Stroker experts Jmort, Drax, DAW

[ToplessZ]

No I just have the microtech mt-4 It was a deal that I could not pass on. Ooks to be a very good unit with alot of adjustability etc. Anyhow I may not use the msd btm. I may use something else If I find a better option. I already have a 6al so the msd muti function ignition controller may be a good option. Wouldn't mind hearing some mre input here though as there may be better options out there.

[z-ya]

Are you going to use an NA distributor? You'll be stuck with the advance curve unless you buy some other ignition box. You are better off with it all in one box, that way you will have complete control from the same unit. With what you will end up spending on ignition add ons, you could probably buy the Microtech with direct fire ignition.

 

Pete

[ToplessZ]

Well I just got the microtech with the hand controller unit for 430 dollars brand new. I was actually planning on using the 82 turbo distributer. I could use the factory computer just to run the ignition. I do like msd's digital programmable ignitions but they are a little pricey. Thats way down the road now Im trying to find a set of stock 3sgte rods somewhere out there. And when I get those and get the calculations done I will see if there are any off the shelf usable pistons or if not get a set made. It will be awhile before I can afford the ignition upgrade after getting the engine work performed. For now Im just running a stock turbo setup so I can have something that runs.

[wheelman]

Jared,

I've read through this thread and am curious about how much you plan on spending on this engine. What is your main focus for the car, drag racing, road racing/autoX, daily driver or combination? I don't want to hi-jack the thread I'm just curious what an engine like you plan to build will cost and what the target application is, for my future reference.

 

Wheelman

[ToplessZ]

Well I dont have a price cap yet but Im hoping to not spend a ton. Im planning to run a refreshed p90 since I have two of them the second one will have some money socked into it and added as a stage two upgrade. I need to verify but it appears that custom pistons through summit racing can be had for just under 500 dollars made by ross I believe. Im going to have 220 in my crank 500 in comlete zxt that engine is coming from but sold some parts and traded wheels for 240 dash so the engine and donar car we could pretty much consider free. Im thinking 1500 in machine work turning and balencing crank. Over bore and hone the block etc it may raise above that cost... may knife edge the crank but not sure yet. another 300 for assembly 200 on fresh valve job and viton seals. Not sure if Im doing anything else to the head yet beside a mild casting cleanup. Im planning on running a t61 turbo or similar between 5 and 700 for that I still need to get a damper probably about 400 for the one Im looking at but thats not verified. It depends what you want to include in the engine cost. Engine management custom intake, DP etc. The list goes forever. Im going to try to do it for about 4000 but its going to be close. Going to have about 200 in my beefy forged arp studded toyota 3sgte rods. Im sure Im leaving out things here but thats a start. I plan on using this as a light duty street car and weekend drag use. Mostly drag but I plan on having the suspension set up nicely for the occasional road course. Ahh very disorganized post. I apologize. What hp do I plan to get out of this.....Hmmm As much as possible. Reason for the longer rod and stroke. Little better on revs and a little better on reliability (detonation resistance). Might as well dare to be different

[DAW]

Jared, I wasn't going to post again on this thread but I feel like I ought to caution you on some options you're considering. You are doing a good job of calculating specs and working "out-of-the-box" to put together a hybrid engine but you are not weighing all the variables.

 

Assuming that you are building an engine using L28 block, L28 or LD28 crank while optimizing r/s, you are searching for rods longer than 133mm. One important parameter I think you haven't included is rod cap width. An advantage in using L-series rods is the consistant cap width. When you attempt to build your hybrid engine and are selecting rod lengths you want a rod with equivelant or slightly wider cap width (wider can be narrowed, too narrow are useless).

 

Ideally, you want a rod with an equivelant rod journal size matched to the stock L6 journal dia. of 1.9670-1.9675". You can use a rod with a slightly larger large-end dia. by selecting bearing undersizes, usually 0.010" or 0.020" increments, for that particular rod to match up to the L6 journal size. Conversely, you can machine the crank journals (added costs) to match a rod with a too-small large-end dia. to the L6 crank. You don't want to trade off crank strength though, and undersizing to 1.768" dia. weakens the crank too much.

 

One category of rods source generally would be V6 engines because the cap widths are usually too narrow compared to L series engines and other inline 4 and 6cyls. Rods in that category include Mitsubishi 6G72 with 1.9650 dia. end, Hyundai Sonata 3.0L with 1.9685 dia., and Acura 3.0L with 1.9676.

 

A rod source you might consider is SR20DE. At 136.3mm length and 1.886" journal you could have you crank machined and still maintain adequate strength. I don't know the cap width, however, to determine if they'd be suitable. Anyone have this spec? Another inline rod to look into would be Volvo B630F. Large-end dia. fits their 1.969" dia. journal so using 0.020" undersize Volvo bearings works out to fit the stock L6 journal if the cap width is useable. Anyone have that spec?

 

Work those variables out first and then look to piston sources to fit. You might be able to transfer a rod-piston assembly unit but to end up with the bore size and pin ht. you want it's unlikely. You could move the rod journal effective centerlines inward or outward in order to change stroke if you have the journals undersized (increase throw length on L28 or decrease LD28) and/or fit the rod choice to correspond to block ht. and piston pin ht. to make it all work out and you could conceivably have an LD28 140mm rod small-end reworked to shorten effective length while reducing the pin dia. and lightening the rod.

 

A long post but I don't feel like I wasted the reader's time or squandered the space. DAW

[ToplessZ]

Thanks Daw. Im going to give the 3sgte rods a shot. They are really strong which is my main concern. They are 137.9982 in length. I dont have a measurement for rod cap width but they look pretty wide. I cant find that measurement anywhere. Im getting a set really cheap so I can measure them before I buy the second cheap set I have lined up. They look like they will work great. They are also already bushed for full floating pistons stock. The con rod journal size is just slightly under the datsun I believe 1.899X The honda rods required a 1.771 journal which seems to compramise strength to me. I have been reading on the mr2 board that these rods are good to over 500 hp if prepped and arp studded and thats in a 4cyl Id say they will be stronger then the 133mm datsun 240z rods. Ill have a picture shortly.

[Doug71zt]

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=2490011598&category=6187

 

I guess the LD28 block will clear the hood, seems like that eliminates one problem. LD28 turbo in a 240Z, looks like stock mounting position.

 

Doug

[DAW]

The diesel head/valve cover assy. is shorter than the gas head/valve cover by about the same distance as the LD28 block is taller than the L28 block. With the gas head on the diesel block it sits 20mm higher. No interference on my Maxima and I think the engine could be dropped slightly on the mounts in the Z to ensure hood clearance. DAW