GT-R Register - Official Nissan Skyline and GTR Owners Club forum - View Single Post - If money was no object

seve7 · 21st July 2008, 09:47 PM

little known project in the late 60s at chrysler was the doomsday project. no, im not joking thats the actual name. its was a 426ci hemi with dohc per bank. rumors are it made 800+hp in the neighborhood of 9000rpm in street trim. this was the next big engine that didnt make it to nascar after hemis were banned and the gas crunch started to hit.

no doubt the jap engines are great, but the problem with them lies in the rod bearing and main bearing area. theres just not enough bearing area. hell even on the nitro coupe hemis there isnt enough area, aluminum rods are used not because they are light, but because the aluminum is soft enough to act as a slight shock absorber. same with the main bearings, they are made out of a softer metal to absorb some shock. and as far as i know, i think this is the current limiting factor on the super high horsepower supras in the states they make so much cylinder pressure they are blowing the oil out of the bearings. also the main caps are enormous on these engines very deep and cross bolted, way larger than on any jap engine i've seen. although one thing i do like about jap engines is on the ones i have worked on they all have an main girdle instead of caps.

one very over looked engine is the quad 4 from gm, it was a dohc 4 cylinder found in some very mundane cars from gm in the late 80s/early 90s, but i believe oldsmobile set the 4 cylinder land speed record with it somewhere around 280mph. iirc a few of these 4cylinders went over 1000hp.

i dont know how much you guys have heard about gm's new ls9 v8 for the zr1 corvette. but i think its in the neighborhood of 635hp from 6.2L i think it even gets roughly 25mpg on the highway. all while expecting 100k mile reliability. which is a lot, i know on all the turbo jap engines i've rebuilt they all seemed pretty tired 80 with basically nothing left of the cylinder hone, and well as piston rings that are trashed. imo the 4g63 was the worst offender. the toyotas werent bad, but were also on their way out. other than a few teething problems when the new genIII gm v8s came out, there is no engine that even comes close with keeping a cylinder hone in good condition. no joke i've taken apart ls1's with over 100k on them apart to find an almost new looking hone still in the block.

21st July 2008, 09:47 PM	#147 (permalink)
seve7 GTR Register Member Join Date: Jul 2008 Posts: 20	little known project in the late 60s at chrysler was the doomsday project. no, im not joking thats the actual name. its was a 426ci hemi with dohc per bank. rumors are it made 800+hp in the neighborhood of 9000rpm in street trim. this was the next big engine that didnt make it to nascar after hemis were banned and the gas crunch started to hit. no doubt the jap engines are great, but the problem with them lies in the rod bearing and main bearing area. theres just not enough bearing area. hell even on the nitro coupe hemis there isnt enough area, aluminum rods are used not because they are light, but because the aluminum is soft enough to act as a slight shock absorber. same with the main bearings, they are made out of a softer metal to absorb some shock. and as far as i know, i think this is the current limiting factor on the super high horsepower supras in the states they make so much cylinder pressure they are blowing the oil out of the bearings. also the main caps are enormous on these engines very deep and cross bolted, way larger than on any jap engine i've seen. although one thing i do like about jap engines is on the ones i have worked on they all have an main girdle instead of caps. one very over looked engine is the quad 4 from gm, it was a dohc 4 cylinder found in some very mundane cars from gm in the late 80s/early 90s, but i believe oldsmobile set the 4 cylinder land speed record with it somewhere around 280mph. iirc a few of these 4cylinders went over 1000hp. i dont know how much you guys have heard about gm's new ls9 v8 for the zr1 corvette. but i think its in the neighborhood of 635hp from 6.2L i think it even gets roughly 25mpg on the highway. all while expecting 100k mile reliability. which is a lot, i know on all the turbo jap engines i've rebuilt they all seemed pretty tired 80 with basically nothing left of the cylinder hone, and well as piston rings that are trashed. imo the 4g63 was the worst offender. the toyotas werent bad, but were also on their way out. other than a few teething problems when the new genIII gm v8s came out, there is no engine that even comes close with keeping a cylinder hone in good condition. no joke i've taken apart ls1's with over 100k on them apart to find an almost new looking hone still in the block.