Mast motorsports l92 small bore 12 degree ls1 heads?
#1
Mast motorsports l92 small bore 12 degree ls1 heads?
I read the article in the latest gmhtp about these heads. Just wondered if anybody is else running a similar setup. The results looked decent, they made 423whp thru a a4 with a mild cam. Not to mention all that power is goin thru a 9" rear too. Im personally not in the market for heads, just want to hear some opinions.
The test car in the article is a 2001 z28 a4
mods:
l76 intake
fast 90mm tb
stock ls1 block
226/240 588/597 114 cam
mast motorsport 61cc ls3 small bore 12 degree heads
rpm built 4l60
vig3600
9" rear
power 423 whp / 405wtq on a dyno jet. 325/326 before heads/cam
Head flow numbers:
lift Intake Exhaust
.300 208 105
.400 266 217
.500 306 222
.600 335 226
.700 351 234
.750 335 238
The test car in the article is a 2001 z28 a4
mods:
l76 intake
fast 90mm tb
stock ls1 block
226/240 588/597 114 cam
mast motorsport 61cc ls3 small bore 12 degree heads
rpm built 4l60
vig3600
9" rear
power 423 whp / 405wtq on a dyno jet. 325/326 before heads/cam
Head flow numbers:
lift Intake Exhaust
.300 208 105
.400 266 217
.500 306 222
.600 335 226
.700 351 234
.750 335 238
#5
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by the way the 405 torque number is not at all accurate.When you look at the dyno graph you can see the 405 is from an agressive converter flash or something.Its as soon as they start the pull.The real torque was like 380ish or 385.not that impressive if you ask me.
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#9
I talked to the guy at Race Krafters who had them on his car awhile back. He wasnt to crazy about them for all the tuning he did, said they were really lazy on the bottom end due to the intake port being so big. For a stroker motor they might be pretty good, but a stock 346 they seem to big. The price of them really kinda did me in too, but I am glad someone did make them still though, maybe GM will release theirs to this year too with a more stock friendly size. I still think there is some where these would really work good, maybe on a motor of a 4 inch bore maybe better.
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i have a futral motorsports f13 cam with a 230/232 .595"/.585" on a 112 lsa in my 01 ws6. its a cam only for now and made 410 on the dyno with stock 241's besides having prc dual valve springs and the rockers being upgraded to trunion bearings instead of needle bearings. my curiosrity is weather a nice set of ported 243's or these small bore l92's would be better? seeing how the intake port on the l92's are so much bigger would the cam benefit more from it? i would like to see some test's of the 243's up against these small bore l92's with some different cam's to see which would come out on top becuase really we are all going on opinion and not cold hard numbers. because to this day so far 243's have come out on top as far as i know. and seeing that they are 12 degree heads i would think that larger cams would benefit more then the 15 degree heads because the in coming air doesnt have to make larger transition curve into the cylinder. i would like to see more on these but still the price is way too high, i mean 3600 for complete set of heads and thats still with out the proper pushrods and the bolts, etc.
#18
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so i read the issue of gmhtpf mag. where they bolt on a set of these heads to an ls1 in a z28, and let me say i am not impressed at all. they supposedly after alot of tuning on the dyno got 426 whp, that is not that impressive especially for the price tag and the hype of these heads of being the best flowing gm heads ever, even better flowing then a set of good ported 243's. let me tell you that i am at 415 whp with a cam only ls1 with stock 241's with the only other valve train upgrade if it could be considered such is stock 1.7 ratio rocker with upgraded trunion bearings instead of the needle bearings. i have a pretty decent intake system and full exhuast. the z28 had a full exhuast except that it was using a y-pipe instead of true duals and had the regular bolt on intake upgrades like a lid and such. i was expecting a whole lot more with this supposedly whole NEW top end combo, my opinion not worth it. just stick to the tried and true 243's and fairly good size bump stick for a lot less.
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Guys don't say anything about any product until you read the details from the vendor it self ! .. simply I go to their website and read that this heads are recommanded for 3.900" bore - 3.930" bore .. which means strocked LS1
http://www.mastmotorsports.com/2010/news-view.php?id=52
http://www.mastmotorsports.com/2010/news-view.php?id=52