stroked small blocks in the race cars?

[olddog]

Considering that they were able to get 450 Hp out of the 289, and they were doing this by porting the cast iron heads, going to a longer stroke 327ish engine would likely not make any more power. It would likely just make the same Hp at a lower rpm. Since the 289 was standing up well to the rpms they were turning them, there was no need to do this and the rules of the day may have limited them to the factory displacement. Had there been a need for more displacement, those engines would be everywhere. A research item here or there makes sense. You have to always be looking for an advantage.

This is just an observation and a personal opinion. I could be wrong and have been several times.

[PDUB]

Originally Posted by olddog

Considering that they were able to get 450 Hp out of the 289, and they were doing this by porting the cast iron heads, going to a longer stroke 327ish engine would likely not make any more power. It would likely just make the same Hp at a lower rpm. Since the 289 was standing up well to the rpms they were turning them, there was no need to do this and the rules of the day may have limited them to the factory displacement. Had there been a need for more displacement, those engines would be everywhere. A research item here or there makes sense. You have to always be looking for an advantage.

This is just an observation and a personal opinion. I could be wrong and have been several times.

While modern technology makes it available now, 450Hp is more than I had heard before from a 289 back in the day. It seems I recall Brent doing one in that range, recently. I thought it was more in the 340-350Hp range, which I've heard said by those in the know to be optimistic. Isn't the 289 head a limiting factor in getting to that power level - even with aggressive porting? That would be awesome, if it was not at 7000rpm. Maybe Brent can chime in here...

[1795]

Brent has been able to pull about 450 HP from a 289. Mine with aftermarket iron heads was able to pull 424 HP at 6500 rpms, and still had 420 HP at 7,000. I have heard of one engine builder claiming 585 HP at 8,000 rpm in a 289 that was using iron heads to be vintage race legal. Not quite sure what he is doing to obtain those numbers. One thing that he is doing is using a Dart iron block. The engine builder that I brought mine too for a refreshing was amazed that I was getting the power that I was with a block from 1965. His opinion was that I was exceeding the strength of the block and that sooner or later it would break.

I never heard of the original 289 cobras obtaining HP in the 400 range, as Ed said it was more in the 375-390 HP range. I am going to be switching to a Dart iron block to ensure engine longevity, it is better suited to road racing applications given the more stout design, better oiling and cooling, and the casting is new, as opposed to 55 years old. The downside is that the Dart block is about 35 lbs heavier than the original block.

Jim

[blykins]

Solid roller lifters fail earlier because of a combination of higher spring pressure and lash. Lash causes the lifter to bounce off the lobe.