Thanks, John, any and all comments are wlecome on this. Valve stem specs on the 327 show at .3407-.3412. On Evilebay there are Elgin manufactured valves with a stem size of .3415, undercut stem in the port area, swirl polished, stainless for about $80 for a full set of 194 and 160 or 194 and 150". Length is 4.905 compared to the Ramblers 4.892 and 4.899. The only variable I see is tip length and no mention is mad eof the 327's, Chevy valves carry a .250 tip length, Sounds pretty standard. I hope to delve into it deeper soon. -- Mark Price Morgantown, WV 1969 AMC Rambler, 4.0L, EFI, T-5 -------------- Original message ---------------------- From: "John Elle" <johnelle@xxxxxxxxx> > > > > SNIP > Isn't there a 1.55" chevy valve? Exhaust? Wouldnt' that fit > intake better? > Snip > > Seems to me that a few of the advantages to go with Chebby > valves on the later V-8s might and I re-emphasize might > cause I have not taken the time to look it up but would have > to or could if someone was interested is that the Chebby > valves are the right length so that they will fit into the > same space in the head/valve train components that the AMC > valve does. However there are two things that make them > better and one is that the are a bit smaller in diameter. > This requires that a valve guide be sleeved to neck it down > so it can be used. This is not unknown in head rebuilding > circles so not a problem. However internal to the port the > there is more room 'cause the valve stem is smaller so you > have in creased port size with out any further machine work > and also the valve is lighter making high rpm work more > efficient. Of course this does raise the question of how > tight you are going to twist an AMC 327 or so V8 or an I-6 > so that might just be a bit moot. > The second reason is the later V8's valve seat is ground > at a shallower angle than the Chebby valve seat. Later > V8's do not use a hardened valve seat, but the head is > induction hardened not needing a hardened valve seat so > when you regrind the valve seat to a Chebby size. The hole > in the head will be larger because you are steepening the > valve sea angle when you use a larger Chebby valve just > because you are regrinding the seat to Chebby specs. > Thus you have better breathing due to the use of a > larger valve. > However this advantage only becomes an advantage when > you are twisting the AMC327 or AMC I-6 tighter so if > you are not twisting it tighter I guess you can ask > yourself whether these are advantages after all! > The logical next question would be does the early V8 use > an induction hardened head and also does the I-6 in any > of it's permutations? > Smoke stated in his engine building dissertations that an > engine is an air pump. The amount of air you can get it > to pump is an indication of the amount of horse power it > will develop. > Thus there are two ways of getting your engine to pump > more air. Build it bigger or twist it tighter. Both > solutions may require a bit of a budget to accomplish > and on the street there is only so much rpm that is > useful, the rest is over kill. > My own experience building a street I6 is with using > an AMC-258 with a stock head and an Iskenderian cam. > It will do 75mph in passing gear and shift hard to > high. It is not as hot as the 225 Slant 6 I once built > but this one will pass smog with out any adjustments, the > slant 6 did not have too. In addition I am running a bit > over 9:1 Compression which is compatible with 91 Octane > high test. The Slant 6 needed 101 Octane to be happy and > it was available at the time and used 13:1 compression. > John. > > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: > http://www.amc-list.com/pipermail/amc-list/attachments/20070425/5e2a4c4e/attachm > ent.htm > _______________________________________________ > Amc-list mailing list > Amc-list@xxxxxxxxxxxx > http://www.amc-list.com/mailman/listinfo/amc-list _______________________________________________ Amc-list mailing list Amc-list@xxxxxxxxxxxx http://www.amc-list.com/mailman/listinfo/amc-list