 2.0 Type IV Vintage Race Engine |
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| jdahl |
 Dec 5 2015, 10:16 PM
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#1
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Newbie  Group: Members Posts: 10 Joined: 16-September 10 From: Peoria, IL Member No.: 12,179 Region Association: Upper MidWest  |
I'm building an engine (2 actually) to run in my 914 for SVRA Group 3 road racing. I've done a lot of research, built a spreadsheet, shopped around, done more research, etc. Before I start spending money on parts, I would appreciate any experienced advice/critique of my build(s).
Conservative Bore 94 mm - flat top Type 1 "stroker" pistons 35mm pin height Stroke 71 mm Rods 5.325" Heads 59 cc, 2.0 42/36 valves, single valve springs (porting/polishing TBD) Rod Ratio 1.905:1 Deck Height .04" (1mm) Compression Ratio 8.5:1 Cam 86a Creative Bore 95 mm - 14cc custom dome pistons 25.8mm pin height Stroke 71 mm Rods 5.7" Heads 56 cc, 2.0 44/38 valves, double valve springs (ported/polished) Rod Ratio 2.039:1 Deck Height .04" (1mm) Compression Ratio 11.5:1 Cam 86b/c or 163/86b Induction Weber 40 IDF Exhaust Kerry Hunter 1.5" header Again, I appreciate any and all constructive feedback. |
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Replies
| jdahl |
Dec 18 2015, 08:50 PM
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#2
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Newbie Group: Members Posts: 10 Joined: 16-September 10 From: Peoria, IL Member No.: 12,179 Region Association: Upper MidWest |
Brett,
Thanks for the initial feedback. I probably should have called the first option "off-the-shelf". The real issue seems to be the lack of high compression "off-the-shelf" pistons for the type 4. I believe your comment about rod length was directed at the second proposal, not the first. Is that correct? As far as the 96mm pistons, trying to build the engine legal. SVRA Group 3 rules http://www.svra.com/wp-content/uploads/201...roup_3_1213.pdf "Engines: Must be standard or optional series, bore and stroke as provided by the manufacturer for make and model Bore may be increased by .047ยด (1.2mm)." Carbs are restricted to 40's. I did reach out to Len on the heads, his quote was reasonable for what he offers (new not rebuilt), but outside the current budget. Tangerine exhaust, I'd love to have one, but again outside the current budget. As for building a stroker motor; again, playing by the rules. If the Datsun guys want to run cheater motors, that's their call. Stugray, Are you running flat top pistons? You compression seems higher than I would expect. My car will also be running DP. |
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| stugray |
Dec 18 2015, 09:39 PM
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#3
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Advanced Member Group: Members Posts: 3,824 Joined: 17-September 09 From: Longmont, CO Member No.: 10,819 Region Association: None |
QUOTE(jdahl @ Dec 18 2015, 07:50 PM)  Stugray, Are you running flat top pistons? You compression seems higher than I would expect. My car will also be running DP. Flat top Keith Blacks. Heads were flycut ~.020 (IIRC) No head gaskets Minimum deck height (~.030) I'll see if I can find my notes from the calcs. |
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Posts in this topic
jdahl 2.0 Type IV Vintage Race Engine Dec 5 2015, 10:16 PM
Brett W
I'm building an engine (2 actually) to run in... Dec 7 2015, 02:55 PM
stugray
If you want to race a T4 there really isn't ... Dec 17 2015, 01:53 PM Racer Chris
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Here's mine (vintage rules, so ~stock dis... Dec 18 2015, 07:53 AM stugray
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Here's mine (vintage rules, so ~stock di... Dec 18 2015, 08:08 AM Brett W http://www.svra.com/race-groups/
The reality is n... Dec 18 2015, 07:05 PM stugray I guess it depends on the club then.
If you check... Dec 18 2015, 08:12 PM Brett W You guys should head east next April for the Walte... Dec 18 2015, 08:55 PM |
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