What a day.. Martyn got the engine to Knight Services (http://www.knightracingservices.co.uk/) who prepare all of the top chevy Mosler/Vette/Sallen engines including RML's Le Mans winning car..
oh oh - I get a message to phone Martyn urgently this morning n the mobile... "bad news - low compression on cylinder #1" (70%) , other cylinders are fine but Martyn is the bearer of more bad newsa few hour slater once prognosis complete:
- The piston and liner in #1 are jammed
- #3 cylinder shows a damaged valve stem and bent valve
- Heads don't appear to be high compression
- No signs of anying boring/honing around the valves/bores
- Valve springs appear to be soft
- Carb jets to large and running rich
It's possible some of this may have occured from sitting around for the last 2yrs - On the plus side - no obvious wear on bores, good top end, good rockers, rods and steel crank but otherwise a "a very used, tired engined".. not exactly what I had paid for or intended to ship from Texas.. ??
Martyn suggests they replace the worn valves and put it back together and run it. I've then to phone back after another few hours.. Martyn comes back on the phone to say that the engine has put out a solid 420ish bhp and 400lbft down on the engine dyno (on pump fuel).. the shop are amazed given the engine face value but clearly it was doing something right.. all this from a 5.7l at only 6000rpm.. some 1400-1800rpm below expected peak!! Alas the soft springs and small carb thwarted any attempts to push the engine beyond 6000rpm..
Given at first we thought engine was scrap.. all respect to the old man for stripping and fixing..
Aye 420bhp is just dandy given cam was supposed to make peak power nearer 7400-7800 and given how peaky Martyn said it was then it might have ramped up quite a bit but both carb and springs were maxxed out so setting pill moduled to say 6800rpm or so to allow for downshifts should be fine. If you check normally crates then you need over 6 litres to get similiar and at 6500rpm (e.g. british american) so there's more to this engine that means the eye.
Martyn said there was 50bhp just in upgrading carb (I'm checking Ebay) - so that'd have been 477bhp and probably similiar + torque so around 440-450lbft which is a monster.
In fact Bary said he reckoned on about 380-410lbft at 5800rpm so 390lbft at 5000rpm makes me think the engine has more to give at the top end. Martyn said there's a pronounced drop-off mid-rpm (typical high left single cam engines) but then pops back in with a bang.
Then I'll find a nice phat 4-barrell carb or a small rotrex type charger (belt driven) and hook that up.. at current compression it'd probably be plug n play.. almost. I'm checking.. ;)400lbft handy also and at 5000rpm not to low down.. as is with the mini fly wtec then if it spools up quick then peak figures academic anyway.With everyting else sorted I reckon there's over 500 in there to come out which for a 5.7l is a lot.
As-is it's as good as a fresh TVR AJP4.2 or a high tune 5-6l Rover. Just means we need to make sure she comes in under the ton :) when she goes on the corner weights.
Lots I can then tweak myself long-term - play with flowed alloy heads, titanium springs, carbs etc.I reckon you'll also get a little more peak with that airbox set-up.In meantime output isn't so insane so I can get used to car before upping power.
I so want a LS7 stroker with quad down-draught throttle bodies...
