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IMSA AMC Spirit
Posted: July 24th, 2015, 11:32 am
by adtarr
I just joined the board and hope to leverage the knowledge on here. I am about to start building a 232 inline six for vintage road racing. Here are some of the basic rules.
Overbore no more then .047
Stock stroke must be retained.
Internals are free.
Iron heads only.
Headers/intake free.
Based on that I have a 232 I am going to put a 4.0 head. For the internals other then a stock crank I have the Eagle Steel Rods and will use forged pistons.
I have a Clifford header and intake and will run a Holley 2300 500cfm two barrel. The heads will get better valves and Harland Sharp roller rockers. Also have an aluminum flywheel but not sure about which balancer to use.
I am not overly worried about max power or trying to win races. I want a reliable motor that can 5-6 races per year and be semi competitive.
I was told these engines can run up to 6000-6200 RPM. Can anyone provide advice on building the engine? Tips, tricks, or things to look for? Any advice is most welcome.
Thanks
Adam
Re: IMSA AMC Spirit
Posted: March 3rd, 2016, 12:43 pm
by amceaglesx4
You won't win any with the 500cfm holley . Put on a 287 cfm motor craft 2100 or 2150 with the 1.08 venturi. Your current barrels are too big. You will have a HUGE improvement in acceleration with the smaller carb. Night anf day throttle response. I have several if your interested.
Re: IMSA AMC Spirit
Posted: March 3rd, 2016, 12:46 pm
by amceaglesx4
Think I also have the 1.14 and 1.21 venturi models as well.
Re: IMSA AMC Spirit
Posted: March 3rd, 2016, 4:35 pm
by SIXPAK
adtarr wrote:I just joined the board and hope to leverage the knowledge on here. I am about to start building a 232 inline six for vintage road racing. Here are some of the basic rules.
Overbore no more then .047
Stock stroke must be retained.
Internals are free.
Iron heads only.
Headers/intake free.
Based on that I have a 232 I am going to put a 4.0 head. For the internals other then a stock crank I have the Eagle Steel Rods and will use forged pistons.
I have a Clifford header and intake and will run a Holley 2300 500cfm two barrel. The heads will get better valves and Harland Sharp roller rockers. Also have an aluminum flywheel but not sure about which balancer to use.
I am not overly worried about max power or trying to win races. I want a reliable motor that can 5-6 races per year and be semi competitive.
I was told these engines can run up to 6000-6200 RPM. Can anyone provide advice on building the engine? Tips, tricks, or things to look for? Any advice is most welcome.
Thanks
Adam
If it were me I would try this. Use the 232 crank in a 4.0 block. The 4.0 is a 3.88 stock bore compared to the 232 being 3.750 bore. This will give you just a shade over 248 inches. Your Clifford intake will not line up with the ports on the 4.0 UNLESS it was bought for a 4.0 which they do sell. The header will need some mods also if it was for a 232/258. As far as carbs, I think the 500 cfm holley will be a good choice. But thats just my opinion for what its worth.
Re: IMSA AMC Spirit
Posted: March 3rd, 2016, 5:00 pm
by SIXPAK
On your pistons try a nice flat top with appropriate valve reliefs. Go with a good durable wrist pin as well. Cam wise, try something in a 240-ish at .050. No real need to go much over .500 lift unless you plan on some head work. A good valve job and some bowl work will serve you well. If you are going to spend money on any one item for me it would be a quality rocker arms. I have zero experience with the factory stamped rockers but I do know some poeple that have welled a brace across the top from side to side then have them cryoed. Of course that will only work if you go with a hyd cam but I would go with a solid instead.
I guess most of your motor plans will start with a budget, then concentrate on making a durable powerplant to maximize fun!