Low cost engine build

[madjak]

I've finished my pneumatic sequential box and realised its probably not a great idea to bolt it up to my race engine. One miss slip (which is likely) and I'll put a piston through the block and maybe destroy the head.

So instead and going to put together a bitser engine from all my spare parts. I figured I may as well document the build as I go as it should be fairly interesting.

I have already have or have sourced the following bits:

Protege solid lifter engine
Lightweight crank
2001 oem pistons
Self ported BP05 head (75% finished)
Sr20DE valves
Subs left over from my race engine (some of the buckets have chips from valve bouncing - ill buy 4 new ones)
Eibach springs... good for 8000rpm
Adjustable cam gears
BP05 cams plus 2 sets of protege cams.
I even have a set of unused bearings and gaskets that I found for free on gumtree.

I'll run all my standard ancilleries. So Honda skunk2 IM, COPs, EWP, twin clutch etc... I'm basically building a long block.

The goal is to build it build a fairly reasonable race engine for as little $ as possible. That means doing as much myself as I can.

[NitroDann]

Lightweight crank = protege cast crank?

[madjak]

Lightweight crank = protege cast crank?

Nah... cut down and bladed MX5 crank. Its forged so maybe stronger than the SOHC cast protege one? Maybe. Part of this is to test the crank too. See if things go bang at 8000rpm or not and check the bearings.

Question: Do I run the oil squirters or not? I don't in my race engine but that's running Wiseco pistons. Do OEM pistons really need the extra cooling in a NA build?

[manga_blue]

BP05 NA8 cams are profiled for hydraulic lifters. They don't work with solids.

BP05 Astina cams are profiled for solid lifters but for maximum smoothness at shopping centre speeds.

Either way you'll need better cams that work with solid lifters. NB8A BP4W cams are the cheapest starting point.

[project.r.racing]

I'd comment also. But it really depends on what year the protege cams are 90-96 hla 96-98 solid.

The solid varient from a Astina is pretty much the same intake cam spec, just opens and closes 2 degrees earlier and has 0.15mm more lift. So nothing a cam gear cannot overcome, and you get some more lift over NA8 specs.

But the ex cam is the rotten egg. 9 degrees less opening duration opening and closing later, but 0.23 more lift.

IF you where going for a cheaper turbo engine and trying for less overlap and more lift from your cams, they'd be great. But you know what. My old Astina did alright with said cams. So you shift at 6K instead of 6.5K. You'll find some extra torque somewhere in the middle of the rev range haha. 78s at Lakeside for a FWD 1150kg car with full interior is okay sihfting at 6K haha. I'm pretty sure a RWD 1000kg should do better.

p.s. I would not use a crank from a B8 SOHC FWD Mazda. Since is was only designed to do 5.5K max, I'm not sure it would be right for your application.

[madjak]

I have 1995 BP05 cams, 1997 protege (hydraulic lifters) and 1998 Protege cams (2Y solid). So I could try a combination of any. Exintake swap or whatever.

The 2Y cams have more lift and visibly more duration. I'll chase down the specs.

The cams can be changed out later to something more decent. Might even move my race cams out if I Rotrex the other engine. For now this build is to test my crank and gearbox so I need to be able to hit high revs... not necessarily make massive power.

But I'll get the compression up so that it's just a cam change away from something more ideal.

[project.r.racing]

Oops I had a typo in my last post, did 69s, not 78s around Lakeside.

I also had both engines over 7000rpm at times in their lifes. One engine lasted 263,000km, and the last engine in lasted 230,000km. Both solid lifter versions. Stock FWD ECU for carpark driving. So 6K was the change point. The only problem I ever had with both engines was the usual valve stem seals and crank end seals.

I'm pretty sure you wont have issues with you plans using FWD engine parts.

[project.r.racing]

in 233 03 btdc 50 abdc 8.3
ex 241 51 bbdc 10 atdc 8.9

if i got the specs written down right. the ramps would be more aggressive, so could be similar allowed airflow to older BP05 hla cams.

I'm curious to see your results. Keep us posted.

[madjak]

Thanks for that... what I've found is that the 2Y cams are supposed to have fairly low 1mm duration, but they visually look wider than the BP-05 cams which is a contradiction. I'll run with them for now and see how the engine goes. I might do a quick degree check on them to see what they are.

So far, I've spent $250 on gaskets and seals but that should be enough for the engine build.
I bought the head and block 12 months ago for $50 from a guy wrecking an Astina.
I picked up the 2001 pistons and rods for $100 and which will also need new rings $75
Head porting only cost me $70 in sanding rolls and abrasive pads... and about 20 hours work.
SR20DE valves are free
Lightweight crank - around 20 hours work.

The only parts that will cost me with be getting the crank balanced, installing new valve guides and machining the seats. I could do the seats myself, however I struggled last time to get a good seal due to the valve guides from Miataroadster.com being drilled way off centre. I had to move the seat a long way which made it tough.

The SR20 valves are 34.15mm intakes (so 1.15mm oversize) and the exhaust valves are 30.15mm (so 2.15mm oversize). I'll post pictures as soon as I start putting it all together.

[StanTheMan]

Are you doing solid lifters or hydrolic? Do you have lots of spacers for the lifter gaps?

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[madjak]

Solid... I have lots of 6mm and 5.6mm shims. Hopefully I can get it close with them. I have ordered specific sizes from Precision Shims before.

One day I'll get my act together and organise a mailout pack of shims. Anyone doing a solid head can borrow it as long as they replace the shims. It would make the process a lot quicker.

[StanTheMan]

I just found that the shims are a significant cost when changing cams. At $12 a pop.
That is.... when trying to do a budget build.
If youre inly doing 1 cam...its not so bad.

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[StanTheMan]

I also had to redo all of mine after reseating valves.

Lesson learned...duh

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[greenMachine]

I just found that the shims are a significant cost when changing cams. At $12 a pop.

Where did you get them Stan - Precision Shims in Melbourne? That is more than I remember, but maybe prices have gone up , it was while ago.

Then again, I have a bag of spare shims somewhere, if ever I find them, I might be able to turn a profit

[StanTheMan]

that's for sure.

yes precision Shims in Melbourne


maybe its because I'm a weekend warrior....and he gives you established builders a much better price.

it was like $210 including postage. His service hasn't changed. I'm told its very quick in the past. Nothing has changed.

once Patchy is back. eventually I'll have to re do them again as I want to also install some aftermarket cams. I installed the standard ones to get it over the pits easier.

perhaps we can combine all our shims & swap. happy to post what I have

I have 3 complete sets with very different thicknesses.
1 standard set around 3.19-3.29 sizes
1x around the 4.25-4.33 sizes
currently fitted is between 3.03-3.17 but eventually they will come out
1 lot thats currenbtly fitted wich will eventually be re done is