Engine Rebuild! Options? Mods? Advice Please.........
Engine Rebuild! Options? Mods? Advice Please.........
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Discussion

TVR Thunder

Original Poster:

274 posts

259 months

Friday 11th June 2010
quotequote all
Hi Folks!

Im removing the engine from the Chim 500 next week and sending it off to a very capable (and very reasonably priced!) RV8 Engine builder up in Morray (N Scotland). The Main bearings are failing and extremely noisy! (sounds like a bag of spanners!).

Prior to this happening, the engine has been very good over 5 years of ownership (MAF failed once).
if you look at my profile you will see a list of Mods, basically a Bosch MAF, larger injectors, MA Chip and RR set-up. with 100K on the engine. Although I think the Cam was getting tired.
She used to pull from 1000RPM, no lumpiness, flat spots etc all.


My question is, What are my options for Cam choice, stage of tune for the heads, oil pump upgrades etc? or, even build for low compression with the option of a 100BHP NOS Kit for later?

Any thoughts or tried and tested recommendations would be appreciated.

Many thanks!
Ian




pwd95

8,459 posts

269 months

Friday 11th June 2010
quotequote all
In your position I'd be either going for a high quality bottom end + a wild cam so that it revs its nuts off to make bin numbers or have it built with an SC conversion in mind.

Wildfire

9,951 posts

283 months

Friday 11th June 2010
quotequote all
As per usual, it's as deep as your pockets are. But good upgrades would be:

ACT smooth bore induction
ACT trumpets
ACT Y-Piece
V8 Developments stage 3 heads.

Most people tend to go for the Kent 218 or MC1 Cam as they offer good road manners. I think you could probably go with a 214, stealth or MC2 (if they still do it).

Or get an Emerald, Omex or suchlike, fit an H404 and map the hell out of it to improve the low end manners.

spend

12,581 posts

282 months

Friday 11th June 2010
quotequote all
Wildfire said:
...V8 Developments stage 3 heads....
Are they an improvement over his 500 heads?


markreilly

795 posts

203 months

Friday 11th June 2010
quotequote all
pwd95 said:
In your position I'd be either going for a high quality bottom end + a wild cam so that it revs its nuts off to make bin numbers or have it built with an SC conversion in mind.
+1

roysum

961 posts

220 months

Friday 11th June 2010
quotequote all
Wildfire said:
As per usual, it's as deep as your pockets are. But good upgrades would be:

ACT smooth bore induction
ACT trumpets
ACT Y-Piece
V8 Developments stage 3 heads.

Most people tend to go for the Kent 218 or MC1 Cam as they offer good road manners. I think you could probably go with a 214, stealth or MC2 (if they still do it).

Or get an Emerald, Omex or suchlike, fit an H404 and map the hell out of it to improve the low end manners.
Quite agree, and I'll be quite willing to take the existing heads off his hands !

Edited by roysum on Saturday 12th June 09:59

TVR Thunder

Original Poster:

274 posts

259 months

Friday 11th June 2010
quotequote all
HHmmm,

I do want a solid bottom end as I'm a bit concerend as thats what has failed (religious oil changes every 6 months by me too!. ans with the Larger and less resitictive Bosh MAF, and larger Bosch Injectors , smooth bore pipe & performance air-filter already fitted. Does it lend itself to a wilder Cam? with higher staged heads for better air-flow?

I take it my Mark Adams RR set-up ECU chip willthen need to be set-up again for whatever state of build I go for?

I have one off "Resonator" boxes (similar to the cherry bomb conversion) too.

Pockets arent deep enough for a SC conversion! but can stretch for a NOS set-up later?

thanks guys!

Markh

2,781 posts

306 months

Friday 11th June 2010
quotequote all
TVR Thunder said:
Hi Folks!

Im removing the engine from the Chim 500 next week and sending it off to a very capable (and very reasonably priced!) RV8 Engine builder up in Morray (N Scotland). The Main bearings are failing and extremely noisy! (sounds like a bag of spanners!).

Prior to this happening, the engine has been very good over 5 years of ownership (MAF failed once).
if you look at my profile you will see a list of Mods, basically a Bosch MAF, larger injectors, MA Chip and RR set-up. with 100K on the engine. Although I think the Cam was getting tired.
She used to pull from 1000RPM, no lumpiness, flat spots etc all.


My question is, What are my options for Cam choice, stage of tune for the heads, oil pump upgrades etc? or, even build for low compression with the option of a 100BHP NOS Kit for later?

Any thoughts or tried and tested recommendations would be appreciated.

Many thanks!

my money would be on the 'Stealth' cam from Rob at V8D
Ian

slideways

4,101 posts

252 months

Saturday 12th June 2010
quotequote all
spend said:
Wildfire said:
...V8 Developments stage 3 heads....
Are they an improvement over his 500 heads?
Dave, when I bought mine I asked how good they were and was told they were a good improvement on 500 heads!

spend

12,581 posts

282 months

Saturday 12th June 2010
quotequote all
They might well work better than 500 heads on a 400 Richard wink You also need high compression & a big cam (read pocketed pistons) to get the best out of them, they are probably just over the top spec-wise for a base engine?

V8D also do stage 4 (UBV in RV8 parlance?) heads IIRC which should be more comparable to TVR BV heads but tickling the 500 guides down would cost an awful lot less for much the same result IMHO.

Markh

2,781 posts

306 months

Saturday 12th June 2010
quotequote all
This is just my opion but the is olny one (I have tried two other well know bulders defore hand)TVR V8 engine builder, Jamie Rogers (Castle Race Engines), he built my 500 engine 368 bhp, very strong and totally tractable, the guy is a genius

TVR Thunder

Original Poster:

274 posts

259 months

Thursday 12th May 2011
quotequote all
Hi Folks!

Been a long time since I first posted this! Finally got around to having the Engine rebuilt, during this time I have kept busy with a chassis & engine bay clean & re-furb. Nearly ready to re-fit.

I decided not to modify the engine further, following investigations by the Engineer as quoted in his report below. Apolgies for the length!

To re-build TVR 5.0 Engine, diagnose source of knocking noise.

Having carefully measured every detail of Knock was traced to a broken crankshaft, fractured across No.8 big end journal. some coolant found in No. 8 cylinder, suspect engine hydraulic locked whilst cranking, causing crank failure. Coolant is thought to have seeped past the head gasket with coolant system pressurized when engine was last switched off.

No damage apparent to block, pistons or con-rods. Camshaft found to be worn, replaced with a TVR 885 unit. Crank replaced using a TVR 500 Crank, along with followers adj timing gears & valve springs. All other parts replaced (rings, shells, gaskets, main head stud sets,& all seals). 2 rocker arms also replaced due to broken pads.

composite cylinder head & inlet manifold gaskets fitted, main bearing & cylinder head bolts replaced with ARP high-tensile studs.

REMARKS:

"having carefully measured every detail of this engines internals, it transpires that this is a 5.2 litre engine, not a 5.0 litre as originally thought. (TVR used 2 different crank strokes, 90mm & 94mm)

The engine number traces historically to a 3.9 litre Morgan +8 unit of 9.35:1 compression ratio. Obviously this block has been as part of a previous rebuild with TVR internals.

This engine currently calculates as 5218cc, with a compression ratio of 11.2:1. The actual dynamic c.r. will be lower due to valve overlap period, however I advise the use of an Octane Booster!"


Engine Build Data:

Engine No. 47A07154B
Block: STD 3.9 with increased web clearance
Crank journals: Main STD size H.D. bearings, Big-ends STD size H.D. bearings
Main Bearing fixings: ARP stud kit
Camshaft: TVR 885
Followers: STD
Cam drive: Chain, Steel ADJ.
Cylinder bores: STD bore, cross hatch honed
Pistons: unconfirmed, suspect TVR. pocketed.
Con Rods: TVR
Head Gaskets: Composite McCord Permatorque
Head fixings: ARP Stud kit
Inlet manifold gasket: Composite
Valves: Inlet : TVR Big-Valve
Exhaust: TVR Big-Valve
Valve Springs: TVR twin assemblies
Head Castings: Ported & Flowed
Oil Pump: STD



It was reported that the heads are "heaily worked" and also the inlet manifolds opened up and matched to the ACT carbon trumpets etc. I decided not to "upgrade" further with a wilder Cam, as the car already has a Bosch AFM, larger Bosch injectors, ACT carbon trumpets, smooth induction kit & heat wrap. also was subject to a MA Rolling road set-up with these mods by the previous owner.

I plan now to get the engine installed and running properly before a trip to the rollers.

All this work cost a little more than I had planned (the Crank = Ouch!!).

I'm curious about it being a 5.2, and destined for a Morgan + 8? any comments by those more knowledgeable? or any comments on the above in general?

Thanks!
Ian.

Edited by TVR Thunder on Thursday 12th May 14:30

v8 racing

2,064 posts

282 months

Thursday 12th May 2011
quotequote all
But a tvr 500 crank is a 90mm stroke? so if yours was a 94 which i cant see the rods and pistons wont be any use now, i think maybe crossed wires somewhere between the engine builder and yourself, also as quinny has said if it really has got over 11-1 espiecially with an 885 cam you will be getting into detonation problems