X overthrottle Boddies

[Slow M]

MPoxon said:

That exhaust system looks too good!

Best regards,
Bernard.

[77racing]

Ok , Sorry its taking a little time to get sorted Xmas , new year and life in general have got in the way but I had a dyno run done yesterday to see what we were starting from to see what difference the new build will give us. This engine is a challenge engine 4.5lt, still with dizzy and 48 Quad Delorto Carbs, heavily ported head, old school as it was in 1989. It looks to be spot on and a strong engine. we are building a 4.8lt new build engine to put the cross over throttle bodies on and are just about to blend / match the manifold to the heads before we put the heads on the new engine. It took an age to get crank back from tuffriding. I will update a little later once engine is in the car, saying that hopefully before first race on April 17th fingers crossed.

379.6BHP and 345.8lbft

DSC_0726 by flat chat, on Flickr

Edited by 77racing on Friday 31st March 19:21

[spitfire4v8]

this is what I'm currently playing about with for my racer perry. Your 4.5 is as good as my 5litre top end but better mid range already. I hope that playing about with inlet lengths will get me some extra midrange.
Not as pretty as the JE x-over but this is only for development and will have cost me under 200 pounds start to finish tosee if it's worth pursuing.

[rev-erend]

spitfire4v8 said:

this is what I'm currently playing about with for my racer perry. Your 4.5 is as good as my 5litre top end but better mid range already. I hope that playing about with inlet lengths will get me some extra midrange.
Not as pretty as the JE x-over but this is only for development and will have cost me under 200 pounds start to finish tosee if it's worth pursuing.

Looks good.

What are you thinking of doing for the TB. Big single on the front ?

What about injectors ?

[Bluebottle]

I recently saw my RS6 inlet manifold in pieces and it got me thinking...has anyone tried a similar idea on the RV8 using the whole of the valley as a plenum chamber?

[spitfire4v8]

Injectors might go in airboxes to begin with, it's a race car project not road car, but if i need them closer to the ports they can go horizontally under the intake. Ive ditched the idea of trying to re-use the rover injector rail. One throttle on the front of each airbox.
Hopefully x-over manifold power (though not emissions or driveability, it's still basically a plenum chamber set up without ITBs) for 1/10th the cost.

[MPoxon]

77racing said:

Ok , Sorry its taking a little time to get sorted Xmas , new year and life in general have got in the way but I had a dyno run done yesterday to see what we were starting from to see what difference the new build will give us. This engine is a challenge engine 4.5lt, still with dizzy and 48 Quad Delorto Carbs, heavily ported head, old school as it was in 1989. It looks to be spot on and a strong engine. we are building a 4.8lt new build engine to put the cross over throttle bodies on and are just about to blend / match the manifold to the heads before we put the heads on the new engine. It took an age to get crank back from tuffriding. I will update a little later once engine is in the car, saying that hopefully before first race on April 17th fingers crossed.

379.6BHP and 345.8lbft

Those original 4.5 challenge engines are proper pieces of kit and very rare now especially with the 48 quad Delorto carbs. The old girl still pushing out an awful lot of power as well, really impressive. Do you know what cam you have in the 4.5?

I will be following with interest regarding your crossover ITBs. That is not going to be an easy target to beat!

[rev-erend]

MPoxon said:

Those original 4.5 challenge engines are proper pieces of kit and very rare now especially with the 48 quad Delorto carbs. The old girl still pushing out an awful lot of power as well, really impressive. Do you know what cam you have in the 4.5?

I will be following with interest regarding your crossover ITBs. That is not going to be an easy target to beat!

I believe the challenge 4.5 RV8 engines ran a 256 mechanical lifter cam.

[77racing]

MPoxon said:

Do you know what cam you have in the 4.5?

I am running a 248 at present, more for the torque than willy waving, as that don't win races. I will let you know what cam in the new engine shortly.

[MPoxon]

77racing said:

I am running a 248 at present, more for the torque than willy waving, as that don't win races. I will let you know what cam in the new engine shortly.

The torque was the main reason for me asking, it has a lovely flat torque band which normally means tame cam but clearly not tame with those figures!

What is it about those challenge engines that allows them to develop so much power and torque? Looks like a really sweet engine that.

Very interested to see how the 4.8 goes. I was thinking of an Eales 5.2 engine with H234 cam and those throttle bodies, I think your challenge engine is pushing out more power though

Could you use the 4.5 Challenge engine on the road or is the drivability and MPG to prohibitive?

[rev-erend]

spitfire4v8 said:

Injectors might go in airboxes to begin with, it's a race car project not road car, but if i need them closer to the ports they can go horizontally under the intake. Ive ditched the idea of trying to re-use the rover injector rail. One throttle on the front of each airbox.
Hopefully x-over manifold power (though not emissions or driveability, it's still basically a plenum chamber set up without ITBs) for 1/10th the cost.

What are you doing about a thermostat /head water flow to rad.

JE does a fairly cheap remote stat assembly that already has water temp / ecu water temp fan controller sensors.

[77racing]

MPoxon said:

The torque was the main reason for me asking, it has a lovely flat torque band which normally means tame cam but clearly not tame with those figures!

What is it about those challenge engines that allows them to develop so much power and torque? Looks like a really sweet engine that.

Very interested to see how the 4.8 goes. I was thinking of an Eales 5.2 engine with H234 cam and those throttle bodies, I think your challenge engine is pushing out more power though

Could you use the 4.5 Challenge engine on the road or is the drivability and MPG to prohibitive?

Good Morning M,
A very good question that is not that easy to answer. "The sum of all parts" springs to mind as to how a challenge Rover Tuscan gets to be a quick car, not forgetting a very talented driver to steer it .As it is the engine you are concerned with I will try not to waffle off subject. Seams like a lot of things TVR, there is a Vail of mysterious mist hanging over the challenge engine. It is just a Rover V8 after all and nothing too complicated about it. Saying that. I'm no engine builder, that's why I take my idea's to a chap down my way who is not very respected on here by a lot of people, but who I think is the most talented engineer I have met. So point one is if you don't have the skill, a very good engine builder (If only to build in reliability) is a must, he or she don't have to be TVR specific, none specific means cheaper labour rates I find.
So to the engine and these are only my thoughts on my challenge engine. Take a Range Rover HSE cross bolted block, add top hat liners, Tuffride the crank, Take the heads to a mate of mine and spend £650 getting them ported to within an inch of there life, Get him to Top and tail the valves at the same time or use stainless wasted valves, add roller rockers, (I am looking at Chevy ones at the moment, could be cheaper than the usual) double vented rocker cover both sides, Put on a good matched to head manifold and throttle bodies of your choice or my favourite Quad Delorto 48 Carburettors, put in a M248 cam which is a competition cam but not the full race M256 which might have been the one of choice in the day. You wouldn't want a M256 in a road engine all power at top end but would be better for the pub sketch Tell my engine builder you want his cam timing added for torque.Breathing to the bodies or carbs is a personnel take and how much room you have, but as a start a cold air flow into a box or boxes is a good start, this bit is worth taking thought and time to think about where to take cold air from (hint) I prefer to take mine from a high pressure area most people don't mind where it comes from. Breathing is very important I think. I would get my exhaust chap to make up the manifolds adding in a spike but any half decent exhaust fabricator would know what to do. Again this manifold and indeed the rest of the exhaust is important. Exiting into low pressure air would be favourite I recon. So I would take the built engine and ancillaries in the car to my friend in my village who will then breath all over the package and set it all up on his rollers. He is the best setup/mapper I have ever met and luckily he lives three doors away from me. He also prepares my race cars and is very successful at it, although he specialises in rally cars with the Vauxhall red top in them. As you are probably thinking there has been a lot of thought gone into the parts of the whole, not just an off the shelf answer but it is only a Rover V8 you should see my chevy .

forgot to say, My engine would be great in a road car, it uses 1.1 litres of vpower a minute does that make it thirsty mpg?

Edited by 77racing on Saturday 23 January 10:46

[MPoxon]

Thank you very much for the detailed explanation. I think "sum of all parts" is a vey good way to sum it up. Yours is tuned for torque and righty so but the BHP figures are still hugely impressive, you would probably be knocking on the door of 400BHP if you tuned purely for BHP pub willy waving which is mad for what is essentially just a 4.5 Rover.

I love the idea of the M248 cam, I bet those Delorto carbs sing at 7k. I think realistically the MPG will be too prohibitive which is a shame as I know Andy Race always said his monster Griff engine was perfectly suitable for road use as well regarding low speed drivability, I think carbs / ITBs really solve the issue of a drivability with cam overlap compared to a plenum car.

I get a max of 21MPG at the moment, I know Peter (phased) gets roughly the same from his 5.5. I know Ian Rose said he was able to get into the 30s with his Eales 5.2 on throttle bodies which seems like a good blend of performance and economy, this might be the best route to go as I am trying to build a road focused car but also suitable on track, like a Griffith Club Sport. Having said that fuel is very cheap at the moment!

I have seen a few videos of your Chevy powered Tuscan. Looks amazing! I love the sequential box with auto blipping on the down change. epic.

Thanks again for the detailed reply, certainly some good points to consider there, in particular the head works and breathing.

Matthew

[77racing]

if you are interested in the JE 5.2 bottom end. I can post up the graph from my griff 5.2 which I used to use on the road and trackdays. just had one done as I plan on getting it back on the road in the next few weeks.Phazed will tell u how it goes, as he spent three years trying to get past it on track LOL

[eliot]

spitfire4v8 said:

this is what I'm currently playing about with for my racer perry. Your 4.5 is as good as my 5litre top end but better mid range already. I hope that playing about with inlet lengths will get me some extra midrange.
Not as pretty as the JE x-over but this is only for development and will have cost me under 200 pounds start to finish tosee if it's worth pursuing.

Those hoses might collapse under manifold vacuum.

[MPoxon]

77racing said:

if you are interested in the JE 5.2 bottom end. I can post up the graph from my griff 5.2 which I used to use on the road and trackdays. just had one done as I plan on getting it back on the road in the next few weeks.Phazed will tell u how it goes, as he spent three years trying to get past it on track LOL

LOL. So that was why he went for the 5.5 if you get some spare time this year you should join us for a few trackdays always a good laugh.

Yes please would be very interested in that if you wouldn't mind posting it up.

[77racing]

Morning Mathew,5.2 JE short engine with 5.0lt standard heads, ACT triple throttle body plenum and large AFM , h218 cam, rest standard 5.0lt stuff in my griff. 300BHP with 340.3lb/ft @ 3675rpm. I could get a lot more BHP and a bit more torque if I had the heads done, but to be honest this is a cracking car to drive as is.

[MPoxon]

77racing said:

Morning Mathew,5.2 JE short engine with 5.0lt standard heads, ACT triple throttle body plenum and large AFM , h218 cam, rest standard 5.0lt stuff in my griff. 300BHP with 340.3lb/ft @ 3675rpm. I could get a lot more BHP and a bit more torque if I had the heads done, but to be honest this is a cracking car to drive as is.

Thank you very much sir.

Looks like a very unstressed engine, I reckon it is chilled out on beach somewhere sipping a G&T. 5.2 with 300BHP, a little different to your 4.5 screamer with 370BHP!

You probably could get quite a lot more power out of that one without ruining the drivability but I 100% agree with you if it is cracking to drive then leave well alone, besides you have faster toys to play with if you need a speed fix.

[77racing]

Just a little update , I have been struggling to match the manifold to heads. We have had a lot of work to match up and we are having to dowel the manifold to heads so they go back on to the matched position when it is refitted as they will be off and on, no dought a fair amount. The bolt holes to heads have a lot of clearance hence the need for dowels. I was expecting some work but this is a fair bit more than I thought. Not sure this casting part suits itself to DIY. Still it is a one size fits all casting, so no complaints. Has anyone had to dowel their set up ? or indeed come up against this straight off. Just wondering if it varies casting to casting.

I am going to go 256 race/competition cam for that bit more power as I think torque will be well looked after.

Edited by 77racing on Thursday 18th February 09:42

[Slow M]

Why don't you just press (or epoxy) a couple of inserts into the manifolds' bolt holes? you could even offset drill them, if required.

Best regards,
Bernard.