3.8" bore?
Did you catch the specs on this one?
[www.britishv8.org] How did he do this? I'd love to know... Greg |
BlownMGB-V8 Jim Blackwood 9406 Gunpowder Rd., Florence, KY 41042 (6468 posts) Registered: 10/23/2007 12:59PM Main British Car: 1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS |
Re: 3.8" bore?
Well, the Buick 350 has a 3.8" bore, as does my 340. There is room enough to do it, if you don't mind a wet sleeve.
Jim |
Moderator Curtis Jacobson Portland Oregon (4576 posts) Registered: 10/12/2007 02:16AM Main British Car: 71 MGBGT, Buick 215 |
Re: 3.8" bore?
I was skeptical too, but two sources told me that Ken really did have a Buick 215 block resleeved by a St Louis machine shop. A quick look at the block would tell us, but alas the photos don't. No one has told me WHY someone would resleeve a Buick 215, instead of starting with a later Rover block and getting four bolt mains in the bargain.
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Re: 3.8" bore?
Westwood Liner in Uk sells T-liner with an O.D. of 99.06mm for later Rover 4.0/4.6 block.
[www.westwoodtrading.co.uk] They can be overbored to an maximum of 3.8''. In Uk an popular option is 3.780'' bore. |
Re: 3.8" bore?
It's not so much the liner that has got me curious. It's the:
1. Choice of blocks. Is there something about the Buick block that lends itself to sleeving it out this far? 2. Why not the Rover block? 3. Is this dry or wet sleeve? 4. How safe is something like this? How thin are the cylinders? That's really what I'd like to know. Greg |
Re: 3.8" bore?
Hi Greg,
It is something I am studying since an long time. I dream to do similar job on my spare P76 block. I think it is because on Buick Block the cost of inserting cast-iron liners into the aluminium block was considered prohibitive so a clever method was to locate pre-heated iron liners in the mould and pour the molten aluminium around them, the outside of the liners having rough corrugations machined into the outer surface to lock them firmly into place once the aluminium had solidified. Unfortunately die-casting was almost unknown in uk in the 60's, so Rover opted for sand-cast block with pressed liners. Due this difference in block manufacturing the Rover V8 block has only an 2.2mm wall thickness liners and a minimum nominal 5.5mm wall thickness in the aluminium casting which surrounded the liner. The Buick Block has thicker liner and thicker aluminium wall thickness (that's why the 3.5 Rover block can be only overbored to a maximum of 3.540'' and the Buick 215 Block to 3.560''). On Rover 3.7'' bore the aluminium wall thickness is between 2.2mm and 3mm. Now for 3.8 bore, here in Europe only selected later 4.0/4.6 rover block called red grade which have an 3mm aluminium wall thickness are modified with T-liners which can be bored to 3.780'' or 3.8''. But in USA it will be cheaper to take Buick Block which has originally thicker aluminium wall thickness than Rover Block. In all case liners are always dry type. |
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hoffbug Tony Hoffer Minnesota (323 posts) Registered: 10/15/2007 05:25PM Main British Car: Olds 215 EFI |
Re: 3.8" bore?
Phil Baker was using a 3.750 x 3/32 sleeve in Buick and Olds 215's long ago.
I believe he was getting them from a place called Ohio sleeve. The Buick and Olds 215s had wet cast blocks with a ripple pattern on the sleeve.. this held them in place since the block was poured around them.. the Rover blocks are sand cast and have the sleeves pressed in. this wasnt a problem till they increased the bore size without adding any beef to the block.. the result was cracks behind the liners that lead to the liners slipping in the bore.. especially in the US where the high temps required by us emission laws exasperated the problem. The fix?? T-top ( flanged) liners... Nick an I both bought ours from Westwood in England. Edited 1 time(s). Last edit at 11/10/2008 06:28PM by hoffbug. |
hoffbug Tony Hoffer Minnesota (323 posts) Registered: 10/15/2007 05:25PM Main British Car: Olds 215 EFI |
Re: 3.8" bore?
Apparntley Ken had the engine done at ATM racing engines in Ferguson MO.. If anyone wanted to follow up on this?? perhaps they know the details..
I had sent them an e-mail with no response.. MAILING ADDRESS: AMT Racing Engines 715 S. Florissant Road Ferguson, MO 63135 PHONE: 1-(314) 522-6222 |
Re: 3.8" bore?
Thanks a bunch for the follow up. I'm burning up with curiosity on how he sleeved a 215 block out to 3.8". I didn't know that could be done.... safely...
Greg |
Re: 3.8" bore?
The 215 (or what I would call a 3.5 litre) is sleevable to 3.8" (96.5mm) by using the Top Hat liners mentioned earlier .. I do this regularly. Personally I would recommend using a later 4.0 / 4.6 block because of the wider range of available crankshaft and piston combinations but it is quite feasible on a 3.5 block. We use the 3.8" bore together with a custom crankshaft and some nice forged pistons to make a 5.2 or 5.3 litre Rover V8 here in the UK. The liner wall thickness is still thicker than the original 215 was so we have no issues with warping or heat transfer and the top hat flange (t top) means that the block cannot leak combustion gasses from the chamber into the water jacket .... even if there is a block flaw (as found in many 4.0 / 4.6's).
Shaun |
NixVegaGT Nicolas Wiederhold Minneapolis, MN (659 posts) Registered: 10/16/2007 05:30AM Main British Car: '73 Vega GT 4.9L Rover/Buick Stroker |
Re: 3.8" bore?
Thanks for the post, Shaun. Good information. I wonder if it's possible to fit the 3.85" 350 crank in the block with the 300 rods (5.9") and pistons from one of those supercharged 3.8l V6s. (Comp height: 1.09"). Deck the block 20 thou. and you still have 20 thou of destroke.
Hmmm. The rod ratio is bad though: 1.54. well it's not small block 400 bad... Edited 1 time(s). Last edit at 01/14/2009 11:52AM by NixVegaGT. |
Re: 3.8" bore?
Hmmm ... I think you would struggle ... unless you could manage to do away with the camshaft :) The longest throw crank we have ever managed is 92mm (3.62") and that requires some 'releiving' of the big end caps on the rods and a good deal of 'releiving' of the sides of the block !!! The 5.5 litre capacity is nice but the rod angle is getting poor and piston speeds start limiting rpm. There are a number of SBC rods that will fit though ... we use 5.75", 5.85" and 6.0" in various applications .. and as long as you stick with the 8.96" overall deck to crank centre you can combine things pretty well as you want. The 3.8" bore with an offset ground 4.6 crank makes a really nice 5.0 / 5.1 litre (5053cc) with an 86.36mm stroke .. they rev well and we use a lightweight H-beam steel rod with hyper eutectic pistons to keep them strong and reliable. To be honest I am a bit shocked that this didn't come from the US in the first place .. you guys have a reputation for mutation :()
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BlownMGB-V8 Jim Blackwood 9406 Gunpowder Rd., Florence, KY 41042 (6468 posts) Registered: 10/23/2007 12:59PM Main British Car: 1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS |
Re: 3.8" bore?
Maybe in about a year or so TA Performance will have some heads for us.
Jim |
spridget bill green Maine (68 posts) Registered: 03/22/2008 01:29PM Main British Car: 3 1980 TR8, 1 TR7 2 Bugeye Sprite 1 MG midget TR8 3.5 and 5.0, Sprite 1098 and ? |
Re: 3.8" bore?
LA sleeves sells the flanged sleeve for 4.0/4.6 Rover for about $94 plus shipping. I'm told they are a shelf item.
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Re: 3.8" bore?
Hello Bill,
To have your block re-linered with T-Top liners at www.v8developments.co.uk is £850 (including new cam bearings, core plugs etc.) which I think equates to around $1,250 includes cost of liners and all machining, and they will bore it to whatever size you want (including 3.8"). I guess shipping to the US could be expensive though. What sort of cost would the machining and fitting be in the US? Shaun |
Re: 3.8" bore?
Shaun do you think this large bore conversion is possible on Ozzie P76 Block which has an tall deck block of 9 1/2'' ? The genuine bore is 3.5''.
With genuine P76 crank (3.5'' stroke) it will give 5200cc :D |
BlownMGB-V8 Jim Blackwood 9406 Gunpowder Rd., Florence, KY 41042 (6468 posts) Registered: 10/23/2007 12:59PM Main British Car: 1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS |
Re: 3.8" bore?
Dimitri, you can fit a 340 crank in the P76 block. 3.850" stroke.
Jim |