
I'd be interested to know what the turn key price was (drive in drive out price) as this is what most people, including me, relate too .

[hollowpockets]

guess it would be 10k+ for the full thing drive in and out and VAT, would there be a way of doing it through a business and claiming back VAT.

[yzf1070]

For those who have asked, I contacted Dave and requested more detailed pricing for full engine and he gave me the following:

Short engine includes
new liners
j.e forged pistons
piston rings
new forged properly balanced conrods with a.r.p rod bolts
new big ends and main bearings
new oil pump
assembly fully balanced

Stage one head
2x autocraft cams
24x mcd/autocrft followers
a.r.p head stud kit
copper head gasket
oil mod upgrade
cooling mod upgrade
plugs
magnecor ignition leads
oil and filter

full engine total cost £6750 + vat plus the installion costs

You must consider tho that just about every car they have done has had one or more of the following issues as well:

Failing Starter motor
Dangerous electrical wiring in engine bay (fire risk)
Collapsed or melted cat/s
Failing or failed clutch mechanism
Worn gearbox
Worn throttle bodies

[cymtriks]

Melling said that the stretch to 4.0 was a bad idea. Why is 4.2 OK?

[tail slide]

All depends on the quality/design of components used to achieve the larger capacity... at rather higher cost than would be viable as original spec

[_Deejay_]

tail slide said:

All depends on the quality/design of components used to achieve the larger capacity... at rather higher cost than would be viable as original spec

The cynic in me would say 'because it's a different design from the one he gave them and he was attempting to promote his specification'.

[yzf1070]

cymtriks said:

Melling said that the stretch to 4.0 was a bad idea. Why is 4.2 OK?

I don’t believe Melling said it was a bad idea, if I recall correctly what he said is that the AJP6 was optimally designed around a 3.6 ltr. He did say that the 4 ltr Speed 6 rod and piston make up was too heavy and created too much stress on the rods at high RPM. The 4 ltr is simply a stroked 3.6 ltr motor and therefore runs a different rod ratio (rod length / stroke of the crank = rod ratio). The 4.2 ltr is achieved by using larger liners and pistons, but the rods and pistons are much lighter and stronger components. By not messing with the rod ratio the 4.2, using the lighter components to keep the rotation mass down it should make a very torquey motor.

I have learned that at least some standard 3.6 ltr engines run 4 ltr cranks that have had the journals ground offset. Also the standard 4 ltr engines can come with 2 different rod lengths (tho not in the same engine of course...!).

Edited by yzf1070 on Sunday 26th November 01:39