V8 engine performance mods

[Deleted User]

Malcom, is that 240hp  you calculated any where near your actual rwbhp?

[leylandracer]

Quoted from andythompson Talking of rolling roads and bhp figures... they mean very little... there is even a school of thought that reckons setting the mixture on a dyno will result in a lean mixture in real life as it is difficult to predict the effect of 100+ mph air on the inlet tract and under bonnet characteristics...



As they say .. the bullshit stops at the start line...

A wideband is the Dogs B-----s £250  best be safe then sorry regarding afr's, I have one in both the RX7 & TR7 (Looks impressive as well ;)) http://www.innovatemotorsports.com/products.php

[steve1365]

;D Just back from the nigh-on 500 mile round-trip (amid snow flurries) to pick up the engine from J.E. It certainly LOOKS powerful!  ;D

[Beans]

Well, lots of fun with it then, keep us posted  8)

There is one nagging thought in my mind though. In CCC magazine (sadly demised) and also in PPC magazine they were/are fairly sceptical about the high BHP figures from the Rover V8 often mentioned. A quote from Dave Walker in PPC from aug 2005 "even in 5-litre form these engines seldom make much more than 330 BHP"  ??)
I am not going to question the V8 engine or all the good work that's been done to it but shouldn't it be better to qoute torque figures for this engine instead, because that's where it really excels  ;)

[steve1365]

I'm not bothered too much about the bhp figure... it's not about "he who dies with the most bhp wins". If that was the issue I could have gone 4.6 or 5L for similar cost and easily got more bhp. I'll try and post the dyno figures but the graph is in a format that my computer won't read.

Steve

[leylandracer]

Sounds good Steve;-) Did you bother with the baffled sump?

[steve1365]

Yes, the sump is baffled...

[steve1365]

As it turns out, the baffled sump is longer than the original and won't clear the subframe by about an inch with the engine in normal position. Could move the engine back 2" like works rally cars but this is a real mission. Would have to shorten the prop and exhaust, move/modify gearlever and even have custom made tubular manifolds.

Solution is either to modify the sump or the subframe. Subframe now modified with a 1" channelled edge, all seamwelded and gussetted. Engine now dropped down into position... now back to the old "still can't close the bonnet" problem!

[Beans]

Quoted from steve ...now back to the old "still can't close the bonnet" problem!

No problem, very simple way to get a nice extra power bulge in the bonnet ...  ;D

[leylandracer]

Could you go a bit bigger with the subframe spacers Steve? think i have 22mm spacers on mine.
Just to add :-( Still no engine back from V8 Developments, Just got back from a weeks hols so hopfully there will/should be some good news tomorrow!!!

[stricky]

steve, what spec did you decide on from V8 developments?

[leylandracer]

5.0 litre with off set ground 86.36 crank, forged 96mm pistons, steel h section rods, stg4 big valve heads, h404 cam kit, 10.5-1 compression ratio-----------
Collecting it tomoz. 345 bhp on there dyno

[stricky]

bloody fantastic.......

I'm still sitting on the fence in terms of what to do with my V8 TR7, I've got a rebuilt 3.9 bottom end with a pair of V8 dev stage 3 heads sitting in the garage ready to go in but keep changing my mind.... I'm sort of thinking well in for a penny, in for a pound.

In real world performance terms what sort of 0-60  or 0-100 should 350bhp buy in a TR7/8?

[steve1365]

Just to clarify... there are 2 Steves here...both with cars in works colours! Steve (LeylandRacer) with 5 litre and Steve (Croydebay) with 3.5Litre....both recently rebuilt by JE Developments which should not be confused with any other JE V8 engine rebuilders!

[leylandracer]

Quoted from steve Just to clarify... there are 2 Steves here.......both recently rebuilt by JE Developments which should not be confused with any other JE V8 engine rebuilders!

Steve (Leylandracer) the 5.0 was built by V8 Developments ;)not JE Developments :) confusing stuff :)
Its been a long wait :( just hope the LT77 is up to it.

[leylandracer]

Quoted from stricky bloody fantastic.......



In real world performance terms what sort of 0-60  or 0-100 should 350bhp buy in a TR7/8?

Ill let you know soon ??) i should be taking it to york dragway if not this month next, got a BIT of comp from our lad in his Renault GT Turbo ( He's got me taking it down south to BB Tuning for a set-up on Saturday, should be around 220 bhp but its very light) i would hope to be in the low 13's i managed a 13.8 last year with about -60bhp on the old set-up, traction is a prob :'( i had to use a 2nd gear start then

[leylandracer]

http://www.york-raceway.co.uk/

[stricky]

cheers steve (leyland racer )  ;) make sure you let u know what 350bhp feels like in the 7.......I'm just trying to justify spending the dosh on the V8 rather than giving up and shelling out for a TVR...............thanks

cheers steve (croyde-bay) I suppose it can be a bit confusing, been an avid fan following your rebuild on your web site for ages btw.

[leylandracer]

Steve, Just had a look on your www, Weber DCO 50's? If u dont mind me asking. what size chokes are u using

[steve1365]

The engine was put together and set up by John Eales. The engine is still not fully installed and has not yet been fired up. I havn't chased JE for exact breakdown of  the spec as yet so the quick answer is, I don't know!

As I am no mechanic, the plan was a turnkey, plug and play engine but it hasn't turned out as simple as it would seem. I also insisted that for the sake of originality, the original block be used. The weber 40's couldn't cope with over 250bhp but JE had some 50's they kindly sold me. Actually when you see the price asked for these new, they did me a good deal on them...drove me way over budget though.

I had planned to have the car pretty much finished by the end of the latest website update but it's obviously not read the script. I am very pleased to have had the chance to improve the engine bay strengthening and of course I can't wait to get the car back on the road. Less than 3 yrs on the road in the last 16yrs since a bought it!

Steve

[Beans]

Are you talking about 4 weber DCOE50 carburators on a 3.5 litre V8 ...  :o
You are talking about 0.44 lt/cylinder here. I hope your engine remains a bit tractable with these, because the bigger the carb, the slower the airspeed, the lower the torque! I am really interested in the choke size.

't Kreng runs on two 45 DCOE with 34 chokes and 0.50 lt/cylinder and that is at the edge off tractability, but than she revs to 7000 in the lower gears if need be.

[steve1365]

I'll let you know spec and drivability once it's running.

[leylandracer]

John Eales is no mug Steve. Its just that when i was going through with the quad conversion on the 4.6 i asked his advice re; carb sizes (at the time i had the option of 45's and 48's) JE's advice was 48's with 42mm chokes, the carbs caused nothing but problems up until the rolling road prob with no one able to get them 100%, i ended up with 38mm chokes but even then the feeling was that the 48's should have been 45's, im hoping that with the recent engine rebuild and upgrades that all will be well.
Should have the engine in next week, so time will tell, Still a bit worried though;-( V8 Developments did say the carbs will want tweeking, which is understanderble, but i didnt like how they kept making a point of it saying that they have set them rich, this was the prob last year:-(. They had both the 38 and 42 mm chokes there to try, they ended up using the 38's even though the engines much higher spec now, ILL LET YOU KNOW :-)

[leylandracer]

The carbs on mine are 48DCOSP's x 4

[steve1365]

Everybody I spoke to recommended him without hesitation and since building V8 engines is way beyond my area of expertise, I followed their advice. Time will tell I'm sure but I have every confidence... at the moment!