Critique My Engine Build

[Sideswipe]

Goal: 200-250hp, smooth street performance.

1955cc (90.5x76), CB bubble block with forged internals
Mahle forged pistons with Total Seal rings
Panchito heads - 61cc chambers with dual springs
Engle TCS-20 cam with 1.25 rockers
.037" deck height gives me 8.3:1 compression ratio

Turbo is a T3/T4 .48AR planning on running ~15 lbs of boost
48# injectors
48mm single throttle body
Crank trigger with wasted spark

Meth/water injection

Any feedback/suggestions are appreciated! Mostly trying to decide on cam choice and compression ratio at the moment.

[slowsixtyduece]

Nice Ghia!
So, do you already have the crank and pistons? Why not go bigger on both, especially if you already have a CB case that is clearanced for up to an 84 crank? You could do an 82x92 thick wall, which would yield more torque and displacement without any other changes, and keep the cylinders thick to combat the heat and fatigue of high cylinder pressure.

Im assuming you will be running this on 91 pump gas or higher octane rating? If so, your compression ratio is looking pretty good for 15 psi as long as you have the tune spot on and keep the water/meth spraying. Will you be retarding under boost with your crank trigger/wasted spark setup? You can always start with low boost and adjust incrementally until you start getting some detonation, then back it off. I was running 8.2 CR on my last 2276 and it was perfect for a street motor, up to about 12 psi on 91 pump gas...but Water meth really helped out. Compression ratio is also sort of a personal thing, to a certain degree. Some like the feel of low compression + high boost and others like higher compression and lower boost for the street. I like to be about in the middle, medium compression, medium boost. I also like to stay at or under 0.060" deck height as it keeps the combustion in the chamber and not in the cylinder...but not everyone can make this happen with their setup.

I would not go with a TCS series cam as they are older technology, back when Rayjay turbos and locked out distributors were the thing. If you want to stay with Engle, you can have them ground you any of their cams on a different lobe center (LC). I was using an Engle V-26 on 112 LC that they ground for me and it worked well for a smaller street cam with a T3/4 turbo. Do consider a newer cam profile design from SLR, VW Paradise or the like. Also, Shag at SL-1 has a few go to custom turbo cam profiles that will get you there.

The rest of your setup looks solid. Those heads are known to perform well and it sounds like you have everything else in line.

[buguy]

I agree. If you don't already have those parts I would use an 82 crank and 92 pistons. I also would choose something other than a TCS cam. Others have reported better low rpm running with sequential over wasted spark/batch fire too.
If you already have the parts it should still be a pretty good runner though.

[Sideswipe]

I already have the pistons and crank, as this was a NA motor that I threw a turbo on. I'm re-ringing the motor and changing putting different heads on it, so I thought that I'd try a different cam while I have it out. I'm not sure what cam is in it now, but I believe it's one of the Eagle cams from CB.

I was going to run the FK-8 but someone at ACN recommended against it saying that it would be a better choice for a high revving motor. They recommended the TCS-20 instead.

[buguy]

Yeah FK8 would be a little high strung for that. How bout a Web 218? Would be pretty good with the 1.25 rockers.

[Clonebug]

250 crank hp will take 6000 rpm and 16 lbs boost....or 18-19 lbs at 5500 rpm.
You would need about 340 CFM so find a turbo that will support that.
W/I will be at the limit to keep your IAT’s in check.
At 18 lbs you will have temps of 229 without cooling.

[madmike]

go with Thick wall 92's , keep the rest since the valve size will keep it limited on how far u can stroke it,lol nothing wrong with a fk 8 w/1:4's ,u will like it ,, ,guys ; they are high strung w/carbs ,,,not w/boost

[Clonebug]

250 crank hp will take 6000 rpm and 16 lbs boost....or 18-19 lbs at 5500 rpm.
You would need about 340 CFM so find a turbo that will support that.
W/I will be at the limit to keep your IAT’s in check.
At 18 lbs you will have temps of 229 without cooling.

[Bruce.m]

Intercooler. You have plenty space in that engine bay. Will bring down the IAT and open up more HP

[bug66]

Shorter crank stroke is stronger than longer stroke and flexes much less.

Build the short block as strong as you can.

Water to air IC > water/meth

[Sideswipe]

I'll definitely start looking at intercooler options.

Right now I'm stuck between the FK8 or Web 218 cam and can't decide. I'm leaning slightly towards the 218 since I wouldn't have to buy new rockers.

[bug66]

I'll definitely start looking at intercooler options.

Right now I'm stuck between the FK8 or Web 218 cam and can't decide. I'm leaning slightly towards the 218 since I wouldn't have to buy new rockers.

How big is the 218?

240°ish degrees if I remember correct?

[buguy]

218 is 242@50 I believe.
Fk8 is 258@50

[slowsixtyduece]

Here’s a few more options to throw your way:

Good old stand by Engle 120: .397" Cam Lift, .496" Valve Lift (1.25 Rockers), 294 degrees of advertised duration, and 253 @ .050".

SLR XR292: .389” Cam lift, .486” Valve lift (1.25 rockers). 254 @ .050”.

SLR XR294: .393” Cam lift, .491” Valve lift (1.25 rockers). 254 @ .050

Or call Shag and have him use SLR to grind you a turbo cam that will get you closer to what you want.

My last cam was so tame, it was .480” Valve lift and 252@ .050. Ran like a sewing machine, no valve train issues and reved to 6k. It was fun but sort of became boring after a while, even after throwing more boost at it. I have gone to a slightly larger cam to see what happens.


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[madmike]

agree when I had the W120 in my 2276 it was 'Tame" the FK10 brought out the 'Beast' ,, really woke the Bitch up