Put these upgrades in correct chronological order: High Comp Head, Cam/Gear, B230F

[fryea]

Hello Turbobrickers

I have 3 major upgrades that I would like to complete (and reachable) within the next month. My question is in which order should they be completed.

Car in question is a '79 GT. It currently has MSnS-E, Wasted Spark, Wideband, stock b21f (9.3), M47, 17.5lb flywheel, 2.5" Exhaust, and upgraded intake.

I have the following things about ready to go in:

1.) B230F (9.8)
2.) K cam and adjustable gear
3.) 11:1ish 530 head w/38mm exhaust valves

Due to tuning being done by hand, I don't want to slap them all in at once and find out I either phucked up in the process or its a completely different beast in the ways of megasquirt mapping. Or am I just overthinking it?

In which order would you advise doing these, and why?

[740ATL]

Why are you swapping out the b21f?

[oldduttyvolvo]

Hello Turbobrickers

I have 3 major upgrades that I would like to complete (and reachable) within the next month. My question is in which order should they be completed.

Car in question is a '79 GT. It currently has MSnS-E, Wasted Spark, Wideband, stock b21f (9.3), M47, 17.5lb flywheel, 2.5" Exhaust, and upgraded intake.

I have the following things about ready to go in:

1.) B230F (9.8)
2.) K cam and adjustable gear
3.) 11:1ish 530 head w/38mm exhaust valves

Due to tuning being done by hand, I don't want to slap them all in at once and find out I either phucked up in the process or its a completely different beast in the ways of megasquirt mapping. Or am I just overthinking it?

In which order would you advise doing these, and why?

What is a 11:1ish 530 head ?

[chungaboi]

Why are you swapping out the b21f?

:nod:

[aussyvolvo]

What is a 11:1ish 530 head ?

a plained head probably

if you have the engine sitting there, then get your head planed, and when its back, fit the new cam and gear, then put in the engine.

theres no point fitting the engine, and then pulling it to bits and not having it running, especialy if there's a complication and it dosn't run properly and takes ages to fix.

[MikeHardy]

i'd do them all at once, your going have to retune MS for each of them so surely better to have to do that once then 3 times. plus easier to assemble it all whist out then drop in as a whole

[Canuckvolvo]

Upgrading to B230 for increased displacement I suspect.

+1 to wtf is a 11:1 head? If using the head with a stock block and head gasket gives 11:1 CR this implies that it has almost no combustion chamber! Someone has mislead you about CR methinks...

Oh, and also +1 about building the engine and swapping all at once.

[MikeHardy]

11.1 would indicate enough skimmed off to give that on a B230F block, about 1.5-2mm

[beckzach05]

Put the K cam in the 11:1 head. Mount the 11:1 head to the B230F block. Swap the B230F for the B21F. Start. Go back and attach the coil wire to the dizzy. Start again. Retune MS. Retune MS again. Retune MS once more for good measure. Profit!

[stylngle2003]

id want to make sure you havent buggered your squish areas completely by skimming too much off the 11:1 head first. but otherwise, all three mods at once

[MikeHardy]

the chambers slope inwards as they go in so if anything the squish areas should get bigger as you skim

531 with 1.5mm off
<a href="http://www.flickr.com/photos/14193327@N02/2639494737/" title="B21531 by minvie2000, on Flickr"><img src="http://farm4.static.flickr.com/3141/2639494737_9d0a564393.jpg" width="500" height="208" alt="B21531" /></a>

[John V, outside agitator]

11.1 would indicate enough skimmed off to give that on a B230F block, about 1.5-2mm

Ding -ding- ding!!!
Winnar!
Damn, somebody's thinking.

Skimmed, and combustion chamber done for unshrouding the valves.

Cannot believe people don't understand 11:1 .

[John V, outside agitator]

id want to make sure you havent buggered your squish areas completely by skimming too much off the 11:1 head first. but otherwise, all three mods at once

Just a note about language: those flat areas next to the chamber are called "Quench Pads".

All this jaw flapping for years about "squish" is OK but what we are acomplishing, the point, is to quench the piston crown. And oddly enough, the term for the flat areas we're skoootching the pistons toward are called quench pads.

The purpose of 'squish' seems to get lost.

[fryea]

To those naysayers about skimming too much on the head alone for 11:1 CR. It has been done already without jumping aboard the Fail boat. +1 to what ravennexus said about increased quench area.

B230F for the increased displacement, increased compression, and slightly better rod:stroke ratio.

All at once huh? Im guessing with that much compression I will need to retard the timing map alot, but then again the K-cam likes lots-o-advance. And with all that compression, do you think the engine (as a whole) will need less or more gas at cruise and WOT? Basically looking for what hot spots in the map I should be looking for. Thanks again for the input

[beckzach05]

All at once huh? Im guessing with that much compression I will need to retard the timing map alot, but then again the K-cam likes lots-o-advance. And with all that compression, do you think the engine (as a whole) will need less or more gas at cruise and WOT? Basically looking for what hot spots in the map I should be looking for. Thanks again for the input

As for K advance - about 4* should do it in a b230f. But that's different from spark timing, which you may want to retard a little, if I'm thinking clearly.

I have an idea about the fuel, but I'm not certain enough about it to post. I'd rather not spout info that's probably wrong :lol:

//edit//

And John V, thanks for the lesson in quench! Taught me something new.

[MikeHardy]

As for K advance - about 4* should do it in a b230f. But that's different from spark timing, which you may want to retard a little, if I'm thinking clearly.


yeah he was talking about ignition advance, the K cam stock came on an engine with a faster ignition advance curve from the dizzy springs hence his statement about the K liking advance.

the dizzy the K's used had one normal spring like 21A and F's of that period and one spring wiht a longer eyelet on the end that allowed the weight on that side to travel a bit before it started to pull on the spring, mean only one spring acted on them at low RPM so they'd swing out sooner for more initial advance and then both springs as RPM rose

timing it straight up in terms of cam timing, you'll have enough compression to overcome usually flat bottom end people complain about (i did on my B21A with 1.5mm skimmed 531)

[klr142]

All at once huh? Im guessing with that much compression I will need to retard the timing map alot, but then again the K-cam likes lots-o-advance. And with all that compression, do you think the engine (as a whole) will need less or more gas at cruise and WOT? Basically looking for what hot spots in the map I should be looking for. Thanks again for the inputKeep the piston-head clearance tight with a thinner headgasket and you may not need to tinker with the ignition timing as much as you think. Probably will, but never know until you try. You're not going to hurt anything too much either, unless you get much too aggressive. And it's not like it's hard to turn all the ignition maps down a few degrees and work them back up.
As for K advance - about 4* should do it in a b230f.It all depends on the rest of the motor, and an 11:1 motor with tight squish and programmable ignition/fuel is going to be a lot more friendly at low RPM than a stock b230F with LH2.4 and a K cam.
timing it straight up in terms of cam timing, you'll have enough compression to overcome usually flat bottom end people complain about (i did on my B21A with 1.5mm skimmed 531)Yep. Even on a stock head and compression ratio Mike(towery) was able to get rid of the weak low end by tuning ignition and such.


DO IT ALL and enjoy. And make me jealous because my headwork won't be done or installed anytime soon, and I still have an automatic transmission.

[towerymt]

Sell the timing gear and put that money towards a thin head gasket. With MS&S, my stock b230f with a K cam made flat torque from 1900-4700rpm on the dyno. I can't see any reason to adjust the cam timing based on my results. YMMV

[volvorsport]

bin the stock exhaust manifold , that should be a starting point .

[fryea]

bin the stock exhaust manifold , that should be a starting point .

From the great repository of recycled information on turbobricks, it is a common rumor that the earlier exhaust manifolds are 'better' because they have longer primaries. I havn't looked too far into it. Not on my list of things to do at the moment.

[Lord_Athlon]

Dont you need an adjustable gear to make up for the 2mm missing off of the head.

[klr142]

From the great repository of recycled information on turbobricks, it is a common rumor that the earlier exhaust manifolds are 'better' because they have longer primaries. I haven't looked too far into it. Not on my list of things to do at the moment.The earlier downpipe section of the exhaust manifolds are better because they're longer before they merge, yes. I wouldn't call the stock exhaust manifold one of the larger restrictions in the big picture though.

[volvorsport]

i would since he has 38mm exhaust valves .

a 3-4 % improvement in mid range torque with a proper length manifold over and above your intended mods ?

140 ft/lbs plus 3-4 % is what ?

[klr142]

Yes, but you said it should be a syarting point, which I interpreted to mean before he does the other things.