| Slant Six Forum https://slantsix.org/forum/ |
|
| My modest engine setup plan https://slantsix.org/forum/viewtopic.php?t=62501 |
Page 1 of 1 |
| Author: | mryuck [ Thu Jun 21, 2018 5:06 pm ] |
| Post subject: | My modest engine setup plan |
Hello all, I'm in the process of restoring an 87 w150 with the /6 np435 np208 combo. I've used this site for a lot of my research, thanks to all of you for sharing your knowledge. I just want to lay out my proposed engine build for any comments. I'm not shooting for the moon with this setup. This is my first engine build and I'm on a college-student budget. I want a reliable driver and stump-puller, albeit with a little more perk to pull all 4000 lbs of my truck than the stock setup offers. The engine is currently at the machine shop awaiting parts. I ordered an engine rebuild kit from S+J here in WA. I believe they're sending me mostly Sealed Power parts: Main and Rod Bearings (.010 under) Cam bearings Pistons and Rings (.030 over) Gasket set Oil Pump Timing kit Then I ordered the cam and lifters separately from Comp Cams. I went with an RV-type cam, 260 duration with .440 lift. So far the machinist and I have agreed to leave the head mostly alone. I'm thinking a 3-angle valve job and gasket matching will be sufficient for my needs. I'm going to build a 2.25" exhaust with the stock exhaust manifold, based on my research here. If anyone has a different recommendation for pipe diameter I'd love to hear it. I don't want to mess around with getting headers to fit, not to mention cost concerns. For intake, I was thinking the Offenhauser intake with a 2 bbl. I was considering a 4 bbl but I think the stock cylinder head would bottleneck that setup. As far as carbs go, I'm leaning towards a weber 38/38. I like what I've read so far about that setup's performance and I did find a kit on Amazon that I believe others have used on slants. https://www.amazon.com/Weber-Redline-Ca ... B00449S2R6 I found a thread from earlier this year where someone figured out how to adapt the weber to the offy intake using the adapter plates included in the kit and the mr. gasket 1933 adapter kit. It might be easier to use a holley, but I think this should work just fine. So that's it so far! Like I said, this is my first build so the goals are pretty modest. I'm open to advice. Thanks for your time. |
|
| Author: | DusterIdiot [ Thu Jun 21, 2018 5:34 pm ] |
| Post subject: | Re: My modest engine setup plan |
Welcome to the board... should be a good first adventure... I wish you would have posted for advice before buying everything, since you are on a college budget and could have saved $$$ on some of your choices. Quote: I went with an RV-type cam, 260 duration with .440 lift.
The Comp 264 is OK but lacks low end grunt compared to the 252... it is a compromise and not my favorite...it does better if you get 9.2-9.5:1 SCR... but it still leaves a bit to be desired... if you just do stock 8:1-ish the cam will be a bit lazy... You could have saved $$$ by getting an Oregon Cam Regrind and lifters....and could have gotten the same lobe pattern... and not tempted oil pump gear failure.... You still want to clean up the ports on the head and a little bowl blending...regardless. The 1987 block will be a hydraulic cam setup, you will need a late 70's rocker shaft, arms and possibly custom pushrods to make your conversion to the mechanical cam shaft... Make sure you get a weber carburator book... if you have to make mods, you will need to know what changes do what... if they work out of the box, it's all good, but if you have to tune it, they have more adjustments than a Holley and it doesn't take much to goof one up...and parts aren't carried by your local auto parts store... |
|
| Author: | DadTruck [ Thu Jun 21, 2018 7:20 pm ] |
| Post subject: | Re: My modest engine setup plan |
Quote: You could have saved $$$ by getting an Oregon Cam Regrind and lifters
I absolutely agree,Adjusting valves on an A body, is not too bad ergonomically Adjusting valves on a D or W truck is doable, but it is a reach. Unless you really want a mechanical cam, perhaps you can get the vendor to take that Comp cam back.. Regardless of what cam you choose, be sure you have a firm agreement with whom ever is doing the cam install that they degree the cam to the setting that you specify. Also, is there a plan to cc the head, check piston recession? So you and the machine shop agree on how much to cut to get to your desired compression ratio? Raising the compression ratio will get you the biggest bank for your buck,, but don't get the compression up where you need premium. You can't over think an engine build plan, to get exactly what you want, and to know exactly what you have. |
|
| Author: | mryuck [ Thu Jun 21, 2018 8:10 pm ] |
| Post subject: | Re: My modest engine setup plan |
Maybe I missed something... I bought a hydraulic cam and lifter set. I’m pretty sure it should work for my engine. As far as the compression rate goes, your advice sounds interesting. About how much of a deck cut would you recommend to achieve that compression? As far as regrinding the cam goes, that might have been a good idea. I have a mentor of sorts, a mopar nut who works at a parts store i go to. He told me the cam was damaged enough that buying a new one would be a better value. I took his word on it as he’s been building engines for 20 or so years. I also picked out the cam profile on his recommendation. But slants are not his specialty. I’ll make sure to mention the bowl blending and port cleaning to my machinist. How does the comp cam tempt oil pump gear failure? Thanks. Andrew |
|
| Author: | halfafish [ Thu Jun 21, 2018 8:39 pm ] |
| Post subject: | Re: My modest engine setup plan |
Quote: How does the comp cam tempt oil pump gear failure?
This is nothing specific to the Comp cam. It is valid for all cams and is a slant six peculiarity. Oil pump gears develop an affinity to the cam they were born with. When swapping a cam but keeping the oil pump gear, there is a tendency for the oil pump gear to self-destruct. The cure for this is to keep the cam and oil pump gear together. That's why folks get their cam reground from OCG instead of buying a new cam.
|
|
| Author: | DadTruck [ Fri Jun 22, 2018 5:54 am ] |
| Post subject: | Re: My modest engine setup plan |
here is a compression calculator https://www.rbracing-rsr.com/compstaticcalc.html from the factory, 225 slants typically had < 8.0 static I am thinking that for your application W150, heavy truck, setting the compression close to 8.5 to 1 would give you a performance boost and keep you on regular gas and give you some room to play with ignition timing. you will need to cc your head chambers, using a syringe from Tractor Supply for the measurement device is acceptable. Keep in mind most aftermarket pistons will have the compression height lowered to make up for the additional displacement and actually reduce compression. Exactly what you don't want to happen. I don't know exactly where you are in the engine machining process, but a nice way to get the compression ratio that you are looking for, is to do the block and crank work first. Have maybe .030 cut from the block. After the block is finished install the crank and #1 and #6 pistons and rods and measure the piston recession. Using those piston recession numbers play with the head cc volume in the compression calculator to zero in on the exact static compression ration that you are after. Then have the head cut to get the head combustion chamber volume that you want. and a question, what was the 'damage' on the OE cam? was it wear on the fuel pump lob? If so that is very normal on a high mileage slant and Oregon Cams would repair that by welding it for about $25.00 If you still have the OE cam core, put it and the OE oil pump together in your parts stash, for future use. |
|
| Author: | slantzilla [ Fri Jun 22, 2018 9:55 am ] |
| Post subject: | Re: My modest engine setup plan |
The biggest things about a hydraulic cam will be making sure your machinist makes all the valve stems the same height and checcking lifter preload when you put the rockers back on. With valve grinding and head/block decking you may need to have pushrods made. |
|
| Author: | mryuck [ Wed Jun 27, 2018 7:49 am ] |
| Post subject: | Re: My modest engine setup plan |
Thanks for the tips. I’ll hold onto that old cam and oil pump. I believe it was fuel pump lobe wear. I have no doubt I’ll be doing another slant six build sometime soon, it’s been a lot of fun so far. As far as intake goes, I found a super six setup on ebay today with a carter bbd. Lucky me! So i’ll be running that instead of the offenhauser for budgetary reasons. Thanks again all. I’ll post an update when I have everything together. |
|
| Page 1 of 1 | All times are UTC-08:00 |
| Powered by phpBB® Forum Software © phpBB Limited https://www.phpbb.com/ |
|