HarryB

I know this has been discussed before, and been through all these threads (especially through Emilio's engine build ideas one) numerous times; just wanna sum up everything for my (and possibly similar) builds.

Goals
Driveability in DD conditions/cursing, occasional trackbacks, a lot of mountain pass driving, RELIABILITY.

Initial plan

7500 max redline, stock CR (10:1), pump gas (no E85 here), Rotrex C30-74
I have sourced a complete BP6D engine with 30k miles, and a BP4W head that I plan on using.

Bottom end:
Forged rods (most probably Manley w. ARP bolts)
Maruha oil pan baffles
Boundary billet oil pump gear
ARP head bolts
OEM BP4W head gasket
Usual service items (seals etc.)
Stock/untouched otherwise (OEM crank bearings/bolts, pistons, rings etc)

Head:
1mm oversize stainless valves
2-angle valve job & de-shrouding
OEM valve seals
Supertech "light double" springs
BP5A intake cam (possibly custom regrinds later down the road)
Stock lifters (for now)
Ports cast flash cleanup

Ancillaries:
EUDM Squaretop manifold
Maxim Works exhaust manifold to custom 2.5" exhaust
Rotrex C30-74 blower

Anything you would do differently? Any "while you are in there" stuff that I am overlooking?

cpierr03

I don't see what you're using for engine management, but if you have a complete BP6D longblock, why not just use the VVT head?

HarryB

Right; I was sure I was forgetting something!

Management & fuel:
MSLabs MS2 Enhanced PnP
FlowForce 640cc injectors
AEM UEGO WB
DW200 fuel pump

Reason for the head swap is ECU and cam options; much cheaper and more options for the non-VVT head AFAIK (although I will be loosing mid range compared to a VVT head)

Stock

matrussell122

iTrader: (1)

Seems like a decent setup. Do you have an ECU already? If not i would suggest a MS3x. Also there are plenty of VVT options, a head can be had for 200-300 and you wont need an aftermarket cam but they are available. Also you could get away with the oem fuel pump.

HarryB

Unfortunately yes, I do have an ECU, else I would be going MS3Mini. My MS2e was bought new by a good friend and used maybe for 2 weeks before parting out his car; I know it is considered "old tech" but my feeling is that I do not need something more for my goals. BTW the engine I have picked up comes complete, so I already have a VVT head, and I have already bought a BP4W (even before picking the engine, was dirt cheap, could not resist). I consider the oil pump just as a safety precaution/"while I am in there" mod.

matrussell122

iTrader: (1)

I still think you should run the vvt head even in you run with the vvt un-hooked. Then down the road upgrade your ecu.

Savington

iTrader: (31)

Foregoing VVT with a Rotrex is just foolish, IMO.

HarryB

This is not a bad idea, but I would have to remove the head anyways to swap to a BP4W HG (due to reroute). Given this, I can always keep the VVT head aside and swap it back at some point. In that case I may want to spare the trouble/expenses "building" the BP4W head tho.

But still better than the current 1.6, no?

Rotrex is staying. I know how most of you guys feel about it, but having experienced both, I like that N/A (call me lack of mid-range) feel. Yes, I know it is going to be slower than a turbo, just do not mind much (yet).

HarryB

Double post (damn)

Savington

iTrader: (31)

My comment wasn't an indictment of the Rotrex, but of the '99 head. Your usage profile is daily-driver and backroads, but all of the modifications you're doing are focused on top end power. Rotrex, head porting, etc. The motor being discussed is going to cost you several thousand dollars, but you won't spend the extra $400 or so to upgrade from your MS2 to an MS3 Mini?

You are telling us what your goals are, and then insisting on a build path which is counter to those goals.

Sell your BP4W head and use the money to upgrade your ECU.

Marioshi

I think Savington was being critical of your choice of not going VVT more than going rotrex.

I don't understand how you can be dropping thousands into an engine build, but not willing to upgrade to an MS3?

Oops, I see he already covered it, this is what happens when you leave a window open for 20 minutes while you are talking to your boss!

HarryB

Thanks for the advice, really appreciate it! I should have mentioned I am located in Europe; all in I have spent way less than 500 so far for the engine and the extra head. For the BP4W, I do not plan any heavy porting, just cleaning up the casting defects on the runners a bit. I see two options ATM:

1. Keep the VVT long block, and use the funds I will save on valves, head rebuild plus any funds recouped from the BP4W head towards an MS3 mini. I would still get uprated valve springs as a "safety measure", plus head bolts/BP4W head gasket. Would you advise oversize valves here as well? This means I will manage to sell my MS2 first; have been advertising it for a couple of months now to no avail.

2. Sell the VVT head and use that money (plus the money I will save on selling the MS2 and buying an MS3 mini) towards rebuilding the BP4W head.

Both options would cost about the same in total, and my understanding is that 1 will make a bit more power. However, 2 would have more mid-range, thus possibly better suited to my overall goals. Hmmm...

Marioshi

Maybe @Twibs415 can weigh in, he has a lot of experience with this rotrex/engine building stuff.

HarryB

@Twibs415 posts were actually what contributed towards the BP4W head choice, as he showed that cams can make significant difference. Thing is that I can find a set of cams for a BP4W for less than half than a set of VVT ones. That difference in cost alone would cover the rebuild of the BP4W head. Might sound like I am cheaping out, but I do not; just looking to get the best value for my money out of the engine itself.

Marioshi

Yeah, I feel that, I still wonder though if a VVT build with MS3 controlling everything wouldn't pay dividends in drive-ability. You are just looking at spending a lot on your build for a street motor IMO. I mean, how aggressive are you going to get with cams on the street anyway? Twibs built my motor and I didn't even go big cams or valves (yet) and I am NA (for now) and mine is a track only car!

I think stockish VVT rotrex build would be amazing, you can do valve springs and rods if you want, but I wouldn't spend the money on all that other stuff personally. Maybe the oil pump, but maybe just a good damper, it's not like this car is going to live purely in the high revs.

HarryB

What you propose is actually pretty reasonable. Valve springs and rods are more of "safety" items, eliminating possible weak links if you may, and the pump gear was actually gifted to me by a friend who changed plans. For the rest I agree that they are not really needed.

HarryB

Thanks everyone for chiming in. After some thought I will be keeping the VVT head, and buying an MS3 to go with it. I also decided against any major head modifications for now, may do so later down the road. New plan summary:

Bottom end:
Forged rods (Manley w. ARP bolts)
Maruha oil pan baffles
Boundary billet oil pump gear
ARP head bolts
OEM BP4W head gasket
Usual service items (seals etc.)
Stock/untouched otherwise (OEM crank bearings/bolts, pistons, rings etc)

I was actually thinking leaving the crank in place, remove rods/pistons, clean up pistons, slap new rods, put it back together. I would consider changing piston rings for piece of mind, but not sure. Also leaving the crank in place means no decking of the block. I will measure flatness and roughness, and will remove crank if needed. I am also torn between ACL and OEM main rod bearings, any suggestions?

Head:
Inspect all valves/seats/guides. I expect them to be in good nick (30k miles motor), and leave them untouched. If they are not, I will consider my options but most probably going to oversize by 1mm. Was thinking Supertech stainless, but also looking at European manufacturers as well.
New OEM valve seals
Eibach 20410.116 intake valve springs
Stock lifters (for now)
Ports cast flash cleanup
Deck/cleanup to get a proper HG surface

Regarding valve springs, I was thinking of using heavier ones only on the intake. Given the OEM cam specs, OEMish rev limiter and Rotrex, I do not see any need for heavier springs on the exhaust side; my logic says that they will only increase wear and parasitic losses, even marginally. On the intake side, and calculating a boost of 14.5psi over a stock valve, I see that I need an additional 37lbf of seat pressure to counteract it. It's oversimplified as a calculation but at least it gives me an idea. Does anyone know the OEM valve seat pressure on a VVT head? AFAIK VVT intake springs are heavier compared to the BP4W ones. I plan on measuring mine when the engine arrives eventually.

Ancillaries:
EUDM Squaretop manifold
Maxim Works exhaust manifold to custom 2.5" exhaust
Rotrex C30-74 blower

shuiend

iTrader: (24)

If pistons come out, then you need new rings. There is no getting around that.

HarryB

Makes sense; wear patterns. Would you suggest OEM or otherwise? I would go OEM, but I would appreciate different experiences.