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Discussion and questions related to the course Engine Building Fundamentals

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I went through the course having forgotten I can ask questions below the video so now I have several and thought it would be better to ask them all in one thread. 1)What brand of engine building/precision tools do you guys recommend? i plan on building many engines in the future and need accuracy, precision, and reliability. 2) how do you determine what the best compression ratio for your application (i know forced induction engines generally require a lower compression ratio because they are more knock prone and the same goes for any engine running lower octane fuels, but how do you arrive at a particular number for your application?) 3)How do you determine what your ideal bore, stroke, and rod to stroke ratio is? 4) Aside from reducing cylinder wall thickness and not leaving any room for future rebuilds, are there any other potential downsides to going as far overbore as your block can handle (i've been told it reduces throttle response but i can't understand why)? 5) With all the new race fuels and ethanol blends out there, how do you determine what you should run? 6) Since bolting on the torque plate will distort the block, does that mean that installing the main caps and girdle (if applicable) or bed plate will do the same? if so, does that mean that whenever the block is being align bored and line honed, or whenever taking any measurements are being taken, that they should be done with all those items installed at the same time (so instead of align boring with just the torque plate, you should align bore with torque plate, main caps, girdle, and bed plate installed?) 7) is the old hot rodder's myth that the crank must always be stood up on its end true? I've always heard letting it lay on its side will bend the crank. 8) How do you determine what clearances to run? I know recommended piston ring end gaps and piston to wall clearances are normally included with your pistons, but what about rod bearing clearances and such? 9) when you go overbore, do you need a different torque plate with larger holes? 10) Is it possible to balance the crankshaft without the flywheel and clutch? Could you balance it if you're using a used flywheel and clutch? 11) Do you guys have any experience with gapless piston rings (total seal)? any insight would be appreciated. are rods bolts, main bolts, and clutch/flywheel hardware one time use fasteners just like head bolts? 12) Is it necessary to line bore the mains when switching from main bolts to main studs even if you don't change the main caps themselves? 13) when using a bore gauge or measuring ring gap, do we need to lubricate the cylinder walls or do we do this dry? 15) can the weight of the head crush the head gasket even if i dont torque it down? Pardon the million questions, I am new and will likely be build a 2J soon. Thank you for your patience!

that's some very good questions:

1)What brand of engine building/precision tools do you guys recommend? i plan on building many engines in the future and need accuracy, precision, and reliability. i personally use Mitutoyo

2) how do you determine what the best compression ratio for your application (i know forced induction engines generally require a lower compression ratio because they are more knock prone and the same goes for any engine running lower octane fuels, but how do you arrive at a particular number for your application?)

i use a combination of experience, class rules, other builders knowledge, and known facts, based around fuel, camshaft, combustion chamber style and head flows along with expected power needed to beat the competition.

3)How do you determine what your ideal bore, stroke, and rod to stroke ratio is?

some times this is what's available of the shelf and is there a need to be different of just build the best you can with the combo available, sometimes it's based on what i want to achieve and customer's budget.

4) Aside from reducing cylinder wall thickness and not leaving any room for future rebuilds, are there any other potential downsides to going as far overbore as your block can handle (i've been told it reduces throttle response but i can't understand why)?

i have never found it to reduce throttle response that does not make any sense to me the down side is flexing of the cylinder walls and poor heat dispersion but this depends on the actual thickness of the bore walls

5) With all the new race fuels and ethanol blends out there, how do you determine what you should run?

this 9 out of ten times is class regulated and if not it will be customers budget and availability of the fuel. the rest of the time it comes down to what you want to achieve.

6) Since bolting on the torque plate will distort the block, does that mean that installing the main caps and girdle (if applicable) or bed plate will do the same? if so, does that mean that whenever the block is being align bored and line honed, or whenever taking any measurements are being taken, that they should be done with all those items installed at the same time (so instead of align boring with just the torque plate, you should align bore with torque plate, main caps, girdle, and bed plate installed?)

in short yes you should if you are wanting to build the best possible engine you can

7) is the old hot rodder's myth that the crank must always be stood up on its end true? I've always heard letting it lay on its side will bend the crank.

i personally hang mine if they have been machined and I'm leaving for any more than a few days before building i also destress my cranks on a home made devise that runs a calculated hz though the block crank rods etc

8) How do you determine what clearances to run? I know recommended piston ring end gaps and piston to wall clearances are normally included with your pistons, but what about rod bearing clearances and such?

this comes down to experience again and knowing the clearances needed for particular engine combos based on materials used most engine rebuilders will openly tell you what the run for a typical combo

9) when you go overbore, do you need a different torque plate with larger holes?

no most torque plates have plenty of clearance to maximum over bore

10) Is it possible to balance the crankshaft without the flywheel and clutch? Could you balance it if you're using a used flywheel and clutch?

yes and yes but always best to balance a rotating assembly complete, i often balance the flywheel and clutch separately and do it to a zero balance before doing the crank so i know i can replace the flywheel / clutch after the job and it should still be very close

11) Do you guys have any experience with gapless piston rings (total seal)? any insight would be appreciated. are rods bolts, main bolts, and clutch/flywheel hardware one time use fasteners just like head bolts?

i have been using gapless rings in many applications for years they are great but i prefer std ring gap type rings for most builds if I'm not chasing 1-2 hp gains because they are easier to manage and use i use a stretch gauge to measure the life of any bolts and always renew if the budget allows even when i spec

12) Is it necessary to line bore the mains when switching from main bolts to main studs even if you don't change the main caps themselves?

i measure first to determine if it is needed on many blocks it is not needed example most 2jz builds it is not been found to be needed where as a rb block is normal to need line boring

13) when using a bore gauge or measuring ring gap, do we need to lubricate the cylinder walls or do we do this dry?

i do this kind of dry i use at fluid wiped in the bore

14 there was no 14

15) can the weight of the head crush the head gasket even if i dont torque it down?

the head gasket is designed to crush to a set thickness at x amount of clamping pressure applied

so it will not hurt it at all to have the head sitting on the head gasket and not pulled down

and your welcome

Regards Ross

Awesome thank you so much for all the answers. I asked the fuel question because I’ve seen certain people in my area running race fuel in their street cars when they go to the track instead of e85 which is extremely common and easy to find in our area and cheap, so i was wondering what benefit it could have over e85 aside from consistency (since e85 is not always 85% ethanol).Ive also heard that some people bore their blocks hot and that it produces a more accurate result. Could the same be applied to the mains? Also, where could i find the crushed thickness of the head gasket for cam degreeing purposes?