So this is a build that was undertaken for a very good friend of mine. The original plan was to replace a blown headgasket over the weekend; but when the head was lifted, I didn't have the courage to just put a new gasket on and bolt the head back on. The sleeves seemed to have quite a few scratches and there was a huge build-up of black oil deposits in the head because the previous owner probably hated this car and didn't bother to service it.
The engine was taken out. The block was given a fresh 75.5mm bore. Since the stock VTEC shows its age now, there was no point in spending a good amount of money to take it back to stock condition. So a decision was taken to bump up the CR and do a budget high-comp build correctly.
Anyways, the new specs:
75.5mm bore
Stock 84.5mm stroke
New high compression pistons with matching connecting rods
A mild-moderate port and polish job done by me.
Stock cam and cam gear
AEM conical filter and intake
Honda standalone ECU tuned by me.
The resultant static CR stands at 10.6:1, as opposed to whatever the stock VTEC offered with its pistons. The new pistons sit flush with the deck. No need to use double head gaskets, shave the pistons or use deck plates LOL
The port job is currently in progress and should be completed during the next week if I have time to go away from my own car that is being prepped for the drags in April. The porting is being done keeping in mind certain facts about Mumbai roads and the need to preserve low-end torque while still flowing well enough to compliment the higher compression nature of the engine. The rest of the internals are kept stock currently because my idea was to build a reliable high-comp motor within a small budget.
However, the groundwork has been done along with a solid bottom end that is enough to make good power in NA which is what the friend in question desires to stick with for now. The next "stage", if you will, should involve a better flowing intake manifold, a nice cam suitable for the street and better headers to start with.
The engine has been built pretty much and should be bolted on by the next weekend. The running in will start after that and will last for around 1000 km after which the standalone will be street tuned with my wideband and knock sensing hardware and reading spark plugs. Until then, a revlimit of around 3k RPM will be set and a conservative fuel/ign map will be created to make sure the run-in goes well. The ECU will be tuned once the running in is complete and should allow the engine to run properly on pump fuel. A small part of the fuel/ign map will be reserved for lean-burn which will allow the engine to cruise at around 2-2.5K RPM/100-120 kph while returning a mileage of around 18-20kmpl. This is being done because the car is regularly taken on outstation trips where the highways are good enough to cruise at said RPMs for most of the journey. I'm very much looking forward to the tuning stage since that's when the motor will show its real character.
Pictures of the engine internals are with my friend and I'll be asking him to either post here (he's a member too) or send them over to me.
For now, a money shot taken a few hours ago.
First startup video will be posted probably during the next weekend. If all goes well, the car should be taking part in the drags next time around.