I always see so many discussions on Forged vs. Cast cranks.When was the last time any of us ever seen a cast crank break.I,ve seen afew but most of these were in race motors and were beaten on run after run.You aint gonna break it on the street, cause most street valve trains will probably peak in the 6,000 range and that 400 cast crank is about as safe as anything out there.Remember,the true killer of any crank is a poor balance job and the rods are as strong as any big block chevy.I'd jump on that deal faster than Micheal jackson was jumping on McCulley Caulkan.Glen
Joined: Mon Oct 10 2005, 10:45PM
Location: Lansing MI
Posts: 513
Am I correct that the lower compression engine will also be happier with lower octane gas? This seems logical, and since putting the 452 heads on my 383 it seems to run fine on midgrade (and there is a chain of stations here that sells 89 and 87 for the same price )
True Dan. The higher compession, the more likely you are to experience preignition. Which is why higher compression engines like the higher octanes. The higher octanes should really only be used to offset preignition. You can typically go up to about 10.5 compression and still get away with pump 91 octane. Not sure what the limit would be for 87.
Is the 89 you are talking about E10? or another ethanol blend? Nothing wrong with ethanol, a buddy and I have been kicking around the idea of converting a slant 6 car and brewing our own! The thing to watch on the older cars is the higher alcohol content can be rough on 30 yr old rubber seals and lines. Keep an eye out if you have any original rubber in the fuel system. Although 10% my not be a larger enough amount to cause any immediate impact.
I know of a dude who's runnin cast 9.5 to 1 flat tops in the high 11s.We all know it's just a matter of time.He,s only going to run flat top forged next time also, as the flame pattern is near perfect.When you unshroud the valves and polish the chambers this will help with detonation also.Change them "slugs" and you got a good basic motor.These 400s were underated and that themoquad is an added bonus.Most T-Qs were thrown out because of 2 O-rings that would fail,but us who knew about this problem can only give them "praise".Glen
Checked one of them Hollander books last nite,still not knowing the correct year,according to the book 72 was the first year for the 400, and was rated at 255 net hp.Now keep in mind that in the book 71 was the transitional year going from gross to net hp.and with a few of the big blocks I compared ther was about a 45 hp decrease.So for those of us who like the comfort of the BIG numbers,that would have been 300 hp. Now doesn t that make us all feel better?(specially me).FYI,225-6 rated at 175 gross and 105 net.Also I found that in 72 or 73 the 440 was rated at a whopping 225 net,30 less than the 400.Go figure.Got to get me one of dem books,Pronto Kimosabie.