Does anyone know where I can get the stock 292ci straight six specs in a bit of a hurry please? Can't find my L.Santucci book anywhere I want to see whether my motor has been worked on before. The measurements I took yesterday are: Bore: 3.875" Rod Journals: 2.100" Main journals: 2.300" I think the bores are stock, but what about the crank? All looks to be in pretty good shape so either low mileage or a recent rebuild I would guess. Cheers, Mark.
The specs are: 3.875 Bore x 4.125 stroke Rod Journals: 2.0990/2.1000 Rod Housing bores: 2.2247/2.2252 Main Journals: 2.2983/2.2993 Main Housing bore: 2.4906/2.4916 The rod bearings are the same as the large journal small block Chevy Aim for .0015 rod clearance and use metal timing gears...I get real nervous with the fiber cam gear. It is nice to shoot for .002 on the mains but good rotation is difficult to obtain unless the block has been align honed.
Thanks for the info RJ! One question though - being a real beginner with this engine building lark (I've rebuilt a total of 2 motors, and one of those broke!), can you tell me what you mean by the two measurements for each journal i.e. Rods: 2.0990/2.1000? Is this for two different models of engine or do you just mean that there is a size 'range' that my journals need to fall into? Sorry for the stupid questions - just trying to learn as much as I can as I go along. Cheers, Mark. P.S. If I can't get .002 clearance on the mains, how far should I go to achieve good rotation? And how can I determine 'good' rotation - is there some way of measuring it e.g. with a torque wrench on the end of the crank at different stages of the build?
"Good rotation" ;Install the crank in the engine without a rear main seal,proper sized bearings lubed with engine oil.Torque the main caps,grab crank by the snout and try to rotate.Should rotate by hand.
Mark, The sizes are the high and low limits for the journal and housing bores. If you were to have the journal diameter at the low and the housing bore at the high limit the oil clearance would be pretty big. Do you have a dial bore gauge to measure the housing bores with? If so you can nail the clearance before assembly. Also, the rod & main caps are not numbered from the factory so take care that they go back in the original spot. If they have not been numbered do so...mixing caps can be a real pain to correct. When assembling it is imperative that rotation is checked with the installation of each piston/rod assembly and when torquing the mains. i always build with white lube on the journals (Lubriplate 105) and when doing the mains I install all of the caps and torque them down to 20 ft/lbs. Then I hit the crank quite hard on the snout then on the rear of the crank with a small sledge and an aluminum block as a buffer. This seats the main cap, in this case the rear, with the thrust bearing. Make sure you have a solid .003 minimum thrust clearance or, if you do not have an indicator & base "feel" the movement back & forth.
you can use a prybar between crank and main cap to gently move crank to check for thrust clearence. also you can use plastigage on the mains and rod bearings in case you don't have a bore gage. also you prob already know but take bore measurements in differentangles and mainly at top- most wear there. i would not trust my measurement on a used 292 that i got a stock bore reading of 3.875". a machine shop can verify measurements for small fee. good luck and glad you are keeping it inline!
I would expect that size at the very top of the bore (the ridge), and also in the lower half of the bore. There should be some wear at the top of the ring travel area. It would be really surprising to see one of those engines that's standard size and has no wear in the bore!
Thanks for the input and help guys - all very useful stuff to a novice like me. Just wish yo guys lived a bit closer as you'd find yourself with a new 'best buddy'!!! I think I will get myself a bore gauge. Initially I just wanted to ascertain whether or not my engine has been rebuilt ant any stage - the 3.875" that I measured was close enough to tell me that it hadn't had a re-bore at any stage. It really doesn't seem to have much of a lip at the top of the bore. I have used plastigauge before, but didn't find it that easy to use as the measurements seemed a bit vague (perhaps i wasn't using it right). Looking forward to having a go with the 292 - currently running a 235ci in my '41 Chevy truck. the trouble is that 292's are such a rarity in the UK, I want to make sure i do it right first time.
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