Engine and Transmission Tech

Jim - some THOUGHTFUL comments on your part regarding T/A heads marketing strategy over on the V8Buick forum - why in the world would a company NOT do a cost/marketing analysis PRIOR to developing a new part!

Sir Art - I shall chip in .51/hr towards the design of that Rover HC/H (height-challenged hemi) Head - and because I'm such a big spender, please don't take your time.


Humm...dreaming out loud...get several of these related forums to come together for a Buick/Rover head design fundraiser - starting price point $1999 - they wouldn't collect dust!

.....and it looks like (a few V8 forum posts) there may be reason why RS hasn't provided any flow numbers for their heads - time and testing will tell.

Nic and all. No, for using deck plates on 4.0/4.6 and getting piston where it belongs and good rod length for-say, 4 valve heads? roverman.

Nik-nixed, your getting my "underalls"-well-pissy. Wer'e one to measure lifter boss wall thickness on P76, they would find it's thicker than 215's, and comparable to sd-1's. I was yakin the "weldability" of BOPandR's.I think welding "before" the block get's room-addition is "better"-Nic. Welding will probably slightly distort lifter bores,(they need bronze bushings anyway) and possibly cam tunnel, depending how "good" you are. Jim, all. Lotus heads with cams, towers and covers run about $100-$300 ea. I mite be off here, but I don't see the TA outflowin the 907 in a 3.7 bore, especially @ .45 lift. Unless the Lotus heads, kocks my sox-off, I see it as a one-timer. roverman.

I was reading about Cliff's stroker project again this evening and something else popped into my head. We were talking about offset grinding the 4.6 crank to get 3.4" stroke. Basically the 300 stroke with the native crank. Smart. I actually didn't think much about the journals in the late block being bigger in dia. till the other day when we were posting about it.

So then the thought occurs to me if the 6.0 "Honda" rod is used, 1.89" journal; The 4.6 crank could be offset ground to 3.525". Paired with the Ford 4.6 stroker 1.190" tall piston and that ends up with the piston only 7 thou below deck. Bitchin'! Just deck the block by 7 thou and that puts the piston at zero deck. Nice.

That would be a solid combo. Displacement with the 30 over Ford piston (3.73"): 5047cc. 308 cid. The 1.7 rod ratio is perfect.

That almost makes me waffle on building the lightweight Buick 360 cid. idea.

Yeah, I like the idea that a 4.6 crank can be used without a custom flywheel. I've got a complete 4.0 engine and I wrestle with the idea of stroking it with an offset ground 4.6 crank.

You just made it worse. ;)

I found a website of a boneyard that sells Rover parts, including cranks. $300 for any 3.5, 3.9, 4.0, 4.2, 4.6 crank. Stroking gets the biggest return for the expense.

OK you "strokers", I'm thinkin the bottom corners of rods are bangin the cam? How bout VW "style" with stud in cap and nut, or cap screw on top? Leaves more room in there. "Slim chance better than no chance", roverman.

Use the late capscrew style 350 rods if you can.

Jim

You're saying that the heads on the rod bolts are hitting for the 3.95" stroke, right?

With that stroke it will be hitting the block in several places or is there a lot more clearance in the 350 block I think you must be talking about, with all the different combos we;ve discussed am getting confused.

Kevin.

I'll defer to Jim there. My assumption would be it's very similar to the 350/340 block on the very bottom. Well, for the sake of feasibility, That stroke will pull the pistons right out the bottom of the sleeves. So, no go, either way… Well I guess unless you get longer sleeves. It's gonna be tight!!

Nic and all, This 3.85+"stroke/oem. Rover block thing is looking like , diminishing returns? I agree with Jim, if you want the mega strokes, use the block designed for them(350), with a proven track record and much less effort. If you "must", I suggest the P76 block or aluminum deck plates with liners through them.Good Luck, roverman.

I feel ya. It's more a thought experiment than a real possibility. I'd prefer to offset grind a 4.6 crank to 3.5", or build the "short" 360 we talked about. With that one the possibility of smacking the cam with our larger base circle roller cam is a pretty real issue, I guess. I don't know how close it is in the 350 as it is with 3.85". Anybody know?

Nic ol' chum, cut to the chase! Get that "Wildcat" 4" bore block with "raised cam"-matching elevated price, TA heads, any ol' stroke you want and WOW us! Cayman account? roverman.

LOL! Done.

Until that happens-Nic., I'm "peepin" that, I-beam, 4340 billet, 2.1"x6",sbc rod from "KMJ"-thanks to Nic. Approx 1k hp. rated for $330 and only 610 grams-before I narrow it ! China-huh. Different Strokes-folks, roverman.

Nic, I seem to remember a Silvolite catalog where a fella could look up pistons by their bore diameter. Do you have any other sources?

Reason I ask is that I was high (only) bidder on a Rover 4.2 crank. I thought it would be pretty trick to use in my Olds engine. Obviously, I hadn't thought it through. If I do that, I'll need pistons.

If my math is right; 8.96" deck height, 1.515" throw, 5.66" rod, I need a piston set that's ~3.500" bore, with a 1.785" deck height.

I looked at summitracing's page and could not find anything with a compression distance of 1.785", but a few with less distance. Maybe some longer connecting rods to compensate, or go with custom pistons from perhaps JE or equivalent manufacturer. It is probably not going to be cheap though.

Hey Paul. I think this will be a cool mod. You'll make what… 240ish? Sweeet. Here's a link to a Silvolite page I've used a lot:

[www.beckracing.com]

Looks like a late 70's Buick 3.2 V6 is the piston you're looking for. 1.78" comp height. Should work great. I doubt there will be any thing other that cast but you should be fine with that.

Brilliant! Amazing, that piston is perfect. I might have to go with Chevy rods to get a better pin fit, but it's so close that it will work fine.

Thank you.

Paul, you might want to consider the merits of a longer rod? More "burn" time, reduced "I" loads, easier on cyl. walls, cheep insurance and fits the zillions of sbc. piston combos avail.? roverman.