1G Trying to freshen up on my motor building knowledge and could use some advice.

[jakk220]

This is a thread in search of all the experienced builders tips, tricks, advice, as well as answers to some questions that I have for my 6 bolt build. I will be using Manley 8.5/1 pistons and Eagle H beam rods. My apologies if it is long, but it has been about 5 years since my last build. 6 years since I have built the motor in my 2g gsx with a fellow DSM'er which is still running strong at 30psi (knocks on wood).

1. The order of the rings should be as follows: compression ring 1, compression ring 2 and then oil ring, oil skirt, oil ring 2 all in the same slot correct? I know that the compression rings are directional. As in they can go in upside down. If I recall correctly, the rings that came with my Manley pistons were not labeled with the dot. So if they are not, which direction do the angled edges go? Same question applies with the oil rings and skirt.

2. If I recall correctly the oil skirt and oil rings should not need gapped? I know that the oil skirt should not overlap, but I can remember exactly how it should sit. It should be the proper size right out of the box correct?



3. I'm trying to prepare a list of questions for my machine shop and was wanting to see if any one else has some they can think of.

1. Do you belt sand your block surface?
2. Request bore sizes before and after
3. How much material was removed from the block surface
4. I would also like to have them match my pistons to the cylinders for me as they will have them to install the rods onto the pistons for me.
5. I will request to have the mains align honed. They should tell me if I need to change bearing sizes I assume?

4. For my ring gaps I am thinking .20 for the top ring and .24 for the bottom ring. The long term goal for the car is to be at 28ish PSI on an FP green. My guess is that the pistons will be .10 over and I am trying not to cut the crank as I know you are not supposed to.

5. For my rod and main bearing clearances I am aiming for about .0003 and will be using plastigauge to check them. I have never used the stuff so any advice would be helpful. I assume the entire rotating assembly / girdle should all be torqued down at once when using this stuff?

I know for a fact I will have more questions as I go, which I will add in the posts below. But for now these are the main things. Some people may say "If you are asking these questions you shouldn't be building an engine" which is not true. I have done it before and am confident in myself, it has just been a long time and I will not have anyone watching over me. So I am a bit nervous, yet excited at the same time. So all your guy's help is much appreciated. Thanks.

 

[bastarddsm]

Always check all the rings. The rings should be directional. Most dsm piston use a napier grove second ring, and that has to go the right way. The top ring is probably not directional. If you are using new eagle rods. have them check the big end for round, and the side clearance on them. Also have them pin fit the pistons/rods.

I would look for a bit more main/rod clearance. .0003 is pretty tight. I run all of mine at about .002"

 

[jakk220]

Always check all the rings. The rings should be directional. Most dsm piston use a napier grove second ring, and that has to go the right way. The top ring is probably not directional. If you are using new eagle rods. have them check the big end for round, and the side clearance on them. Also have them pin fit the pistons/rods.

I would look for a bit more main/rod clearance. .0003 is pretty tight. I run all of mine at about .002"

Thanks for the tips! I'll be sure to bring all that up to my machinist! I assume the .002 is for a race car? This will be more of a street / weekend warrior car. Would you still reccomend .002?

 

[bastarddsm]

Yes I think that I would still go .0015 to .002. I don't think there is really any downside to doing .002" You just need to run a thicker oil like a 15W40 or a 20w50. We think of a crankshaft being infinitely stiff, but it's not. Think it's gonna try and move less than .0003" when there is 2000psi in the cylinder at TDC?

 

[jakk220]

Yes I think that I would still go .0015 to .002. I don't think there is really any downside to doing .002" You just need to run a thicker oil like a 15W40 or a 20w50. We think of a crankshaft being infinitely stiff, but it's not. Think it's gonna try and move less than .0003" when there is 2000psi in the cylinder at TDC?

You know what I realized on my spec sheet I wrote down .003 and added an extra 0 by accident when I made the thread. My apologies. So if it's somewhere between .0015 and .003 I'll be happy.

 

[bastarddsm]

I would try and go on the smaller side of that range.

 

[jakk220]

I would try and go on the smaller side of that range.

Got it. In your expert opinion, is cutting the crank a bad thing to do? I'm just wondering in case it needs done. I have read it's bad due to the factory nitride treatment. I didn't know this 6 years ago when I built my 2g and I cut it .010 and it's been fine at 450hp / 40k miles since then. And I don't baby it .

 

[jakk220]

So I have never really messed with the oil squirters before. Do I have to just replace the crush washers and clean them out with some brake cleaner? I also read something about a check valve. Is that build into the squirter? Also is there usually an interference issue with them using aftermarket pistons / rods? I would assume not but have heard of it happening before.

 

[turbo6692]

Most of the time with using after maker pistons you will have to bend the factory oil squirters or trade them out for a newer version. It is always best to replace the crush washers when removed.

 

[1990TSIAWDTALON]

I am with @bastarddsm on advice! Its about the same thing I do. Nice tight bottom end. It will wear in.

 

[jakk220]

I am with @bastarddsm on advice! Its about the same thing I do. Nice tight bottom end. It will wear in.

Awesome! Thanks for the input. I will aim to stay around .0015 - .0020.

 

[jakk220]

Quick question. When I installed my oil squirters I used permatex red thread locker on the banjo bolts just so there was no chance of them backing out. I am now questioning that choice and was just wondering if this is okay to do or is bad. I guess my worry is if it were to ooze out or something and get in the oil.

I have had a few people tell me that it's fine. But im paranoid and just wanted to get a few more opinions on what other people think.

I used Evo 8 squirters and new crush washers. Re-used and cleaned the banjo bolts.