Value of tuned engine?

[DAMO666]

I've got a mate who is considering stripping a zxr400l race bike and he was wondering what the engine might be worth, it's 75ish bhp with recent dyno print-out.

[mark400]

Might get £500, might make £100...Depends on how many hours since the refresh, who refreshed / built the motor, if it has kit cams / sp carbs / sp gearbox etc...Having the reciepts and maybe some results history might help.
We have just had a motor fully refreshed including new pistons by a very popular zxr race specialist, we paid about £1700. A complete build from scratch can cost double, but I also have a motor that was fully refreshed last year, but has now done enough hours for me not to want to use it in its current state, as it will pop at any moment. If I got £500 quid for it, I would be made up!!

[Geffro]

How often should you refresh/rebuild a race engine?

[cargo]

one race before it blows up

[mark400]

Cargo - EXCELLENT answer !

[rmkd177]

I.M.O..
It will depend on what people call a refresh? Some people 'mark400' ....feel in neccesary to take it to the letter and judging by his bill he must have alot of new parts in there...and that is his perogative.
Personaly i feel 400 racing must be kept cheap and do my best to use parts that are still within there service limits...i measure and check and use my experience to judge what new parts are neccesary...and which parts 'will go to the moon' mileage wise..
Our main race bike has 1989 h2 pistons in and hasnt had a set of rings in...in four seasons of racing and last time on the dyno made just short of 81 bhp and hasnt had a mechanical DNF in the last two seasons.
e.g I never ever fit new valve stem seals.
Always fit a new cam chain
Always check valve clearances regularly, and take note of them before a strip and rebuild..this give the best indication
of the condition of the valves and can save the 'engine wrecking dropped valve' senario.
Always check the valve timing regularly..as the cam chain wears it retards the valve timing slightly and reduces the
'exhaust valve' drop...which again can lead to a 'dropped valve'
Many many more things that need looking at throughly...these little bikes can be as reliable as the day they were made and on a budget...even at 16,100rpm if set up rite from the off and checked and service regularly.
The 'base gasget removed' always put a smile on my face...as a tuning mod...and there is really alot more to it than just pulling it out and sealing it with instant gasget...it can actually have the reverse effect and cause crank problems..
Anywys...Refresh? or rebuild ? it will depend what you have to spend and how it is approached.

[Geffro]

I.M.O..
It will depend on what people call a refresh? Some people 'mark400' ....feel in neccesary to take it to the letter and judging by his bill he must have alot of new parts in there...and that is his perogative.
Personaly i feel 400 racing must be kept cheap and do my best to use parts that are still within there service limits...i measure and check and use my experience to judge what new parts are neccesary...and which parts 'will go to the moon' mileage wise..
Our main race bike has 1989 h2 pistons in and hasnt had a set of rings in...in four seasons of racing and last time on the dyno made just short of 81 bhp and hasnt had a mechanical DNF in the last two seasons.
e.g I never ever fit new valve stem seals.
Always fit a new cam chain
Always check valve clearances regularly, and take note of them before a strip and rebuild..this give the best indication
of the condition of the valves and can save the 'engine wrecking dropped valve' senario.
Always check the valve timing regularly..as the cam chain wears it retards the valve timing slightly and reduces the
'exhaust valve' drop...which again can lead to a 'dropped valve'
Many many more things that need looking at throughly...these little bikes can be as reliable as the day they were made and on a budget...even at 16,100rpm if set up rite from the off and checked and service regularly.
The 'base gasget removed' always put a smile on my face...as a tuning mod...and there is really alot more to it than than just pulling it out and sealing it with instant gasget...it can actually have the reverse effect and cause crank problems..
Anywys...Refresh? or rebuild ? it will depend what you have to spend and how it is approached.

Thanks very much mate! Have you got a big waiting list now for refreshing engines, considering getting mine done as the person I bought it of has no idea how long ago it was done as he bought it for trackdays & only used it once. Thanks again!

Lachie

[mark400]

On reflection, our £1700 bill was more of a rebuild than refresh !

The engine had a holed piston, so a fair bit more work was required. We also took the complete bike with engine still fitted, and had it dyno'ed and set up, which was all included in the bill, as was a fair bit of work on the carbs as they were about 15 years old and only ever had the main jets changed once. From memory, also changed were the cam chain,tensioner & slipper and a camshaft