So, after much deliberation and saving, I have decided to try my hand at converting my 157 000 mile 3.2 Carrera motor to 3.5 N/A motor with mild cams & twin plugs. I am hoping to get close to 280hp at the crank on 93 octane pump gas in Dallas Tx.
It is quite possible I'm going to get chewed up on this forum for what Im about to say, but Im trying to do this as inexpensively as possible.
The reason I am writing about the build, is because I need help on my approach to the project. I am a rookie and I dont know, what I dont know. So I am running blind down this very expensive road. I have been preparing for this for 2 years and feel I might be ready for the plunge. This cost saving theme will be an important one for me as I need to make my budget go as far as possible, without making cheap decisions. A challenge, to be sure.
I plan to pull the motor and tranny. Send the tranny off to be rebuild. Send the engine parts out to be machined and have the heads worked on and then attempt to reassemble and reinstall again myself.
Im posting my progress and my thoughts here, because Im hoping to get some considerate input from friends who have gone down a similar road to prevent me from making avoidable mistakes. And I will need help sourcing the parts and machine work for the build. So if you are willing to be friendly and helpful - I would LOVE your input.
Engine plan- 3.5 Pistons & Cylinders
- Stronger bolts for conrods and heads
- 20/21 Web cams
- Dual plug heads and distributor
- SW Chip & enlarged throttle body
It all starts around the pistons and cylinders so after some reading and investigation I opted to give the QSC pistons and cylinders a try. I have noted that some regular contributors on our forums use their cylinders, but have opted for JE pistons. I decided to give the QSC P&C's set a try and measured the pistons and cylinders extensively when they arrived.
Pistons
I measured the pistons at the crown where the rings sit in a North-South & East-West measurement and then again at the skirt at the bottom of the pistons at the widest point. All Pistons measured between 99.69 to 99.73 on the upper N-S & E-W measurement.
The skirt measurements had a variance between 99.93 to 99.95.
All in all I think the tolerances are pretty reasonable. I was using a digital micrometer.
Manufacturer claims the compression ratio on factory heads is 11.2:1
I dont believe this to be accurate as much of the reading I have done on this forum shows me that claimed CR's and actual CR's OFTEN seem to vary.
My problem is, I dont know how close that number will be to reality and if it isnt, I dont know if it will get higher or lower in reality. Im also not sure how to measure it without a burette or more sophisticated tools.
Cylinders
I measured the cylinders N-S and E-W at the top and the bottom of the cylinders.
The top measurements ranged between 99.94 to 99.98 and the bottoms measured between 99.95 to 99.99 across all cylinders.
The build will spread out over the next few months and with your help, hopefully conclude in the spring.