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kiwi1955
05-17-2020, 07:42 PM
I'm looking to build a mid range cost 350-358 for my DLM here in NZ. Tracks are mainly 1/4 mile, flat, stop and go, slick come feature time. Weight of car increases with motor size, 350=2368lbs with driver, 377=2443, 415=2549 and so on. At 2368lbs my car has almost perfect LS and rear %.I was thinking a 4.00x3.50 combo, SHP block, Compstar LW crank and rods, AFR 195 or 210cc race heads, flat tappet. Compression is open, will run on alky. I don't see the need to turn it past 6800rpm. I'm looking more for low down torgue rather than horsepower. We get down to 2800 rpm in the corners. An engine builder has suggested I go with a 4.125x3.335 combo with AFR 235cc heads and roller everything. I understand this motor will make more horsepower but will it be more suited to what I am trying to achieve? I don't want to have the national debt tied up in this motor either.What are your thoughts on the best combination? Thanks in advance to anyone who takes the time to offer their advice.

billetbirdcage
05-18-2020, 02:49 PM
I'm looking to build a mid range cost 350-358 for my DLM here in NZ. Tracks are mainly 1/4 mile, flat, stop and go, slick come feature time. Weight of car increases with motor size, 350=2368lbs with driver, 377=2443, 415=2549 and so on. At 2368lbs my car has almost perfect LS and rear %.I was thinking a 4.00x3.50 combo, SHP block, Compstar LW crank and rods, AFR 195 or 210cc race heads, flat tappet. Compression is open, will run on alky. I don't see the need to turn it past 6800rpm. I'm looking more for low down torgue rather than horsepower. We get down to 2800 rpm in the corners. An engine builder has suggested I go with a 4.125x3.335 combo with AFR 235cc heads and roller everything. I understand this motor will make more horsepower but will it be more suited to what I am trying to achieve? I don't want to have the national debt tied up in this motor either.What are your thoughts on the best combination? Thanks in advance to anyone who takes the time to offer their advice.

Not sure about your engine rules, mostly what heads or what valve angles are legal over there but here is my opinion:

I would listen to the engine builder, I would want least 2000 to 3000 more RPM out of my engine if allowed by the rules. Obviously this costs more money to maintain and I'm not sure you need that power at that track. I personally wouldn't want a low RPM torque engine, it will be harder to hook up in the slick. I want to run the engine's corner RPM at or above the TQ peak, having it run a long ways below the torque peak is asking for wheel spin.

kiwi1955
05-18-2020, 03:45 PM
Our engine rules are steel block with ally 23 degree heads. Everything else is free.

perfconn
05-18-2020, 06:11 PM
Build an SHP block w/3.335 stroke,4.125 bore,Brodix Track 1 or Dart Pro 1 cnc ported 245cc heads.Never use a flat tappet if you can run a roller.The quality of parts depends on your budget.The stroke can vary according to whats available at a deal.Same as bore.How big you want to go(up to 4.185) is up to you.

Jking24
05-24-2020, 03:27 PM
I would build a full roller and i agree 100% with billet the afr stuff is good but their are better options at least in the states. If i were working off those rules i would build a 4.155 bore 3.28 or similar stroke with 200cc before porting heads and it would have valve train good for 8500+ abs like billet said it would turn that in the slick

Krooser
06-07-2020, 08:46 AM
Big bore first...then go to the stroke if you need more cubes. Roller cam. Don't be afraid of bigger heads.

I wish I had all these option with my engine combo.