Which engine upgrade route ?

[steve-v8s]

I have a 42k 98 Griff and feel the engine is not quite as it should be. It sounds fine ticks over smoothly and starts well. I just feel it may be a bit down on power and runs out of steam a bit early. So what to do ? Have done plugs, plug leads, coil, induction pipe, but still not happy. If being super critical it may sound just a touch camy particularly when hot, so I suspect a cam lobe or lifters. Usually I do things myself and wondered about buying a cam kit, solid lifters one of the various induction kits, bigger injectors, throwing it all on the car and then taking it along to a knowledgeable person to set it up. But the idea of handing over some cash and not getting my hands dirty does appeal, provided it is worth the money, but were do I go. The TVR Power route seems quite appealing because they work on the whole engine rather than just getting the fuel in, however. I have no concerns about the bottom end so is that actually best left alone on a “if its not broke don’t fix it”basis.

I sort of asked this question before but are you Griff / Chim owners who are keeping the tuning companies wealthy, happy with what you got ? and which route do you recommend ? I understand that getting more power requires getting more fuel in along with obviously the appropriate amount of cold air. So the big injector, AFM, Trumpets, set up argument does seem valid but will someone who is happy with the result please say so.

[bluebottle]

Hi steve.

I have just got my car back after a total engine rebuild, which started out as a "Oh thats your camshaft sir". As they started to test inspect and strip the engine down it was in a pretty poor state despite having a full service from a reputable TVR dealership 2 months previously and getting a clean bill of health.
Botom line is have the engine checked over before embarking on an upgrade path to ensure you are starting with a good lump.
The compression leak down test they did on my engine was pretty depressing. It does seem to be good indicator of engine condition as they were able to diagnose most of the faults from that one test. as it not only tell them the compressions but also if you have leaks (in my case past exhaust valves on 3 ports and past the piston rings on 2).

[geoffvalenti]

While I normal subscribe to the "if it aint broke, don't fix it" school of thought, when trying to get more power from an (already tired) engine, it is not always the best policy.

You need a firm foundation to work on when trying to forced an already fairly highly stressed engine to produce even more power.
IME just dealing with the "top end" issues to help breathing, and mapping to suit, will only bring to light any hitherto unknown problems with the bottom end

Far better to plan a systematic rebuild with all components selected for the expected power output, than to maybe waste money on a short lived power gain, only to have to fully rebuild the engine when it finally gives up the ghost

[trackcar]

Agree on all the advice so far.

In fact reconditioned engines are such good value for money that it'd be very unwise not to get it done.

For instance about 18 months ago I got a 4 litre chimaera engine done by v8 developments : 8 top hat liners, new rings, reground crank and shells and new camshaft/followers all built and ready to install for 1600 pounds. Absolutely the bargain of the century, all I had to do was take it out and reinstall it .. dead easy for you at home if you're handy with the spanners.

This then gives you a very good base for adding anything else you might like .. choose your cam spec during the rebuild anyway, and get any other goodies put in place by the reconditioner.

Top banana. I unreservedly recommend v8 developments, they were stunning for me.

[jellison]

Waste of time unless you have HUGE pockets to tune RV8 - hey are reasonably quick.

Best leave alone or go NUTS! Go blowing Ferrari off - but an RV8 that can do this will be 12-15k just for the engine.

[Guillotine]

flog the std engine (2-3k) and buy a tweaked unit.

as trackcar says, a modified V8D unit can be VERY good value.

net cost? about 2-2.5K, tuning will gain you 25bhp for this money...IF your lump can do it!

worked for me

but had already done the Tuning bit anyway!!!

andy
monster

[Boosted Ls1]

Steve, get a compression check done for all the cylinders and post the results Then we can discuss options or repairs.

Boosted.

[Steve-V8s]

OK it was suggested that I do a compression test so as to decide what tuning route to take. And the results in Psi are below. I am calling the left hand front as 1, RH front as 2 and so on

1 165 2 180
3 180 4 180
5 180 6 170
7 180 8 180

So what does that tell me ? I guess either the bore or rings are not as good on 1 or it has a leaky valve compared to the others. Any comments anybody ? Being hyper critical the engine sounds just a little “cammy” particularly when hot but I can’t see how that goes with the compression test results.

Currently I am veering towards the TVR Power route, which should give me at least a good base on which do additional work.

[GreenV8S]

They all look great, #1 seems typical and if anything the others are a little higher than I'd expect. Nothing there that indicates a problem.

[Guillotine]

Look OK to me to.

10% rule.

andy

[geoffvalenti]

I wouldn't be pulling mine apart with compressions like that