RV8 inlet manifold

[number 7]

Been thinking about the possible benefits of a 45mm trumpet set (steel / ally not trick CF) with suitable mods to the inlet manifold. Now I know that several companies offer these items, but am I right in thinking that its only the entries to each of the tracts that is opened out to suit the larger trumpets? To open out each of the tracts for their entire length would presumably be very time consuming because of the convoluted shape – and I’m not sure if there’s enough material to do that anyway. Anyone have any experience of this?

Thanks.

7.

[mongoose]

When i bought mine from v8d,i was told that only half needs doing,as tvr have already done the other half.I'm guessing its just opening out and matching the ports that tvr do,then you need to do the top to match to the larger trumpets?

[Wildfire]

Best off talking to ACT about this as they have a lot of experience in this area.

[350matt]

only the top half of the manifold port needs opening out to meet the trumpet and give a taper from it, the best design for intake ports is to have a taper along most of it in any case. In any case there not enough mateial in rover manifold to open it out along its length

Matt

[mongoose]

Wildfire said:

Best off talking to ACT about this as they have a lot of experience in this area.

No where near as much experience as the likes of v8d or john eales etc for sure.I always think its better to go to those that specialise,as they will know all the pro's and cons and give sound advice.Act sell a varied range of products,for a varied range of applications,many of which they share with other suppliers and or do not/cannot develop themselves.

[number 7]

Very informative pics. Quinny. Always makes me smile when I see the std. 500 trumpets - or should I say exhaust pipes

It looks like your modified base is slightly larger than 45mm, but I assume the trumpets themselves are tapered (not including the flare at the top). Does the 98mm dimension include the flare?

As far as the manifold goes, if I've understood correctly, other than opening out each end of each runner to suit the trumpet base and head, all that you've done to the central portion of the runners is to polish them ?

I assume that yours is a 500 - what difference did you find these changes made to the engine characteristics?

Seems like it will be the way to go for me, but I just need to figure out the best means of achieving it.Thanks.

7.

[number 7]

Quinny said:

(old 2 stroke tuner) .

Ahh..... brings back memories of my old Yam. LC......the whiff of two stroke oil and the ring- a-ding- ding of a set of Allspeeds.

Quinny said:

Anyway I'm pleased with the ACT trumpet base, I've no idea what it contributes to power output, but my engine is making just over 300 bhp at the flywheel and has a really smooth power curve, so I'd like to think its contributing to that in some way.

Mines now very close to that, and I'm hoping that this will help a bit more.

Thanks again.

7.

[antonyj]

This for your 4.3 Paul?

[number 7]

antonyj said:

This for your 4.3 Paul?

Yep. Did you speak to JE?

7.

[2 sheds]

mongoose said:

Wildfire said: Best off talking to ACT about this as they have a lot of experience in this area. No where near as much experience as the likes of v8d or john eales etc for sure.I always think its better to go to those that specialise,as they will know all the pro's and cons and give sound advice.Act sell a varied range of products,for a varied range of applications,many of which they share with other suppliers and or do not/cannot develop themselves.

Clarification:

ACT are trumpet specialists we have 6 different types for the RV8 alone alloy & CF. We currently produce around 150-200 per month for various cars/ engine builders/ teams, with our own tooling facility and unlimited dyno use, we only use carbon fibre when we can't easily get the required shape in alloy.

ACT don't do any manifold porting, we "farm out" to V8 Developments as Paul who does this could probably do it with his eyes shut, we have a good working relationship with V8 Developments and JE, TVR Power etc, we would always recommend their engine building facilities.

The TVR 500 manifold is ported to 44mm and fully opened at the head port area, i would call this stage 1 porting, stage 2 which is offered by V8 Developments, TVR Power, Lund engines etc involves porting right through the bend and taking out to 45mm at the top there would be a small gain from this.

TVR 4.0L and post 93' 4.5 manifolds are as standard Landrover.

[number 7]

Thanks Tim - I didn't know there were so many to chose from. I'll call you to discuss the options.

7.