Recipe for 250+ hp with 3400/3500?

[v2rocket]

After doing a lot more reading into the last 15 years of 60V6 it sounds like I might be able to get pretty good results with a pair of the 3.5 front exhaust manifolds instead of buying/making headers, at least to get started. Looking at them I believe I should have clearance in my chassis for this manifold on both sides with a short radius 90 bend coming off the RH ("rear" in FWD terms) head.

Superdave and Redbird seemed fond of these manifolds and Redbird had good results just by using a good cam/valvetrain, ~250whp give or take.

Does WOT-Tech offer (or know how to) thin out an OEM engine harness to get rid of EGR and emissions stuff and just make it fuel+spark+sensors?

[Pyramid_head]

I'm sure they can answer all your questions if you email them. They answered all mine. I'm presently in the process in swapping out my beat up 2.8l mpfi for a full lx9 swap with my stock t5, 3.42 posi rear end from an ls1. Family, work, and home repair are slowing me down though. I can't wait to get my 88 camaro sc to run again!

[v2rocket]

I asked someone on Youtube who had a vid comparing the LZ and 3x00 cams but maybe you can look at this too.
Is the cam sensor HOLE in the block in the same location on the 3x00 vs the LZ? Pictures suggest it's slightly moved but could be wrong.
However the LZ cam trigger is much further back than on the3x00 cam and the LZ cam sensor is also angled towards the back.

Basically, want to know if an 3x00 cam in an LZ block will actually be "visible" to the 3x00 cam sensor.

You should be able to fit a 3x00 balancer onto the LZ crank, you'd just need to make a bracket (or drill/tap the timing cover) to hold the 3x00 24x crank sensor.

Then maybe running an LZ on a 3x00 OBD2 ECU would be feasible after all these years.

The cam sensor would only be needed for SFI/sequential ignition, or if you run an OEM ECU that requires it. I'll hopefully be able to look at getting a cam sensor to work with a 3400 style cam in the stock location in an LZ9 soon.

[ericjon262]

I still think OBD1 with an add on board like the EBL from dynamic EFI, or an MS3 would be your best bet. They have come such a long way from the OG megasquirt days. I'm honestly not sure it would be worth anything to run a stock PCM unless you need it to control gauges and things like that.

[v2rocket]

My concern with OBDI is that it's harder to tune or get tuned, and that all the OBDI ECUs are ~10 years older than the 3400 ECUs I can get my hands on. Lot more time for cracked solder joints and dried out caps etc to happen vs a more modern and capable OBD2.

Is this not the case or are the OBDI ECUs still going to be reliable in 5-10 more years? I know computer tech improves at a rapid rate but "old" ECUs is one of the major problems with 944s as they approach their 4th decade.

I can buy a custom wiring harness and tuned PCM for the same cost as a MS PnP kit if they even make one for this engine. I'll have to look into MS more as my perceptions may be dated.

[ericjon262]

if you haven't looked at them yet, the Dynamic EFI stuff is really nice, when I bought my old one ~10 years ago, the customer service was second to none, and most of the tuning headaches go away as the EBL boards are flash based and have their own(included) tuning software.

https://www.dynamicefi.com/EBL_P4_Flash.php

I personally would stay away from 60V6 OBD2 stuff, in my experience, it makes for a ton of headaches that shouldn't be. as far as MS is concerned, you probably won't find a PNP option, but harnesses are simple enough to build.

[v2rocket]

I am curious to know what kind of headaches you're referring to with the OBD2 stuff?
GM ECU tune-ability is the envy of the rest of the automotive world.

[ericjon262]

For V8 applications, I agree, for 3100, 3400. 3500(LX9), they have minimal support at best. the later VVT 3500 and 3900 might better if they share operating systems with the V8's, but the market for V6 stuff overall, isn't big enough for most coders to mess with.

the fuel and spark tables of the 3400 PCM also only go to 6400 RPM, so if you plan to spin faster than that, that is something to consider.

[v2rocket]

6400 is fine for me. But can the 3x00 oiling system, rod bearings, and rods handle much over 6400 anyways ?

[ericjon262]

I'm sure guys have spun them faster, if I were a betting man, I would say the valvetrain would be the limiting factor before anything else. I intend to spin mine until valves float, then back off 200. lol.

[Will'sFiero]

Yeah, I'm late to the party.
Where TF is the quote button? Warning: This forum has basically never sent me topic reply notifications...

Edit; Oh, idiot forum must have logged me out while keeping my name at the top; now that I post, there's the quote button.

6400 is fine for me. But can the 3x00 oiling system, rod bearings, and rods handle much over 6400 anyways ?

Yes. The 3.4 TDC has been turned 7k by quite a few users. It's a DOHC engine, but based on the same architecture as the pushrod engines. You may need/want ARP rod bolts though.

Running coolant one-directional is alien to me - everything I've ever dealt with had the double-pass/U-flow; block first, then up to heads at rear, exit heads at front and back to radiator.

The "single pass" cooling system makes way more sense for FWD than the way you're used to seeing it. It means that GM can run a short hose from the radiator lower connection to the waterpump, then another short hose from the radiator upper connection to the block outlet. With "two pass" cooling, they have to run a long hose from the upper connection all the way across the engine bay to the block coolant outlet at the pulley end of the engine.

Also, I think the single pass method probably results in more consistent coolant temps. The coolant that goes into the block then straight up through the head gasket travels a short distance in the block then a long distance in the cylinder head. The coolant that goes all the way to the back of the block before it goes through the gasket travels a long distance in the block then a short distance in the head.

In "two pass" systems, the cylinders that are furthest from the coolant outlet tend to run the hottest since the coolant goes a long distance through the block, then a long distance through the head. This is well documented in BMW engines, as well as LS and Chevy engines. BMW's S engines (for M cars) tend to have extra coolant manifolding to pull some of the return coolant off each cylinder to equalize cylinder temps. Ferrari also does this. LS and Chevy engines (and V6/60's for that matter) can go to 4 point coolant return to compensate.

what do you think of having cams for the LZ4/9 made by taking a 3x00 hot cam and welding up/grinding the journals to size?

I think Web Camshafts can definitely do it.

An LZ9 is certainly cheap and can get you to your power goals, but have you considered an LLT or LFX 3.6 liter High Feature V6? That's what's in the 5th Gen and later Camaros. It even comes with a longitudinal 6 speed, although I don't know how adaptable that is to the 944 body, or if you'd need to stick to the stock transmission. The LLT makes 300 HP stock and the LFX makes 320ish. They're all aluminum, DOHC, direct injection, 11.3ish compression and have 4 cam variable cam phasing. Having aluminum blocks, they're not a lot heavier than the pushrod engines.

[v2rocket]

I think Web Camshafts can definitely do it.

An LZ9 is certainly cheap and can get you to your power goals, but have you considered an LLT or LFX 3.6 liter High Feature V6? That's what's in the 5th Gen and later Camaros. It even comes with a longitudinal 6 speed, although I don't know how adaptable that is to the 944 body, or if you'd need to stick to the stock transmission. The LLT makes 300 HP stock and the LFX makes 320ish. They're all aluminum, DOHC, direct injection, 11.3ish compression and have 4 cam variable cam phasing. Having aluminum blocks, they're not a lot heavier than the pushrod engines.

First off, I have read your stuff a lot over the years on various forums and always enjoyed your projects and thoughts.

I did pick up an LZ9 last month and tore it down for inspection, everything looks great inside for 150k miles so I am just going to put new gaskets all around and put it in the car with a V6 Cavalier flywheel/PP and a Ford clutch disc that matches my transmission spline.

I used to live down the street from WebCam and have had work done by them before. I did call them about this and they were not interested and didn't think it would be doable; their opinion was that maybe 30 or 40 thousandths was the max, I don't know why and I didn't press them on that point. Neither COMP nor Delta Cam wanted anything to do with it either...I really think it would be a simple enough operation for any shop with a crank welder/grinder setup to do though.

I have looked into the LFX but the DI is more complex to control (and I am just unfamiliar with DI so I wouldn't want to try to Megasquirt it). The stock ECU can be tuned, sure, but that would require adding a lot of extra stuff to my car like DBW pedal, clutch pedal sensor, and a lot of other stuff that Sinister told me would be required. Additionally, the DOHC means that even though a 60 degree V6, it is the same width as an LSx.

My interest in the late 60V6 family is that it is similar to and inspired by the LSx but in a much more compact package which would free up nice working room in my 944's engine bay. I know Fiero guys can sympathize with cramped conditions...

A 3.9 with some work should be able to get to at least 300hp which is more than enough for a car that is 3000lbs with me and a full tank in it.

[SappySE107]

I should have the cam bearing spacers any day now to use the older cams. no VVT option that way but a cam option beats nothing and will work for swaps.

[v2rocket]

Good to know - do you have an idea of pricing for those spacers?

As far as VVT, I',m fine without it.

After doing some reading on the VVT function as implemented in the LZ engines and measuring my LZ9 cam and phaser, I am convinced it's just a clever approach to fuel economy, sort of an Atkinson cycle effect, rather than having any real benefit to the torque curve. This has secondary benefit of lowering NOx emissions by bleeding compression under light load. As I see it, locked fully "advanced" is where the cam needs to be anyways because it is otherwise so puny.

Maybe an aftermarket grind could be made to better use the VVT capability but it seems like a lot of hassle for questionable gain.

FWIW I measured the cam from my '06 LZ9 and got these figures. I haven't reassembled the phaser, so I don't have valve events yet.

Int Dur 196 @ 0.050
Exh Dur 208 @ 0.050
Lobe lift 0.285/0.285 (measured on the cam lobe itself vs base circle)
Rocker ratio ~1.7 (my measurement came to 1.6

[SappySE107]

Yeah, I'm late to the party.
Where TF is the quote button? Warning: This forum has basically never sent me topic reply notifications...

Edit; Oh, idiot forum must have logged me out while keeping my name at the top; now that I post, there's the quote button.

Most of our emails are blocked because of an issue about 15 years ago maybe. Depending on the email used, such as hotmail or yahoo, will never get a notification. As for the logged in thing, that is odd. Our site has been down for 3 days due to a hacker and sorting out the backup. Brad put in quite a bit of time to make this site operational again.