Street Sweeper pre-build

7233 Views 39 Replies 12 Participants Last post by madhatterpdc, Mar 26, 2005

madhatterpdc

Discussion Starter · Jul 21, 2004

This post has a couple different intentions. Primary, is to post my planned motor specs and expectations and recieve feedback from the community. Secondary, is to recruit recommendations for suppliers for the necessary outstanding components.

The Street Sweeper name just came to me as I was trying to find a subject for this thread. Expectations include a motor that can provide enough juice so that the GT can keep up (150 -175 HP), retain at least a little bit of streetability (to get to and from cruises and the track). It must rev quickly, and run on 93 octane (the best available in the area). A 5-speed conversion will be installed from OGTS with a lightened flywheel and S-10 clutch. Handling will be probably be addressed with 1.5" lower springs, Koni reds and OGTS sway bars. Braking will more than likely be the big stuff from a '75 Manta.

But the motor is what is important in the nearest future. Items that I have on hand include:
- a good block already torn down with minimal wear
- stock crank is in good shape
- Dual side draft manifolds with dual SK DCOE 40's
- a built head, specs include
-- Cam: .488 lift, 295 adv duration (262 @ 0.050), 110 lobe center
-- Valves: 44mm intake, 35mm exhaust, with 11/32" stem size, tapered at seat
-- Titanium springs and Deep titanium retainers (remember the deep part for a later question)
-- RallyBob/Samdog Roller Rockers with stud girdle.

Parts I am not sure about what to choose, where to find,
- 11:1 compression ratio pistons, 3.74", Venolis vs. Arias vs. other?
- 2.2 vs. 2.0
- if 2.2, then should I start the search for an Opel 2.2 crank or have my 1.9 crank stroked
- recommended supplier of flat titanium retainers that don't interfere with roller rockers.
- are the dual 40's going to be "enough" for the RPM's that the cam require

Does anyone out there have parts that I am looking for (crank, pistons, retainers). My preference is to purchase from other OGT.com members, then OGTS, then direct from suppliers.

Any insight, recommendations, corrections appreciated.

Brian

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Gary

· #21 · Nov 11, 2004

madhatterpdc said:
...I will also be seeking out a burette today...

If I were Madhatter, I'd be seeking out a brunette after all those late night calculations.

madhatterpdc

Discussion Starter · #22 · Nov 11, 2004

I already have a brunette, although sometimes I wish I didn't. Although it may work out that said brunette is going to help me find a burette (she's a nurse and they use them for admixtures). My quest to find one in town was fruitless.

The bad habit of grinding out calculations until absurd hours of the morning started when I was in High School and fascinated with physics. It became more ingrained in my lifestyle when I went to Pharmacy School and would stay up late cramming for exams. Now that I am out of school I am still fascinated with figuring things out, whether it's drafting a design for a custom built computer case, calculating CR or even projecting my finances. You should see my notebook! I've even gone so far as to draft a design of lightsaber. The only limiting factor was power, it would have needed the entire annual production of energy from a nuclear power station... or a set of double-A batteries... I might have forgotten a decimal somewhere.

Sometimes I wake up in the morning and look at my work and say "Brilliant!" Other times I look at my work and say "What was even trying to accomplish?" Insomnia, the disease of a mind that can't sit still, but a body that won't move.

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GTJIM (R.I.P.)

· #23 · Nov 12, 2004

tekenaar said:
Taking cam profile into consideration when estimating (calculating) dynamic CRs certainly helps explain why my 10.7 CR, domed piston, large valve, stroked engine runs on 87 RON without any pinging or resorting to retarded ignition.
Result: Street sweeping TORQUE MONSTER!

Otto, Ran your specs through the kb-silvolite dynamic compression ratio calculator and it shows how much intake closing point affects the "running" CR

Used 77mm stroke and 128 con rod length. Intake closing position is not directly available from your cam specs so have used several different closing points to show the effect. Cam duration is taken at .050" lift. Took static CR as 10.7:1 as in your specifications.

30 degrees after bottom dead centre effective CR = 10.23:1
40 = 9.87:1
50 = 9.40:1
60 = 8.83:1

That longer cam duration sure has a big effect on the compression ratio the motor "sees" when it is actually measured from the intake closing point!

madhatterpdc

Discussion Starter · #24 · Nov 15, 2004

I have been in the process of cc'ing my head for the last few days. The reason that it has taken me a few days is because my first attempt yielded a result of 56.2 cc's. I was pretty sure that was just plain wrong and blamed my technique. I revised my prep and measurement processes (including a better seal), and I now consistently return a result of 53.8 cc's on the #2 cylinder. I haven't gone back to cc the rest, but I will as soon as I have more time.

I was under the impression that a stock head should be under 52.6 cc's, and with a decked head and oversized valves, that number should be decreased accordingly. With the oversized valves (44mm/35mm) and the head appears to at least been shaved I would have expected a much smaller combustion chamber.

I have attached a picture of #1 chamber, the pic is crappy becuase my camera pitches a fit in close-ups. Maybe there is something that has been done to this head that my untrained eye can't see.

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Paul

· #25 · Nov 15, 2004

Brian,

Misc. thoughts on chamber volume and Compression Ratio...

Were new hardened seats installed under the new oversize valves? Its hard to tell from the picture if/how much the valve sticks up into the combustion chamber reducing volume (cc's) and increasing CR. If the valves (intake especially) are sitting down in the valve seat, then chamber volume will increase dropping CR.

I can tell from the picture that the CC wall near the intake valve was not reshaped/deshrouded causing in increase in chamber volume and a decrease in CR.

You can measure the head thickness from the head/block mounting surface up to the valve cover mounting surface to determine if/how much the head has been milled. I don't have that dimension handy at the moment, but several probably know it by heart..... Travis, Bob........ Anyone.....Anyone.

GL

RallyBob

· #26 · Nov 15, 2004

These chambers have been unshrouded somewhat, this most likely is the cause of the 'high' cc's. Don't feel bad, I just spoke to someone with a big valve 2.4 head that measured 64 cc's, even though they're 54 cc's stock!

So you lose some compression, it is easily 'retrieved'.....

103mm is the stock thickness.

Hiro

· #27 · Nov 15, 2004 (Edited by Moderator)

RallyBob said:
Don't feel bad, I just spoke to someone with a big valve 2.4 head that measured 64 cc's, even though they're 54 cc's stock!
.

Yes indeed... *sigh*
The inlet valve is so recessed it sits behind the exhaust valve...
I think this head will end up with a blower AND a turbo

Hiro

(trying to post a pic...)

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madhatterpdc

Discussion Starter · #28 · Nov 16, 2004

It's not that I was concerned about losing the compression, it was more concern that I was measuring wrong. I have a bad habit of assuming that my methods are wrong. Thanks for the words of encouragement everybody.

After I posted previously, I took another well-used head that I have that I believe to be stock. I cleaned out all the carbon build-up and looked at them side-by-side. Now that I am looking more critically and at a *clean* stock chamber, I can definitely see the differences. For one, the little bump in between the valves is almost gone, the valves are pretty close to being seated flat, and the all the surfaces are much smoother. I feel a lot more confident about my measurements now. Now that I am a lot more confident about it and am getting much better at it, I am going to cc the clean, stock head and the remaining 3 pots on my big head. If I can get my camera to behave, I will post as many pictures as feasible.

So, with a combustion chamber volume of 53.8cc, a 2.2 crank (3.05" stroke), assume 3.74" pistons, and a target CR of 11:1, my calculations indicate that a piston with a net volume of 6cc, after valve reliefs would be necessary. Any seconds?

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RallyBob

· #29 · Nov 16, 2004

madhatterpdc said:
So, with a combustion chamber volume of 53.8cc, a 2.2 crank (3.05" stroke), assume 3.74" pistons, and a target CR of 11:1, my calculations indicate that a piston with a net volume of 6cc, after valve reliefs would be necessary. Any seconds?

I threw some numbers at it, came up with 9.415:1 with a flat-top piston, assuming zero deck height, .032" compressed gasket thickness, 1.0 cc ring land volume, and 4.5 cc valve relief volume (typical for 'big' valves). Consequently, a 5 cc dome yields 10.113:1 compression, and a 10 cc dome yields 10.937:1 compression.

But it's late, I'm tired, and I could easily be wrong....

Bob

davegt27

· #30 · Nov 16, 2004 (Edited)

_Hows this look _______________________________________________________________
+¦ Motion-PC Dyno Shop--Registered To: david ligon
¦ Bore/Stroke CylinderHead C/Ratio Induction Exhaust Camshaft
¦Label1
¦ __ Short Block: Opel 2.2 Bore: 3.740 Stroke: 3.050
¦ Number Cyl: 4 Cyl Volume (cc): 549.1 CID: 134.0
¦ ----------------------------------------------------------------
¦ __ Cylinder Heads: SmallBlock/Pocket Porting, Large Valves
¦ Intake Valve: 1.73 (Man) Exhaust Valve: 1.50 (Man)
¦ ----------------------------------------------------------------
¦ __ Compression Ratio: 11.00 Combustion Space (cc): 54.9
¦ ----------------------------------------------------------------
¦ __ Induction Flow: 600 CFM 4/8-BBL Carb Or Fuel Inj
¦ Manifold Type: Individual Runner (I.R.)
¦ ----------------------------------------------------------------
¦ __ Exhaust System: H.P. Manifolds And Mufflers
¦ ----------------------------------------------------------------
¦ __ Camshaft Type: opelcam Lifter Type: Solid
¦ Cam Specs @: 0.050-Lift Int Centerline: 109.0
¦ IVO (BTDC): 22.0 IVC (ABDC): 60.0 Int Duration: 262.0
¦ EVO (BBDC): 62.0 EVC (ATDC): 20.0 Exh Duration: 262.0
¦ Int Lift @Valve: 0.488 (Man) Lobe-Center Angle: 110.0
¦ Exh Lift @Valve: 0.488 (Man) Advance(+)/Retard(-): 0
¦ ----------------------------------------------------------------
¦

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madhatterpdc

Discussion Starter · #31 · Nov 16, 2004

Thanks Dave, I appreciate the information. The only thing different that I noticed is the cam is 110 deg for intake and exhaust.

Bob, I think we are both correct... sort of (you're more right than I am). The reason I say that is becuase my 6cc's is net piston volume including both dome and reliefs, where your 10cc's is the gross dome volume and then the reliefs would be subtracted from that... I think.

Although I do have to make the concession that your calculations include ring land volume and a slightly thinner head gasket (.032 vs .038). With those additional figures, my 6cc's should actually be 4.2cc's.

So in order to obtain a CR close to 11:1, a piston with a *dome volume* of 10cc's and a *piston volume* of 4.2cc's is required.

I hope I explained that correctly.

GTJIM (R.I.P.)

· #32 · Nov 16, 2004

madhatterpdc said:
For one, the little bump in between the valves is almost gone, the valves are pretty close to being seated flat, and the all the surfaces are much smoother.

BTW: Just for interests sake that "little bump" is a machining datum that is used to set up the head for initial machining operations. The fixture the head is mounted in for machining probably has pins on it that locate off these "little bumps" so that the combustion chambers will end up the same depth when the head face is surface cut in a subsequent operation.

Scott McDonald

· #33 · Dec 7, 2004

Pistons

BRC makes aluminum 94mm pistons.

davegt27

· #34 · Dec 20, 2004

well Brian hows the project going?

i decided to take the plunge

I have a 2.2 short block at the machinist right now

Hope to get it back sometime after the Holidays.

its just going to be a street, track day motor

next problem is coming up with a Head
Oh I forgot I need a front cover someone told me you cant get them anymore.

Davegt27

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madhatterpdc

Discussion Starter · #35 · Dec 20, 2004

The 2.2 crank is currently at the machinist right now getting wet-mag'ed, and if it passes that test, then it is going to get turned. Pretty much, everything is on hold because tuning a 2.0 is a world away from a 2.2, and I hate to invest too much time and parts into it, then have to change course (as I already have done repeatedly).

That and the holidays have kicked me in the neither regions.

tekenaar

· #36 · Dec 21, 2004

Or is it ?

madhatterpdc said:
The 2.2 crank is currently at the machinist right now getting wet-mag'ed, and if it passes that test, then it is going to get turned. Pretty much, everything is on hold because tuning a 2.0 is a world away from a 2.2, and I hate to invest too much time and parts into it, then have to change course (as I already have done repeatedly).

That and the holidays have kicked me in the neither regions.

UNLESS you're trying to tell us something else entirely, I think that's supposed to be "nether regions".

greensmurf20

· #37 · Dec 21, 2004

and you can't use the "4 AM" excuse this time brian!!!

davegt27

· #38 · Dec 21, 2004

I understand

I turned the 2.2 stuff in right before Thanksgiving and they said a few weeks

So I figure some time in the spring Ha Ha. that will give me enough time to pay back taxes on my House and save up enough to pay for the motor.

What's your thinking on the Head did you nail down that part of the setup?

I don't think there will be to much difference in tuning a 2.0 or 2.2.

I do plan to use FI. Either 4AG 20v Throttle bodies or some ORE Throttle bodies I picked up.

Davegt27

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madhatterpdc

Discussion Starter · #39 · Dec 21, 2004

Yes, Indeed I included an extra "i" in my spelling. Regardless, I'm confident that my point was made, that this holiday seasons has been serious pain in the a$$.

Dave, the head is pretty much set. The only component that I was debating was the cam, and I've decided to stay with what I have. My crank was dropped of about the same time as your motor, and I was given the same estimate. I am also expecting hear back sometime this spring.

madhatterpdc

Discussion Starter · #40 · Mar 26, 2005 (Edited)

I've been pretty quiet here recently for a number of reasons, but I took the GT out today for a run and it felt great. Well, until the clutch wouldn't disengage anymore (this is directly attributable to my ham-fisted driving style, I'll fix it later). Felt great to have some good weather, drive the Opel around and not have anyone chasing me for blood (ie, bill-collectors).

Regarding the project work, the crank is back from the machine shop and it looks great. I was even able to get a good deal on a full set of crank bearings. Also was able to pick up a 15 lb. flywheel which should be a good balance between streetability and reving. I still have a lot more work to do, and an equal amount of parts to source, but every step is a step closer.

I suppose I should get a real job soon so I can get this done in time for Carlisle... 2008

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