Some a$$ (no names) posted a stupid comment on the VQ35 thread, and a moderator had to remove it. Here's the spec info on the VQ30/VQ35 for the thread, to piggy back on MardiGrasMax info:


VQ30DE ~ ~ VQ35DE Data Specifications

PISTON
Dia …….. “30”– (3.6606 – 3.6610 in)
Dia …….. “35”- (3.7590 – 3.7594 in)

Height … “30” - (1.787 in)
Height … “35” – (1.614 in)

ROD
Center Distance . “30” – ( 5.8110 – 5.8149 in)
Center Distance . “35” – ( 5.6752 - 5.6791 in)

CRANK
Center Distance…”30” – (1.4413 – 1.4445 in)
Center Distance…”35” – (1.5890 – 1.5921 in)

CAMS
Duration Intake…”30” - 232
Duration Exhaust”30” – 232

Duration Intake..“35” – 240
Duration Exhaust “35” – 238

VALVES

Intake……..”30” – 1.417
Intake……..”35” – 1.4567

Exhaust……”30” – 1.228
Exhaust……”35” - 1.228

Basically, on the VQ35, pistons are larger in diameter, shorter in height, intake valves are larger, cam is more agressive, conn rods are shorter and the crank has a longer throw.

We are gonna "sticky" this post, post BS and it will be removed

Don

 

Haha. Thanks Don. Mardigras, please follow up to this thread thanks!

 

He pretty much got it all

Block deck heights are the same and cylinder heads are very close.

What does all this mean?

Putting a VQ35 crank and rods and pistons in a VQ30 motor is very doable.

Putting the VQ30 heads on a VQ35 short block is very doable.

However neither of these will be "plug and play". Custom pistons to compensate for the compression ratio will be needed.

I havent examined this close, but it is my thought that you could use the VQ35 in a VQ30 car as long as you swapped over all your sensors. It dosenot appear that the variable valve control is electronic so this could also be intagrated. What I may possibly do since I am supercharged is get custom pistons for the short block for lower compression. Cryo the stock rods. I will need to remove the variable valve timing control to clear the SC mounting plate and use the VQ30 timing chain and cam sprockets and timing cover etc. I dont se being able to do this until perhaps mid year because its $$$$.

M

 

http://64.252.159.123/~matt/mattinfo.htm

 

Sorry to post in here, you can delete my post after the Don sees this, but looks under the CAMS section...intake/exhaust is messed up. Just thought I'd let yall know.

 

This will all be great! A few questions though... for those of us who have a non 95-96 4th gen or who have a 5th gen, how do we get the ecu to handle all of these changes. Also, if swapping in the vq35 crank and rods into the vq30, the peak horsepower would be higher than 6500. So we'd have to get rid of the speed limiter. I remember Keven97SE mentioning something that if we had custom pistons made to reduce the CR, that a lot of the extra top end hp would be lost. So would custom cams be better? Or even the vq35 cams since they're more agressive? Sorry I don't know the formula's to figure out if it'd work. It seems as though it would be a cheaper option to just modify the vq30 than to actually do the engine swap.

By the way, great job guys on coming up with all of this information. Hopefully we can get somewhere with doing all of this

 

Maybe I can clear up a few things.

If you simply dropped in the 3.5L crank and rods into your 3.0L (assuming it would work), you'd have a motor that ran an 11:1 static compression ratio. The ECU fuel maps would work fine (not tuned optimally, but pretty good), as the ECU would simply read an increase in airflow into the engine and correspondingly increase the fuel addition (or would read the air/fuel ratio and adjust as needed when cruising). That part of the ECU would work fine. What wouldn't work fine is the ignition timing. It'd be too aggressive for the high compression and the motor would likely knock. That would require a custom ECU program (JWT could do this...use a 95 ECU and send it to them). HOWEVER, I doubt that even new timing maps could eliminate the detonation. That is too high of a static C/R for the stock cams.

BUT, if one were to get custom pistons (as Mardi suggested), you could lower the C/R to a reasonable 10:1 (or slightly higher, probably). OR, as I suggested, you could get custom cams (intake only would be required) and have ~15-20 degrees added to the intake valve closure timing. This would effectively lower the compression ratio by decreasing the dynamic C/R. Dynamic C/R is what matters in terms of detonation, not static C/R. In the situation of new pistons, you would likely NOT need a custom ECU. In the situation of the new cams, you wouldn't need a custom ECU but it would be a really good idea to do so, as you will have substantially changed how the engine operates internally and hence the stock timing and fuel maps would be off. The engine would run okay, but not nearly as good as you'd prefer. I think with just new pistons (not new cams), the characteristics of the engine would be close enough that the stock maps would be pretty good still.

 

I don't know if this is any help but the VQ30 cams are very very mild. The VE30DE/VG30DE run 248* duration cams themselves, while the VG30E's have a 252* and 248* (used in 3rd gens) cams. It would be nice to know what the overlap is on the VQ30 and VQ35. The VE runs 9* overlap on the low cam, while the VG30 runs 18* on the low cam. FYI Isky will do custom cam grinds for $150 .

 

The VQ30DE cams run 3 degrees overlap, I believe, which is effectively none. I son't know but I seriously doubt the VE or VG30DE cams would fit the VQ. But ya never know.

Bottom line is, it makes little difference to me because there's no way I can afford to undertake this project. I'll sit on the sidelines and just see if anyone decides to try it. FYI if anybody in Austin is seriously interested in doing this, I'd be more than happy to lend a hand. I want to see a VQ33DE!

 

Well I have some friends in Austin, I can show you it after I do a 3.3 or 3.5...

Can you e-mail me that spread sheet you were talking about in the other thread? matchou@home.com

Does any one have any desk top dyno software to share? Desktop Dyno 2000 looks really nice.

I also noticed that the 3.5L has under piston oil squirters for piston cooling, COOL! It also appears to have a factory engine oil cooler!

 

Cams are definitely a weak point in VQ30 power production. A VQ-owning member had a set of prototype cams in his car. The thing couldn't idle at all, but gained 40hp and 22lb-ft at the wheels

 

Cant we all just share! Who, What, When, Where, How?

 

In that case it would probably be better to have the 3.5L block from the start. Otherwise you'd have to drill the block to install the oil squirters (jwt does this to SR20 and VG30 engines). On car-part.com I've found around 75 VQ35DEs in the US for sale from pathfinders. Either way making a VQ30 into a stroked VQ33 would cost around $2000+, so might as well get the VQ35 for the same price.
Wow 3 degrees of overlap, talk about power dropping. Also the SR20 has 248* duration and 16* overlap in the high port engines. Actually getting the cams made shouldn't cost over $300-500 tops. The problem is getting access since the DOHC requires the IM to be removed it isn't a walk in the park. But then again it's still easier than installing cams in a VG which require either you lift the engine 1ft or pull the heads. I'm thinking a grind simular to the VG30DE/VE should produce a nice gain in toppend power however it might drop the lowend alittle. Hell maybe a SR20 spec grind would work.

 

[QUOTE]Originally posted by MardiGrasMax
[B]

He pretty much got it all

Block deck heights are the same and cylinder heads are very close.

What does all this mean?

Putting a VQ35 crank and rods and pistons in a VQ30 motor is very doable.

Putting the VQ30 heads on a VQ35 short block is very doable.

i know that most of us are trying to get more hp by getting the VQ35 crank, but i do have 1 Q. what about using the VQ30 block and the VQ35 heads so you can get more aggresive cams, bigger intake valve and vlave timing control. or do both use the VQ35 internals and the heads? (at this point it might be easier to install the whole motor)

 

I doubt you will be able to find heads seperate from a motor just yet. It takes a few years for those to make it into the yards.

But, from what I have seen in the FSM's you can put the 3.5 heads on the 3.0 motor.

However, a 3.5L block and heads mated to 3.0L timing chains and timing chain covers, 3.0L intake and injectors and 3.0L exhaust manifolds will be the easiest way to do this. You will loose the variable cam timing.

You may be able to get the variable cam timing to work. but this will require hands on the motor to find out.

 

Just curious here, but which would be more expensive: dished pistons or shortened rods? Both would effectively lower static CR, which would probably bring the stock ECU maps closer to optimal. With stock pistons though, you wouldn't upset normal flame propagation.

 

pistons

 

Ermm...I think it was Dennis(MaxedBandit)?

 

Could we combine all this with what Don in Texas is doing?

 

who here wishes you could just stick a big fat carb on the sucker and tune it the way it should be tuned instead of spending 1000+ on programmable efi, or waiting till some company makes a computer for us ?
-pete

 

If we could find a Carb system that could outperform similar flowing EFI, I'd be up for that. But we can't, so we might as well just learn how to program EFI maps and stuff, kinda like most people had to learn how to tune carbs. 'Sides, we still have the manually adjustable idle and throttle cable.
-Justin

 

its more about ease then anything , learning to adjust efi isnt that hard it just takes time however it still isnt a physical adjustment and as such can never be completely controlled. i hate computers even though i know quite a bit about them. anyways when efi is cheap itll be on my cars -pete

 

What kind of cars are you referring to? Edelbrock has the Pro-Flow EFI system that's MPI, Holley has something similar and Kinsler Fuel Injection has Injected throttle bodies. I don't know if they're very cheap though.

 

Errmmm. If you have a 1998 Maxima Se like your name implies, you already have computor controlled fuel injection.

 

i know what i have , and i know what im trying to sell, its impossible to tune these things without thousands of dollars and frankly i dont want thousands of my dollars invested in a car thats made to go fast, cars that go fast crash hard and there goes all the money

 

Ok so when you say the ignition timing would be too agressive, what exactly does that mean. I read a few posts by max'n out, he said that when one uses the S-AFC with our car our ecu doesn't change anything if it's within 10% of stock settings. But if it's over that, then our ecu retards the timing. I was hoping this could be a possible fix for the problem. Or am I working backwards and the timing needs to be anti-retarded (sorry for the lack of knowledge on terminology). Also, if that would work, the S-AFC could obviously be used to help correct the fuel maps. Right?

 

By aggresive (and I could be wrong, please correct if necessary) he means that it would be advanced too far, or the ignition would start too soon (anti-retarded = advanced BTW). With 10:1 or so compression, the timing might be fine, but with 11:1, the increase in compression creates a significantly larger amount of heat within the cylinder. Combine that with ignition that starts too soon (too much advance) and you either get detonation at Top Dead Center (TDC) or you will simply blow the motor because there will simply be too much heat and pressure created while the piston is still moving up. If however, you retarded the timing, the ignition would start much later, or when the piston is closer to TDC. This would allow a similar amount of heat/pressure to be generated, but the piston would be able to move back down the cylinder by the time this happened, hence, no blown motor.

 

Hello, sorry about the delay but it took me quite a while to find this thread...didn't know it was a sticky. Anyhow, I called my shop that I had the work done and they are digging up all the specs/info we had on it. The project was cut short due to frustrations and a lack of financial support on my end and I don't expect to continue it until I put my blower in (since forced induction is the route I decided on going). I will go ahead and email the whole thing to you, charts, dimensions, material, yada yada. However, there might be too much to email...so in that case, I'll burn it on a CD-R and ship it to you. If you want to email me, use maximadriver888@yahoo.com instead of the one posted from here.

 

I'm interested too

 

Thanks!

 

Hey I've been reading about this all over the place (about replacing cams, pistons con rods yada yada) Does any one know anything about sleeving the cylinders? Is the stock block strong enough that it doesn't need sleeves?

I am really interested in building a motor when I've got the funds. I am in the process of finishing off my Turbo 4th gen project.

Also to do the pistons, crank and rods do you have to pull the whole engine or can you get good enough access through the top and bottom? I don't have an engine crane . I have done this several times with four bangers but not sure with V6 Max. I imagine it would be the same, but the rear bank might be a pain to get to.

 

I thought any aluminum block motor *has* to have sleeves, those sleeves being made of iron. The sleeves are to protect the block from being worn away by iron (or other metal stronger than aluminum) based piston rings.

DW

 

I am interested, and live in Austin. I would like to look at the possibility of swapping the 3.5 in, or creating the VQ33DE.... It may be later on this year, I will be getting a 350Z, and I would like to wait till I have another car, but I am very intested.

A few questions, what all would I need, a entire VQ35DE, tranny, ecu?
Will the Pathfinder VQ35 work (ecu/Tranny?)

MardiGras please email me if you head to Austin, it sounds like it may be a while before you make it....

 

Maybe some time in early April.

 

I sent you email bro.