The 14b Drag Race Discussion Thread

[jjrock5]

If you need a hand on the weekends, let me know, man.

I'm in the next town over to you.

 

[Phil1320]

If you need a hand on the weekends, let me know, man.

I'm in the next town over to you.

Thanks John! That would be cool! It appears this Sunday morning we will be pulling the engine at around noon or slightly before. If you want to stop over, shoot me a pm and I'll give you my address.

 

[bullettdsm]

Well then, maybe this Sunday morning at around noon or slightly before, I'll be stopping down to laugh....er help you out


Its up to the 2.3 install

MB

 

[Phil1320]

Well then, maybe this Sunday morning at around noon or slightly before, I'll be stopping down to laugh....er help you out


Its up to the 2.3 install

MB

Hey! This is no laughing matter Sure, swing by if you can, that would be cool.....

 

[DJ23GSX]

Sunday hmm.... If I can coax the old lady into grocery shopping saturday I'd love to give you a hand. I've never pulled a dsm engine before but I'd like to get some hands on training. I've got big ideas for mine but it might mean brushing the cob webs off one of my credit cards I haven't used in years .


Happy Thanksgiving!!!

 

[Phil1320]

Sunday hmm.... If I can coax the old lady into grocery shopping saturday I'd love to give you a hand. I've never pulled a dsm engine before but I'd like to get some hands on training. I've got big ideas for mine but it might mean brushing the cob webs off one of my credit cards I haven't used in years .


Happy Thanksgiving!!!

Sure! Not a ton to do as all the peripherals are removed but if you want to stop by shoot me a pm and I'll give you my address. Happy Thanksgiving!

 

[Phil1320]

The engine came out yesterday. Overall looks good as far as I can see. A bit of slight seepage from the rear main seal and oil pan. Not bad at all. Checked the VIN on the block, it does match the chassis so it is the original engine.

Special thanks to Mark(bullett) on Saturday for getting the engine stand cleared of the 300 Z block with me, Craig D. for lending me the stand for the winter, and last but not least, Bobby Wright Jr. on Sunday for bringing the cherry picker and helping out with the pull.

So, at this point I have some decisions to make. Obviously, the balance shafts will come out. Cams, Gears, and springs will go in. 99% gonna pull the head to do this so that it can be disassembled, cleaned, and reassembled. May have some polishing of the exhaust ports done, but that's it. No "work" other than that on the head. At that time I'll pull the oil pan as well, and based on what the bottom end looks like, make a decision wether or not to do anything with it. A few are suggesting at least new rings and such, but, at that point I may as well take advantage of the 2G pistions compression bump if I'm gonna do new rings. Not really interested in doing forged pistons, however I would like compression to be more in the 9.5:1 range, but, beggers can't be choosers!

Thoughts ?

 

[SBstar]

Having the 2g pistons I'm definately a fan, however, then you're talking about alot more machine work and cost and you already have good compression. I'll leave that one up to you. It definately won't hurt your performance if you bump the compression up though!

Good to hear it's coming along again though! My parts are on the way as well!

 

[Phil1320]

Having the 2g pistons I'm definately a fan, however, then you're talking about alot more machine work and cost and you already have good compression. I'll leave that one up to you. It definately won't hurt your performance if you bump the compression up though!

Good to hear it's coming along again though! My parts are on the way as well!

Yeah, I know there is some machine work involved with running 2G pistons on 1G rods. My compression is ok I suppose, I haven't comp tested in almost 10 years.....and back then cylinder #2 was at 148......so, I'd love to enjoy comp numbers in the 180 range....isn't that what the 2G pistons will offer? This is all a refresher for me and some of it new as I've never done any of it before.

Thanks! What parts do you have coming? I don't have any on the way right now, probably not til next year......

 

[SBstar]

2g motor compression is around 178. I thought you'd compression tested since then and it was still good, oh well. I think my compression is still around 160-170 across the cylinders but my head could use some freshening.

I've got some bushings on the way.

 

[Phil1320]

2g motor compression is around 178. I thought you'd compression tested since then and it was still good, oh well. I think my compression is still around 160-170 across the cylinders but my head could use some freshening.

I've got some bushings on the way.

Nope, car ran great all along so never had a reason to do another comp test.

It was 150-148-155-160 way back....so even 175 across the board would be a significant increase. I'm sure cylinder #2 is still the weakest. I'm not saying I couldn't leave the bottom end alone, the compression is probably still decent...but at this point, why not take advantage of as much as I can. I'm in no rush to be ready for March or even April. Would rather do it all in one shot.

Bushings are good. The last bushings I need to do are the front lower radiator support, and the full front engine mount rather than the inserts I just removed from the original front mount, otherwise, all my bushings are done and it's awesome.

 

[SBstar]

Then get it done!

 

[Steve93Talon]

A few are suggesting at least new rings and such, but, at that point I may as well take advantage of the 2G pistions compression bump if I'm gonna do new rings. Not really interested in doing forged pistons, however I would like compression to be more in the 9.5:1 range, but, beggers can't be choosers!

Thoughts ?

Bear in mind that OEM 2G pistons aren't really any cheaper than a set of forged aftermarkets. The reason is that OEMs don't come with rings, you have to buy them separately. Then factor in the cost of having the rods machined.

I'm personally a big fan of untouched stock bottom ends, no chance of something being machined or assembled incorrectly and trashing everything. You could always do a thinner head gasket to bump compression, you'll already have the cam gears to dial in the timing correctly.

 

[chanley talon]

I run 2g pistons on 1g rods. I would suggest you back your base timing up a few degrees. I run around 2 degrees btdc. I do this because of the agressive timing curve in the 1g ecu. Unless you have a tuned chipped to compensate for the compression being higher. I do like the setup and i feel it has made my car faster.

 

[DJ23GSX]

I say you got the motor out so you'd might as well freshen up the bottom end regardless of what pistons you decide on. No sense having to pull it out later if somethings worn and decides to go after you put it all back together and make some passes. My train of thought is to do things right the first time so you don't have to worry about them later. I was steered away from 2g pistons in my 1g a while back by a very knowledgeable long time dsmer but I can't for the life of me remember the reason

 

[Nate Crisman]

IMHO, 2g pistons are a complete waste of time for your goals. It's a negligible Increase in compression ratio compared to the major cost and hassle of having the block honed and the rods machined to fit (on top of nearly $400 in pistons/rings.

If you are going to change the pistons which necessitates the block be torn down and machine work done, you might as well buy 9:1 or 10:1 pistons instead of 8.5:1 stockers since they cost about the same. The machine work will cost you the same either way.

Not to mention resale value on a forged piston motor is better than a "stock rebuild" should you ever have to recoup some investment in the future.

 

[Phil1320]

Then get it done!

I wish it was that simple! We'll see. A few different paths I can take here. Once I can inspect the bottom end, I'll be able to make a better decision.

Bear in mind that OEM 2G pistons aren't really any cheaper than a set of forged aftermarkets. The reason is that OEMs don't come with rings, you have to buy them separately. Then factor in the cost of having the rods machined.

I'm personally a big fan of untouched stock bottom ends, no chance of something being machined or assembled incorrectly and trashing everything. You could always do a thinner head gasket to bump compression, you'll already have the cam gears to dial in the timing correctly.

Wasn't really sure about that. I can probably get a set of 2G pistons for nothing. But, as you said, there is machine work involved...and it's to the rods your saying? So, not to the 2G pistons then....hmmm...not really interested in altering the stock '90 rods--short of shotpeening and balancing.

I hear you on the untouched bottom end thing...but, that's really not a big deal to me...the whole "stock bottom end" stuff. I hear you on the integrity of the stock bottom end though. Basically, because I've decided to remove the head, anything goes now. Honestly though, I'd rather just pull the balance shafts and that's it. But, with 80,000 on the clock, a refresh would be nice. We'll see. Thanks for your thoughts on it though.

I run 2g pistons on 1g rods. I would suggest you back your base timing up a few degrees. I run around 2 degrees btdc. I do this because of the agressive timing curve in the 1g ecu. Unless you have a tuned chipped to compensate for the compression being higher. I do like the setup and i feel it has made my car faster.

Cool. I'm sure my timing will have to be altered if I bump compression, but 2 BTDC? Remember I run only VP C16 117 octane. No pump gas. I do have a chip that timing has been altered but only above 6000 rpm, all other parameters are stock.

Anyway, I thought the 2G piston route would be easiest and cheapest if I decided to do anything at all, but, it seems that may not be the case. Thanks for posting.

I say you got the motor out so you'd might as well freshen up the bottom end regardless of what pistons you decide on. No sense having to pull it out later if somethings worn and decides to go after you put it all back together and make some passes. My train of thought is to do things right the first time so you don't have to worry about them later. I was steered away from 2g pistons in my 1g a while back by a very knowledgeable long time dsmer but I can't for the life of me remember the reason

This has been suggested to me a while back even when all was fine--freshening the bottom end---rings etc. This was my immediate thought at a minimum. It would be nice to just pull the b-shafts and call it a day. But, as you say, everything is all ready apart and out of the car, so it would make sense to do it now and not have it all bolted back together with new head gasket etc. only to find a cylinder really weak or something else within next season. Not to mention, every little bit will help my efforts, even the smallest thing like a 1 point bump in compression. Especially as light as my car will be next year. Total race weight target is sub 2400 lbs. It was 2470 lbs. at this last outing in October.

So you were steered away from 2G pistons...would love to know why as from what I've read, it's a common upgrade from the 7.8:1 1G stuff.

IMHO, 2g pistons are a complete waste of time for your goals. It's a negligible Increase in compression ratio compared to the major cost and hassle of having the block honed and the rods machined to fit (on top of nearly $400 in pistons/rings.

If you are going to change the pistons which necessitates the block be torn down and machine work done, you might as well buy 9:1 or 10:1 pistons instead of 8.5:1 stockers since they cost about the same. The machine work will cost you the same either way.

Not to mention resale value on a forged piston motor is better than a "stock rebuild" should you ever have to recoup some investment in the future.

Ok....so if I'm reading correctly here, leave the bottom end alone(aside from b-shaft removal) or definitely do a forged piston set if I decide to do more work. Never really thought about resale, interesting point though, as all cars are losing endeavors. Yeah, I suppose 9:1 would be the arena I'd want for comp. Do you know what the difference is in weight of a stock cast 7.8:1 vs. a forged piston? I love a fast revving engine and that could be a selling point if I was actually going to trim some decent weight, or are we talking only a few grams? Granted, even that would be nice.

Let's also talk RODS: I won't be making 600 hp anytime soon. Maybe 400 to the wheels would be my cap. So, I know the '90 rods are supposedly the cat's ass for DSM rods.....the strongest. I know alot of people run Eagle....nice and cost effective. But, I've also heard they are heavier than stock rods? I really don't have any plans to do upgrade rods, but, if someone has a case against the stock '90 rods vs. Eagle, I'm listening. I'm really not looking for some nutty rebuild here. Just wanna do it right for what my goals are and not over-do anything. I'm not one of those guys that needs the pretty mod list, just a pretty timeslip.

Thoughts? And thanks!

 

[Nate Crisman]

Phil, here's the deal with the piston/rod info as I see it:

With stock con rods, the wrist pin is pressed into the rod. In order to remove your stock pistons and put new pistons on, they have to go to a machine shop for wrist pin to be pressed in/out. 1G and 2G wrist pins are different diameter, with the 2g pin being I think, 2mm bigger. The 2G rod is also a few mm "skinnier" where it goes into the piston. What this means is if you want to match 2G pistons to 1G 6bolt rods, the machine shop has to bore the wrist pin hole in the rod to a larger dia (accurately so it is still a press fit) and also shave an equal amount of the small end of the rods to make it fit inside a 2g piston. If memory serves me, the work on the rods is like $120-$150 the last time I had it done many years ago.

To put forged pistons on stock 6bolt rods...you still need a machine shop to heat the rod/freeze the pin and assemble it for you. Figure maybe $50 for the machine shop to simply swap pistons.

Aftermarket con rods all use floating bushed wrist pins that are held in by circlips on the piston. This means you can assemble them yourself with a little patience. The wrist in rotates in both the piston and con rod.

The cost difference between a forged piston and 2g pistons can easily be justified by the machine work your going to save in not having to modify the con rods.

In any case, you need to have the block dissassembled to a bare casting to either bore/hone for an oversize piston or at the very least honed correctly so that a new set of piston/rings will break in correctly and have good ring seal. There is no point in replacing piston/rings with the goal of making more compression for a bit more power and have it come out with less compression because the ring/bore seal is crap from it not being honed perfect. If your going to run a metal HG, it would also be smart to have the block hg surface decked to insure you never have HG issues.

IMHO high compression forged pistons are what you want. 9:1 at least. If you can find 10:1...go for it, as you said it only runs on racegas and it's not a streetcar anymore. All the compression you can get! Maybe even consider going to a larger overbore of +.040" for just a tiny bit of displacement and the larger bore helps unshroud the valves. overbore doesn't cost any more, so why not.

On the other hand...if your oem motor has good compression, maybe the investment in building a higher compression bottom end is better spent elsewhere? better intercooler? better tuning system? some dyno time with a Link expert?

 

[Phil1320]

Phil, here's the deal with the piston/rod info as I see it:

With stock con rods, the wrist pin is pressed into the rod. In order to remove your stock pistons and put new pistons on, they have to go to a machine shop for wrist pin to be pressed in/out. 1G and 2G wrist pins are different diameter, with the 2g pin being I think, 2mm bigger. The 2G rod is also a few mm "skinnier" where it goes into the piston. What this means is if you want to match 2G pistons to 1G 6bolt rods, the machine shop has to bore the wrist pin hole in the rod to a larger dia (accurately so it is still a press fit) and also shave an equal amount of the small end of the rods to make it fit inside a 2g piston. If memory serves me, the work on the rods is like $120-$150 the last time I had it done many years ago.

To put forged pistons on stock 6bolt rods...you still need a machine shop to heat the rod/freeze the pin and assemble it for you. Figure maybe $50 for the machine shop to simply swap pistons.

Aftermarket con rods all use floating bushed wrist pins that are held in by circlips on the piston. This means you can assemble them yourself with a little patience. The wrist in rotates in both the piston and con rod.

The cost difference between a forged piston and 2g pistons can easily be justified by the machine work your going to save in not having to modify the con rods.

In any case, you need to have the block dissassembled to a bare casting to either bore/hone for an oversize piston or at the very least honed correctly so that a new set of piston/rings will break in correctly and have good ring seal. There is no point in replacing piston/rings with the goal of making more compression for a bit more power and have it come out with less compression because the ring/bore seal is crap from it not being honed perfect. If your going to run a metal HG, it would also be smart to have the block hg surface decked to insure you never have HG issues.

IMHO high compression forged pistons are what you want. 9:1 at least. If you can find 10:1...go for it, as you said it only runs on racegas and it's not a streetcar anymore. All the compression you can get! Maybe even consider going to a larger overbore of +.040" for just a tiny bit of displacement and the larger bore helps unshroud the valves. overbore doesn't cost any more, so why not.

On the other hand...if your oem motor has good compression, maybe the investment in building a higher compression bottom end is better spent elsewhere? better intercooler? better tuning system? some dyno time with a Link expert?

ahhhh.....good explanation! Cool, now I fully understand.....and I say screw all that machine work to the rods. Sounds like more of a PITA than what I'd like to get involved in. So, if anything, Eagle rods and forged pistons then with the required maching work to the block. Once I can pull the head and oil pan and get a look inside at the bearings and cylinder walls I'll be able to make a better decision. If all looks well, then it stays the way it is. You are right, the money will be better spent elsewhere for sure and for far better gains. I would like to keep the bottom end stock if all looks good for more reasons than one, but, I'm definitely not opposed to the idea of upgrading or hung up on the whole stock internals/bottom end thing. If there was a decent rotational weight loss plus having the assembly balanced, that would be the best thing about it for me vs. the compression bump. I've been in a few inline fours with lightweight components that have been fully balanced and the way they rev sends chills up my spine.


Overall, I don't want to make too big of a project here. Just exploring my options and trying to get educated on what the norm is and what works best. I mean it's great to have been able to say that my entire engine is BOX STOCK, but with the cams going in and balance shafts coming out, it will no longer be that.... anything goes is the way I see it. If you don't have balance shafts, you don't have a "stock" bottom end any longer in my book--it's been altered from it's original state....so it's not stock to a "T" anyway.

So, something I will definitely need, a headgasket. I've heard so many different things here.......OEM, Cometic, etc. I will definitely need one of these so what do you think about that part of the equation?

 

[fastrst]

Glad i could help Phill.

 

[pneumo]

I weighed a set of Eagle Rods and Wiseco pistons when I did my first rebuild. They save 20 ounces over the stock piston/rod combo. That's for all 4. It's not a huge savings, but it's nice. The best component you can get to gain the ability to rev quickly is a twin disc clutch, or at least an aluminum flywheel.

 

[Phil1320]

Glad i could help Phill.

As always, I appreciate it bigtime And we had some fun

Thanks again Bobby!

I weighed a set of Eagle Rods and Wiseco pistons when I did my first rebuild. They save 20 ounces over the stock piston/rod combo. That's for all 4. It's not a huge savings, but it's nice. The best component you can get to gain the ability to rev quickly is a twin disc clutch, or at least an aluminum flywheel.

Wow, I think 20 ounces is huge. Ok.....

I have the ACT Streetlight flywheel and the DSS driveshaft, both helped revving and response dramatically.

I have considered a twin disc clutch but I'm having a tough time convincing my wallet that it's a worthwhile purchase. But, I'm working on it.....

 

[Phil1320]

Here's some pics from last Sunday. Crazy to think the engine hasn't been out of the car since 6/90! So here's my 20+ year old, 80,662 original mile 4G63...

 

[GRAVEDIGGER]

So here's my 20+ year old, 80,662 original mile 4G63...

Something about an unopened stock 4G63 engine that makes me smile.

 

[Black95TSIawd]

Your motor looks brand new.