4.3 to 5.7 budget build
05-22-2008 | 08:08 PM
#24
does anyone know how 853 heads will do with this combo? cam is still undecided. i have the stock 706s but, i figured the bigger combustion chamber from the 853s would be nice when we go to mill em.
05-30-2008 | 04:30 PM
#28
The 853's if I'm not mistaken are just your standard LS1 head, aren't they? Same as my 241's? They'll flow about the same as the stock 5.3L heads you had from idle-4000 but flow better after that to red line. The bigger intake valve over the 5.3L heads is a plus for breathing room up top as well. If you're using LS1 replacement pistons or something of the type, keep in mind your compression ratio will already be 10:1 with stock LS1 heads and stock replacement LS1 pistons. Mill them down a hair to clean up the heads and you'll be sitting just right. With my 5.7L I think the math came out to 10.3:1 compression and the right quench volume.
06-04-2008 | 07:14 PM
#30
I'm not even going to dance around this one. That camshaft is too aggressive.
Try this one for the maximum camshaft I'd stuff into the 5.7L if this truck will be driven on a regular basis. Remember less is more when picking out your camshaft. Changing the valve timing with cams and springs can only get you so far, if later on you need more power look into nitrous or forced induction.
http://store.summitracing.com/partde...1&autoview=sku
You're looking at a broader torque band instead of 3000-6800. Here you've got at least 1500-6800 with some form of manners at idle.
Try this one for the maximum camshaft I'd stuff into the 5.7L if this truck will be driven on a regular basis. Remember less is more when picking out your camshaft. Changing the valve timing with cams and springs can only get you so far, if later on you need more power look into nitrous or forced induction.
http://store.summitracing.com/partde...1&autoview=sku
You're looking at a broader torque band instead of 3000-6800. Here you've got at least 1500-6800 with some form of manners at idle.