β€œMerlin F85” heads for the Rover V8 from Real Steel

β€œMerlin F85” heads for the Rover V8 from Real Steel

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Discussion

ChimpOnGas

9,637 posts

138 months

Friday 12th December 2014
quotequote all
v8bloke said:
My Merlin heads sold on Ebay for £716 which I think was a bargain.
Here is a pic of my new 5.0L engine with TA heads. Nearly ready for fitting back in the MGB.


Hoping to make over 400bhp
What cam are you using?

I would imagine valve timing is critical to getting the best from the TA heads, and my guess is there's nothing off the shelf that will come close to being suitable.

If you make 80hp per litre you've brought the old Rover V8 up to modern Chevy LS power levels.

That's impressive, but how much do a set of TA heads cost?



v8bloke

255 posts

170 months

Friday 12th December 2014
quotequote all
I am using a (conservative) 248 mechanical cam with 0.533 thou of lift.
To be honest I am more interested in how it drives than chasing meaningless numbers.
Including tax they were £3.5k so not exactly cheap.

Cheers
Mark

ChimpOnGas

9,637 posts

138 months

Friday 12th December 2014
quotequote all
v8bloke said:
I am using a (conservative) 248 mechanical cam with 0.533 thou of lift.
Thanks, just wondered as I hear they flow way better than the best Tuscan race heads.

v8bloke said:
To be honest I am more interested in how it drives than chasing meaningless numbers.
Good man, too many people chase numbers and end up with a car that drives like a pig, you can make good figures on carbs at WOT but that's meaningless when it's craap everywhere else.

v8bloke said:
Including tax they were £3.5k so not exactly cheap.Cheers Mark
Thanks Mark, I guess there's valve gear & manifolds on top of that too?

phazed

19,244 posts

163 months

Saturday 13th December 2014
quotequote all
What do you think your 5.0 will make?

spend

12,581 posts

210 months

Saturday 13th December 2014
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[quote=v8bloke...Hoping to make over 400bhp
[/quote]
Did you read that bit Peter, or is it all getting too much for an old fart like you hehe

Is the offset on the exhaust valve - pushrod as big as the picture makes it look from the rocker arms? Looks to me like inclined/staggered rocker arms might be a better design when the valve centre is shifted so much (which I thought they used on the V6 originals)?

phazed

19,244 posts

163 months

Saturday 13th December 2014
quotequote all
spend said:
Did you read that bit Peter, or is it all getting too much for an old fart like you hehe

Is the offset on the exhaust valve - pushrod as big as the picture makes it look from the rocker arms? Looks to me like inclined/staggered rocker arms might be a better design when the valve centre is shifted so much (which I thought they used on the V6 originals)?
Thanks Dave, it was late. !

v8bloke

255 posts

170 months

Saturday 13th December 2014
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The price included the very nice quality shaft mounted roller rockers.

v8bloke

255 posts

170 months

Monday 9th February 2015
quotequote all
Rolling road info. 429bhp @6500rpm 390 lb ft torque. 380bhp at wheels.
Result!

ChimpOnGas

9,637 posts

138 months

Monday 9th February 2015
quotequote all
v8bloke said:
Rolling road info. 429bhp @6500rpm 390 lb ft torque. 380bhp at wheels.
Result!
My god that's bonkers bow

DonkeyApple

38,954 posts

128 months

Monday 9th February 2015
quotequote all
Wow. Fantastic numbers. Well and truly into the LS2/3 ballpark.

Any feel yet as to how smooth it drives or has it been built for top end delivery?

Well done. You must be over the moon.

Chuffmeister

3,597 posts

96 months

Monday 9th February 2015
quotequote all
v8bloke said:
Rolling road info. 429bhp @6500rpm 390 lb ft torque. 380bhp at wheels.
Result!
yikessmokin

v8bloke

255 posts

170 months

Monday 9th February 2015
quotequote all
Havent got it back yet. I will post the dyno sheet when I have it.
First track day is on 10th march at Silverstone grand prix track.

Slow M

2,581 posts

165 months

Monday 23rd February 2015
quotequote all
v8bloke said:
Rolling road info. 429bhp @6500rpm 390 lb ft torque. 380bhp at wheels.
Result!
Nice results! Congratulations.

Best regards,
Bernard.

Else

Original Poster:

781 posts

197 months

Monday 20th April 2015
quotequote all
Hi all, didn't quite make my target 400bhp & 400lbs/ft, got to 373bhp & 395ft/lbs on Joolz dyno.

My inlet manifold set up seems to be working well, the throttle bodies are too big though, no increase in power above approx 70% open so I might look to source some 65 or 70mm versions but not desperate to change it cos it drives so nicely. Pulls cleanly from 1000rpm right up to 6000rpm

Next I'm going to redesign the exhaust, make it less restrictive especially where it splits into 2 just before the silencer. Joolz thought that part was a poor design and could be improved. Not sure how I'm going to do it but would like to incorporate a motorised valve so that I can switch between quiet (silenced) and loud (straight through).

Got a couple of annoying oil leaks to try and cure on the engine but Rob is on it, prob leave it till the winter, they're not bad enough to worry about.

Else

phazed

19,244 posts

163 months

Monday 20th April 2015
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That's interesting Andy.

Joolz thought exactly the same with my 5.5 on a triple plenum.

Nothing over about 80% throttle so assumed my big valve stage 4 heads and ported manifold were the restriction.

You have the same BHP as near as dam it but about 50 less torque, maybe that's down to the extra 300 ccs scratchchin

Can you put up a graph?

Else

Original Poster:

781 posts

197 months

Monday 20th April 2015
quotequote all

Else

Original Poster:

781 posts

197 months

Monday 20th April 2015
quotequote all
Hi Peter, As you can see the torque rises pretty rapidly at around 2000 rpm and stays fairly level until about 5000rpm which makes for a nice flexible engine on the road. would have been nice to break into the 400 bhp/ft/lbs target but i am happy with it as it is at the moment. Fuel economy is poor at around 15mpg but i am resisting the temptation to play around with the mapping as Joolz made such a good job of it.

Just going to enjoy driving it around for the summer then maybe tinker a bit once winter comes.

Else

phazed

19,244 posts

163 months

Monday 20th April 2015
quotequote all
Thanks for that, always good to compare and see what gives what.

Your power band extends a little further which is what I would like.

My mpg is similar to yours. If I drive like Miss Daisy I can achieve 22 on a motorway!

Here's mine for reference.

The lower figures are my old 4.6 iirc.


Else

Original Poster:

781 posts

197 months

Monday 20th April 2015
quotequote all
Thanks Peter,

I'll have to find out what cam Rob fitted, all i know is that its hydraulic.

Andy

phazed

19,244 posts

163 months

Monday 20th April 2015
quotequote all
Else said:
Thanks Peter,

I'll have to find out what cam Rob fitted, all i know is that its hydraulic.

Andy
Mine was an H404, the power was slightly more.

That graph is the solid 404 which is fitted now, it reduced power slightly but increased torque!