IHRA Engine Blueprint Specs ????

[BillK]

Hey guys,
Am I just being blind, or does IHRA not have blueprint specs on thier website like NHRA does ???

[Chris1529]

use NHRA specs except for Crate motors which are listed on IHRA. A few other exceptions as well such as can run an automatic in a car that originally was manual only, some different carbs allowed, etc. If you have a question about a specific spec, call them.

[442OLDS]

Originally Posted by Chris1529

use NHRA specs except for Crate motors which are listed on IHRA. A few other exceptions as well such as can run an automatic in a car that originally was manual only, some different carbs allowed, etc. If you have a question about a specific spec, call them.

Thats not really true according to the IHRA rulebook.

Super Stock connecting rods are legal in Stock Eliminator in IHRA.Not so in NHRA.

[Chris1529]

Since NHRA publishes a list of acceptable stock/superstock replacement rods, I figure most professional engine builders go with one that is on the list for a given combination.

If someone builds two identical engines, with the exception of stock legal rods in one, and superstock legal rods in the other, how much performance gain could be expected?

[Mike Carr]

Maybe try this. I haven't looked at it all, but it might offer some help.

http://www.ihra.com/ClassRacing/

http://www.ihra.com/CompetitionGeneral/

http://www.ihra.com/ContactUs/

[442OLDS]

Originally Posted by Chris1529

Since NHRA publishes a list of acceptable stock/superstock replacement rods, I figure most professional engine builders go with one that is on the list for a given combination.

If someone builds two identical engines, with the exception of stock legal rods in one, and superstock legal rods in the other, how much performance gain could be expected?

Its not just the rods,its also the pistons:

Only the top (combustion chamber side) of the piston has to "LOOK" correct when viewed from an assembled short block. The dish/dome still have to measure correct. They dont care what it is like below the deck (moved rings, thinner ring pack, lite pins, lite pistons, valve relief location and depth, etc.).


Performance gain?

I would think the IHRA car could beat the NHRA car in a heads up!

[Chris1529]

This is just my guess, but I figure the majority of people building or running a regular stocker in IHRA can or do run it in NHRA as well. I don't think there are too many purpose built IHRA regular stockers.

[Lew Silverman]

Originally Posted by 442OLDS

Its not just the rods,its also the pistons:

Only the top (combustion chamber side) of the piston has to "LOOK" correct when viewed from an assembled short block. The dish/dome still have to measure correct. They don't care what it is like below the deck (moved rings, thinner ring pack, lite pins, lite pistons, valve relief location and depth, etc.).

Maybe I'm missing something here, but part of the engine specifications are piston, piston ring and pin weights. So other than having a certified replacement piston (published by manufacturer/part number) as listed in the guide, you can't modify them, at least in Stock Eliminator.

Lew